US2486858A

US2486858A - Heavy-duty container opener

Info

Publication number: US2486858A
Application number: US33499A
Authority: US
Inventors: Woodward J May
Original assignee: MAY S AUTO PARTS Inc
Current assignee: MAY S AUTO PARTS Inc; MAY'S AUTO PARTS Inc
Priority date: 1948-06-17
Filing date: 1948-06-17
Publication date: 1949-11-01
Anticipated expiration: 1966-11-01

Description

v.. L w49 W. J. MAY

HEAVY-DUTY CONTAINER OPENER 3 Sheets-Sheet l Filed June 17, 1948 @xml NN W. J. MAY

HEAVY-DUTY CONTAINER OPENER Nov. 1, 1949 5 Sheets-Sheet 2 Filed June 17, 1948 WooDwARD J MAY NQ IMWIIH |H m Nov. l, 1949 w. J. MAY

HEAVY-DUTY CONTAINER OPENER 3 Shee'ts-Sheet 3 Filed June 17, 1948 Y mul nl l' n /Za' Waoawnfp f/.MAV

(1t comma-9 Patented Nov. 1, 1949 HEAVY-DUTY CONTAINER OPENER Woodward J. May, Pittsfield, Mass., assigner to Mays Auto Parts, Incorporated, Pittsfield, Mass., a corporation of Massachusetts Application June 17, 1948, Serial No. 33,499

14 Claims.

This invention relates to container openers, and more particularly to a mechanism for opening containers of the cupped head type.

It is now the rather common practice to ship articles such as ammunition and ordnance of various types, instruments, etc., in hermetically sealed containers in which they can remain indefinitely in any climate without rusting or corroding. These containers are of various shapes and sizes. For example, some of the containers are cylindrical `but differ greatly in their proportions, while others of the containers are generally rectangular in cross-sectional shape with rounded corners. Containers of this type have cup shaped heads, corresponding in shape to the ends of the containers, and the heads are inserted in position and welded at their edges to the edges of the containers.

While containers of this type are highly effective for the purpose stated, the opening of the containers presents a substantial problem. In the absence of an adequate mechanical device for opening containers of this character, the opening operation usually requires a substantial length of time and results in the destruction of the container so that it can not be salvaged for further use.

An important object of the present invention is to provide a novel mechanism for opening containers of the character referred to wherein the container itself is cut parallel to the top edge thereof below the welded connection of the cap to the container body, thus permitting the cap to be lifted out without destroying the container.

A further object is to provide an apparatus of this character wherein the rotation of a shaft causes the device to travel relatively around the container periphery to cut through the Wall thereof adjacent the welded connection of the cap to the container, thus cutting off only the top edge of the container body without destroying the container or otherwise damaging it, whereby the container may be salvaged for iurther use.

A further olbject is to provide a device of this character having novel means for cutting through the body of the container, such means being adapted to cut through various materials of different thicknesses to make a clean cut to permit the easy removal of the cap of the container.

A further object is to provide a novel cutting device in a mechanism of this character which is readily adjustable for operation according to the thickness of the material of the container,

and to provide in conjunction therewith a stop for limiting the depth of the cut to the proper point.

A further object is to provide a novel apparatus of this character which embodies cutting wheels and driving or gripping wheels so arranged as to secure and maintain the proper relation ybetween the cutting wheels and the flange of the head and the body of the container for the cutting of the latter, and to provide novel mounting means for the cutting wheels whereby the latter automatically assume proper cutting positions regardless of the adjustment of the cutting device in accordance with the thickness of the material of the container.

A further object is to provide novel means for engaging the inner surface of the flange of the cap during the cutting operation to steady the movement of the mechanism around the container as the cutting takes place.

A further object is to provide novel leveling and height adjusting means for the mechanism to predetermine the position of the line aiong which the cutting operation will take place.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the drawings I have shown two embodiments of the invention. In this showing,

Figure 1 is a plan view of the apparatus, parts being shown in section and parts being broken away;

Figure 2 is a sectional view on line 2-2 of Figure 1;

Figure 3 is a longitudinal sectional view on line 3-3 of Figure 1;

Figure 4 is a detail sectional view on line 4-4 of Figure 1;

Figure 5 is a detail perspective view of the cutting elements and the carrier arm therefor, the parts being shown separated;

Figure 6 is a bottom plan view of the base plate of the device;

Figure 7 is a detail sectional view on line 1-1 of Figure 1;

Figure 8 is a detail perspective view of a combined clamping and leveling device, parts being shown separated;

Figure 9 is a plan View on a reduced scale showing the device in position on the top of a container;

Figure 10 is a fragmentary bottom plan view of the mechanism;

Figure 11 is an enlarged fragmentary face view of one of the gripping wheels;

Figure 12 is a fragmentary bottom plan view of a modified form of the device, parts being broken away; and

Figure 13 is a fragmentary sectional v iew on line |3-I3 of Figure 12.

Referring to Figures 1, 2, 3 and 6, the numeral I9 designates a substantially triangular, relatively heavy base plate to which is welded as at II an upstanding housing I2 normally closed by a cover I 3 secured in position in any suitable manner, for example by screws I4 (Figure l). Within the housing I2 are arranged the power driven means for operating the mechanism in accordance with the following description.

Referring to Figure 3, the numeral I8 designates a sleeve seated at its lower end on the base plate I8 and preferably Welded thereto as at i9. This sleeve contains a bearing bushing or bearing bushings 29 rotatably receiving a primary drive shaft 2|. This shaft projects through an opening 22 in the base plate and this opening is capped as at 23. Between the upper end of the sleeve I8 and the cover I3, the shaft 2| is cut to form a driving pinion 25 for a purpose to be described. The shaft 2| thrust sleeve 26 in the cover I3 and a bearing 21 rotatably receives the thrust sleeve 26. The shaft projects substantially above the cover I3 and is provided with a preferably substantially square section 28 for connection with a suitable handle indicated in dotted lines by the numeral 29 in Figure 1. The shaft 2| thus may be operated by hand, or the chuck of an electric drill or other power source may be connected to an upper extension 39 on the shaft 2 I.

A sleeve 34 is welded as at 35 to the base i9 and a bearing bushing 36 is arranged in this sleeve and in an opening 31 in the base i9. This opening is capped as at 38. A shaft 49 is journaled at its lower end in the bushing 36 and is formed with a vertically elongated pinion 4i engageable with gears to be referred to later. At its upper end, the shaft 49 slips into the hub 42 of a gear 43 which meshes with the pinion 25 as shown in Figures 1 and 3. The gear hub 42 may be keyed as at 45 to the shaft 49, and is rotatable in a bushing 45 projecting upwardly into an opening 41 in the cover I3 and into a sleeve 48 welded to the cover I3 as at 49. The opening 41 is capped as at 59.

Referring to Figures 1 and 2, the

numerals

55 and 56 designate a pair of shafts, each of which is provided at its lower end with a gripping Wheel 51 to be referred to in detail later. The shaft 55 is rotatable in a bushing 58 arranged within a sleeve 59 welded as at 69 to the base I9. The shaft 55 carries a gear 62 meshing with the pinion 4I (Figures 1 and 3). Above the gear 62, the shaft 55 is journaled in a bushing 64. This bushing is arranged in a sleeve 65 welded at 66 to the cover I3, and the opening in the cover I3 in which the bushing 64 is arranged is capped as at 61.

A sleeve 19 contains a bushing 1 I in which the shaft 56 is journaled. The sleeve 19 is substantially shorter than the sleeve 59 to provide space for a gear 1I, identical with the gear 62, and xed to the shaft 56. The

gears

62 and 1| may be held in position in any suitable manner, for example by snap rings 12 on their respective shafts. The sleeve 59 is cut away as at 13 to provide space for the gear 1I, as shown in Fig-- ure 2. The gears 62 and 1I are identical as stated, and have their rotational axes equi-distantly spaced from the axis of the shaft 49.

projects through a 4 The gear 1I meshes with the pinion 4| in the same manner as, but below, the gear 62.

Referring to Figures l, 3 and 5, the numeral 89 indicates a cutting mechanism as a whole. This mechanism comprises a channeled body 9| pivotally connected at one end to the base plate I9 by a heavy pivot pin 32. At its opposite end, the body or arm 8| is slotted as at 85 to receive a bolt 86, the outer end ofA which is threaded in a clamping member 81 operable by a handlebar 88. The'opposite end of the bolt 86 is provided with an eye 89 arranged in a slot 99 formed in a block 9| welded as at 92 to the bottom of the base plate I0. A pin 93 (Figure 1) pivotally connects the bolt 86 to the block 9|.

The rotation of the clamping device 81 moves the free end of the arm 8| inwardly for a purpose to be described, and a stop bolt 95 limits such movement. This bolt is provided with a, head 96 engaging the arm 8| as shown in Figure 1, and the inner end of the bolt 96 is threaded in the block 9| and fixed in adjusted positions by a lock nut 91.

The cutting of the body of the container in a manner to be further described below is accomplished by a pair of rotary sharp edged cutters |99 carried by stub shafts IUI journaled in a carrier |92. This carrier is substantially U- shaped in cross-section in the center thereof, and a pivot pin |93 extends through the carrier and through the arm 8|, suitable openings |94 and |95 being respectively provided in these elements to receive the pin |93.

The device is operable for opening containers of the general character referred to. One of these containers is shown in plan in Figure 9 and in dotted lines in Figure 3, each container comprising a container body III) and a cupped head I I I. The head I I has an upstanding flange II2 fitting within the upper end of the container wall, and the upper edge of the flange and the upper edge of the container body are welded to each other to hermetically seal the container. It will be obvious in Figure 3 that the cutters |99 are operative to cut through the container body below the weld between the container body and the upper edge of the fiange I I2.

As will become apparent, the upper edges of the container body and the flange I I2 sometimes directly contact with the bottom of the base plate I9. To minimize wear on such plate, the latter has portions of the lower face thereof cut away as at I5 preferably to a depth of about one-r eighth of an inch, and this space is filled with any suitable hard material IIB, such as hard welding rod electrically welded in the recesses I I5.

A clamp |35 (Figures 3 and 8) is provided with an opening |36 slidable over the bolt I2I. The

clamp |35 has a depending flange |31 along one edge engageable with the top of the base |0. The remainder of the bottom face of the clamp |35 is relatively flat except for the provision of a notch |38 receiving a bar |39 resting on the base l0. The depth of the notch |38 plus the depth of the flange |31 is equal to the vertical thickness f the bar 38, and it will be obvious that rotation of the clamping device |23 by a handlebar |40, provided for this purpose, will clamp the bar |39 in any desired adjusted position.

The bar |39 has its free end overhanging the base plate I0 turned downwardly as at 4| and provided at its lower end with a roller |42. When opening cylindrical cans, the clamp |35 is loosened and the arm |39 is slid endwise in slot |38 to move the roller |42 into engagement with the inner or outer surface of the flange ||2. The clamp is then tightened, and in operation, the roller |42 follows around the ilange I2 and steadies the operation of the mechanism as further described below. The roller |42 and associated parts possess a further advantage which will be described in `connection with the operation of the apparatus.

At each side thereof, the base plate Ill is provided with a block |45, welded to the base 0 as at |46, and preferably also welded to the housing l2. This block is provided intermediate its height with a recess |41 for a purpose to be described. A threaded stem |48 is vertically slidable in openings |49 formed in the block |45, and a knurled adjusting nut |50 is arranged in the recess |41 and threaded on the stem |48. The lower end of the stem |48 is provided with a non-circular head (Figures 4 and 10) arranged in a similarly shaped opening |52 formed in the base plate |0. A knurled lock nut |53 is threaded on the upper end of the stern |48. By loosening the nut |53, the stem |48 may be adjusted vertically and then tightened by screwing down on the nut |53. The head |5| of each of the adjusting devices referred to is adapted to contact the upper face of the container head to level and vertically adjust the device as a whole, being used in conjunction with the adjusting screw |29. This is sometimes necessary because of the depth of the ange l2 of the container head and sometimes because of the substantial curve between the head and flange I2.

As will become more apparent, the gearing in the housing l2 is operable to rotate the gripping wheels 51, and these wheels, gripping against the inner surface of the flange ||2, will cause the device to progressively move along the periphery of the container. It is preferred that the gripping wheels be serrated as at |55 to provide teeth slightly flattened at the outer ends as at |56 to prevent the teeth from being too deeply ernbedded in the flange I2 while at the same time affording an efhcient gripping action for the purpose stated.

Except as indicated below, the form of the invention shown in Figures 12 and 13 is the same as that previously described, and corresponding elements have been similarly indicated by reierence numerals. The rocking carrier |02 previously described operates to permit the cutting wheels |00 to adjust their engagement with the flange of the container head regardless of the adjusted position of the arm 8| in accordance with the thickness of the material of the container body. In other words, if the cutting wheels were bodily immovable relative to the arm 8|, the condition would exist wherein one cutter travelsy through an arc of longer radius than the other cutter. This condition would result in one cutter doing all or most of the cutting on cans of different diameters and different thicknesses. In this form of the invention, the arm 8| (Figure 13) is carried by a pivot pin |6| which is substituted for the straight pivot pin 82 previously described. The pin ISI is provided with a flange |62 arranged between the arm 8| and base plate I0, and above this flange, the upper end |63 of the pivot pin is eccentric to the lower end thereof. By engaging the upper end of the pivot pin with a suitable tool, the pin may be turned to adjust the position of the pivot axis of the lower pin portion |6|, and the pin may be xed in the proper adjusted position by the set screw |84. In this way, the arm 8| and `cutting wheels |00 are properly adjusted according to the thickness of the material of the container.

Operation When it is desired to remove the head from a container of the type referred to, the device is placed in position over the head and the leveling and adjusting screws |29 and |48 are vertically adjusted, if necessary to place the apparatus at the proper height, level and parallel to the head I0. If a circular container is to be opened, the arm |39 is adjusted and clamped in proper position with the roller |42 engaging the inner or outer surface of the container head llange ||2 with the gripping wheels 51 engaging the iiange ||2 of the container. The arm |39, while unclarnped, may be moved into adjusted position with some force, for rmly seating the gripping wheels 51 against the flange ||2. The foregoing operations preferably take place with the arm 8| open. By rotating the clamping device 81 to loosen it, the bolt 80 may be swung out of the notch 85 so that the arm 8| can be swung outwardly. When the parts have been placed in the position described above, the arm is closed, whereupon the bolt 88 is replaced in operative position and the clamp 81 rotated until the edges of the cutting wheels |00 are forced through the material of the container body ||0 and preferably partially into the flange H2 to insure the complete clean cutting of the container body I0 entirely therethrough. If the material of the container body is relatively hard and the foregoing operation is found too diilcult, it may be performed progressively while moving the apparatus around the container in the manner described below.

The handle 29 is rotated, or suitable power means is employed for rotating the shaft 2|, this shaft being rotated in the proper direction to cause the clamping wheels 5'! to rotate counter-clockwise as viewed in Figures l0 and ll. Rotary motion is transmitted from the pinion 25 to the gear 43, thence from the pinion 4| to both of the gears |32 and 1| to simultaneously rotate the gripping wheels 51 in the same direction and at the same speed. Pressure having been applied to the cutting wheels to at least partially embed them in the wall of the container, the upper end of the container wall and the flange ||2 will be gripped between the wheels container, if this operation has not been previously accomplished.

Movement of the apparatus around the container takes place completely through 360, or slightly more if movement of the apparatus around the container is depended upon to assist the cutting wheels in completely penetrating through the container body. This operation of moving the apparatus around the container takes place with the cutting wheels moving perfectly horizontally, and accordingly, the upper portion of the container body below its welded connection to the head III will be completely cut through, thus permitting the head III to be easily removed. The container will be left with a smoothly cut upper edge, except for the removal of the extreme upper end of the container body, the container will be undamaged and may be salvaged for further use.

The depth of the cutting of the wheels is regulated by the stop screw 95 in each form of the invention. This screw is positioned to engage the arm 8i at such a point that the wheels Ill will have cut entirely through the container body and partially through a flange I I2. By following this procedure, the smooth and complete cutting through the container body is assured.

The apparatus may be used with cylindrical containers of widely diiiering sizes and proportions. It also may be used with containers of shapes other than round provided the corners are curved on a radius of, for example, at least two inches. The apparatus is readily set up and easily and quickly operated, and has been found in practice to act efficiently as a heavy duty portable container opener, the use of which requires little or no skill and does not damage the relatively expensive containers.

While it has been generally described that the 'present device travels around the periphery7 of the container, it will be obvious that the device itself may be anchored with the container rotatable during the cutting operation. It is understood, therefore, that where reference is made in the claims to movement of the device around the container, this expression deiines relative movement rather than specic movement of the device with the container remaining stationary.

claim:

1. An opener for containers having cupped heads provided with upstanding flanges iitting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, a pair of cutting wheels engageable against the outside 0f the container body respectively opposite said gripping wheels, means for clamping said cutting wheels toward said gripping wheels to cause said cutting wheels to penetrate through the container body, and means for simultaneously rotating said gripping wheels in the same direction to cause them to travel, together with said cutting wheels, around the container body to completely sever the upper edge thereof.

2. An opener for containers having cupped heads provided with upstanding iianges tting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against .the inner face of said flange, a pair of cutting wheels engageable against the outside of the container body respectively opposite said gripping wheels, means for clamping said cutting wheels toward said gripping wheels to cause said cutting wheels to penetrate through the container body, means for limiting the movement of said cutting wheels toward said gripping wheels, and means lor simultaneously rotating said gripping wheels in the same direction to cause them to travel, together with said cutting wheels, around the container body to completely sever the upper edge thereof.

3. An opener for containers having cupped heads provided with upstanding flanges fitting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, an arm pivotally connected to said body to swing toward and away from said gripping wheels, a pair of cutting wheels carried by said arm and movable into engagement with the container body at points respectively opposite said gripping Wheels, means connected between said body and said arm for moving the latter toward said gripping wheels to cause said cutting wheels to penetrate through the container body, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said gripping wheels, said arm and said cutting wheels to travel around the container body and completely sever the upper edge thereof,

4. An opener for containers having cupped heads provided with upstanding flanges fitting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, an arm pvotally connected to said body to swing toward and away from said gripping wheels, a pair of cutting wheels carried by said arm and movable into engagement with the container body at points respectively opposite said gripping wheels, means connected between said body and said arm for moving the latter toward said gripping wheels to cause said cutting wheels to penetrate through the container body, adjustable means carried by said body and engageable with said arm to limit movement of said cutting wheels toward said gripping wheels, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said gripping wheels, said arm and said cutting wheels to travel around the container body and completely sever the upper edge thereof.

5. An opener for containers having cupped heads provided with, upstanding flanges tting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, an arm pivotally connected to said body to swing toward and away from said gripping wheels, a pair of cutting wheels carried by said arm and movable into engagement witn the container body at points respectively opposite said gripping wheels, means connected between said body and said arm for moving the latter toward said gripping wheels to cause said cutting wheels to penetrate through the container body, means for effecting bodily adjustment of said cutting wheels relative to the container body whereby said cutting wheels are adapted to uniformly cut through the container body, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said gripping wheels, said arm and said cutting wheels to travel around the container body and completely sever the upper edge thereof.

6. An opener for containers having cupped heads provided with upstanding flanges fitting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, an arm pivotally connected to said body to swing toward and away from said gripping wheels, a pair of cutting Iwheels carried by said arm and movable into engagement with the container body at points respectively opposite said gripping Wheels, means connected between said body and said arm for moving the latter toward said gripping wheels to cause said cutting wheels to penetrate through the container body, means for connecting said cutting wheels for pivoted turning movement relative to said arm on an aXis parallel to the pivot axis of said arm whereby said cuting wheels are bodily movable about the pivot axis of said arm to uniformly cut through the container body, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said grip-ping wheels, said arm and said cutting wheels to travel around the container body and completely sever the upper edge thereof.

'7. An opener for containers having cupped heads provided with upstanding flanges fitting within the container bodies and secured thereto at the upper edge thereof, comprising a body, a pair of gripping wheels carried by said body and engageable against the inner face of said flange, an arm pivotally connected to said body to swing toward and away from said gripping wheels, a pair of cutting Wheels carried by said arm and movable into engagement with the container body at points respectively opposite said gripping wheels, means connected between said body and said arm for moving the latter toward said gripping wheels to cause said cutting wheels to penetrate through the container body, the pivotal connection of said arm to said body comprising a pivot point having portions engaging said body and said arm arranged eccentric to each other, means for xing said pivot pin in adjusted rotary positions to vary the cutting action of said cutting wheels according to the thickness of the container body, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said gripping wheels, said arm and said cutting wheels to travel around the container body and completely sever the upper edge thereof.

8. An opener for containers having cupped heads provided with upstanding lianges fitting within the bodies of the containers and secured thereto at the upper edges of the container bodies, comprising a plate adapted to be arranged over and parallel to the container head, a pair of gripping wheels rotatably supported by said plate and engageable against the inner face of the flange of the container head, a gear xed to each gripping wheel, a cutting wheel arranged outwardly of the container and engageable lwith the container body at a point opposite each of said gripping wheels, means for forcing said gripping Wheels toward the container to cause them to penetrate therethrough, and means for rotating said gripping wheels at the Same speed and in the same direction to cause them to travel around the container together with said cutting wheels,

l0 comprising asingle pinion meshing with both of said gears.

9. Apparatus constructed lin accordance with claim 8 provided with vertically adjustable means carried by said plate at spaced points and engageable with'the head of the container to level said plate relative to the container head.

1G. Apparatus constructed in accordance with claim 8 provided with means carried by said plate for adjustably determining the extent of penetration of said cutting wheels through the container body.

11. An opener for a container having a cupped head including a relatively fiat body and an upstanding iiange fitting within the top of the container body and xed thereto at the upper edge thereof, comprising a plate adapted to be arranged over the body of the container head, a pair of gripping wheels rotatably carried by said plate and rotatable on parallel vertical axes in engagement with the inner surface of the iiange of the container head, an arm pivotally connected at one end to said plate and having a free end portion arranged outwardly of and movable toward and away from the container body, a wheel supporting member carried by said arm adjacent the free end thereof and connected thereto for turning movement relative thereto on a Vertical axis, a pair of cutting wheels carried by said wheel supporting member and movable by said arm inwardly to positions engaging the container body at points respectively opposite said gripping wheels, means connected between said plate and said arm for forcing the latter inwardly toward the container body to cause Said cutting wheels to penetrate through the container body, and means for simultaneously rotating said gripping wheels in the same direction and at the same speed to cause said cutting wheels, said arm and said gripping wheels to move around the container and completely sever the upper end of the container body.

12. Apparatus constructed in accordance with claim 11 provided with an adjusting screw carried by said plate, said screw projecting toward and engaging said arm adjacent the free end thereof to limit the movement of said arm toward the container body and thus limit the extent of movement of said cutting wheels toward said gripping wheels.

13. Apparatus constructed in accordance with claim 11 provided with a plurality of vertically adjustable screws carried by said plate and movable downwardly into engagement with the body of the container head to level said plate relative thereto.

14. An opener-for a cylindrical container having a cupped head comprising a horizontal body and an upstanding cylindrical ange tting within the top of the container body and secured thereto at the upper edge thereof, comprising a plate adapted to be arranged over the body of the container head, a pair of gripping wheels carried by said plate and rotatable on parallel vertical axes in engagement with the inner face of said flange, cutting wheels supported with respect to said plate radially outwardly of and respectively opposite said gripping Wheels, means for forcing said cutting wheels toward said gripping wheels to cause said cutting wheels to penetrate through the container body, means for simultaneously rotating said gripping wheels at the same speed and in the same direction to cause said cutting wheels and said gripping wheels to move around the container to completely sever the upper end of the container body, a bar pro- REFERENCES CITED jecting from said plate, a roller carried by said bar, and means for clamping said bar to said plate in adjusted positions with said roller in engage- The following references are of record in the file of this patent:

meni-I with the inner face of said ange at a point 5 UNITED STATES PATENTS ciroumferentially remote from said gripping Number Namo Date wheels.

WOODWARD J. MAY. 1,360,256 Anderson Nov. 30, 1920