Abstract:
An automobile lift and straightening platform is useful for performing repairs on motor vehicles received thereon, and includes a base, a bench which includes treadways for permitting the vehicle to roll thereon and receiving anchors for coupling the vehicle body to the bench, a lifting unit for raising and lowering the bench relative to the base, and a locking unit for locking the bench in an elevated position relative to the base and thereby inhibiting undesired lowering of the vehicle. An unlocking member is provided which may be actuated by the foot of the worker. A hand held control is connected to a power unit for operating an extensible ram of the lifting unit to raise and lower the bench, thus permitting one worker to lower the bench when simultaneously actuating the control and the unlocking member. The platform receives a pulling assembly which is more readily aligned and coupled to the bench by the provision of for and aft suspension assemblies which permits assisted tilting of the pulling assembly to insert a tongue of the pulling assembly into a receiver on the bench.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a platform for lifting automobiles for use in small repair facilities requiring the platform to be readily moved and capable of one person operation. More particularly, it is concerned with a lifting platform capable of receiving pulling towers in a multiplicity of different locations for straightening an automobile chassis and body with enhanced ease of use. 
     2. Description of the Prior Art 
     Automobiles involved in collisions often require extensive body work to return the automobile to its original body alignment. The work often includes the use of strategically positioned pulls on the chassis and/or body to straighten the chassis. This technique of straightening is well known in the art, but until recently has required large, heavy platforms to support the automobile and withstand the pulling forces. These platforms are very useful, but because of their size and expense have been limited to larger and more specialized body shops which have sufficient size and volume of repair work to justify the space and expenditure of large platforms. Smaller repair shops could not devote the space, funds, or manpower necessary to utilize such large platforms. In addition, larger repair shops would benefit from a lighter platform which could be readily moved and used for work not involving high force pulls. 
     More recently, various efforts to providing a smaller repair platform have been initiated. These platforms have been generally small scissor lifts designed to have a lifting tower coupled at one location on the platform. Their configuration thus has limited capability in regard to the pulling force or direction which may be applied to the automobile. Moreover, these existing platforms are not designed to permit drive-on/drive-off capabilities, making usage more difficult for a single individual. 
     There has thus developed a need for a small, economical repair platform which not only lifts the vehicle to permit access to the undercarriage and usage for purposes other than body straightening, but also accommodates the needs of the small repair shop for improved positioning of pulling towers and facilitates one-person usage. 
     SUMMARY OF THE INVENTION 
     These objects have largely been met by the present invention which enables a worker to quickly and easily position the automobile on the platform, position a pulling tower, and raise and lower a deck on which the automobile is supported without additional assistance. Moreover, the platform permits the automobile to be driven onto the platform into a predetermined position, and then driven off. Moreover, the platform includes as a safety feature a locking bar assembly which prevents unintended lowering of the deck unless the worker performs two simultaneous operations. 
     Broadly speaking, the automobile lift and straightening platform of the present invention includes a base, a lifting assembly, a bench having a pair of drive-on decks, a locking assembly, and optionally, or at different times during the course of use, a pulling assembly which may be mounted to the bench or to an extension, and runways having ramps to permit a vehicle to drive onto the deck. The runways may be coupled to the base and detachably receive ramps and chocks thereon so that the automobile may be driven on to the deck until stopped by the chocks at a predetermined position, and then backed off or alternatively the ramps may be repositioned in place of the chocks whereby the automobile may be driven in the same direction. 
     Moreover, the bench and extension present a multiplicity of receivers for enabling attachment of a pulling assembly including a tower to the platform, thereby providing improved pulling force capability as the tower or towers need not tilt in order to be positioned opposite a damaged portion of the vehicle and then to pull from the desired location relative to the vehicle. Further, the configuration of the bench makes it possible for more than one tower to be employed for simultaneous pulling at multiple locations. The tower thus retains the same pulling power at different elevations relative to the bench or extension. The tower preferably includes a spring assist in regard to its height above the supporting surface, whereby the tower may be more easily attached to a receiver. The deck is configured to receive anchoring stands for coupling the automobile to the deck. Thus, the automobile may be driven onto the deck, coupled thereto by the anchors, and then be raised, such that for the large majority of automobiles and trucks, there is no need to lift either the automobile or the deck prior to coupling. 
     In order to facilitate operation by a single worker, the platform hereof includes removable wheel assemblies and a trolley which may be mounted to the platform for moving by a single person. The locking assembly is gravity actuated and prevents the deck from undesired lowering relative to the base, and an unlocking arm actuated by a foot pedal permits the worker to actuate a hand control to lower the deck while using his foot to disengage the locking assembly. Thus, lowering of the deck requires two independent operations which may be performed by a single person, thereby making it unlikely that the deck will be unintentionally lowered until ready. 
     These and other features will be readily apparent to those skilled in the art with reference to the drawings and the following description of the preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left rear perspective view of the automobile lift and straightening platform of the present invention, showing the deck elevated relative to the base and the ramps and chocks in position on the runways; 
     FIG. 2 is a front right perspective view of the platform of the present invention showing the front tower mount and the deck elevated relative to the base; 
     FIG. 3 is a front right perspective view of a pulling extension for attachment to the front tower mount for providing additional locations for attachment of one or more pulling towers; 
     FIG. 4 is a top plan view of the platform of the platform of the present invention showing the location of the deck relative to the runways when in a lowered position; 
     FIG. 5 is a left side elevational view of the platform of the present invention shown in a lowered position; 
     FIG. 6 is a top plan view of the platform of the present invention showing the deck in an elevated position; 
     FIG. 7 is a left side elevational view thereof; 
     FIG. 8 is an enlarged plan view with portions of the top plate of the deck broken away, showing longitudinally slidable anchor blocks in the interior of the deck, demountable transport wheel assemblies, and a tower coupled to the pulling extension positioned in the front tower mount; 
     FIG. 9 is an enlarged, fragmentary side elevational view of the platform showing a pulling tower coupled to the pulling extension as illustrated in FIG. 8; 
     FIG. 10 is a fragmentary vertical sectional view taken longitudinally through the platform hereof, showing the upper and lower cylinder mount and rear lift arms in an elevated position; 
     FIG. 11 is a fragmentary side elevational view of the rear of the platforin showing attachment of a transport trolley for moving the platform after the attachment of the wheel assemblies; and 
     FIG. 12 is a fragmentary elevational view in partial section through a channel of the base showing one of the wheel assemblies mounted to a runway receiver. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, a portable lift and straightening platform  20  used in the repair of automobiles in accordance with the present invention broadly includes a base  22 , a bench  24 , and a lifting unit  26 , and a locking unit  28 . Optionally or at different times during the use of the platform  20 , runways  30  having ramps  32  or chocks  34 , a transport unit  36 , a pulling assembly  38 , and an extension  40  may be connected to the bench  24 . The lifting unit  26  further includes a power unit  42  and a control  44  for controlling use of the power unit  42 . 
     In greater detail, the base  22  is designed to rest upon the floor of a garage or the like and has a pair of parallel, spaced, elongated and longitudinally extending tubular base bars  46  and  48 , a rear pan  50  having parallel, spaced, elongated and longitudinally extending pan bars  52  and  54  on either side of the pan  50 , a front tube  56 , a middle tube  58 , and a rear tube  60  all connected by welding. The front tube  56  and middle tube  58  each include a pair of laterally spaced lower swing mounts  62 . The longitudinally extending tubular base bars  46  and  48  also each have respective diverging, laterally extending support angle members  64  and  66  which serve to stabilize and support the bench  24  when the latter is in a lowered position. 
     The bench  24  includes four substantially parallel longitudinally extending stringers  68 , two of the stringers  68  being relatively more closely spaced along each side to support thereon decks  70  and  72 . Front channel  74 , middle channel  76  and rear channel  78  are welded to and extend transversely and substantially normal to the stringers  68 , the middle channel  76  including a centrally located pivot bracket  80 , and braces  82  and  84  are welded to stringers  68  and front channel  74 . The front channel  74  and rear channel  78  are open at their ends to provide receivers  86 . A front tower mount  88  extends forwardly from front channel  74  having channel beams  90  and  92  extending longitudinally and a cross beam  94  connecting the beams  90  and  92  at their forward ends  96  and  98  to provide receivers  86  therein as well. The front channel  74  and rear channel  78  also include laterally spaced upper swing mounts  100 . 
     The decks  70  and  72  define longitudinally extending treadways  102  and  104  which are parallel to one another. The treadways  102  and  104  each include a top plate  106  supported on the channels  74 ,  76  and  78  and stringers  68 , and a bottom plate  108 , visible in FIG. 8, spaced below the top plate  106  about the thickness of the tubular channels and stringers. Laterally spaced and longitudinally extending guides  110  and  112  are welded between the plates  106  and  108  to define a track  114  and receive for slidable movement therealong anchor blocks  116 . The anchor blocks  116  are provided with a threaded hole  118 , two anchor blocks  116  being located in each track  114 . The top plates  106  include a number of rectangular openings  120  which may receive therein chains or vehicle anchors. Additionally, the top plates  106  have longitudinally extending slots  122  each having an enlarged keyway  124 . The anchor blocks  116  receive threaded fasteners to couple vehicle anchors thereto, the vehicle anchors being adapted to clamp the pinch welds along the rocker panels of automobile bodies or otherwise fasten to an automobile body to facilitate working on the vehicle when the wheels are removed. The treadways  102  and  104  are preferably shorter longitudinally than the wheelbase of most automobiles, whereby when an automobile is driven onto the bench  24 , its wheels will be forward and rearward of the treadways. 
     The lifting unit  26  interconnects the base  22  and the bench  24 . The lifting unit  26  includes, as well as the power unit  42  and the control  44 , an extensible member  126 , front swing arms  128  and  130 , and rear swing arms  134  and  136 . The front swing arms  128  and  130  are slightly longer than rear swing arms  134  and  136 , each including a swing bearing  138  at each end. For example the front swing arms  128  and  130  are slightly more than 31 inches, while the rear swing arms are slightly less than 29 inches. The swing bearings  138  connect to the swing mounts  62  and  100  on the base  22  and bench  24 , respectively, by pivot pins  140  to permit the bench  24  to swing upwardly between the lowered position shown in FIGS. 4 and 5 to the raised position shown in FIGS. 1,  2  and  7 . The extensible member  126  is shown as a single action hydraulic ram, but double acting rams or screw driven rams would also be useful. The extensible member has a housing  142  and an extensible arm  144 , the latter being pivotally coupled to the pivot bracket  80  by a pivot pin  140 , while the housing  142  is pivotally connected to shoe  144  by a pivot pin  140 . The shoe  144  is welded to the pan  50 . The power unit  42  is an electrically powered low pressure hydraulic pump which is connected to the housing  142  by hydraulic conduit  146  and powered by conventional 110 or 230 volt electrical current. The control  44  is hand-held and electrically connected to the power unit  42  by a length of electrical cord  148  and has a switch for selectively actuating the power unit  42  to extend or retract the extensible arm  144 . The conduit  146  is of sufficient length to position the power unit out of the way of the worker doing repairs, and the electrical cord  148  is of sufficient length to permit the worker to position himself around the vehicle for peak visibility and safety. 
     The locking unit  28  includes a lock arm assembly  150  pivotally coupled to the middle channel  76  by a pair of lock arm brackets  152  on either side of pivot bracket  80 , with pivot pins  140  pivotally connecting bearings on the upper end of the lock arm assembly  150  to the lock arm brackets  152 . The lock arm assembly includes laterally spaced lock bars  154  and  156  which are influenced by gravity to swing downwardly. The lower ends of the lock bars  154  and  156  each have feet  158  configured to ride over a plurality of longitudinally spaced lock teeth  160 , which are welded to the pan  50  and pan bars  52  and  54 , when the bench  24  is moving upwardly relative to the base  22 . Conversely, the feet  158  engage and hold fast against the lock teeth  160  when the bench  24  when static or under a downward load on the bench  24 . An unlocking member  162  is provided for selectively lifting the feet  158  clear of the lock teeth  160  to permit the bench  24  to be lowered. The unlocking member  162  includes an arm  164  normally transverse to the longitudinal axis of the pan bars  52  and  54 , a foot pedal  166  at the outboard end of the arm  164 , an elongated trip bar  168  extending longitudinally a length corresponding to the longitudinal extension of all of the lock teeth  160 , and a rocker  170  positioned intermediate the foot pedal  166  and the trip bar  168  and preferably more proximate the former. The rocker  170  extends below the bottom of the arm  164  to provide a fulcrum and pivot axis for the unlocking member  162 . The length of the arm  164  and the position of the rocker  170  are sufficient so that when the worker steps on the foot pedal  166 , the trip bar  168  engages one of the feet  158 , which thereby lifts both feet  158  upwardly above the lock teeth  160 . The trip bar  168  is relatively smooth and uninterrupted along its upper surface, such that the engaged foot  158  is able to slide along the trip bar  168  above the lock teeth  160  as the bench  24  is lowered. 
     Runways  30  have a deck  172  which is substantially as wide as the width of each top plate  106 . The deck  172  is elevated by stands  174  and  176  to be substantially the same height and substantially coplanar to each of the treadways  102  and  104  when the bench is in a lowered position. Each runway includes keyholes  178 , a pair of longitudinally extending rails  180 , end plates  182  which includes the keyholes and extends from the stands, and key  184 . The keyholes  178  are adapted to receive the heads of ramp mount bolts  186  for securing the ramps  32  to the stands  174  in an inclined orientation. The end plates  182  adjacent stand  176  and opposite stand  174  are configured to receive therein the heads of coupling bolts  188  for securing the chocks  34  thereto. The chocks  34  include a pair of upright stanchions  190  and crossbar  192  for engaging the tire of a vehicle. A roller  194  is provided on at least one of the stands  174  and  176  to facilitate movement of the runway  30 . The transverse keys  184  fit within the ends of the tubes  56  and  60  to inhibit undesired movement of the runways  30  relative to the base  22 . 
     The transport unit  36  includes a transport trolley  196  and a plurality of wheel units  198 . The transport trolley  196  as shown in FIG. 11 has an elongated pullbar  200  with a handle  202  at one end and a lifting flange  204  at the other end, the lifting flange being angularly oriented relative to the pullbar  200 . A pair of spaced trolley wheels  204  aid in not only transporting the  20 , but also serve as a fulcrum whereby downward force on the handle  202  causes the lifting flange  204  to pivot upwardly against a lip  206  welded to the rear tube  60 . The wheel units  198 , as seen in FIG. 12, include a wheeled caster  208  which includes wheels  210  and a yoke  212 . The caster  208  permits the wheels  210  to rotate about a horizontal axis. The wheeled caster  208  is mounted on an angle member  214  having an upright wall  216  with a foot  218  extending horizontally therefrom, the foot being complementally configured with the ends of the front tube  56 , the middle tube  58  and the rear tube  60  whereby the foot  218  may be inserted into the ends of each of the tubes  56 ,  58  and  60  to support the base and permit the platform  20  to be transported to a different location. 
     The pulling assembly  38  includes an attachment member  220 , a pulling arm  222  coupled to the attachment member  220 , a driver  224  which shifts the arm  222  vertically, an arm support  226  on which the arm  222  and the driver  224  are supported, suspension members  228 ,  230 ,  232  and  234 , corresponding carriage assemblies  236 ,  238 ,  240  and  242 , and a tongue  244  pivotally coupled to the arm support  226 . The attachment member  220  is shown as a chain  246  with a hook  248  for attachment to a body or frame member. The pulling arm  222  is shiftably mounted within the driver  224  which includes an extensible hydraulic ram therein for exerting a pulling force to the attachment member  220 , the pulling arm including a holder  250  at the upper end thereof which retains a part of the chain  246  remote from hook  248  as shown in FIGS. 8 and 9. The chain  246  is redirected by pulley assembly  252  which is adjustably mounted to driver  224 . The driver  224  is mounted for pivoting about a vertical axis on arm support  226 . Link pin  254  connects tongue  244  to a second end  256  of the elongated leg  258  of arm support  226  to permit pivoting about a vertical axis, with lock pin  260  holding the position of the arm support  226  relative to the tongue  244 . The leg  258  has a first end  262  positioned adjacent the bottom end of the driver  224 . The tongue  244  is configured for insertion into a receiver  86 , whereby the pulling assembly  38  may be coupled to the bench  24 . 
     The suspension members  228 , 230 , 232  and  234  are welded or otherwise secured in a vertical orientation when arm support  226  is in its normal, horizontal orientation. The suspension members each include a spring  264  which is contained therein as shown in FIG.  9  and compressed by the weight of the arm support  226  and the members carried thereby on the carriage assemblies  236 , 238 , 240  and  242 . Preferably, suspension members  228  and  230  are positioned proximate to the first end  262  on either side of the leg  258  as viewed in FIG. 8, and suspension members  232  and  234  are positioned more proximate to the second end  256  than the first end  262 , again on either side of the leg  258  as viewed in FIG.  8 . The carriage assemblies each include a rotatable wheel which rotates about an axis which is substantially perpendicular to the leg  258 . In this manner, the operator may more easily position the tongue  244  into a receiver  86  by applying his weight proximate the first end or pulling on the driver  224  to pivot it in a clockwise direction as viewed in FIG.  2 . This causes more weight to be borne by the suspension members  228  and  230  and less weight to be borne by the suspension members  232  and  234 , thereby raising the second end  258  to facilitate insertion of the tongue  244  into the receiver  86 . After the end of the tongue  244  is in place, the operator may push against the driver  224  in a counterclockwise direction as viewed in FIG.  9 . The weight of the arm support and parts carried thereon continues to be supported by all of the suspension members  228 ,  230 ,  232  and  234 , with an assist in pivoting the driver  224  and therefor in inserting the tongue  244  provided by the suspension members  228  and  230 . A pin extends inwardly from the carriage assemblies to contact an outwardly extending stop on the suspension members when the pulling assembly  38  is elevated to prevent the carriage assemblies from dropping free when the pulling assembly  38  is elevated. 
     In order to provide greater flexibility for different pulling directions, the bench  24  may be provided with an extension  40 . The extension  40 , as shown in FIG. 8, includes times  264  and  266  configured complemental to and for receipt within the receivers  86  of channel beams  90  and  92 , and bridge  268  extending perpendicular to and outwardly from each of the times  264  and  266 . The bridge presents receivers  86  at each end  270  and  272  thereof which thereby receive the tongue  244  of pulling assembly  38 . The bridge  268  is thus located forwardly of the front tube  56  and permits the pulling assembly  38  to be positioned at additional locations for providing precise pulling on the vehicle. 
     In use, the platform  20  is positioned within an area sufficiently large to permit a motor vehicle to be placed thereon and for the worker to move about the vehicle during repairs. The power unit  42  may be positioned in any convenient location accessible to a source of electrical power to which it is connected by an extension cord, as its associated hydraulic conduit  146  is of sufficient length to reach the housing unit  142  as shown in FIG.  1 . The control  44  includes a switch which may be hand operated when the worker is standing on or near the unlocking member  162 , thus enabling one worker to exercise full control over the platform  20  during its raising or lowering. 
     In preparation for receipt of the vehicle to be repaired, the worker installs the runways  30  as shown in FIG. 1 with the ramps  32  inclined so that a vehicle may be rolled onto the runway  30  from the rear end of the platform  20  and roll forwardly across the treadways until the leading tire is engaged by the chocks  34 . By the term leading tire, it is to be understood that the vehicle may be rolled with either its front end facing forwardly or the rear end facing forwardly to permit the most advantageous position for effecting the repair, and thus either the front tire or rear tire may be the leading tire depending on the orientation of the vehicle. 
     The bench  24  is configured to permit the vehicle to roll thereacross and thus by using the runways  30  and ramps  32 , the vehicle readily clears the bench  24 . Once the platform  20  is in place and the vehicle positioned so that its wheels are on the runways  30 , the pulling assembly  38  is coupled for receipt in one of the receivers  86  of the bench  24  or its extension  40 . The control  44  is then actuated to raise the bench  24  above the base  22  until the anchors coupled to the bench  24  are coupled to the vehicle frame. The bench  24  is then further raised until the bench  24  raises the vehicle to a convenient working height. While various repairs may be effected using the platform  20  hereof, it is especially adapted to perform pulling operations on the body and frame of the motor vehicle on the bench  24 . To that end, the attachment member  220  is then coupled to the portion of the body or frame to be pulled, and the driver  224  actuated by attachment to the power unit  42  whereby the arm  222  is extended to place tension on the chain and cause the portion of the body or frame to which the hook is attached to be pulled toward the pulling assembly. 
     In order to lower the bench  24  and thus the vehicle, the worker stands on the foot pedal  166  of the unlocking member  162  while manually actuating the control  44 . The application of downward force to the foot pedal  166  causes corresponding upward force to be applied to the trip bar  168 , which engages one of the feet  158  and thereby lifts both feet  158  of the lock arm assembly  150  upwardly above the lock teeth  160 , permitting the bench  24  to be lowered. This enhances the safety of the operation, as two simultaneous operations must be performed in order to lower the bench  24 . The vehicle may then be rolled off of the rear end of the platform  20  after uncoupling the anchors from the vehicle and the bench  24 , or forwardly by replacing the chocks  34  with the ramps  32 . 
     Although preferred forms of the invention have been described above, it is to be recognized that such disclosure is by way of illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
     The inventor hereby states his intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.