Vacuum cup

Sept. 23, 1958

2,853,333

F. M. LITTELL

VACUUM CUP

Original Filed Sept. 7, 1955

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United States Patent Office Patented Sept. 23, 1958

2,853,333

VACUUM CUP

Frederick M. Littell, Winnetka, III., assignor to F. J. Littell Machine Company, Chicago, HI., a corporation of Illinois

Original application September 7, 1955, Serial No. 532,817. Divided and this application March 2, 1956, Serial No. 569,030

Claims. (Cl. 294—64)

The invention relates to material handling apparatus and has reference more particularly to improvements in suction cups for gripping a metal sheet or the like as a preliminary step to lifting the sheet and transporting the same from place to place within the shop.

In the manufacture of apparatus for handling large aluminum sheets, such as may form the wing of an air·/ plane, it is desirable to provide suction cups for the most satisfactory gripping of the aluminum sheets and quick release of the same. One type of such apparatus incorporates suction cups for gripping the smooth top surface of the metal sheet so that the same may be lifted by the cups and rotated for turning the metal sheet over, whereby the sheet will rest on the top of the cups and can therefore be safely transported.

Accordingly, an object of the invention is to provide suction cups for the purposes described, which will incorporate anti-friction means for improving the suction grip of the cups on the metal sheets, whereby the cups will securely grip and hold a sheet so as to prevent slippage thereof during the turnover operation.

Another object is to provide a suction cup for industrial use such as described and which will have a flexible lip of substantially circular contour whereby the area within the cup will be effectively sealed when the cup is caused to contact the surface of a metal sheet.

A more specific object is to provide a suction cup having anti-friction means and also having a metal plate for a hacking member and wherein the anti-friction means will consist of ribs having a zig-zag formation.

Another object of the invention is to provide a suction cup having anti-friction ribs located within an encircling flexible lip and wherein the ribs and the flexible lip are both backed by a metal backing plate. A conduit has connection with the backing plate so as to extend through the same and into communicating relation with the grooves between the ribs for subjecting the area within the flexible lip to sub-atmospheric pressure.

With these and various other objects in view the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto.

In the drawings, which illustrate an embodiment of the invention, and wherein like reference characters are used to designate like parts—

Figure 1 is a sectional view, taken substantially along line 1—1 of Figure 2, of a suction cup having articulated relation with a supporting arm, the said cup embodying the improvements of the invention; and

Figure 2 is a plan view of the bottom surface of the cup.

In the illustrated embodiment of suction cup as shown in Figure 1, the carriage for supporting the cup is indicated in its entirety by numeral 10. At both ends of said carriage 10 the same has articulated relation with a suction cup by means of structure including a stud such as 11, suitably welded to the undersurface of the car10 riage 10 adjacent the end and depending therefrom. The stud 11 is apertured at 12 for receiving the support pin 13 by means of which the yoke 14 is pivotally connected to the carriage. Set screws (not shown) may be provided for locking the yoke 14 in the desired rotative position on pin 13 and the degree of swinging movement of the yoke 14 about said pin as an axis can be controlled by the addition of other screws 15.

For a more detailed description of the yoke and carriage reference is made to the copending application of Frederick M. Littell, Serial No. 532,817, filed September 7, 1955, and entitled Vacuum Pickup and Turnover Device.

Whereas the support pin 13 extends transversely of the carriage 10 the pins identified by numerals 16 and 17 extend in a longitudinal direction as regards the carriage. The said longitudinal pins project outwardly from the respective sides of the yoke 14 and each pin is fixed or locked to the yoke by means of a set screw such as 18. The projecting outer ends of the pins 16 and 17 have a pivotal mounting in studs 20 and 21, respectively, which project upwardly from the metal backing plate 22 of the suction cup indicated in its entirety by numeral 24. Said suction cup is accordingly supported on an axis formed by the pins 16 and 17 which allows for pivotal movement of the suction cup about said axis, Additional pivotal movement of the suction cup and its yoke 14 as a unit is permitted by means of the support pin 13 which is horizontally aligned with the pivot pins 16 and 17 but which is disposed at right angles thereto.

The suction cup 24 is formed of relatively soft rubber or other suitable resilient material and the same is characterized by an annular flexible lip 25 which has encircling relation with an interior face composed of a plurality of ribs 26 alternating with grooves 28. The flexible lip 25 extends a short distance below the interior face of the suction cup and said lip is directed outwardly in a diagonal direction so that when the cup is caused to contact the surface of a metal plate the lip will automatically have sealing engagement with the plate so that a vacuum or suction can be produced within the space encompassed by the flexible lip to thus cause the cup to adhere to the plate. The annular rib 3ft surrounds the interior face of the cup and accordingly the rib 30 defines the said interior face. Immediately adjacent the inside edge of the annular rib 30 a relatively deep groove 31 is provided which is also annular in extent and which is in communicating relation with the grooves 28 extending between the ribs 26.

In accordance with the invention the ribs 26 have a zig-zag formation and as a result thereof their grip on the metal plate is increased and they additionally function as anti-friction means whereby to prevent slippage of the metal plate during the turning-over operation. Of course, the grooves 28 between the zig-raz ribs have communicating relation with each other both centrally of the interior surface, due to the central cavity 32, as well as circumferentially, due to the annular groove 31. A nozzle 33 extends through the backing plate 22, the same having threaded relation with the lug 34 provided for the purpose. The nozzle in turn connects with a flexible hose 35 and by means of said hose the interior of the suction cup can be subjected to a sub-atmospheric pressure. Due to the extremely flexible lip 25 the cup automatically seals with the metal plate upon contacting the same and when the operator connects the cup with the source of subatmospheric pressure, the vacuum created within the shallow cup securely grips the cup to the plate and the grip is maintained as long as the vacuum is maintained on the cup.

The cup 24 is relatively shallow so as to reduce the space which must be evacuated to produce the vacuum

2,853,333 for adhering the cup to the plate and which is thus gripped thereby. The grooves 28 between the ribs 26 form passageways having connection with each other and thus all the passageways communicate with the nozzle 33. Accordingly, the interior of the cup: is evacuated very quickly after the flexible lip has been placed in contact with the surface of the plate to be gripped. The suction firmly grips the cup to the plate and · the ribs are thus caused to contact the surface of the plate. The ribs form anti-friction means and thus improve the grip of the cup with the plate. However, even a better grip is effected by forming the ribs in the shape of connected V’s or what is best described as a zig-zag formation.

This is a divisional application of the copending application Serial No. 532,817, filed September 7, 1955, in the name of Frederick M. Littell as inventor and entitled Vacuum Pickup and Turnover Device.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings as various other .forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.