US1397305A - Sheet-feeding mechanism - Google Patents

Description

E. WHITE.

SHEET FEEDING MECHANISM.

APPLICATION FILED OCT. 9, I920.

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E. WHITE.

SHEET FEEDING MECHANISM.

APPLICATION FILED OCT. 9, 1920.

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E. WHITE.

SHEET FEEDING MECHANISM.

APPLICATION FlLED 00?, 9. 1920.

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APPLICATION FILED OCT. 9, 1920.

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SHEET FEEDING MECHANISM.

APPLICATION FILED OCT. 9. 1920.

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SHEET FEEDING MECHANISM APPLICATION FILED 0619,1920.

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SHEET FEEDING MECHANISM.

APPLICATION FILED OCT. 9, I920.

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CONTINENTAL CAN Col /I- YOBK, A CORPORATION OF NEW] YORK.

SHEET-FEEDING- MECHANITSM.

Application filed October 9, 1920.

To all 20710222. it may concern."

Be it known that I, EDWIN WHITE, a citizen of the United States, residing at Baltimore, State of Maryland, have invented cer tain new and useful Improvements in Sheet- Feeding Mechanisms, of which the following is a description, reference being bad to the accompanying drawing, and to the figures of reference marked thereon.

The invention relates to new and useful improvements in sheet feeding mechanisms and more particularly to a sheet feeding mechanism adapted to separate sheets from a stack and move them edgewise, one at a time, into the machine operating thereon.

An object of the invention is to provide a machine of the above type with means for moving the sheets edgewise, suction cups for raising the sheets, one at a. time, from the stack, which edgewise moving means and suction cups are timed so that the suction cups release the sheet prior to its edgewise movement, and the edgewise moving means receives and supports the outer edge of the sheet and moves said sheet edgewise.

A further object of the invention is to provide a sheet feeding mechanism of the above type with means cooperating with the suc tion devices for straightening out the sheet so as to insure the edgewise moving means passing underneath the edge of the sheet.

A still further object of the invention is to provide a sheet feeding mechanism of the above. character wherein the suction cups are controlled by means movable with the devices for moving the sheet edgewise.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of the invention Figure 1 is a side view of a press for punching sheet metal having my improvements applied thereto;

Fig. 2 is a detail showing one of the suction cups. the means for supporting and moving the same. one of the devices for moving the sheet edgewise. and the, means controlled thereby for releasing the suction in the suction cup;

Fig. 3 is a perspective view showing one of the suction cups. the devices associated Specification of Letters Patent.

. disclosed in the Patented Nov. 15,1921.

Serial No. 415,820.

therewith for straightening out the sheet, and the means for tripping the valve;

Fig. at is a perspective view of one of the suction cups showing the manner of extending the machine for extremely long sheets;

Fig. 5 is a detail in side elevation showing the controlling cam for the air valve and the manner of mountin the same on the sheet feeding device;

Fig. 6 is a perspective view of the controlling cam;

Fig. '7 is a view showing more or less diagrammatically the stacked sheets, the suction cup, the straightening out devices, and the sheet feeding devices with the parts in position for lifting the sheets from the stack:

Fig. 8 is a similar view but showing the parts in position so that the sheet is straightened preparatory to the releasing of the sheet:

Fig. 9 is a view showing more or less diagrammatically the arrz'ingement for using three suction cups and two feeding devices;

Fig. 10 is a view in part similar to Fig. 2 but showing the members moved to the position where the sheet is to be released;

Fig. 1] is a sectional view through the control valve, and

Fig. 12 is a section on the line 12 l? of Fig. 11;

Fig. 13 is a detail view of the friction gripping means for preventing free operation of the vacuum valve.

The invention is directed broadly to a sheet feeding mechanism. and more particularly to a feeding mechanism for lifting metal sheets, one at a time. from a stack and feeding the same edgewise into an operating machine. I have shown the invention as applied to a die punching press of the type patent to McDonald. granted h'larch 7, 1905, Number 784.415. The sheets are raised from the stack by a plurality' of suction cups which are preferably made of rubber so that they will effectively grip the sheet even though the sheet may be slightly bent at the points where gripped. lt is well understood that it is not practical to move the sheet edgewise while held suspended by a flexible suction cup. lily device includes means whereby the suction cups may release the sheet prior to the edgewise movement thereof. The sheets are moved edgewise by reciprocating devices located above the sheet, and each device carries at its outer end a depending member adapted to extend beneath the edge of the sheet. A cam for controlling the valve for releasing the suction is mounted upon one of these reciprocating devices and as said devices move forward, the valve is released, but not until the carrying devices at the end of the reciprocating feeding devices have moved sufficiently underneath the edge of the sheet so as to receive and support the outer edge of the sheet and move the sheet forward into the operating machine. Devices are associated with the suction cups for straightening out the sheets so that these edge supporting members which engage the outer edge of the sheet and which move the sheet edgewise will with certainty move beneath the plane of the sheet.

Referring more in detail to the drawings, I have shown the invention as applied to a die press consisting of a supporting frame 1 having a stack holder 2 on which the stacked sheets, indicated at 3 are placed. The details of construction of the die press are fully explained in the patent referred to. and will not be further described. The sheets pass into the machine over a supporting plate 1 which has an inclined receiving opening 5 and underneath the plate (3. The sheets are raised from the stack. one at a time. by a series of suction cups 7. I have shown in the drawings three suction cups. but it will be understood that the number of suction cups will depend upon the length of the sheets which it is desired to feed. Each suction cup is carried by a rod and these rods 8 are attached to a cross head 9 which is reciprocated by means of a link 10 connected to a lever 11 pivoted at 12. The other end of the lever 11 is connected to a link 13 which is pivoted to an eccentric pin 11 rotating with the shaft 15. A friction clamping means 16 connects the link 10 to the cross head 9, and this friction means runs in a slot 17, and thus the stroke of the head is determined by the height of the pile of sheets, and the sheets are lifted through the suction cups, one at a time, from the stack. The cross head 9 is in the form of a hollow pipe, and the rods 8 are also in the form of hollow pipes, connected with the pipe 9. and thus the pipe 9 is connected with each suction cup.

Located in the pipe 9 is a valve 18. Said valve consists of a casing in the usual form, having an opening 19 which is controlled by a valve disk 20. This valve disk 20 is connected to a valve stem, which in turn is secured to a yoke 21. Threaded into the valve casing is a cap 22 having a cylindri 'al portion 23, and a valve stem is also formed with a cylindrical portion 2-1 which is adapted to fit, when the valve is raised. snugly within the cylindrical portion 23. Just above the cylindrical portion 24, the valve stem is three-sided in cross section as clearly shown in Fig. 12, thus forming openings 25 which connect the passages 26 with the atmosphere. \Vhen the valve is seated as shown in Fig. 11, the pipe 9 is open to the atmosphere and when the valve is raised from its seat, the cylindrical portion 24 will close the connection to the atmosphere and allow a vacuum in the pipe 9 to be established very quickly and with no loss as when drawing against an open vent to the atmosphere, as is often the case. Furthermore. when the valve is closed, and the vacuum cut off. the pipe 9 will be quickly vented to the atmosphere thus releasing the suction cups very quickly from their grip on the sheets. y

The sheets are moved edgewise as shown in the drawings, by two feeding devices 27 and 28. As to the feeding of the sheet, these devices are similar in construction and only one will be described. Said feeding device consists of a reciprocating rod 29 which moves in suitable bearings, and which is connected by a link 30 to a bell crank lever 31 pivoted at 32, and this bell crank lever 31 is oscillated by a link 33 connected to an arm 31 connected to the member which is oscillated by the link 13. Each rod 29 carries a sleeve 35 which is rigidly secured to the outer end of the rod. The sleeve has a depending arm 36 in which an L-shaped plate or member 37 is secured. This L-shaped member 37 serves as a. support for the outer edge of the sheet and as a means for moving the sheet edgewise.

Associated with one of the suction devices and one of the sheet feeding devices is a controlling mechanism for the vacuum valve. The valve, as above noted, is operated by means of the yoke 21. This yoke 21 is rigidly secured to a rod 38. This rod 38 extends through a bearing block 39 supported by an arm 41) connected to the head l1 which supports one of the suction cups. This head is carried by the rod 8 for this cup. Located in a recess in the bearing block 39 is a friction gripping member 12 which is forced by the spring 43 into gripping contact with the rod 38. A screw it serves as an abutment for the spring 43, and as a means for varying the tension of said spring. Surrounding the rod 38 is a spring l5, which spring bears against a block 46 secured by a set screw 4.? to the rod The other end of this spring bears against the block 39. The tendency of the spring is to move the yoke so as to open the valve or to the right as viewed in Fig. 3.

Mounted on a suitable plate carried by the frame isa rock lever 48. This rock lever has a depending arm 49adapted to extend into the path of a finger 50 carried by the block 46. Mounted upon the feeding device 28 is a controlling cam 51. This controlling cam 51 is shown in detail in Fig. 6, and is formed with slots 52 adapted to receive bolts 53 which serve as a means for clamping the cam to the feeding device and also to permit a slight endwise adjustment of the cam. The plate forming the cam 51 is bent so as to provide a relatively wide cam ledge 54 having inclined ends 55 and 56. This controlling cam 51 is adapted to engage the end 57 of the lever 48. To swing the lever 48 will move the rod 38 and close the valve to the vacuum creating means and open the suction cups to the atmosphere.

Associated with each suction cup is a sheet straightening means which consists of two l.-shaped plates 58 and 59. These l -shaped plates house the suction cups, and when the sheet is raised by the suction cups it is brought against the edges of these L-shaped plates, and they serve as a means to line up the surface of the sheet preventing any banding or buckling of the sheet and thus insuring that the feeding devices located between the suction cups will pass beneath the outer edge of the sheet. In case of an extra long sheet, as shown in Fig. 9, the rod 8 is provided with a lateral extension 60 and an auxiliary rod 61 carrying the cup is carried by this rod 60. The rod 60 is hollow, and serves as a means for creating a vacuum in the cup. Also mounted on the rod 8 are plates 62 which serve to support the L-shaped straightening plates 58 and 59.

The operation of my device is as follows The valve connecting the pipe 9 with the suction creating means is normally closed and the parts are in the position as shown in Fig. 2. It will be noted that the valve moves bodily with the cross head cairying the suction cups. As the suctiop cups move into contact with the top sheet in the stack, the rod 38 projects a short distance in front of the plane of the suction cups and will first make contact with the sheet which will move the rod endwise a sutlicient distance to carry the valve disks 20 away from the valve seat and also carry the cylindrical portion 2% into the cylindrical portion 23 of the cap and thus close the pipe 9 to the atmosphere. As soon as the cups make contact with the sheet, they will be placed under vacuum and will firmly grip the sheet. These suction cups are flexible as above noted, and will grip the sheet firmly, even though there be creases'or bends of any kind in the sheet. The cross head is then moved upwardly carrying the suction cups; and the sheet supported thereby. The spring 45 serves merely to help sustain the weight of the yoke, and the valve parts also the weight of the rod 38, but is not of sutlicient tension to hold the valve open. The friction member 4.2 serves to prevent the valve from too free movement through the action of the spring or gravity upon the parts. If the weight was not taken off the parts, or the rod frictionally held from movement, the weight of the rod might bend the sheet sutficiently to cause the suction cup adjacent the rod to loose its grip, but by the use of the spring and the friction pad, there is no danger of the rods breaking the suction at the cup adjacent the rod. The continued upward movement of the suction cups carries the sheet against the L-shaped supporting members, and these suction cups are so timed that the sheet will be forced with suflicient pressure against these L-shaped members to cause the straightening of the sheet. The feeding devices are timed to move forward so as to carry the L-shaped members 37 underneath the edge of the sheet. As the feeding devices move forward, the controlling cam 51 will engage the end 57 of the lever 48 and swing said lever against the tension of the spring 63. The upward movement of the suction cups brought the fingers 50 carried by the finger 56 into engagement with the arm 49, and as the lever 48 swings the arm 49, will therefore move the rod 38 positively downward and close the valve to the suction creating means and open the pipe 9 to the atmosphere. This quickly releases the suction grip of the suction cups. The edge supporting members 37 have also moved underneath the outer end of the sheets, so that the sheets as they drop, will be supported by these L-shaped members 37, and the sheets will be moved forward by said members. The parts are so timed that the inner or lower edge of the sheet will be moved on to the face 5 of the supporting plate 4, and the sheet will therefore be led in between the plates t and 6 to the machine.

From the above it will be apparent that T have provided means which includes elastic suction cups for raising the sheets, one at a time, from the stack and means for feeding the sheets edgewise which operates to receive and feed the sheet after release by the suction cup, and I have also provided means for straightening out the sheet and insuring proper engagement of the sheet by the edgewise moving means.

It will be obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters-Patent, is

1. A sheet feeding mechanism comprising means for supporting a stack of sheets, suction cups, means for reciprocating the same to remove the sheets one. at a time from the stack. means whereby the stroke of said reciprocating means is automatically altered to compensate for the changing thickness of said stack, means for moving said separated sheets edgewise, and means for releasing the suction cups prior to such edgewise movement.

2. A sheet feeding mechanism comprising means for supporting a stack of sheets, suction cups, means for reciprocating the same to remove the sheets one at a time from the stack, means whereby the stroke of said reciprocating means is automatically altered to compensate for the changing thickness of said stack, means for moving said separated sheets edgewise, means for releasing the suction cups prior to such edgewise movement, said sheet moving means being constructed and arranged to support the sheet during edgewise movement thereof.

3. A sheet feeding mechanism comprising devices movable above the sheet and each carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, a plurality of elastic suction cups, means for reciprocating the same to lift the sheets, one at a time,

from a stack, means whereby. the travel of said reciprocating means varies with the changing thicknessof the stack of sheets, and means for releasing the suction cups prior to the edgewise movement of the sheet, said supporting members being timed to receive the sheet and support the outer edge thereof during the edgewise movement of the sheet. 7

4. A sheet feeding mechanism comprising a device movable above the sheet and carrying a supporting member adapted to extend underneath the edge of the sheeet for moving the sheet edgewise, suction cups, means for reciprocating the same to lift the sheets, one at a time, from a stack, means for releasing the suction cups prior to the edgewise movement ofthe sheet, said sheet supporting member being timed to receive the sheet and support the outer edge thereof during the edgewise movement of the sheet, and means associated with the suction cups for straightening out the sheets.

5. A sheet feeding mechanism comprising devices movable above the sheet and each carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, a plurality of suction cu s, means for reciprocating the same to 1i t the sheets, one at a time, from a stack, means for releasing the suction cups prior to the edgewise movement of the sheet, said supporting members bein timed to receive the sheet and support the outer edge thereof during the edgewise movement of the sheet, and means associated with the suction cups for straightening out the sheets.

6. A sheet feeding mechanism comprising devices movable above the sheet and each carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, a plurality of elastic suction cups, means for reciprocating the same to lift the sheets, one at a time, from a stack, means for releasing the suction cups prior to the edgewise movement of the sheet, said supporting members being timed to receive the sheet and support the outer edge thereof during the edgewise movement of the sheet, and means associated with the suction cups for straightening out the sheets.

7. A sheet feeding mechanism comprising a device movable above the sheet and carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, suction cups, means for reciprocating the same to lift the sheets, one at a time, from the stack, means for releasing the suction cups prior to the edgewise movement of the sheet, said sheet supporting member being timed to receive the sheet and .support the outer edge thereof during the edgewise movement of the sheet, L-shaped plates surroundin the suction cups for engaging and straig itening out the sheets.

8. sheet feeding mechanism comprising devices movable above the sheet and each carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, a plurality of elastic suction cups, means for reciprocating the same to lift the sheets, one at a time, from a. stack, means for releasing the suction cups prior to the edgewise movement of the sheet, said supporting members being timed to receive the sheet and support the outer edge thereof during the edgewise movement of the sheet, means associated with the suction cups for straightening out the sheets, and Lshaped plates substantially surrounding the elastic suction cups for engaging and straightening out the sheets.

9. A sheet feeding mechanism comprising devices movable above the sheets and each carrying a supporting member adapted to extend underneath the edge of the sheet for supporting the outer edge of the sheet and moving the sheet edgewise, a plurality of suction cups, means for reciprocating the same to lift the sheets, one at a time, from a stack, a valve for controlling the suction creating means, a rod for operating the valve, means for preventing the rod from moving through the weight of the parts connected therewith, and means operated by one of the feeding devices for shifting the rod to release the suction.

10. A sheet feeding mechanism comprising devices movable above the sheets and each carrying a supporting member adapted to extend underneath the edge of the sheet for supporting the outer edge of the sheet and moving the sheet edgewise, a plurality of suction cups, means for reciprocating the same to lift the sheets, one at a time, from memos a stack, a valve for controlling the suction creating means, a rod for operating the valve, means for preventing the rod from moving through the Weight of the parts connected thereto, and an adjustable cam carried by one of the feeding devices for shiftin the rod to release the suction.

11. sheet feeding mechanism comprising devices movable above the sheets and each carrying a supporting member adapted to extend underneath the edge of the sheet for supporting the outer edge of the sheet and moving the sheet edgewise, suction cups, means for reciprocating the same to lift the same, one at a time, from a stack, a valve for controlling the suction creating means, a rod for shifting said valve, said rod being normally positioned so as to engage the stacked sheets and be moved thereby to open the valve to the suction creating means, de vices for preventing the rod from moving through the weight of the parts connected thereto, a lever carried by the frame, a finger carried by the rod and adapted to move into the path of oscillation of the lever when the sheet is in raised position, and an adjustable cam carried by one of the feeding devices and adapted to engage said lever for shiftin the rod to close the valve.

12. sheet feeding mechanism compris ing reciprocating feeding devices movable above the sheets and each carrying a supporting member adapted to extend underneath the edge of the sheet for moving the sheet edgewise, means for releasing the suction devices prior to the edgewise movement of the sheet, and L-shaped plates at opposite sides of each suction device and disposed so as to engage the sheets when in extreme raised position for straightening the sheets.

In testimony whereof, ll aiiix my signature.

EDWIN WHITE.

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