US3000662A

US3000662A - Sheet grip

Info

Publication number: US3000662A
Application number: US670797A
Authority: US
Inventors: Robert R Scarlett
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-07-09
Filing date: 1957-07-09
Publication date: 1961-09-19
Anticipated expiration: 1978-09-19

Description

Sept. 19, 1961 R. R. SCARLETT SHEET GRIP Filed July 9, 1957 INVENTOR ROBE/P7 R. SCARLET 7' ATTORNEY 3,000,662 SHEET GRIP Robert R. Scarlett, 14881 Altamont Road, San Leandro, Calif. Filed July 9, 1957, Ser. No. 670,797 6 Claims. (Cl. 294-86) The present invention relates to a sheet grip, and in more particular to a grip with opposing jaws which obtain their gripping action from the load which the grip carries. There have been many types of grips made for the lifting of objects such as sheets, pipe, ice, lumber, and irregular objects. Some of these grips have been dependent for their operation on the weight of the grips jaws and of the material being lifted, and, also, some have been dependent on the frictional contact between the grip and the object being lifted.

However, many of the prior devices have not been satisfactory for many and various reasons such as holding power, size, complexity, and difiiculty of operation.

Having in mind the defects of the prior art, it is an object of the present invention to devise a sheet grip that may be engaged with successive sheets without adjustment of the grip or manipulation thereof other than engaging it with the sheet.

Another object of the present invention is the devising of a sheet grip that seizes and releases a sheet by a slight frictional contact therewith.

A further object of the present invention is the construction of a sheet grip which when secured to a sheet will have its handle substantially in the plane of the sheet so that when the sheet is lifted by such handle the direction of the lifting force will be substantially thru the center of mass and substantially in the plane of the sheet.

Still another object is the use and construction of a grip having a cam and follower of simple design for effective closing of the grip upon frictional contact of the grip jaws with the sheet to be lifted.

A sheet grip embodying the above objects and which remedies the mentioned defects of the prior art is constructed by forming a U-shaped member so that a long leg serves as one jaw of the grip. This member carries the other jaw which is movable with respect thereto for adjustment to various thicknesses of sheets, and

- which is guided to and from the fixed jaw by a cam and follower action upon frictional contact of the grips jaws and a sheet, and by the load of the sheet on the grip.

This construction is hereinafter described in detail and shown in the perspective view of the drawing illustrating one form of the present invention.

In the drawing, there is a U-shaped member 11 that has a short leg 12 that forms a handle with a guard 13 secured to the free end thereof, and a long leg 14 that forms one jaw of the grip and is joined to the handle by a stem 16. As the long leg 14 is fixed with respect to the handle, it may be called the fixed jaw of the grip. The free end of the fixed jaw 14 is enlarged to form a cheek 17 that has its inner face covered with a sheet of rubber 18 bonded to the metal of the cheek in any suitable manner. There is secured normal to the inner face of the fixed jaw a pair of parallel spaced apart threaded

studs

21, 22, a pivot stud 22 adjacent the stem 16 and a guide stud 21 adjacent the cheek 17. The U-shaped member 11 carries on the studs 21, 22 a mating jaw 23, the movable jaw, in opposition to the fixed jaw 14. The movable jaw 23 is provided with a cheek 24, in form similar to the check of the fixed jaw, opposed thereto, and having a sheet of rubber 26 secured to its inner face.

The pivot stud 22 has threaded thereon a pivot sleeve Patented Sept. 19, 1961 27, or nut, which passes thru the pivot end of the movable jaw 23. The movable jaw fits very loosely on the sleeve and is loosely spaced from collars 28, 29 which are secured to the sleeve, one on each side of the movable jaw. Turning of the sleeve travels it along the pivot stud 22 due to the coacting threads therebetween, and with it the collars 28, 29 which are secured thereto so as to abut and carry between them the pivot end of the movable jaw, thus to move the pivot end of the movable jaw to or from the fixed jaw as the sleeve travels along the stud. The lower edge of the movable jaw is close to the guide stud 21 when the grip is removed from clamping position on a sheet. The guide stud has threaded thereon a right truncated cone 31 which points toward the jaws. Secured to the outer face of the movable jaw and directly above the guide stud are a pair of bearing blocks 32 which carry between them a follower roller 33 that is adapted to engage and roll on the outer face of the cone 31, which cone face acts as a cam with respect to its follower roller 33. As the movable jaw pivots on the sleeve 27 and the pivot stud 22, and the roller 33 rides up, from base to apex, and then down on the cone, the movable jaw will move to and from the fixed jaw and the

cheeks

17, 24 will move together and then apart. Also, rotation of the cone on its guide stud 21 moves the cone longitudinally of such stud and, thru its contact with the follower roller 33, moves the jaws together or apart, depending on the direction of rotation of the cone on its stud. The cone and roller are a guide for moving the checks to and from each other. Turning of the threaded cone 31 on the guide stud 21 and of the threaded sleeve 27 on the pivot stud 22 adjusts the space between fixed jaw and movable jaw for use with sheets of different thicknesses.

Secured to the cone 31 is a sprocket 36 and secured to the sleeve 27 is another sprocket 37 of the same pitch and number of teeth as the first one. The sprockets are aligned in the same plane and connected by a drive chain 38. Thus, turning of either the sleeve 27 or the cone 31 will turn the other.

At the truncation of the cone 31 there is provided a cylindrical surface which acts as a stop 39 for the follower 33. This stop holds the jaws and the

cheeks

17, 24 in approximate registry when they are not gripping a sheet. The center of the inner face of the movable jaw cheek 24 is in a plane normal to such face, and which plane includes the follower contact with the cone and the center of the pivot opening of the movable jaw. This means that the gripping force of the grip is centered in this plane, and on the follower and the movable jaw pivot. The movable jaw is loosely pivoted on the sleeve 27 so that it may rock and not bind as the jaws grip a sheet, and as the follower travels on the cone.

A lock nut 40 may be placed on each of the studs to secure the cone 31 and the sleeve 27 against movement when the grip has been adjusted for a particular thickness of sheet to be handled.

The grip is used by first adjusting it for a particular sheet thickness. This may be done by placing the grip on a sheet so that each

cheek pad

18, 26 contacts an opposite face of the sheet adjacent an edge of the sheet. The handle guard 13 is placed against the edge of the sheet with the handle 12 above the grip jaws in the direction in which the sheet is to be lifted. The cone 31 and the pivot sleeve 27 are then turned to move these parts toward the jaws until the sheet is firmly 'held between the cheeks, and the cam follower 33 is well away from the stop shoulder 39. Then as the sheet is lifted by the grip in a direction parallel tothe edge against which the handle guard 13 rests, the follower will move slightly along the cone toward its apex to firmly force the cheeks together and to hold the sheet. It is intended that for lifting a sheet, one of the grips be used at each of two opposite edges of the sheet.

it has been found that the apex angle of the cone should be very close to 144, a .base angle of 18. A greater apex angle causes the jaws to lock on the sheet so tightly that it is difficult to remove them therefrom. A lesser angle reduces the gripping action to when the sheet will easily slip from the grip. Plus 4 and minus 8 to the cone apex angle of 144 are probably the practical limits for the apex angle.

Having thus described my invention, its construction and use, I claim:

1. A sheet grip comprising in combination: 7 a U-shaped member having a short leg and a long leg joined by a stern, said short leg forming a handle and said long leg forming the fixed jaw of a pair of gripping jaws; a cheek carried by the free end of said fixed jaw; fixed to and on the grip side of said fixed jaw and extending normal thereto, a pair of spaced apart parallel studs, one of said studs being a pivot-stud placed adjacent said stem and the other stud being a guide-stud placed adjacent said cheek carried by said fixed jaw; a movable jaw carried by said studs, said movable jaw having a free .end and a pivot end; a cheek carried by the free end of said movable jaw, said cheeks being in opposition for gripping a sheet therebetween; a pivot sleeve on said pivot-stud, adapted to move longitudinally along said pivot-stud and the pivot end of said movable jaw being loosely mounted on said pivot sleeve so that it may pivot about said sleeve and may be moved longitudinally along said pivot-stud upon longitudinal movement of said sleeve on said pivot-stud; a camming means engaging the free end of said movable jaw such that a shear load applied to said movable jaw cheek, in tending to pivot said movable jaw about said sleeve, causes said movable jaw free end to engage said camming means to tend to move said movable jaw cheek toward said fixed jaw cheek, said camming means being longitudinally adjustable relative to said guide-stud whereby the spacing between said movable jaw and fixed jaw cheeks may be varied.

2. The combination of claim 1 including connecting means linking said sleeve and said adjustable camming means for effecting simultaneous adjustment of said sleeve and said adjustable carnming means.

3. The combination of claim 2 in which said connection means includes a chain and a pair of sprockets carrying said chain, one of said sprockets being secured to said sleeve and the other sprocket being secured to said adjustable camming means.

4. The combination of claim 1 in which said camming means includes a oamming surface in the form of a right truncated cone which has its axis coaxial with the axis of said guide-stud, and a follower secured to said movable jaw so as to contact the conical surface of said cone.

5. A grip, comprising in combination: a pair of sub stan'tially parallel and opposed jaws adapted to receive therebetween an article to be gripped, one of said jaws being a fixed jaw and the other a movable jaw; a handle fixed to said fixed jaw; means secured to said fixed jaw for supporting and maintaining said movable jaw in substantially parallel opposed relationship to said fixed jaw; each jaw being provided adjacent one end thereof with an article gripping face in opposition to the face of the other jaw; saidsupporting means including means for loosely pivoting thereon said movable jaw in a plane substantially parallel to the fixed jaw; said supporting means also including adjacent but outside of the gripping face of the movable jaw an adjustable cam and follower means such that a shear load applied to said movable jaw face, in tending to pivot said mandible about said sleeve, causes said movable jaw free end to engage said camming means to tend to move said movable jaw face toward said fixed jaw face, said camming means being adjustable relative to said fixed jaw whereby the spacing between said movable and fixed jaw faces may be varied. V

6. A sheet grip, comprising in combination: a pair of opposed jaws which when in use are adapted to receive and grip therebetween a portion of a sheet adjacent an edge thereof so that such sheet may be lifted by such grip, one of said jaws being a fixed jaw and the other a movable jaw; a handle fixed to said fixed jaw, said handle being vertically remote from such jaws when so used and lying substantially in the plane of said sheet, said handle having a guard portion adapted to contact such vertical edge when such grip is so used; support means secured to said fixed jaw for supporting said movable jawin opposed substantially parallel relationship to said fixed jaw; each jaw being provided adjacent one end thereof with an articlegripping face in opposition to the face of the other jaw; said support means including means for loosely pivoting thereon said movable jaw in a plane substantially parallel to the fixed jaw; said support means also including camming means comprising anaadjustablecam and follower means suchthat a shearload applied to said movable jaw face, in tending to pivot said movable jaw about said sleeve, .causes said movable jaw face to move toward said fixed jaw face, said camming means being adjustable relative to .said fixed jaw whereby the spacing between'said movable and fixed jaw faces may be varied.

References Cited in the file of this patent UNITED STATES PATENTS 836,740 xDettenborn Nov. 27, 1906 1,182,313 Randal et al May 9, 1916 1,221,400 Wilhelm et al Apr. 3, 1917 1,837,425 Gastan Dec..22, 1931 1,982,225 Miller Nov. 27, 1934 2,782,063 Ziegfeld Feb. 19, 1957 2,821,426 Hanner Jan. 28, 1958