US3078499A - Door closer - Google Patents
Door closer Download PDFInfo
- Publication number
- US3078499A US3078499A US764400A US76440058A US3078499A US 3078499 A US3078499 A US 3078499A US 764400 A US764400 A US 764400A US 76440058 A US76440058 A US 76440058A US 3078499 A US3078499 A US 3078499A
- Authority
- US
- United States
- Prior art keywords
- piston
- cylinder
- door
- pin
- hydraulic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000012530 fluid Substances 0.000 claims description 25
- 230000009471 action Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 230000036316 preload Effects 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 239000004677 Nylon Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000013016 damping Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- 101100460844 Mus musculus Nr2f6 gene Proteins 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 235000014121 butter Nutrition 0.000 description 1
- 239000002783 friction material Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000010985 leather Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 230000037390 scarring Effects 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05F—DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
- E05F3/00—Closers or openers with braking devices, e.g. checks; Construction of pneumatic or liquid braking devices
- E05F3/04—Closers or openers with braking devices, e.g. checks; Construction of pneumatic or liquid braking devices with liquid piston brakes
- E05F3/10—Closers or openers with braking devices, e.g. checks; Construction of pneumatic or liquid braking devices with liquid piston brakes with a spring, other than a torsion spring, and a piston, the axes of which are the same or lie in the same direction
- E05F3/108—Closers or openers with braking devices, e.g. checks; Construction of pneumatic or liquid braking devices with liquid piston brakes with a spring, other than a torsion spring, and a piston, the axes of which are the same or lie in the same direction with piston rod protruding from the closer housing; Telescoping closers
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF
- E05Y2900/00—Application of doors, windows, wings or fittings thereof
- E05Y2900/10—Application of doors, windows, wings or fittings thereof for buildings or parts thereof
- E05Y2900/13—Type of wing
- E05Y2900/132—Doors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T137/00—Fluid handling
- Y10T137/7722—Line condition change responsive valves
- Y10T137/7837—Direct response valves [i.e., check valve type]
- Y10T137/7859—Single head, plural ports in parallel
- Y10T137/786—Concentric ports
Definitions
- Another object of the invention is the provision of a novel arrangement for varying the terminal closing force of the device.
- One feature of the invention is the provision of an hydraulic piston and cylinder door closer including a fluid passageway through the piston for flow of fluid on movement of the piston during opening of the door, the passageway having an inlet spaced from the piston proper.
- the inlet of the fiuid passageway is a port formed in the lower surface of a boss extending from the piston, and spaced from the piston face.
- a further feature is that the liuid passage inlet port means is elongated in a dimension along the axis of the cylinder, so that the fluid is drawn into the passage over a substantial area.
- the piston is provided with a fluid return passageway having a flow restricting orifice therein, a pin is associated with the flow restricting orifice, and operable therein to change the rate of flow of fluid through the orifice at the termination of the closing movement of the door, together with means for adjusting or varying the point of operation of the pin.
- the pin is movably mounted on the piston, extending through the flow restricting orifice, and has portions of differing cross-section, the pin engaging the end of the cylinder and moving relative to the orifice to change the cross-section of the portion in the orifice during the terminal portion of the piston movement.
- the piston is provided with a fluid return passageway having an exposed flow restricting orifice therein, a pin is mounted in the cylinder and projects into the flow restricting orifice as the piston nears its terminal position, and means are provided for varying the relative positions of the piston and the pin, to provide differing terminal closing rates.
- the stop position of the piston is varied by changing the point of connection of the piston rod to the door.
- the check valve in the fluid fiow passage through the piston includes a surface having a plurality of orifices therein carried in a recess in the face of the piston, with the orifices forming a portion of the flow passage, an annular member mounted in the ,recess and having a valve restraining portion, and the valve member carried between the surface and the annular member, for covering a portion of the orifices.
- bracket member for secur- 3,078,4@9 Patented Feb. 26, 1963 ice ing the piston rod to the door has mounting holes therein which are offset or unequally spaced from the point at which the piston rod is connected with the bracket, so that the bracket may be placed in one position with the piston closed for marking the point of attachment to the door, and then secured to the door in reversed position, to apply a preload to the return spring of the closer.
- the closer includes a bracket secured to the door frame and a pin for securing the closer to the bracket, including means for preventing rotation of the pin relative to the bracket.
- FIG. l is a horizontal section taken through a door and frame, illustrating the mounting of the door closer;
- FIG. 2 is a longitudinal section taken through the door closer
- FIG. 3 is an enlarged fragmentary section through the piston and a portion of the cylinder, in one position
- FIG. 4 is an enlarged fragmentary section through the piston and a portion of the cylinder, in another position
- FIG. 5 is an enlarged fragmentary section through the piston and a portion of the cylinder in a third position
- FIG. 6 is a fragmentary plan and sectional view illustrating one step in securing the piston rod bracket to the door
- FIG. 7 is a view similar to FIG. 6 with the bracket secured to the door and the rod attached to the bracket;
- FIG. 8 is a View taken generally along line 8 3 of FIG. 3;
- FIG. 9 is a bottom view of a modified piston
- FIG. l0 is a sketch illustrating the flow of hydraulic iiuid with the novel fluid passageway inlet port arrangement of this invention
- FIG. ll is an enlarged fragmentary section through the piston and portion of the cylinder, similar to FIG. 3,
- FIG. l2 is a view similar to FIG. 11 showing the parts in another position
- FIG. 13 is a view similar to FIG. 11 showing a further modified form of the invention.
- FIG. 14 is an enlarged sectional view through the frame bracket and connecting pin.
- Door closers for general purpose home use, as for screen and storm doors, are usually air buffered piston and cylinder devices. These closers normally have a relatively short life, as of the order of six to eight years. A few types of hydraulic closers, both piston and cylinder, and rotary vane constructions, have been marketed for home use. These closers are generally subject either to the air bounce problem discussed above, or are relatively expensive. The hydraulic piston and cylinder closer disclosed and claimed herein not only eliminates the air bounce problem, but is of rugged yet relatively inexpensive construction, having a long life while well within the price range for home use.
- a storm door 15 is mounted by hinge 16 on a frame i7. Closing movement of the door is limited by stop I3 secured to the jamb portion I9 of frame i7.
- a closer, indicated generally as 20, includes a cylinder 21 secured to frame bracket 22 attached to the door frame adjacent the hinged edge of the door.
- a piston rod 23 extends from the opposite end of cylinder 21 and is secured to door bracket 24 attached to an intermediate point of the door 15.
- the cylinder 21 is provided with two end members 26 and 27.
- End member 26 has an ear 28 projecting therefrom with a hole 29 formed in the end to receive a pin connecting the cylinder with door frame bracket 22.
- Piston rod 23, which extends through a bore 3u provided in end member 27, is afxed at its inner end to piston 32, slidably carried within the cylinder
- the piston 32 and rod 23 are urged toward the position shown in FiG. 2 by return spring 33 which has one end bearing against the face .34 of the piston, and the other end on cup washer 35, which in turn is seated on end member 2'7 and serves as a retainer for sealing ring 36.
- a relatively heavy buffer spring 37 is located inside return spring 33 and is centered by a conical portion 35a of cup washer 35.
- a sleeve 37a preferably of a plastic material as nylon, surrounds piston rod 3.2.3 inside the buffer spring, to prevent the spring from scarring the piston rod.
- piston 3?. has an elongated boss or extension portion itl extending from the face 34, to which piston rod is secured, by pin ai.
- a fluid passage through the piston includes bore 42 which extends longitudinally through boss 40 and communicates through recess d3, formed in the face 44 of piston, with the space 435 to the left of the piston as viewed in the drawings. Bore 42 communicates with space d6, to the right of the piston, through a plurality of ports 47, 4S and 49 formed in the enlarged lower portion of boss 40 which is thicker than the top portion so that the lower surface of the boss is closely adjacent the cylinder wall.
- valve seat plate 52 Carried in the recess 43 is a check valve arrangement including valve seat plate 52, provided with a plurality of peripherally located apertures S3 (FIG. 8) and a centrally located aperture 51%.
- annular valve retainer 55 Overlying plate 52 is an annular valve retainer 55, having an L-shaped crossssection with an inturned flange 55a.
- check valve S6 Carried between iiange 55a and valve seat plate 52 is check valve S6 which has a centrally located orifice 57 that is several times the size of orifice 51tin plate 52.
- a portion 52% of the piston 32 is formed over the top of annular valve retainer 5S as by a rolling operation, holding the entire valve assembly in recess 43.
- Cylinder 21 is filled with a fluid having a high viscosity index, as an hydraulic damping lluid.
- the quantity of i'luid placed in the cylinder is such that the level is about 1A; to 3/16 of an inch below the top of the cylinder 21 with the parts in the fully closed position, as shown in FIG. 2.
- FIGS. 4 and 5 show the portions 6in1 and 61h, respectively, or" the pin extending into ow controlling orifice 54.
- the portion ola of the flow restricting pin has a diameter of 0.034 inch
- the portion 61h has a diameter of 0.040 inch.
- the opening .S7 inthe valve member is suiciently l large so that the flow through it is not aiected by the ⁇ member 6l.
- ports 47, 48 and 49 which open at the bottom of piston extension ttl reduces the possibility of air being drawn through the piston into the space 45 when the door is opened. Furthermore, the spacing of the ports along the length of piston extension 40, with the largest opening the farthest away from the face 34 of the piston, provides an elongated port means which causes the iluid to tlow into the piston in a uniform manner.
- FiG. l0 the action of the surface of the hydraulic fluid with the port arrangement of FG. 3 is illustrated at da, showing how the fluid is drawn through each of the spaced ports. Where only a single port is provided in the face of piston 34, the surface of the hydraulic iiuid follows the broken line 65, and air is often drawn through the piston, resulting in the objectionable bounce operation discussed above.
- FIG. 9 is a bottom View of a modified piston with a single wedge shaped intake port 67 located in the bottom or lower surface of piston extension 40, with the opening tapering downwardly as it approaches the face 34 of the piston.
- the cross sectional area of the ports is equal to the area of bore 42, for ecient fluid ilow.
- the needle valve or pin 6l which provides slowing of the door at the end of the closing operation, may be utin lized to provide a terminal speed control.
- the door bracket 24 is provided with three sets of holes 68, 69 and '70, to one of which piston rod 23 is secured by pin 71. With piston rod 23 connected in holes 68, the piston closes fully, almost to the surface of end member 26, with full slowing of the operation. If piston rod 23 is connected with holes 69, the terminal position of the piston is as shown in FIG. 4, with only partial slowing action as pin 61 is in orifice 54 for a shorter portion of the movement. If the piston rod is secured in holes 70 of the door bracket, the terminal position of the piston is as illustrated in FIG.
- the mounting holes 72 and 73 for door bracket 24 are oset from the connecting pin holes 63, 69 and 70, with holes 68 being spaced farther from mounting hole 73 than the distance between holes 'itl and mounting hole 72. This arrangement facilitates the installation of the closer with the necessary amount of pre-load on return spring 33.
- door bracket 24 is initially connected with piston rod 23 by pin '71 through holes 7i), with mounting hole 72 toward the left or hinge edge of the door.
- the return spring 33 is fully extended, with the face 44. of piston 32 engaging end member 26.
- the positions of holes 72 and 73 are marked on door l5, as by a pencil '74.
- Door bracket 24 is removed from piston rod 23, inverted and attached to the door with hole 73y to the left and hole 72 to the right. Piston rod 23 is then reconnected with door bracket 24, by pin 7l in holes 68. As these holes are spaced farther from mounting hole 73 than the distance between hole 7u and mounting hole 72, piston 32 is moved away from the face of end member 26, as shown in FIG. 2, applying a pre-load to closing spring 33.
- Cylinder end Z7 through which piston rod 23 extends, has mounted in bore 30 a bearing sleeve 75, preferably of a low friction material, as nylon. Mounted in an enlarged portion 39a of the bore at the outer end of end.
- member 27 is an annular rod seal 76 of flexible sealing material backed up by supporting washer 77.
- a leather rod wiper 78 is located outside supporting washer 77, and held in place by a retaining washer 79.
- the parts 77, 78 :and '79 are of any suitable construction and may be conventional.
- a pin '71' is carried in the bore 42 of piston 32 and is urged outwardly thereof through ow controlling ori'iice 54 by a spring 7i", which has an end portion 71a tightly coiled about pin 71' and engaging a shoulder 71a' formed thereon, supporting the pin.
- the portion 71b' of the pin which is normally Within orifice 5ft whenever the piston is spaced a substantial distance from cylinder end member 26, reduces the ow of hydraulic uid through the orifice to such a degree that the door closes slowly.
- the end surface of plug 72' which is engaged by the pointed end 7ilc' of the pin is provided with a conical depression 72a', so that the pin is properly aligned during the relative movement between it and piston 32.
- Plug 72 has a threaded portion 72b received in a nut '73' secured in the portion 26a of cylinder end member l 26.
- a knurled knob 72e is manually engageable to permit adjustment of the position of plug 72 relative to cylinder end member 26, and thus to control the point at which the closing rate of the door is changed.
- An O-ring 74 seals the joint between plug 72 and end member 26, and is held in position by a retainer washer '75.
- a moditied control pin '7S' is shown carried by spring 71 having a portion of reduced crosssectional area 78a', which is normally positioned within ow controlling orifice S4, and a portion of enlarged cross-sectional area 'b' which is moved into the iiow controlling orifice 54 during the terminal closing movement of the door. This slows the movement of the door as it latches.
- the frame bracket 22 includes two spaced portions 22a and 221: between which is received the end portion of ear 2?.
- a pin St is inserted through aligned openings in bracket portions 22a and 22b, and through opening 29 in ear 23.
- the pin 80 is provided with a portion 81 which engages with bracket portion 22a, preventing pin S0 from rotating during operation of the closer.
- the shoulder portion 81 of pin lSti may be knurled and of such a diameter that it has a driven engagement with the bracket. All relative motion between the closer and the bracket occurs along the surface of hole 29 and the body of pin St), and there is no wear on the relatively small surfaces of engagement between the pin and the bracket.
- a hydraulic door closer In a hydraulic door closer: a cylinder adapted to contain hydraulic uid; a piston slidable in said cylinder;
- a spring urging said piston toward one end of said cylinder; means for connecting sai-d piston and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss having a lower wall extending outwardly from said pist0n, and having a bore; and means defining a iiuid passage through said piston for flow of hydraulic uid on movement of the piston toward said other end of the cylinder, said passage including said bore and port means through the wall of said boss, horizontally spaced a substantial distance from the face of said piston, said port means opening through the lower wall of said boss and having a greater extent in a direction along the axis of the cylinder than in a direction transverse thereto.
- a hydraulic piston and cylinder device ot' claim l wherein said port means comprises a series of openings of graduated size extending longitudinally along said boss, with the largest opening spaced the farthest from the face of said piston.
- a hydraulic piston and cylinder device of claim l wherein said port means is a wedge-shaped opening having its base portion spaced farthest from the face of said piston and tapering toward the piston face.
- a hydraulic door closer a cylinder adapted to contain hydraulic uid; a piston slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means for connecting said piston and cylinder to a door and an associated trame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss extending outwardly from said piston, and having a bore; and means defining the principal uid passage through said piston for iiow of hydraulic fluid on movement of the piston toward said other end of the cylinder, said passageway including said bore and port means through the wall of said boss, spaced a substantial distance from the face of said piston, the cross section of said port means geing substantially equal to the cross section of said ore.
- a hydraulic door closer a cylinder adapted to contain hydraulic fluid; a piston and rod slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means, including a bracket, for connecting said piston rod and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; means defining a fluid passage through said piston for flow of hydraulic liuid on movement of the piston toward a stop position at said one end of the cylinder, said Huid passage including an exposed flow restricting orifice; a stepped pin having portions of diiering cross-section mounted in said cylinder and pro- Jecting into said flow restricting orifice as said piston nears stop position, said bracket connecting said piston rod to said door having a plurality of spaced connection points selectively receiving said piston rod for adjusting ghe stepped portions of said pin with respect to said ori- 6.
- a hydraulic door closer In a hydraulic door closer: a cylinder adapted to contain hydraulic iluid; a piston slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means for connecting said piston and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss havmg a lower wall extending outwardly from said piston and having a bore therethrough; and means defining a fluid passage through said piston for ow of hydraulic duid on movement of the piston toward said other end of the cylinder, said passage including said bore and port means through only the lower wall of the boss, said port means being spaced from the face of said piston a distance greater than the distance between the port means 3,95%,499 and the botiom of the cylinder, and the bottom surface References Cited in the le of this patent of the lower Wall of the boss being closer to the botorn of the cylinder han he top surface of ille boss
Landscapes
- Closing And Opening Devices For Wings, And Checks For Wings (AREA)
Description
Feb. 26, 1963 R. K. GRAY ETAL DOOR CLOSER Filed sept. so, 195e 4 Sheets-Sheet 1 un l! 4 Sheets-Sheet 2 772W Jaz/C 46:2 g?
MIMI@ fr@ DOOR CLOSER R. K. G RAY ETAL Mm, NN vm Nm @1+ wm Filed sept. so, 1958 lleb. 26, 1963 R. K. GRAY ET AL 3,078,499
' Dooa cLosER Filed sept. so, 1958 4 sheets-sheet :s
" em Afef 56a dz-f l 2154352( C. mig@ Feb. 26, 1963 R. K. GRAY ETA. 3,078,499
` DooR CLOSER Filed Sep't. 30, 1958 4 Sheets-Sheet 4 United States Patent O1 corporation of Illinois Filed Sept. 30, 1958, Ser. No. 764,400 7 Claims. (Cl. 16--52) This invention relates to an hydraulic piston and cylinder door closer.
Many previously known piston and cylinder door closing or checking devices utilizing hydraulic damping fluid are so constructed that a certain amount of air is trapped with the fluid in front of the piston, causing an objectionable bounce at the start of the closing operation of the door. Solutions have been proposed for this problem, but they are generally unsatisfactory commercially, as they involve either complicated fluid passageway arrangements or complicated mechanical linkages which permit mounting the cylinder in a vertical rather than a horizontal position. As a result, such devices are too expensive to be commercially practicable.
It is a principal object of the present invention to provide a novel, yet simple, piston and fluid passageway arrangement for an hydraulic door closer, which reduces the air bounce problem.
Another object of the invention is the provision of a novel arrangement for varying the terminal closing force of the device.
One feature of the invention is the provision of an hydraulic piston and cylinder door closer including a fluid passageway through the piston for flow of fluid on movement of the piston during opening of the door, the passageway having an inlet spaced from the piston proper. Another feature is that the inlet of the fiuid passageway is a port formed in the lower surface of a boss extending from the piston, and spaced from the piston face.
A further feature is that the liuid passage inlet port means is elongated in a dimension along the axis of the cylinder, so that the fluid is drawn into the passage over a substantial area.
Still another feature is that the piston is provided with a fluid return passageway having a flow restricting orifice therein, a pin is associated with the flow restricting orifice, and operable therein to change the rate of flow of fluid through the orifice at the termination of the closing movement of the door, together with means for adjusting or varying the point of operation of the pin. Yet a further feature is that the pin is movably mounted on the piston, extending through the flow restricting orifice, and has portions of differing cross-section, the pin engaging the end of the cylinder and moving relative to the orifice to change the cross-section of the portion in the orifice during the terminal portion of the piston movement.
Another feature is that the piston is provided with a fluid return passageway having an exposed flow restricting orifice therein, a pin is mounted in the cylinder and projects into the flow restricting orifice as the piston nears its terminal position, and means are provided for varying the relative positions of the piston and the pin, to provide differing terminal closing rates. Yet a further feature is that the stop position of the piston is varied by changing the point of connection of the piston rod to the door.
And another feature is that the check valve in the fluid fiow passage through the piston includes a surface having a plurality of orifices therein carried in a recess in the face of the piston, with the orifices forming a portion of the flow passage, an annular member mounted in the ,recess and having a valve restraining portion, and the valve member carried between the surface and the annular member, for covering a portion of the orifices.
A further feature is that the bracket member for secur- 3,078,4@9 Patented Feb. 26, 1963 ice ing the piston rod to the door has mounting holes therein which are offset or unequally spaced from the point at which the piston rod is connected with the bracket, so that the bracket may be placed in one position with the piston closed for marking the point of attachment to the door, and then secured to the door in reversed position, to apply a preload to the return spring of the closer.
Yet another feature is that the closer includes a bracket secured to the door frame and a pin for securing the closer to the bracket, including means for preventing rotation of the pin relative to the bracket.
Further features and advantages will readily be apparent from the following specification and from the drawings, in which:
FIG. l is a horizontal section taken through a door and frame, illustrating the mounting of the door closer;
FIG. 2 is a longitudinal section taken through the door closer;
FIG. 3 is an enlarged fragmentary section through the piston and a portion of the cylinder, in one position;
FIG. 4 is an enlarged fragmentary section through the piston and a portion of the cylinder, in another position;
FIG. 5 is an enlarged fragmentary section through the piston and a portion of the cylinder in a third position;
FIG. 6 is a fragmentary plan and sectional view illustrating one step in securing the piston rod bracket to the door;
FIG. 7 is a view similar to FIG. 6 with the bracket secured to the door and the rod attached to the bracket;
FIG. 8 is a View taken generally along line 8 3 of FIG. 3;
FIG. 9 is a bottom view of a modified piston;
FIG. l0 is a sketch illustrating the flow of hydraulic iiuid with the novel fluid passageway inlet port arrangement of this invention;
FIG. ll is an enlarged fragmentary section through the piston and portion of the cylinder, similar to FIG. 3,
.illustrating a modified form of the invention;
FIG. l2 is a view similar to FIG. 11 showing the parts in another position;
FIG. 13 is a view similar to FIG. 11 showing a further modified form of the invention; and
FIG. 14 is an enlarged sectional view through the frame bracket and connecting pin.
Door closers for general purpose home use, as for screen and storm doors, are usually air buffered piston and cylinder devices. These closers normally have a relatively short life, as of the order of six to eight years. A few types of hydraulic closers, both piston and cylinder, and rotary vane constructions, have been marketed for home use. These closers are generally subject either to the air bounce problem discussed above, or are relatively expensive. The hydraulic piston and cylinder closer disclosed and claimed herein not only eliminates the air bounce problem, but is of rugged yet relatively inexpensive construction, having a long life while well within the price range for home use.
Referring now to the drawings and particularly to FIG. l, a storm door 15 is mounted by hinge 16 on a frame i7. Closing movement of the door is limited by stop I3 secured to the jamb portion I9 of frame i7. A closer, indicated generally as 20, includes a cylinder 21 secured to frame bracket 22 attached to the door frame adjacent the hinged edge of the door. A piston rod 23 extends from the opposite end of cylinder 21 and is secured to door bracket 24 attached to an intermediate point of the door 15.
In FIG. 2 it is seen that the cylinder 21 is provided with two end members 26 and 27. End member 26 has an ear 28 projecting therefrom with a hole 29 formed in the end to receive a pin connecting the cylinder with door frame bracket 22. Piston rod 23, which extends through a bore 3u provided in end member 27, is afxed at its inner end to piston 32, slidably carried within the cylinder The piston 32 and rod 23 are urged toward the position shown in FiG. 2 by return spring 33 which has one end bearing against the face .34 of the piston, and the other end on cup washer 35, which in turn is seated on end member 2'7 and serves as a retainer for sealing ring 36. A relatively heavy buffer spring 37 is located inside return spring 33 and is centered by a conical portion 35a of cup washer 35. A sleeve 37a, preferably of a plastic material as nylon, surrounds piston rod 3.2.3 inside the buffer spring, to prevent the spring from scarring the piston rod.
As best seen in FlG. 3, piston 3?., has an elongated boss or extension portion itl extending from the face 34, to which piston rod is secured, by pin ai. A fluid passage through the piston includes bore 42 which extends longitudinally through boss 40 and communicates through recess d3, formed in the face 44 of piston, with the space 435 to the left of the piston as viewed in the drawings. Bore 42 communicates with space d6, to the right of the piston, through a plurality of ports 47, 4S and 49 formed in the enlarged lower portion of boss 40 which is thicker than the top portion so that the lower surface of the boss is closely adjacent the cylinder wall. Carried in the recess 43 is a check valve arrangement including valve seat plate 52, provided with a plurality of peripherally located apertures S3 (FIG. 8) and a centrally located aperture 51%. Overlying plate 52 is an annular valve retainer 55, having an L-shaped crossssection with an inturned flange 55a. Carried between iiange 55a and valve seat plate 52 is check valve S6 which has a centrally located orifice 57 that is several times the size of orifice 51tin plate 52. A portion 52% of the piston 32 is formed over the top of annular valve retainer 5S as by a rolling operation, holding the entire valve assembly in recess 43.
When the door is opened, the piston 32 is retracted, compressing return spring 33. The movement of the piston away from end member 26 creates a vacuum or reduced pressure in the space 45 to the left of the piston, drawing the hydraulic iluid from the space 46 through the piston. The flow of iluid during this movement is through ports d?, 43 and 49, bore 42, apertures S3 and 54 in plate 52, and the central aperture 57 of valve 56, which is unseated. If the opening movement of the door is continued, butter spring 37 will also be compressed.
When the door is released, the return spring, or springs if both are compressed, urge the piston to the left, tending to close the door. This action moves valve member 56 to the right, causing it to seat on plate 52 closing orifices 53, so that the return ilow of fluid must pass through ow restricting orifice 54. The size of this orifice, as related to the viscosity of the hydraulic uid and the pressure of the return spring, Igoverns the closing speed of the device.
In the embodiment of FIGURE 3, as piston 32 nears its terminal position, adjacent end member 26, the point 6@ of a pin 61 mounted in the end member, enters speed control oriiice Sli, restricting the rate of iiow therethrough, and slowing the closing action of the door. The outer portion 6in of pin 6l has a smaller diameter than the base portion 61h, so that the closing movement of the door is slowed in two stages. This is illustrated in FIGS. 4 and 5, which show the portions 6in1 and 61h, respectively, or" the pin extending into ow controlling orifice 54. In one embodiment of the device where the How restricting oriice 5d has a diameter of 0.050 inch, the portion ola of the flow restricting pin has a diameter of 0.034 inch, and the portion 61h has a diameter of 0.040 inch. The opening .S7 inthe valve member is suiciently l large so that the flow through it is not aiected by the `member 6l.
The location of ports 47, 48 and 49 which open at the bottom of piston extension ttl reduces the possibility of air being drawn through the piston into the space 45 when the door is opened. Furthermore, the spacing of the ports along the length of piston extension 40, with the largest opening the farthest away from the face 34 of the piston, provides an elongated port means which causes the iluid to tlow into the piston in a uniform manner. In FiG. l0, the action of the surface of the hydraulic fluid with the port arrangement of FG. 3 is illustrated at da, showing how the fluid is drawn through each of the spaced ports. Where only a single port is provided in the face of piston 34, the surface of the hydraulic iiuid follows the broken line 65, and air is often drawn through the piston, resulting in the objectionable bounce operation discussed above.
FIG. 9 is a bottom View of a modified piston with a single wedge shaped intake port 67 located in the bottom or lower surface of piston extension 40, with the opening tapering downwardly as it approaches the face 34 of the piston.
Preferably the cross sectional area of the ports is equal to the area of bore 42, for ecient fluid ilow.
The needle valve or pin 6l, which provides slowing of the door at the end of the closing operation, may be utin lized to provide a terminal speed control. In FIG. 7, it will be seen that the door bracket 24 is provided with three sets of holes 68, 69 and '70, to one of which piston rod 23 is secured by pin 71. With piston rod 23 connected in holes 68, the piston closes fully, almost to the surface of end member 26, with full slowing of the operation. If piston rod 23 is connected with holes 69, the terminal position of the piston is as shown in FIG. 4, with only partial slowing action as pin 61 is in orifice 54 for a shorter portion of the movement. If the piston rod is secured in holes 70 of the door bracket, the terminal position of the piston is as illustrated in FIG. 3, with the flow restricting orilice 54 stopped short of the end 61a of needle valve 6l. With this arrangement of the closer, the door is moved at a constant speed and there is no slowing as it latches. The differing cross-sections of portions 61a and Gib of the pin enhance this control, as the closing speed is slower in the nal portion of the movement (using bracket holes 63) due to the further reduction in flow area through the oriiice.
The above described arrangement permits adjustment of the closer to accommodate different types of doors, latches and operating conditions.
The mounting holes 72 and 73 for door bracket 24 are oset from the connecting pin holes 63, 69 and 70, with holes 68 being spaced farther from mounting hole 73 than the distance between holes 'itl and mounting hole 72. This arrangement facilitates the installation of the closer with the necessary amount of pre-load on return spring 33. As shown in FIG. 6, door bracket 24 is initially connected with piston rod 23 by pin '71 through holes 7i), with mounting hole 72 toward the left or hinge edge of the door. The return spring 33 is fully extended, with the face 44. of piston 32 engaging end member 26. The positions of holes 72 and 73 are marked on door l5, as by a pencil '74. Door bracket 24 is removed from piston rod 23, inverted and attached to the door with hole 73y to the left and hole 72 to the right. Piston rod 23 is then reconnected with door bracket 24, by pin 7l in holes 68. As these holes are spaced farther from mounting hole 73 than the distance between hole 7u and mounting hole 72, piston 32 is moved away from the face of end member 26, as shown in FIG. 2, applying a pre-load to closing spring 33.
Cylinder end Z7 through which piston rod 23 extends, has mounted in bore 30 a bearing sleeve 75, preferably of a low friction material, as nylon. Mounted in an enlarged portion 39a of the bore at the outer end of end.
member 27 is an annular rod seal 76 of flexible sealing material backed up by supporting washer 77. A leather rod wiper 78 is located outside supporting washer 77, and held in place by a retaining washer 79. The parts 77, 78 :and '79 are of any suitable construction and may be conventional. The provision of an elongated bearing surface 75 at the inner face of end member 2'7, with the sealing element at the outer face thereof, eliminates undue wear on the sealing element due to misalignment of the piston rod during operation.
In the modification of FGS, ll and l2, parts corresponding with parts illustrated and identified in preceding gures are designated by the same reference numerals. A pin '71' is carried in the bore 42 of piston 32 and is urged outwardly thereof through ow controlling ori'iice 54 by a spring 7i", which has an end portion 71a tightly coiled about pin 71' and engaging a shoulder 71a' formed thereon, supporting the pin. The portion 71b' of the pin, which is normally Within orifice 5ft whenever the piston is spaced a substantial distance from cylinder end member 26, reduces the ow of hydraulic uid through the orifice to such a degree that the door closes slowly. As the piston nears end member 26, the sharpened point 'lc' of the pin engages a plug 72. carried by end member 26, and the movement of the pin is stopped. As piston 32 continues to move toward the left, the reduced portion 71d of the pin enters flow controlling orifice 54, and the nal closing movement of the door is accelerated. This insures that the door will latch securely, even with a latch that is hard to operate.
The end surface of plug 72' which is engaged by the pointed end 7ilc' of the pin is provided with a conical depression 72a', so that the pin is properly aligned during the relative movement between it and piston 32.
In FiGURE 13, a moditied control pin '7S' is shown carried by spring 71 having a portion of reduced crosssectional area 78a', which is normally positioned within ow controlling orifice S4, and a portion of enlarged cross-sectional area 'b' which is moved into the iiow controlling orifice 54 during the terminal closing movement of the door. This slows the movement of the door as it latches.
Referring now to FIGURE 14, it will be seen that the frame bracket 22 includes two spaced portions 22a and 221: between which is received the end portion of ear 2?. A pin St) is inserted through aligned openings in bracket portions 22a and 22b, and through opening 29 in ear 23. The pin 80 is provided with a portion 81 which engages with bracket portion 22a, preventing pin S0 from rotating during operation of the closer. For example, the shoulder portion 81 of pin lSti may be knurled and of such a diameter that it has a driven engagement with the bracket. All relative motion between the closer and the bracket occurs along the surface of hole 29 and the body of pin St), and there is no wear on the relatively small surfaces of engagement between the pin and the bracket.
While we have shown and described certain embodiments of our invention, it is understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.
We claim:
l. In a hydraulic door closer: a cylinder adapted to contain hydraulic uid; a piston slidable in said cylinder;
a spring urging said piston toward one end of said cylinder; means for connecting sai-d piston and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss having a lower wall extending outwardly from said pist0n, and having a bore; and means defining a iiuid passage through said piston for flow of hydraulic uid on movement of the piston toward said other end of the cylinder, said passage including said bore and port means through the wall of said boss, horizontally spaced a substantial distance from the face of said piston, said port means opening through the lower wall of said boss and having a greater extent in a direction along the axis of the cylinder than in a direction transverse thereto.
2. A hydraulic piston and cylinder device ot' claim l, wherein said port means comprises a series of openings of graduated size extending longitudinally along said boss, with the largest opening spaced the farthest from the face of said piston.
3. A hydraulic piston and cylinder device of claim l, wherein said port means is a wedge-shaped opening having its base portion spaced farthest from the face of said piston and tapering toward the piston face.
4. In a hydraulic door closer; a cylinder adapted to contain hydraulic uid; a piston slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means for connecting said piston and cylinder to a door and an associated trame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss extending outwardly from said piston, and having a bore; and means defining the principal uid passage through said piston for iiow of hydraulic fluid on movement of the piston toward said other end of the cylinder, said passageway including said bore and port means through the wall of said boss, spaced a substantial distance from the face of said piston, the cross section of said port means geing substantially equal to the cross section of said ore.
5. In a hydraulic door closer: a cylinder adapted to contain hydraulic fluid; a piston and rod slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means, including a bracket, for connecting said piston rod and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; means defining a fluid passage through said piston for flow of hydraulic liuid on movement of the piston toward a stop position at said one end of the cylinder, said Huid passage including an exposed flow restricting orifice; a stepped pin having portions of diiering cross-section mounted in said cylinder and pro- Jecting into said flow restricting orifice as said piston nears stop position, said bracket connecting said piston rod to said door having a plurality of spaced connection points selectively receiving said piston rod for adjusting ghe stepped portions of said pin with respect to said ori- 6. In a hydraulic door closer: a cylinder adapted to contain hydraulic iluid; a piston slidable in said cylinder; a spring urging said piston toward one end of said cylinder; means for connecting said piston and cylinder to a door and an associated frame, opening movement of said door moving said piston toward the other end of said cylinder and thereby compressing said spring; a boss havmg a lower wall extending outwardly from said piston and having a bore therethrough; and means defining a fluid passage through said piston for ow of hydraulic duid on movement of the piston toward said other end of the cylinder, said passage including said bore and port means through only the lower wall of the boss, said port means being spaced from the face of said piston a distance greater than the distance between the port means 3,95%,499 and the botiom of the cylinder, and the bottom surface References Cited in the le of this patent of the lower Wall of the boss being closer to the botorn of the cylinder han he top surface of ille boss is io the UNITED STATES PATENTS the relative position of said piston and pin being adjustable for selectively varying the rate of iiow of the 20 FOREIGN PATENTS hydraulic iuid, by changing the point of connection of 1,158,223 France Ian. 20, 1958 the closer t0 Said dom- 444,046 Great Bain Mal'. 12, i936
Claims (1)
1. IN A HYDRAULIC DOOR CLOSER: A CYLINDER ADAPTED TO CONTAIN HYDRAULIC FLUID; A PISTON SLIDABLE IN SAID CYLINDER; A SPRING URGING SAID PISTON TOWARD ONE END OF SAID CYLINDER; MEANS FOR CONNECTING SAID PISTON AND CYLINDER TO A DOOR AND AN ASSOCIATED FRAME, OPENING MOVEMENT OF SAID DOOR MOVING SAID PISTON TOWARD THE OTHER END OF SAID CYLINDER AND THEREBY COMPRESSING SAID SPRING; A BOSS HAVING A LOWER WALL EXTENDING OUTWARDLY FROM SAID PISTON, AND HAVING A BORE; AND MEANS DEFINING A FLUID PASSAGE THROUGH SAID PISTON FOR FLOW OF HYDRAULIC FLUID ON MOVEMENT OF THE PISTON TOWARD SAID OTHER END OF THE CYLINDER, SAID PASSAGE INCLUDING SAID BORE AND PORT MEANS THROUGH THE WALL OF SAID BOSS, HORIZONTALLY SPACED A SUBSTANTIAL DISTANCE FROM THE FACE OF SAID PISTON, SAID PORT MEANS OPENING THROUGH THE LOWER WALL OF SAID BOSS AND HAVING A GREATER EXTENT IN A DIRECTION ALONG THE AXIS OF THE CYLINDER THAN IN A DIRECTION TRANSVERSE THERETO.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US764400A US3078499A (en) | 1958-09-30 | 1958-09-30 | Door closer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US764400A US3078499A (en) | 1958-09-30 | 1958-09-30 | Door closer |
Publications (1)
Publication Number | Publication Date |
---|---|
US3078499A true US3078499A (en) | 1963-02-26 |
Family
ID=25070626
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US764400A Expired - Lifetime US3078499A (en) | 1958-09-30 | 1958-09-30 | Door closer |
Country Status (1)
Country | Link |
---|---|
US (1) | US3078499A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3204287A (en) * | 1962-03-31 | 1965-09-07 | Gronbach Wilhelm | Spring-loaded hinge for balancing the weight of a wing, lid or the like |
US3216050A (en) * | 1962-03-29 | 1965-11-09 | Gen Motors Corp | Hydraulic door closing mechanism |
US3343203A (en) * | 1966-11-17 | 1967-09-26 | Schuermann & Co Heinz | Telescoping door closer |
US3375542A (en) * | 1965-09-13 | 1968-04-02 | Lock Inc | Door closer |
US3708826A (en) * | 1970-11-30 | 1973-01-09 | Hartzell Mfg Inc | Adjustable hydraulic door closure |
JPS4836571A (en) * | 1971-09-13 | 1973-05-30 | ||
US3934307A (en) * | 1972-06-19 | 1976-01-27 | Lasier Thomas R | Spring adjustment mechanism |
US4412362A (en) * | 1981-01-15 | 1983-11-01 | Nylund Kenneth G | Partial flush apparatus utilizing pneumatic time delay mechanism |
US20070039130A1 (en) * | 2003-11-12 | 2007-02-22 | Jang-Woo Song | Door closer |
US20100310733A1 (en) * | 2007-11-28 | 2010-12-09 | Steve Hoffman | Pressurized cooking oven |
US9538776B2 (en) | 2013-04-27 | 2017-01-10 | KitchenTek, LLC | Pressurized oven assembly |
Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1115305A (en) * | 1914-08-29 | 1914-10-27 | American Hardware Corp | Door-controlling means. |
US1455691A (en) * | 1922-07-01 | 1923-05-15 | Leonidas D West | Automatic door closer |
US1738123A (en) * | 1926-02-20 | 1929-12-03 | Elevator Supplies Co Inc | Doorcheck |
US1849417A (en) * | 1927-04-13 | 1932-03-15 | Elevator Supplies Co Inc | Door operating mechanism |
US1965805A (en) * | 1931-12-24 | 1934-07-10 | David E Riggins | Doorcheck |
US1966445A (en) * | 1931-07-30 | 1934-07-17 | Gurney Elevator Co | Elevator door control mechanism |
GB444046A (en) * | 1934-11-06 | 1936-03-12 | William Henry Jones | Improvements in or relating to door-closing and checking apparatus |
US2053053A (en) * | 1932-07-30 | 1936-09-01 | Curtiss Aeroplane & Motor Co | Aircraft landing gear |
US2416316A (en) * | 1945-12-03 | 1947-02-25 | Norwalk Lock Company | Door check bracket |
US2441037A (en) * | 1944-11-17 | 1948-05-04 | Max H Sherrin | Bathroom scale support |
US2681468A (en) * | 1950-03-01 | 1954-06-22 | Bert A Quinn | Door check |
US2735132A (en) * | 1956-02-21 | Wartian | ||
US2812533A (en) * | 1953-12-21 | 1957-11-12 | Wright Products Inc | Door check |
FR1158223A (en) * | 1955-09-13 | 1958-06-12 | Close door | |
US2866223A (en) * | 1954-09-08 | 1958-12-30 | Albert Van Dillen | Doorcloser and doorcheck |
US2942291A (en) * | 1957-01-14 | 1960-06-28 | Lcn Closers Inc | Door closing and checking device |
US2949625A (en) * | 1956-02-21 | 1960-08-23 | Hubert A Guyer | Door closer |
-
1958
- 1958-09-30 US US764400A patent/US3078499A/en not_active Expired - Lifetime
Patent Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2735132A (en) * | 1956-02-21 | Wartian | ||
US1115305A (en) * | 1914-08-29 | 1914-10-27 | American Hardware Corp | Door-controlling means. |
US1455691A (en) * | 1922-07-01 | 1923-05-15 | Leonidas D West | Automatic door closer |
US1738123A (en) * | 1926-02-20 | 1929-12-03 | Elevator Supplies Co Inc | Doorcheck |
US1849417A (en) * | 1927-04-13 | 1932-03-15 | Elevator Supplies Co Inc | Door operating mechanism |
US1966445A (en) * | 1931-07-30 | 1934-07-17 | Gurney Elevator Co | Elevator door control mechanism |
US1965805A (en) * | 1931-12-24 | 1934-07-10 | David E Riggins | Doorcheck |
US2053053A (en) * | 1932-07-30 | 1936-09-01 | Curtiss Aeroplane & Motor Co | Aircraft landing gear |
GB444046A (en) * | 1934-11-06 | 1936-03-12 | William Henry Jones | Improvements in or relating to door-closing and checking apparatus |
US2441037A (en) * | 1944-11-17 | 1948-05-04 | Max H Sherrin | Bathroom scale support |
US2416316A (en) * | 1945-12-03 | 1947-02-25 | Norwalk Lock Company | Door check bracket |
US2681468A (en) * | 1950-03-01 | 1954-06-22 | Bert A Quinn | Door check |
US2812533A (en) * | 1953-12-21 | 1957-11-12 | Wright Products Inc | Door check |
US2866223A (en) * | 1954-09-08 | 1958-12-30 | Albert Van Dillen | Doorcloser and doorcheck |
FR1158223A (en) * | 1955-09-13 | 1958-06-12 | Close door | |
US2949625A (en) * | 1956-02-21 | 1960-08-23 | Hubert A Guyer | Door closer |
US2942291A (en) * | 1957-01-14 | 1960-06-28 | Lcn Closers Inc | Door closing and checking device |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3216050A (en) * | 1962-03-29 | 1965-11-09 | Gen Motors Corp | Hydraulic door closing mechanism |
US3204287A (en) * | 1962-03-31 | 1965-09-07 | Gronbach Wilhelm | Spring-loaded hinge for balancing the weight of a wing, lid or the like |
US3375542A (en) * | 1965-09-13 | 1968-04-02 | Lock Inc | Door closer |
US3343203A (en) * | 1966-11-17 | 1967-09-26 | Schuermann & Co Heinz | Telescoping door closer |
US3708826A (en) * | 1970-11-30 | 1973-01-09 | Hartzell Mfg Inc | Adjustable hydraulic door closure |
JPS567090B2 (en) * | 1971-09-13 | 1981-02-16 | ||
JPS4836571A (en) * | 1971-09-13 | 1973-05-30 | ||
US3934307A (en) * | 1972-06-19 | 1976-01-27 | Lasier Thomas R | Spring adjustment mechanism |
US4412362A (en) * | 1981-01-15 | 1983-11-01 | Nylund Kenneth G | Partial flush apparatus utilizing pneumatic time delay mechanism |
US20070039130A1 (en) * | 2003-11-12 | 2007-02-22 | Jang-Woo Song | Door closer |
US7464437B2 (en) * | 2003-11-12 | 2008-12-16 | Jang-Woo Song | Door closer |
US20100310733A1 (en) * | 2007-11-28 | 2010-12-09 | Steve Hoffman | Pressurized cooking oven |
US9538776B2 (en) | 2013-04-27 | 2017-01-10 | KitchenTek, LLC | Pressurized oven assembly |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3078499A (en) | Door closer | |
US3584331A (en) | Hydraulic door checking mechanism | |
US2591476A (en) | Hinged closure control | |
US2298542A (en) | Door operator | |
US2586135A (en) | Door closer | |
US4386446A (en) | Door closer | |
US3408683A (en) | Door closer | |
US4196924A (en) | Automatic door closing device | |
US2702398A (en) | Door closer | |
US2723416A (en) | Door check and closer | |
FI52491B (en) | ||
US2680263A (en) | Double-acting door check and combination | |
DE102010004134A1 (en) | Frame joint for door frame, has stationary part and movable part, where rotating movement of movable part is coupled with axial movement of part of frame joint | |
US2159067A (en) | Door closer and check | |
US2890474A (en) | Hydraulic door check | |
US1952070A (en) | Door closer and check | |
US2769195A (en) | Door check with fluid bumper | |
US1759649A (en) | Pneumatic door closer | |
GB1576292A (en) | Door closer having an opening brake | |
GB1392727A (en) | Automatic door-closing device | |
US1586901A (en) | Checking mechanism | |
GB2140076A (en) | Door closers | |
US2979759A (en) | Door closer | |
JPS5938862Y2 (en) | Door check back check device | |
GB1220007A (en) | Automatic door closers |