Force-cup.

Application filed July 31

To all whom it may concern:

_ Be it known that I, George C. Reeves, a citizen of the United States of America, and a resident of Chicago, county of Cook, and 5 State of Illinois, have invented certain new and useful Improvements in Force-Cups, of which the following is a specification.

The main objects of this invention are to provide an improved form of force cup such 10 as is used by plumbers for forcing obstructions through and from pipes; to increase the efficiency of cups of this kind and provide for accomplishing the desired results with the use of less material than is em15 ployed in the cups now in ordinary use; to increase the bending strength of the cup in a direction.radially of the cup; and to permit greater circumferential elasticity of the cup with the same bending strength in a ra20 dial direction, than is permitted in other force cups now in common use.

An illustrative embodiment of this invention is shown in the accompanying drawings, in which:—

Figure 1 is a bottom view of a fbrce cup constructed according to this invention. Fig. 2 is a vertical section of the device taken on the line A—A of Fig. 1.

In the construction shown in the draw30 ings, the force cup comprises a concave elastic body 1 having its inner surface provided with the downwardly extending ribs 2 which are preferably uniformly spaced apart and are - preferably tapered at their 35 lower ends 3 so as to terminate a considerable distance upward or inward of the rim or edge 4 of said concave body. This rim is preferably provided with an annular ridge or thickening 5. The body is pro40 vided with an upper tubular extension 6, the inner surface 7 of which is adapted to engage a handle in the usual way. In the specific form of cup shown in the drawings, which is-known as a “valve” cup, the exten45 sion or neck 6 is separated from the inner concave surface of the body by means of a wall 8. This wall is provided v ith the usual extension 9 through which a cut or slot 10 is formed which connects the inner part of the >0 extension 6 with the inner part of the cup or body 1.

The inner part of the extension 6 is formed with a depression 11 into which the cut or slot 10 extends. In the construction shown f Letters Patent. Patented. Sept. 21,1915.

, 1912. Serial No. 712,464.

in the drawings the wall 8 is thickened at 55 12 below the depression 11. The cut or slot 10 and walls thereof form the usual air valve used in devices of this kind. This cut or slot is exaggerated in size in Fig. 1. The walls of this slot normally lie close together. 60 When pressure is exerted downwardly on the extension 6, and the lower edge 4 of the cup bears against a surface with which it may have an air-tight contact, the air pressure within the cup closes the valve in the 65 usual way. When the downward pressure on the extension 6 is released the cup resumes its normal form, and the air is sucked into the cup through the depression 11 and fae riot 10 in the valve in the usual way. 70 When thus operating the device a downward pressure is exerted on the extension 6, the air pressure within the cup 1 tends to bulge the walls of the cup outward in the direction indicated by the dotted lines 13 75 shown in Fig. 2.

This invention also applies to the type of cup known as the “open” cup, in which· an opening corresponding to the opening or slot 10, is so large as to have no valve action. 80 The invention also applies to the type of cup in which there is no opening between the inner part of the body 1, and the upper parts of the device.

The ribs 2 strengthen the cup against 85 bending outwardly or in a radial direction, but the parts 14 of the wall of the cup in the spaces between the ribs permit this wall to stretch in a circumferential direction or. laterally of the ribs. These ribs stiffen and 90 strengthen the walls of the cup when bending in a direction radially of the cup, while they do not materially interfere with the circumferential stretch of said walls.

The annular ridge or thickening 5 at the 95 rim of the cup strengthens the lower edge so that the circumferential stretch is mainly above said rim, as is common in devices of this kind. ¹

The wall of the cup is preferably made 100 thinnest at 15, being the part between the ridge or thickening. 5 and the lower ends of the ribs 2. The device may be made entirely of vulcanized rubber.

Although but one specific embodiment of 105 this invention has been herein shown and described, it will be understood that some of the details of the construction shown may

1,154,055 be altered or omitted without departing from the spirit of this invention as defined by the following claim.