Floor puller to straighten a bent member
BACKGROUND OF THE INVENTION 
     This invention relates to the field of floor pullers for straightening bent members, particularly bent portions of auto bodies. 
     Floor pullers are used in auto body repair shops to pull bent portions of a damaged auto body while it is being held and clamped to a supporting bench. The floor puller is moved to a desired location facing the damaged part of the auto body, an anchor chain is connected between the floor puller and an anchor post or ring in the floor of the shop, and a pull chain is connected between the bent member and the mechanism of the floor puller which exerts the pulling force usually powered by a hydraulic pump or similar power source. 
     Prior art floor pullers include such things as pulleys and levers as part of the pulling mechanism which besides being cumbersome and expensive impose excessive force on pivot pins and pulley shafts. They are subject to excessive wear and breakage. They also are unable to pivot and rotate while a bent part is being pulled to continually adjust to a true straight line between the part being straightened and the direction being faced by the pulling mechanism. A typical prior art floor puller includes a pair of spaced apart, upwardly extending beams having pulleys rotatably mounted in between on pulley shafts supported by the pair of upright beams. The pull chain extends around the pulleys to a drive mechanism powered by a hydraulic pump. The pulling mechanism is not able to rotate about the longitudinal axis of the upright beams, nor can two separate pulling mechanisms be mounted on the same support member. If two pull chains are needed for pulling at different angles, two separate floor pullers of this prior art design must be used. 
     The floor puller in accordance with the present invention is able to solve these problems. The pulling mechanism including the power drive mechanism is free to both rotate on a vertical axis and pivot on a horizontal axis to continually orient itself in a straight line with the direction of pull from the connection to the bent part. No pulleys or levers are needed. And two pulling mechanisms in accordance with the present invention may be mounted and used on the same single floor puller. The detail construction which enable accomplishment of these features is described herein below. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a floor puller to straighten a bent member such as portions of a damaged auto body wherein the pulling mechanism is both rotatable on a vertical axis and pivotable on a horizontal axis for continuous straight line orientation with the direction of pull. 
     It is an object of the invention to provide a floor puller to straighten a bent member such as portions of a damaged auto body wherein pulleys and levers are not needed. 
     It is an object of the invention to provide a floor puller to straighten a bent member wherein the operating portions of the pulling mechanism are assembled on a sleeve member which is slidable on a cylindrical post to any desired operating height and securable at such point in a way whereby it can then rotate on the cylindrical post. 
     It is an object of the invention to provide a floor puller to straighten a bent member on which more than one pulling mechanism may be mounted for operation together from different angles when that is needed for straightening a bent member in certain situations. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a side elevation view of a floor puller for straightening a bent auto body or other bent object, showing two pulling mechanisms in accordance with this invention mounted on a single post, both connected to portions of the bent frame for pulling at different angles to achieve more true straightening of the bent part. 
     FIG. 2 is a top plan view of a floor puller in accordance with this invention. 
     FIG. 3 is a perspective view of the anchor chain connector for connection of an anchor chain to anchor the floor puller while the pulling mechanism is being operated. 
     FIG. 4 is an elevation view from the rear of the pulling mechanism portion of the floor puller in accordance with this invention. 
     FIG. 5 is a side elevation view of the sleeve portion of pulling mechanism which is slidingly mounted on the upright post. 
     FIG. 6 is an end elevation view of the coupling member which receives and holds the free end of the ram of the hydraulic cylinder used to operate the pulling mechanism. 
     FIG. 7 is a section view taken on line 7--7 of FIG. 6. 
     FIG. 8 is a side elevation view of the elongated reciprocating frame member portion of the pulling mechanism. 
     FIG. 9 is an end view of the elongated reciprocating frame member shown in FIG. 8. 
     FIG. 10 is a section view taken on line 10--10 of FIG. 9. 
     FIG. 11 is a side elevation view of a hydraulic cylinder to operate the pulling mechanism. 
     FIG. 12 is a side elevation view showing one of the wheel chambers and a portion of the connecting base arm broken away. 
     FIG. 13 is a section view taken on line 13--13 of FIG. 12. 
     FIG. 14 is a section view of one of the wheel chambers illustrating a modified form of resilient support member wherein the wheel is in its outwardly extended position. 
     FIG. 15 is a section view of the wheel chamber and modified support member of FIG. 14 showing the wheel in its retracted position within the wheel chamber. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     A floor puller 2 for straightening auto bodies in accordance with this invention includes an elongated cylindrical post 4 supported by a base 6 and extending upwardly therefrom to receive a pulling mechanism 8 thereon. 
     A plurality of apertures 10 are provided through the cylindrical post 4 spaced apart longitudinally thereof to receive a retaining bar 12 on which the pulling mechanism 8 is mounted. 
     A second pulling mechanism 14 may be mounted on a second retaining bar 16 through a second one of the apertures 10, spaced apart from the first pulling mechanism 8. The first pulling mechanism 8 can be connected to one part of an auto body 18 for straightening while the second pulling mechanism 14 is connected to another part thereof, the two pulling mechanisms being operated in conjunction with each other. 
     The pulling mechanism 8 includes a mounting sleeve 20 which is slidably positioned on the post 4. The mounting sleeve 20 has a pair of arcuately extending slots 22 and 24 through its cylindrical wall 26, slot 22 being diametrically opposite of slot 24. These slots 22 and 24 are aligned with one of the apertures 10 through the post 4 at the desired height for the pulling mechanism 8, and retaining bar 12 is placed through arcuate slot 22, aperture 10 and arcuate slot 24 to mount the pulling mechanism 8 on the post 4. The elongated arcuate slots 22 and 24 permit limited rotation of the pulling mechanism 8 on the post 4. 
     A pair of spaced apart projections or ears 28 and 30 project outwardly from the cylindrical wall 26 of sleeve 20, parallel to each other and having apertures 32 therethrough. A coupling member 34 is pivotally mounted between the projections or ears 28 and 30, having a connecting bore 36 therethrough in registration with apertures 32 of the ears 28 and 30. A connecting bar 38 is placed through the apertures 32 and connecting bore 36 to pivotally mount the coupling member 34 to the sleeve 20. The coupling member has a cylindrical wall 40 surrounding a cylindrical coupling recess 42 having internal screw threads 44. The axis of the coupling recess 42 extends at a right angle to the connecting bore 36, and in a vertical plane that extends at a right angle to the longitudinal axis of the post 4. 
     An anchor chain connector 46 is also pivotally mounted on the connecting bar 38, having a pair of curved arms 48 and 50 in parallel spaced apart relationship with aligned apertures 52 through end portion 54 in registration with apertures 32 of the sleeve ears 28 and 30 and connecting bore 36 to receive the connecting bar 38 therethrough. The curved arms 48 and 50 are spaced apart a sufficient distance to receive the coupling member 34 therebetween, and to themselves be received between the spaced apart ears 28 and 30 of the sleeve 20. The opposite end portion 56 of the anchor chain connector 46 includes a cleat 58 welded in place between the pair of curved arms 48 and 50, having a connecting slot 60 to receive and hold a link 62 of one end of an anchor chain 64. The other end of the anchor chain 64 is secured to an anchor ring or post 66 embedded in the floor of the work shop. 
     The anchor chain connector 46 is free to pivot on the connecting bar 38 on which it is mounted. 
     An operating frame 68 is also mounted on the connecting bar 38 for both pivotal and sliding movement thereon. The operating frame 68 includes a pair of elongated spaced apart side member 70 and 72, a pull chain connecting member 74 across one end between the side members 70 and 72 and an operating coupling member 76 across the opposite end thereof. The side members 70 and 72 are spaced apart a sufficient distance to receive the sleeve 20 and its projections or ears 28 and 30 therebetween. Each side member 70 and 72 includes an elongated slot 78 extending longitudinally thereof in registration with the apertures 32 of ears 28 and 30 to receive the connecting bar 38 through the slots 78 for mounting the operating frame 68 on the sleeve 20 and post 4. The elongated slots 78 enable sliding movement of the operating frame 68 between an extended position for connection of a pull chain 80 to a bent portion 82 of an auto body 18 that is to be straightened and a retracted position in which the auto body portion has been pulled sufficiently to straighten it. 
     The pull chain connecting member 74 includes a connecting slot 86 to receive a link 88 at one end of the pull chain 80 therein, the opposite end of the pull chain 80 being connected by a hook or other connecting device to the bent portion 82 of the auto body 18 that is to be straightened. 
     The operating coupling member 76 has a tubular wall 92 surrounding a cylindrical bore 94 extending therethrough, the cylindrical bore 94 having internal screw threads 96. The operating frame 68 and coupling member 34 may be pivoted on the connecting bar 38 to bring the coupling recess 42 of coupling member 34 into axial alignment with the cylindrical bore 94 of the operating coupling member 90 of the operating frame 68. A hydraulic cylinder 98 is then connected to the coupling member 34 and operating frame 68. The hydraulic cylinder 98 includes a cylindrical pressure chamber 100 and a reciprocating ram 102 mounted therein for reciprocating movement between an extended position and a retracted position. The ram 102 has a cylindrical wall 104 of a cross-sectional diameter corresponding to that of cylindrical recess 42 of the coupling member 34. Screw threads 106 are provided on the cylindrical wall 104 at the free end 108 thereof, whereby the free end of the ram 102 may be screwed into the internally threaded recess 42 of the coupling member 34. The cylindrical pressure chamber 100 has a cylindrical wall 110 of a cross-sectional diameter corresponding to that of the cylindrical bore 94 of the operating coupling member 90 of the operating frame 68. Screw threads 112 are provided on the cylindrical wall 110 at the ram end 114 thereof, whereby the ram end of the cylindrical pressure chamber 100 may be screwed into the internally threaded bore 94 of coupling member 90 of the operating frame 68. 
     When the hydraulic cylinder 98 is thus connected, it is in axial alignment with the longitudinal axis of the elongated operating frame 68, extending outwardly from one side of the cylindrical post 4 while the opposite end of the operating frame 68 having the pull chain connecting member 74 thereacross extends outwardly from the diametrically opposite side of the cylindrical post 4. The operating frame 68 may thus be slidingly moved on the connecting bar 38 by the hydraulic cylinder 98. When the ram 102 is in its retracted position, the coupling member end of operating frame 68 is drawn up close to the coupling member 34 and sleeve 20 whereby the pull chain end of operating frame 68 is in its extended position for connection of the pull chain 80 to a portion of an auto body that is to be straightened. Hydraulic pressure is then applied to the pressure chamber 100 by hydraulic pump 116 through hose 118 and hydraulic coupling 120 which forces the ram 102 toward its extended position. Since the post 4 is anchored by anchor chain 64 connected at one end to anchor chain connector 46 and at the other end to anchor post 66 whereby it cannot move relative to the floor, the pressure chamber 100 of hydraulic cylinder 98 is forced rearwardly as the ram 102 is moved toward its extended position. This carries with it the operating frame 68 whose coupling member end is coupled to the pressure chamber, and the operating frame thereby is moved from its extended toward its retracted position, pulling the pull chain 80 and portion of the auto body to be straightened a sufficient distance in that direction to straighten it whereupon operation of the hydraulic cylinder 98 is discontinued. 
     While the operating frame 68 is being pulled from its extended toward its retracted position, it is free to rotate on the post 4 with sleeve 20 by virtue of the arcuate slots 22 and 24 provided through the cylindrical wall 26 thereof. The operating frame 68 is also at such time free to pivot on the connecting bar 38. Thus, the pull chain end of the operating frame 68 and pull chain connecting member 84 across that end are free to continually adjust in both a horizontal plane of rotation and in a vertical plane of rotation as the damaged part of the auto body is being pulled whereby a continuously straight axial line of force is maintained between the hydraulic cylinder 98, the operating frame 68 and the pull chain 80. The longitudinal axes of these three components, hydraulic cylinder 98, operating frame 68 and the stretched pull chain 80, are able to stay in continuous axial alignment throughout the pull, from the extended position of operating frame 68 throughout its travel toward the retracted position. This enables a continuously straight pull on the damaged part which enables straightening it more nearly to its true original position, and it also prevents skewing of the post 4 as the damaged part is being pulled. This continuous in-line axial construction for the pulling force also reduces stress on the pivot pin or connecting bar 38. 
     The pivot pin or pins in pulling devices which use a leverage mechanism wherein the pivot pin serves as a fulcrum are subject to increased forces resulting from the mechanical advantage provided by the lever mechanism. The same is true for pulling devices which use a pulley, increased forces being applied to the pin on which the pulley rotates. Such pins are weak links in the total line of force for pulling devices which use levers and pulleys, and such weak links are eliminated by the continuous in-line axial structure of the pulling mechanism in accordance with this invention. 
     The connecting bar 38 includes removable hand grips 122 of rubber or comparable material at each projecting end. The retaining bar 12 may also include a hand grip 124. 
     The base 6 includes three outwardly extending arms 126 projecting outwardly from the cylindrical post 4 and terminating at respective wheel chambers 128. Each wheel chamber 128 includes a wheel 130 mounted for rotation on a resilient support 132 which is movable vertically to retract the wheel 130 into the wheel chamber 128 where it cannot roll on the floor and to extend the wheel 130 out of the wheel chamber 128 far enough to be in rolling engagement with the floor. When the wheels 130 are retracted into the wheel chambers 128, the floor puller 2 can&#39;t be rolled on the floor. The bottom edges 134 of the wheel chambers 128 are in frictional contact with the floor surface to act as a brake against movement of the floor puller 2 when the wheels 130 are retracted into the wheel chambers. The resilient support 132 normally biases the wheels 130 to their extended position outward of the wheel chambers 128 far enough for rolling engagement with the floor whereupon the floor puller 2 can be easily rolled from one location to another. When the anchor chain 64 is anchored to a floor post 66, the pull chain 80 connected to a part 82 for straightening, and the pulling mechanism 8 operated to pull on the pull chain 80, downward force is applied to the post 4 and base 6 forcing the wheels 130 to their retracted position within the wheel chambers 128, and the bottom edges 134 of the wheel chambers are forced into frictional and braking contact with the floor to hold the base 6 against movement while the pulling mechanism 8 is being operated. 
     The resilient support 132 may take a number of forms, including cylinders of compressed fluid connected to the wheels 130, resilient and compressible material such as rubber to normally bias a wheel support mechanism to the extended position but compressible enough to permit the wheels to retract into the wheel chambers under pressure, and various other means. The form shown and described herein includes a pair of compression springs 136 and support shafts 138 connected to the axle 140 of the wheel 130, the opposite end 142 of the springs being secured to the inner surface of the top wall 144 of the wheel chamber 128. 
     Another form of resilient support includes the modification shown in FIGS. 14 and 15. The wheel 130 is mounted so it can swivel on swivel post 146 which is secured to the inner surface of the top wall 144 of the wheel chamber 128 in this modification. The floor puller 2 can be more easily turned and steered when moved from one location to another when the wheels 130 are mounted so as to enable them to swivel. A connecting member 148 is pivotally connected at one end to the lower end of the swivel post 146 by pivot pin 150, and at the other end to the axle 140 of the wheel 130. Thus the wheel 130 can be pivoted from its extended position outward of the wheel chamber 128 as shown in FIG. 14 for rolling engagement with the floor to its retracted position where it is withdrawn from rolling engagement with the floor as shown in FIG. 15. A block of compressible material 152 such as rubber is provided as a compressible wedge between the inner surface of the top wall 144 and the bearing plate 154 formed on the upper surface of the connecting member 148. The block of compressible material 152 has sufficient rigidity to normally bias the wheel 130 to its extended position in rolling engagement with the floor, but is sufficiently resilient to enable the wheel 130 to retract into the wheel chamber 128 when the pulling mechanism 8 is being operated to pull on the bent member 82 thereby applying downward force on the cylindrical post 4. When such pressure is released, the block of compressible material 152 biases the wheel 130 back to its extended position in rolling engagement with the floor. 
     A stop bar 156 extends across the cavity of wheel chamber 128 to limit pivotal movement of the connecting member 148 and wheel 130 in the direction toward its extended position, and to hold it from further movement in such direction and when the wheel&#39;s extended position in rolling engagement with the floor has been reached. 
     The block of compressible material 152 extends entirely across the cavity of the wheel chamber 128 whereby the bearing plate 154 remains in continuous facing relationship therewith as the connecting member 148 and wheel 130 are swiveled for turning of the floor puller when the wheels 130 are in their extended position and the floor puller is being moved to a different location. At such time the block of compressible material 152 is in its relaxed or uncompressed state wherein it does not exert significant pressure against the bearing plate 154 thereby enabling the connecting member 148 and wheel 130 to swivel. 
     When two pulling mechanisms are mounted on the same support post as shown in FIG. 1, the rotatably mounted sleeves 20 permit rotating the two mechanisms to point in different lateral directions as well as at two different vertical angles. This unique feature enables one floor puller to do bi-directional pulling, such as in repairing a damaged auto body for example one pulling mechanism can be connected to pull out a bent frame rail and the other can be connected to pull out a bent portion of the upper cowl.