US3503021A - Direct action latching device with electrical and manual release means - Google Patents

Description

w H. DE BRUIN ETAL March 24, 1970 3,503,021

DIRECT ACTION LATCHING DEVICE WITH ELECTRICAL AND MANUAL RELEASE MEANS 3 Sheets-Sheet 1 Filed May 28, 1968 March 24, 1970 H. DE BRUI ETAL- 3,503,021

DIRECT ACT LATC G DEV WI ELECTRICAL I AND MANU RELEASE ME Filed May 28, 1968 s Sheets-Sheet z IV////// 'III'I March 24, 1970 w. H. DE BRUIN ETAI- 3,503,021

DIRECT ACTION LATCHING DEVICE WITH ELECTRICAL AND MANUAL RELEASE MEANS Filed May 28, 1968 5 Sheets-Sheet 5 United States Patent 3,503,021 DIRECT ACTION LATCHING DEVICE WITH ELEC- TRICAL AND MANUAL RELEASE MEANS Willard H. De Bruin, Milwaukee, and Nobel H. Koertge,

Elm Grove, Wis., assignors to Cutler-Hammer, Inc.,

Milwaukee, Wis., a corporation of Delaware Filed May 28, 1968, Ser. No. 732,679 Int. Cl. H011? 7/08 U.S. Cl. 335-254 6 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION 1 This invention relates to latching devices. In particular this invention relates to latching devices that are incorporated with electromagnetic relays, and which have electrical and manual release mechanisms.

Latching devices of the type disclosed herein are generally mounted upon the housing of an electromagnetic relay switching device and have an axially movable shaft which is coupled to the relay armature. Operation of the relay coil to actuate the relay contacts moves the shaft of the latching device to a latched position wherein the relay coil may be deenergized and the latching device will hold the contact mechanisms actuated.

A common construction for such latching mechanisms is exemplified in US. Patent No. 3,101,434 to H. Kitscha. A-plurality1of balls are biased into a conical housing to wedge against the shaft and prevent movement of the shaft in a reverse direction. In the above patent, a shoulder on the shaft drives the balls along the conical surface until the balls reach a point therealong of sufiicient width to allow the balls to move outward to contact the periphery of the shaft above the shoulder. A spring member biases the balls in a reverse direction, toward the narrower part of the conical surface, to wedge against the cylindrical surface of the shaft and prevent its return movement. In this construction consistent latching positions become difficult to control due to occasional slippage on the cylindrical surface.

A known variation of the above construction comprises a shaft which has a pair of base-to-base conical portions substituted for the reduced diameter portion.

In the variation the balls are initially moved outwardly by one conical portion and are driven against the bias of the spring to a wider portion of the conical housing by the shoulder formed by the base-to-base junction on the shaft. When the balls clear the junction, the spring member biases them in a reverse direction toward the narrower portion of the' conical housing where they wedge against the shaft at the other conical portion thereof. The coacting conical surfaces in the latched position allow the position of latching to be somewhat better controlled.

One disadvantage to each of the above described constructions is that the spring member must overcome the dynamic energy of the balls and reverse their motion in the latching action. While the amount of time involved 3,503,021 Patented Mar. 24, 1970 therein is relatively small, such adverse inertial character- 1st1cs can occasionally result in a failure to latch when the relay coil is pulsed. To provide a positive and quick acting latching mechanism it is extremely desirable to have the ball members move directly to the latching positron from a static, or at rest, condition.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an lmproved latching device which is particularly well suited for use with an electromagnetic relay device.

It is a further object of this invention to provide an improved latching device which has a quick and' accurate latching action. 4

It is still a further object of this invention to provide an improved latching device wherein the latching mechanism moves directly to a latched condition from a static condition.

It is still another object of this invention to provide an improved latching device which may be released either electrically or mechanically.

These and other objects and advantages will become more apparent in the following specification and claims when read in conjunction with the accompanying drawmgs.

DESCRIPTION OF THE DRAWINGS I FIGURE 1 is an elevational view of the latching device lncorporated with a schematically depicted relay device and control circuit therefor;

FIG. 2 is a top plan view of the latching device drawn to an enlarged scale;

FIG. 3 is a longitudinal sectional view of the latching device taken along line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 3;

FIG. 5 is a sectional view similar to FIG. 3 but taken along the partially rotated line 55 of FIG. 2 and showing the device in the latched position;

FIG. 6 is a fragmentary sectional view taken substantially along the line 6-6 of FIG. 4 and showing a manual release feature of the device; and

FIG. 7 is a cross-sectional view of the one member of the latching device drawn to a greater scale than the foregoing figures.

DECRIPTION OF THE PREFERRED EMBODIMENT The latching device of this invention is indicated in the drawings by the general reference character 2 and is shown in FIG. 1 as being mounted upon an electromagnetic relay device 4. While the relay device is depicted schematically herein, the same may preferably be of the type disclosed and claimed in a copending application Ser. No. 663,067, filed Aug. 24, 1967, and assigned to the and assigned to the assignee of this invention.

Relay device -4 comprises an operating coil 6 and a reciprocally movable armature member 8. Armature 8 is normally biased to a retracted position relative to the relay housing by a helical compression spring 10 disposed between an-annular flange on armature 8 and a rigid wall portion of the relay housing. Armature 8 is further mechanically coupled to the bridging contacts of a plurality of switch poles 12 of either the normally open or normally closed types to actuate the switches 12 in response to energization or deenergization of the operating coil 6. The outer end of armature 8 is provided with a coupling member 8a for mechanical connection to an operating member of the latching device 2 as will be described in greater detail hereinafter. Energization of operating coil 6 causes armature 8 to be extended, or driven outwardly toward the latching device 2.

In the preferred relay of the above mentioned copending application the mechanical coupling of the armature to the bridging contacts is accomplished through a push bar member which in turn is coupled to the operating member of the latch. This construction allows the armature to return after deenergization under its own spring pressure, while the latching device holds the contacts actuated through the push bar.

The latching device 2 responds through a mechanical action to latch the armature 8 of relay 4 in its extended position after operating coil 6 is deenergized. Release of the latching device 2 may be accomplished either electrically from some remote point by energizing an electromagnitic rlease coil 14 or manually at the relay and latching device location by movement of a lever 16 in the direction of arrow 18.

The electrically responsive portions of latching device 2 and relay device 4 are adapted to be energized by either an AC. or DC. source of electrical power having supply lines L1 and L2. The operating coil 6 of relay 4 is connected across the lines L1 and L2 in series with a normally open pushbutton switch 20. The twitch poles 12 of relay device 4 are connected across the lines L1 and- L2 in series with a load device 22 which is to be controlled by the relay 4. The release coil 14 of latching device 2 is also connected across the lines L1 and L2 in series with a normally open pushbutton switch 24 by means of a pair of wiring terminals 26 provided on the coil 14.

The construction of latching device 2 will now be described with particular reference to FIGS. 1-4 of the drawings. The mechanism of the latching device is housed in a hollow molded insulating case 28 which is open to the outer end, or top as viewed in FIGS. 1 and 3. The outer portions of an opposite pair of sidewalls of case 28 have been recessed to expose the release coil 14 and its terminals 26.

The interior configuration of the case 28 varies peripherally at two major levels.

A first interior portion betweenthe outer end and a first level 28a is generally rectangular uniformly within the sidewalls of the case 28, and communicates with the exterior thereof at the recessed sidewalls for coil 14. A second interior portion extends between the level 28a and a lower level 28b. The inner periphery of the second portion may be seen in FIG. 4. A central circular recess 28c is formed in the surface of lower level 28b. Concentric within the recess 280 is a cylindrical opening 28d which extends between the hollow interior of case 28 and the lower exterior surface thereof as viewed in FIG. 3.

The upper portion of case 28 houses the electromagnetic release components of the latching device 2 and will be described first with particular reference in FIGS. 3 and 5. A rectangular steel support plate 30 rests upon the first level 28a of case 28. Support plate 30* has a central circular opening therein. A steel collar member 32. is welded to the underside of support plate 30, the

collar member also having a circular opening therein' which is in alinement with the opening in plate 30. The reduced portion of a shouldered, non-magnetic cylindrical bushing 34 is pressed into the circular opening of support plate 30'. Bushing 34 serves as a bearing member for a movable armature assembly as will be described later.

The electromagnetic release coil 14 is of the cast resin type wherein the exterior may be molded to the desired shape to be readily retained by the case 28 without undue hardware. The coil rests upon the support plate 30 and is prevented from rotating by exterior rectangular portions which fit within the aforementioned recessed sidewalls of case 2 8.

. A U-shaped magnet frame 36 is disposed over the coil 14, the legs of which depend along the coil within case 28 to rest upon the support plate 30. A resilient spring washer 38 is disposed between the bight portion of magnet frame 36 and the upper surface of coil 14 to bias the coil against the support plate. The bight portion of magnet frame 36 is provided with a central circular opening to receive a reduced cylindrical portion of a depending core piece 40'. The core piece 40 is preferably secured to the frame 36 by riveting over the protruding end of reduced cylindrical portion. The inner end of core piece 40 is provided with an annular shading coil 52 which is brazed within a circular groove formed by a steel retaining sleeve 44 pressed over the core piece 40. Core piece 40 is further provided with an axial bore therethrough to rceive a shaft 46 to be described later.

The support plate 30, coil 14 and magnet frame 36 are all held securely 'within the case 28 by a molded insulating cover 48 which is secured to the case by'four screws 50. Screws 50 pass through clearance openings at each corner of cover 48, extend along the coil and magnet frame at the four corners of the upper portion of case 28 and take into alined threaded holes28e in surface 28a. of case 28. It may be seen that the magnet frame 36 extends slightly beyond theouter end of case 28 and that the cover 48 bears directly upon the frame to hold'the latter securely upon the support plate 30. i

Latching device 2 is further provided with an arma ture assembly which comprises a movable core piece 52, a spring gland 54 and a ball cage 56. A reduced cylindrical end of ball cage 56 extends through a central circular opening in spring gland 54 and is press fit into a mating recess in one end of the movable core piece 52 to trap the spring gland between the end of the core piece and the annular shoulder of ball cage 56.'

Core piece 52 is received within bushing 34 and the movable assembly is guided for axial movement therein:

A helical compression spring 58 extends between the underside of support plate 30 and the upper surface of an annular flange of spring gland 54 to bias the armature assembly downwardly, or inwardly of the latching device.

The movable core piece 52 and ball cage 56 are provided with alined axial bores for receiving the aforementioned shaft 46, the bore in ball cage 56 being of somewhat larger diameter than that of core piece 52. Additionally, ball cage 56 is provided with three equally spaced, radially extending cylindrical apertures 56a (FIG. 4) which extend through the sidewall of the 'ball cage. Each aperture 56a is constricted atthe inner end adjacent the axial central bore of the ball cage by reducing conical portions.

A cylindrical housing member 60 is seated within the recess 28c in lower level surface 28b. Housing 60 has a peripheral groove therein into which the inner ends of a pair of diametrically opposed clips 62 extend. Clips 62 lie within rectangular recesses 28] (FIGS. 4 and 5) which are slightly lower than the groove in housing 60. A pair of threaded cut screws 64 extend through clearance openings in clips 62 and are turned.

diameter of the lower portion of ball cage 56. A concentric frusto conical recess portion 60b extends upwardly from bore 60a and flares outwardly thereof. Conical portion 60b is relieved near the upper end of housing 60 by a concentric cylindrical recess 600. The frusto conical surface 60b and cylindrical recess 600 are joined by a concentric second frusto conical portion 60d.

Surrounding the exterior of housing member 60 and resting upon the surface 28b of case 28 is a ring-shaped yoke portion 16a of the manual release lever 16. The exteriorly extending portion of lever 16 is connected to yoke portion 16a by a radially extending dog-leg portion16b (FIG. 4). Diametrically opposed from dog-leg portion 16b on .yoke 16a is an outwardly extending circular tab 16c. Tab 160 is positioned within a key hole recess 28g=in case 28 as seen particularly in FIG. 6, tab 16c serves as the fulcrum for lever 16 when it ismoved in the direction of arrow 18.

A helical compression-spring 66 extends within the recess 28g to bear between the-tab 16c and the support plate 30, thereby affording a downward bias to lever 16; Yoke portion'16a is further provided with a pair of upwardly formed bearing portions 16d. These portions are diametrically opposed on the yoke and are on an imaginary centerline which is perpendicular to a similar line between tab .160 and dog-leg 16b.

The aforementioned shaft 46 has a slotted outer end for receiveing'the blade of a screw driver or the like and has a threaded shank formed on its inner end. The inner end of shaft '46 is threaded into a secondaryshaft member 68 which has a cylindrical upper portion 68a and a lower conical portion 68b. A threaded shank depends from the conical .portion 68b to be threaded into the coupling portion 8a of relay device armature 8.

To complete the latching device assembly, three steel ball members 70 are inserted within the cylindrical apertures 56a of ball cage 56. Ball members 70 are of a. greater diameter than the wall thickness of ball cage 56 and may therefore extend exteriorly of the ball cage 56 and interiorly of the bore therein simultaneously.

OPERATION The latching device 2 is shown in its unlatched, or released position in FIG. 3. It may be seen therein that the ball members 70, only one of which is shown, are in engagement with the cylindrical surface portion 68a of shaft 68. The ball members 70 are also resting in the relieved portion of housing 60, namely on the surface of the conical portion 60d. It may be noted that the ball members in the released position are very near the point at which the second conical portion 60d joins the conical portion 60b.

Relay device 4 may be operated by depressing the pushbutton 20 to connect the operating coil 6 to the lines L1 and L2. Energization of coil 6 extends armature 8 to actuate the relay switch contacts and drive the end 8a of the armature upwardly into the latching device 2. The latter movement of armature 8 drives shaft 68 and hence shaft 46 upwardly, or outwardly of the latching device.

Since the balls.70 are resting against the cylindrical portion 68a of shaft 68, the latter is allowed upward movement without moving the ball cage 56. As the line formed by the juncture of surfaces 68a and 68b moves to and beyond the points of tangency on balls 70, the latter contact the conical surface 68b to move inwardly toward the axis of shaft 68. Such inward movement of the balls allows them to move out of the relieved portion of housing 60 and directly downward into the conical portion 60b under the bias of spring 58. The ball members are thus in engagement with the conical surfaces 60b and 68b and for each upward increment of movement of shaft 68, the balls 70 move further downward along surface 60b to wedge between the two cooperating conical surfaces as shown in FIG. 5 and latch the shaft against reverse movement.

The pushbutton 20 may be released to deenergize the operating coil 6. However, the armature 8 will not be returned by the spring 10 while the shaft 68 is in the latched position and the relay switches will therefore remain in their actuated condition. As mentioned earlier, the latching device may be released either electrically or manually. The electrical release will be described first.

The pushbutton 24 may be depressed to energize. the release coil 14 across the lines L1 and L2. The energized coil establishes a magnetic flux field which effects magnetization of the core piece 40. The latterin turn exerts an attractive force on the movable core piece to cause the movable armature assembly to move 'upwardly against the bias of spring 58. Ball' cage 56 thereby pulls ball members 70 out ofthe conical portion 60b and into the relieved portion of housing 60. As the balls move into the relieved portion of housing 60 they release the conical portion 68b of shaft 68 to allow the latter and armature 8 to move downward under the bias of spring 10, thereby deactuating the relay switches 12.

The same release action may be accomplished manually by moving lever 16 upwardly in the direction of arrow 18. In FIG. 6 it may be seen that such movement pivots the lever 16 upwardly about the tab 16c to cause the bearing portions 16d to engage the underside of the annular flange of spring gland 54. The lever movement thereby drives the spring gland 54 upwardly against the bias of spring 58 and such movement pulls the ball cage 56 and balls 70 out of the latching position.

Thus there is provided a latching device which provides positive and instantaneous latching of a relay armature or the like wherein the latching members move directly from a static position to the latching position. While but one preferred embodiment is disclosed herein, it should be apparent that the device is susceptible of various modifications without departing from the scope of the appended claims.

We claim:

1. The combination with a rectilinearly movable member having a normal position and another position displaced from said normal position;

(a) of a latching mechanism for automatically locking said movable member in said other position when moved thereto and comprising:

(b) means on said movable member providing a cylindrical surface and a contiguous frusto conical surface converging at an angle with the axis of movement of said movable member;

(0) a ball cage concentrically disposed about said means and having at least one ball mounted in a side operture and engaging with said means;

(d) a fixed, annular member concentrically disposed about said ball cage and having a frusto conical inner recess and a cylindrical recess connecting with, and having an inner diameter greater than, the major inner diameter of said frusto conical inner recess;

(e) means biasing said ball cage toward the normal position of said movable member so that said ball engages the cylindrical surface of the first mentioned means and a portion joining said frusto conical recess with said cylindrical recess in said annular member; I

(f) said movable member when moved to said other position causing said ball to roll on said cylindrical surface of said first mentioned means and thereafter upon movement of said ball cage under its bias causing said ball to be interposed in wedging relation between the wall of said frusto conical recess and the frusto conical surface of said first mentioned means;

(g) and means for moving said ball cage in a direction opposing its biasing means to move said ball out of wedging relation into the space between said cylindrical recess and said cylindrical surface to release said movable member for return movement.

2. The combination according to claim 1 wherein the portion joining said frusto conical inner recess with said cylindrical inner recess in said annular member is a sec-- ond frusto conical inner recess formed at a greater angle to the axis of movement of said movable member than said first mentioned frusto conical inner recess.

r .7 r N 3. The combination according to claim 1 wherein said means for moving said ball cage in a direction opposing its biasing means includes a lever member movable in said direction to engage an extending portion on said ball cage and move the latter in said direction to move said ball out of Wedging relation and effect release of said movable member.

4. The combination according to claim 3 wherein said lever includesa yoke portion surrounding said fixed annular member and having a pair of bearing portions formed at diametrically opposed points thereon, said bearing portions being offset from the plane of said yoke portion toward said extending portion of said ball cage to engage the latter at diametrically opposed sides of said movable member.

5. The combination according to claim 1 wherein said means for moving said ball cage in a direction opposing its biasing means includes electromagnetic means comprising an electrically energizable coil member having a central opening therein, a stationary core member extending into said coil opening, and a movable core member secured to said ball cage and extending into said coil opening toward said stationary core member and wherein energization of said electrical coil member causes attraction of said movable core member toward said stationary core 8 v member to move said ball cage in said direction tomove said ball out of wedging relation and against the bias effect release of said movable member; p

6. The combination according to claim Spwherein said means for moving said ball-cage in a direction opposing its biasing means further includes a lever member movable in said direction independently of said electromagnetic means to engage any extending portion on said ball cage and move the latter in said directionto move said ball out of wedging relation-and effect release of said movable member.

References Cited UNITED STATES PATENTS 1,326,359 12/1919 Mahoney .Q 335-254 3,101,434 8/1963 Kitscha 335-254 3,209,102 9/1965 Boley 335 170 3,235,777 2/1966 Hatashita 335-254 G. HARRIS, Primary Examiner U.S. Cl. X.R. 335170

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