Patent Publication Number: US-2010111661-A1

Title: Vehicle lift

Description:
PRIORITY CLAIM AND CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. §119(e) and any other United States or other law of the following: U.S. Ser. No. 60/844,522 (Atty. Docket No. 0201-p19p) filed Sep. 14, 2006, entitled VEHICLE LIFT, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to methods, systems and apparatus for implementing lifts, hoists and the like in motor vehicles, especially for use in connection with personal-mobility devices such as scooters, wheelchairs, etc. 
     BACKGROUND 
     With the growing aging population, there are increasing numbers of mobility-impaired persons relying on mobility devices such as powered wheelchairs (PWCs) and power operated vehicles (POVs), or scooters, for an independent lifestyle. In order for those disabled persons to drive or ride as passengers in private motor vehicles, several means of transporting their mobility devices have been devised, such as trunk lifts, platform lifts and ramps. Crane-type hoists have been known and used for several years to accommodate loading and transporting mobility devices in hatchback-type vehicles such as minivans and SUVs. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  is an isometric view of a lift according to one or more embodiments of the present invention. 
         FIG. 2  is an exploded view of a lift according to one or more embodiments of the present invention. 
         FIG. 3  is another exploded view of a lift according to one or more embodiments of the present invention wherein a driver side configuration and a passenger side configuration are illustrated. 
         FIGS. 4 and 5  are side views of a lift according to one or more embodiments of the present invention. 
         FIG. 6  illustrates a reversible base usable in connection with one or more embodiments of the present invention. 
         FIG. 7  illustrates a reversible base usable in connection with one or more embodiments of the present invention. 
         FIG. 8  is an exploded view of a reversible base usable in connection with one or more embodiments of the present invention. 
         FIGS. 9 ,  10  and  11  are top plan views of a lift according to one or more embodiments of the present invention mounted in various orientations relating to a vehicle cargo area and support surface, wherein driver side configurations and passenger side configurations are illustrated. 
         FIG. 12  illustrates top plan and side views of a drive unit according to one or more embodiments of the present invention. 
         FIG. 13  illustrates various detailed views of a drive unit according to one or more embodiments of the present invention. 
         FIG. 14  illustrates an exploded view of a drive unit according to one or more embodiments of the present invention. 
         FIG. 15  illustrates left hand and right hand mounting of a head assembly mount on a mast according to one or more embodiments of the present invention. 
         FIGS. 16-21  illustrate a head assembly, including boom extension and belt compensation systems, according to one or more embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description of the invention will refer to one or more embodiments of the invention, but is not limited to such embodiments. Rather, the detailed description is intended only to be illustrative. Those skilled in the art will readily appreciate that the detailed description given herein with respect to the Figures is provided for explanatory purposes as the invention extends beyond these limited embodiments. 
     As mobility devices have increased in size and weight, it has become essential to provide hoists that require less space in vehicle cargo compartments which, if anything, are becoming smaller as vehicles are downsizing. Additionally, as the variety of hatchback vehicle models has proliferated, so has the variety of mobility devices. In many motor vehicles, the bumper designs also have grown. In order to provide a more universal hoist to accommodate the increasing variety of vehicle and mobility device combinations, certain improvements in design have been made. 
     One of the most popular types of hoist for hatchback-type vehicles comprises a mounting base used to fasten the hoist to the vehicle floor. A mast assembly coupled to the mounting base provides a vertically elevated position for a lifting means, for example a boom to extend outside the vehicle and rotate the cargo (for example, mobility device) into the vehicle, a hoist drive system (for example, lift head assembly) for lifting the cargo, and an additional mast drive system to rotate the mast assembly (and any cargo carried by the lifting means) into the vehicle. For some vehicles, a third axis of horizontal linear motion is desired and/or required to extend the mast and mobility device beyond the vehicle (for example, beyond a vehicle bumper or the like). Embodiments of the present invention described and claimed herein are improvements over previous crane-type hoists. 
     As seen in the example of  FIG. 1 , the present invention includes embodiments of a lift  100  having a reversible base  200  to which a drive unit  300  is mounted. The drive unit can include a direct drive according to some embodiments of the present invention, a drive that does not use any flexible linkages between the motor or similar device and the mast assembly component being rotated. A mast  400  that can incorporate a reversible head mount is coupled to the drive unit and a lift head assembly  500  is then coupled to the mast. A boom extension compensation system can be employed in some embodiments of the present invention to compensate a lift belt position for horizontal extension and/or retraction of the boom. 
     The phrases “coupled to” and “connected to” and the like are used herein to describe a connection between two elements and/or components and are intended to mean coupled either directly together, or indirectly, for example via one or more intervening elements, where appropriate. 
     A mounting base according to one or more embodiments of the present invention is less confusing to assemble and install as compared to bases of earlier systems. It typically is desirable to mount the hoist as close to the rear hatch and adjoining interior wall (driver or passenger side) of the cargo area as practical. To accomplish this, a configurable base geometry is necessary. The mounting base provides a means of securing the hoist drive system and mast assembly to the vehicle floor using two leg extensions, generally at a right angle, to spread the loads resulting from lifting and rotating the mobility device. Instead of providing incremental adjustment of the base mounting legs via spaced holes, continuous adjustment is provided using telescoping tubes secured with set screws. This simplifies floor hole alignment during installation. The base provides, optionally, 3 or 4 fastening locations to secure the base to the vehicle floor. An additional offset leg position is provided for the forward-facing leg to clear the fender well on some applications. Also, the base assembly is symmetrical and can be turned upside down for mounting either on the passenger side (for example, the right side in the United States) or the driver side (for example, the left side in the United States) at the rear of the cargo area, adjacent to the hatch door. Additionally, flipping the base in this manner can provide a rear offset configuration. 
     Lifts according to embodiments of the present invention are modular in the sense that a multi-configurational positioning apparatus can include a base assembly described in detail below and/or a reversible head mount described in detail below to permit a wide variety of mounting configurations, positions and/or orientations using the a single set of components comprising the multi-configurational positioning apparatus, without the need for component customization or numerous different parts for achieving different orientations (for example, driver side versus passenger side configurations, right hand versus left hand head assembly orientations, rear offset spacing in a vehicle&#39;s storage space, side offset (from a wheel well or the like, for example) in the vehicle&#39;s storage space, etc.). This modularity means that a simple set of parts can be configured in many different ways to achieve a highly flexible and adaptable lift unit that can be installed, maintained and altered by a dealer or other individual responsible for the installation and implementation of vehicle lifts. 
     The base unit  200  (also referred to as a base assembly), shown in  FIGS. 1-3 , is configured to be mounted to a vehicle floor, trunk floor, etc. or any other generally structural support that usually is a horizontal support surface  105 . As seen in  FIGS. 6 and 7 , the base unit  200  can include a pair of reversible mounting plates  202 A,  202 B to which are affixed a first leg  204 , a second leg  206  and a third leg  208 . Legs  204 ,  206 ,  208  can be welded or attached to plates  202 A,  202 B in any appropriate manner. 
     Leg  204  and leg  206  are set at an angle that permits stable mounting of the lift  200 . Typically a 90° angle can be used as the mounting angle, though the present invention is not limited to this configuration. An angle brace  212  can be used to help hold legs  204 ,  206  in a fixed mounting angle. 
     Leg  208  is mounted parallel to leg  204  in the embodiment of  FIGS. 6 and 7  for reasons discussed in more detail below. A support leg  210  can be used to help hold legs  204 ,  208  in parallel relation to one another. As seen in  FIGS. 6 and 7 , when plate  202 A is on top of the base unit  200 , parallel legs  204 ,  208  are angularly displaced from leg  206  by an acute angle counterclockwise from leg  206 . Likewise, when plate  202 B is on top of unit  200 , then legs  204 ,  208  are displaced from leg  206  by an acute angle clockwise from leg  206 . This feature, too, will be discussed in more detail below. 
       FIGS. 1-3  and  8  show one or more legs  204 ,  206 ,  208  including telescoping components  214  that allow the legs to be adjusted as to length and anchoring point (which can be anchored to a support surface using a bolt, rivet or any other equivalent anchoring means). Likewise, an extender  214  may have one or more mounting feet  216  for assisting in anchoring the base unit  200  to the support surface  105 , as seen in  FIGS. 1-3  and  8 . Other legs and anchoring apparatus to assist in securing the base unit  200  to an appropriate support surface. As will be appreciated by those skilled in the art, the base box  218  shown secured to plate  202 A can be similarly secured to plate  202 B when base unit  200  is flipped over to provide other configurational options. 
       FIGS. 9 ,  10  and  11  show different configurations/positions for the lift  100  in the trunk of a car, the back of an SUV, floor of a minivan, etc. Each  FIGS. 9 ,  10  and  11  has two configuration layouts that in turn each show two positions for mounting an embodiment of the present invention. As will be seen in  FIGS. 9 ,  10  and  11 , the configurations on the left side are “driver side” configurations (or DS configurations) and the configuration on the right side are “passenger side” configurations (or PS configurations). These various configurations achievable using the multi-configurational positioning apparatus described herein reflect the ability of embodiments of the present invention to accommodate different locations and obstacles (for example, a wheel well, spare tire, etc.) with regard to the support surface on which the lift is mounted. 
     In each  FIGS. 9 ,  10  and  11 , support surface  122  ends on one side with a vehicle rear bumper  222 . In the two configuration layouts shown in  FIG. 10  legs  204 ,  206  are used for anchoring the lift  100  to support surface  122  and leg  208  is either unused or is supplemental to the other legs. In the configurations of  FIG. 10 , no wheel well or other obstruction is present that would otherwise require use of a different configuration regarding the side of the vehicle storage space and no rear setback or offset is required along the rear of the storage space. In the two configuration layouts shown in  FIG. 11  leg  208  is used parallel to bumper  222  so that a rear offset configuration is provided. Finally, in the two configuration layouts shown in  FIG. 9 , wheel wells  124  adjacent the support surface  122  make use of leg  208  more desirable. Again, leg  204  is unused and leg  206  is used in its normal configuration, this time parallel to the rear bumper  222  with no rear offset. Those skilled in the art will appreciate that other configurations of the “flippable” base unit of the present invention can be implemented. As shown in  FIGS. 9-11 , a base box  218  is used as a spacer and mounting platform between one of the base plates  202 A,  202 B and the drive unit  300 . Depending on the intended use and/or environment in which lift  100  is used, this base box (which can be part of the multi-configurational positioning apparatus) can be oriented in any suitable fashion. 
     In some embodiments of the present invention, the mast drive system is comprised of an enclosed gearbox with an external, serviceable, motor that is fastened directly to the mounting base and supports the mast assembly. Limit switches can be pre-set to provide rotation end points constraining the mast rotation while moving the mobility device out from or in to the vehicle cargo area. Because the limit switches can be adjusted to restrict rotation between any two points over 360 degrees, the mast drive system can be configured in the field to a passenger side, driver side or other location. 
       FIGS. 12-14  show one embodiment of the drive unit  300  of the present invention which, in the embodiment illustrated in the Figures, is a direct drive system (which may use a gear cluster or the like, but not using belts, chains, or other flexible linkages to transmit motion from the motor to the mast for rotation of the mast). A mounting plate  302  can be affixed to base box  218  using bolts or any other equivalent mounting means so that base box  218  provides spacing for the drive unit. A motor  310  likewise is mounted to plate  302  adjacent a generally vertical mounting tube  320  that can include limit switches  322  used to establish the rotational limits of the mast  400  during normal operation of the lift  100 . A gearbox cover  330  can be used to house the gear cluster  332  that transmits the output of the shaft of motor  310  to a final drive gear  334  to which mast rotation tube  320  is secured (for example, by threaded screwing of the mast rotation tube  320  to the final drive gear  334 ). A cross-member  324  can be used in the interior of gear  334  and tube  320  to transmit rotational motion from the gear cluster  332  of the drive system to the tube  320 . Other drive means are well known to those skilled in the art and can be used in lieu of the specific structure illustrated in the Figures for rotating the mast assembly  400 . 
     As will be noted from the Figures, embodiments of the present invention use a direct drive system for rotating the mast assembly  400 . That is, the motor  310  drives tube  320  directly; no chains or other flexible linkages are used. The sealed gearbox requires no adjustments (as a chain drive would), lubrication, or other scheduled maintenance for the life of the hoist. It also resists entry of contaminants such as water or grime. Being more compact than bulky chain drive systems, additional vehicle applications can be accommodated where cargo space is restricted. 
     As seen in  FIGS. 1-3 , a hood or other cover  350  can be used to enclose the entire drive unit including motor  310 , mounting tube  320 , etc. for cosmetic reasons as well as to prevent dirt and other materials from accumulating, etc. A collar  340  can be placed over the upper end of the mounting tube  320  to enclose the joint between the mounting tube  320  and the vertical post  410  of mast  400 . 
     The mast assembly  400  is mounted on top of the mast drive means  300  and features an optional offset arm  420  to facilitate positioning a mobility device or other cargo alongside a vehicle for lifting (for example, on a sidewalk).  FIGS. 3 and 15  show one embodiment of the mast  400 , which includes a vertical segment or upright, in this case a post  410  (providing mounting and option vertical adjustment) and the optional horizontal offset arm  420 . As seen in the Figures, post  410  has height adjustment holes  412  that allow post  410  to be mounted to tube  320  at a desirable height setting. A bolt  414  or other locking means can be used to hold post  410  in position relative to tube  320 . In embodiments where such height adjustment is available, the bolt  414  also transmits the rotational motion of the mast rotation tube  320  to the post  410 . Notches  416  in the bottom of post  410  provide clearance of the member  324  when the height of post  410  is lowered. Thus when motor  310  rotates tube  320 , post  410  and mast  400  rotate in a generally equivalent manner due to the transmission of rotation motion by member  324  and bolt  414 . In embodiments of the invention using a mast rotation tube  320  and post  410 , the combination of these two components can be considered the vertical upright as a whole. In other embodiments where a mast rotation tube  320  or the like is not used, the direct drive of the drive unit  300  can directly engage the post itself without the intermediate rotation tube. 
     Optional horizontal offset arm  420  can be welded or affixed to post  410  by any other suitable means. Alternatively, arm  420  and post  410  can be components of a unitary mast  400 . 
     As seen in the Figures, especially  FIGS. 3 and 15 , the outer end of arm  420  has a reversible head mounting mechanism  430 , so that the hoist can be configured by the dealer/installer for passenger or driver side mounting. Mechanism  430  is part of the modular mounting system according to some embodiments of the present invention that provides a wide variety of mounting configurations and/or orientations using the same components. Mechanism  430  is used to mount head assembly  500  to the mast  400 . In the embodiment of the present invention shown in  FIGS. 3 and 15 , mechanism  430  includes a mounting sleeve  432  that is designed to slide axially over the outermost end of offset arm  420  using either end of sleeve  432 . Sleeve  432  can be secured to the offset arm  420  using a set screw  435  or any other suitable securing means. A brace  434  and offset pivot  436  are affixed to sleeve  432  in a generally perpendicular orientation relative to the axis of sleeve  432 . In this way mechanism  430  can be used for both “right hand” and “left hand” mountings of the head assembly  500 . If the head assembly  500  is mounted in a left hand orientation and a right hand orientation is desired, the head  500  is removed from mechanism  430 , the mechanism  430  is “flipped,” and the head is then re-mounted to the right hand orientation. This embodiment of the present invention provides a very simple and easily implemented way of reversing the orientation of head assembly  500 , thus enhancing the multiple configuration capabilities and capacity of a hoist according to one or more embodiments of the present invention. 
     The head assembly  500  (also referred to as a lift head assembly or boom assembly) is modular, can be provided with optional lifting features, and typically is pivotally mounted atop the mast assembly. A simple embodiment of the head assembly  500  includes a continuously-adjustable boom  520  with a winch-type hoist mechanism, as described in more detail below. 
     The boom angle can be pivotally adjusted by means of a turnbuckle  516 , displaced opposite the lifting end of the boom to maximize the under-boom clearance when elevating the mobility device or other cargo. One end of the turnbuckle  516  is attached to the bracket  434  of mast offset arm mount  430  and the other end to the boom assembly  500 . When the hoist  100  is not under load, the boom can be folded vertically by removing a hitch pin and pivoting it to a closed position, as shown in  FIGS. 4 and 5 . This creates additional cargo space access and improved rear vision in some vehicles. 
     In some embodiments of the present invention, the head assembly  500  uses two motors or equivalents thereto—a belt drive motor and a boom extension motor, as described in more detail below. Head assembly  500  is mounted to mast  400  using the head mounting bracket  430  (discussed above with regard to mast assembly  400 ) and is used to control raising and lowering of cargo. As seen in  FIG. 16 , a boom  520  according to one embodiment of the present invention includes 3 telescoping segments—inner segment  522 , middle segment  524  and outer segment  526  (the terms “inner” and “outer” refer to the relative diameters of the telescoping segments). A belt  510  is fed through the boom  520  using a roller  528  adjacent the outer end terminus  502  of boom segment  522 . Belt  510  is accumulated on a winding drum or spool  512  or the like in head assembly  500 . In some embodiments, belt  510  can be stored in an apparatus at the outer end terminus  502  of the boom so that belt  510  is not enclosed by the boom at all. 
     As shown in the Figures, a chain drive speed reduction  514  can be used to transmit motion from the output shaft of belt drive motor unit  530  to control rotation of the spool  512  to play out and reel in belt  510 . An appropriate latching, hook or lifting link  518  (also referred to herein as a cargo attachment point) can be attached to the end of belt  510  to engage the docking means on the mobility device or otherwise assist in lifting cargo (for example, a scooter, wheelchair or other personal mobility vehicle). 
     Further hoist movement is provided with an optional boom extension drive in the lift head assembly. This boom extension drive consists of a linear actuator unit extending and retracting the boom length when cargo needs to be placed farther outside the vehicle (for example, to clear the motor vehicle bumper or other external structure), or to accommodate motor vehicle hatch geometry. This boom extension drive system is located at a fixed position at the inboard end of the boom. 
     In some embodiments of the present invention, the cargo attachment point vertical position can be maintained at a constant height while the boom is being extended and retracted (that is, while the length of the boom is increased and decreased). A controller coordinates the boom extension drive and the belt drive, thus providing desired belt length compensation. By placing the bulky belt drive system in proximity to the mast in some embodiments, more vertical hoist travel is available to lift large mobility devices in a limited vertical space. Also, this position counterbalances the boom while being folded vertically. 
     Thus, some embodiments of the present invention include a system for extending and retracting the boom outer end terminus  502 , as seen in the multi-positional diagram of  FIG. 16 . The boom extension drive uses a boom extension motor unit  540  to control extension and retraction of the middle boom segment  524  (inner segment  522  and middle segment  524  maintain a constant position relative to one another (though their position relative to one another can be adjusted at installation, maintenance, refitting into a new motor vehicle, etc. using a set screw or the like, as seen in the Figures); the middle segment  524  moves only relative to outer segment  526  in the illustrated embodiment of invention). In the embodiment of the present invention shown in  FIGS. 16-21 , boom extension motor  540  turns a screw actuator  542  over which a sleeve  544  traverses. The outer end of sleeve  544  is mounted to middle segment  524  of boom  520 . Full extension of boom segment  524  is shown in  FIG. 17 , with varying degrees of retraction shown in  FIGS. 18-21 . 
       FIG. 4  shows an embodiment of the present invention in which no power boom length adjustment is available, the boom length being set and/or adjusted by a dealer or other installation individual.  FIG. 5 , on the other hand, shows an embodiment of the present invention using a linear actuator to provide power adjustment of the boom length (which makes belt compensation possible, though not required). In both embodiments shown in  FIGS. 4 and 5 , the lift can be folded to some degree to further reduce storage size of the lift in a motor vehicle storage space. In both  FIGS. 4 and 5 , the head assembly of the lift is foldable about the offset pivot  436  of the head mounting mechanism  430 . Folding can be achieved in various ways, including releasing at least one end of the turnbuckle  516 . As seen in  FIGS. 3 and 4 , a fold down pin can be used to secure the lift in its folded position. Other means for folding and locking the lift in its folded position will be apparent to those skilled in the art. 
     Using embodiments of the present invention, motor units  530 ,  540  can coordinate their operation so that sufficient, but not excessive, slack is available in the belt  510  at the outer end terminus  502  of boom  520 . This typically involves maintaining the belt&#39;s cargo attachment point  518  at a constant height. A controller  550  can include a microprocessor or the like that coordinates operation of the motors in units  530  and  540 . In one system, controller  550  uses a closed loop system that actually measures the rotation of the shafts of motors in units  530  and  540 , takes into account any gear reductions or other adjustments, and then proportionally plays out or reels in the belt  510  using spool  512  so that a generally constant amount of slack of belt  510  is available outside of roller  528 . In an open loop system, controller  550  can measure the EMF, current or other electrical signals used in connection with the belt and boom extension motors in  530  and  540 . With these measured values, the controller  550  can use a lookup table or other reference to determine how much operation of the belt motor is needed to maintain a generally constant slack of belt outside of roller  528 . 
     As noted above, the belt compensation system more particularly can use a combination of motors to assist a person in moving a scooter, wheelchair or similar device into and out of a vehicle. To keep the lifted device at a particular height while adjusting the boom length (that is, when extending or retracting the lift head&#39;s boom outer end terminus  502 ), the amount of belt extending through the boom can be adjusted automatically. In some embodiments of the present invention, the boom extension motor unit  540  is a linear actuator that includes encoding capability. One example of such a device is the LAS3-1 model linear actuator made by Hiwin Mikrosystem Corporation. This type of device can provide a signal to the controller  550  (for example, a microprocessor, microcontroller, etc.) that collects and adds/subtracts pulses sent from the motor unit  540  to determine the relative position of the linear actuator and thus the position/length of the boom  520 . 
     Controller  550  then controls the belt motor unit  530 , which can include encoding capability as well (for example, an encoder integral to or coupled to the belt motor itself). The belt motor unit  530  can include an optical shaft encoder coupled directly to the motor output shaft (which turns the belt winding spool  512 ). One example of an appropriate optical shaft encoder is the S5 model made by US Digital of Vancouver, Wash. The optical shaft encoder can also provide positional data to the controller  550  (for example, pulses indicating the position of the belt winding drum  512 ). The controller  550  can then reconcile positional differences as desired, again taking into account the amount of belt on spool  512 , the thickness of the belt, etc. It may also be possible for an encoder or the like to actually measure the length of belt that has been extended by optically “viewing” belt movement itself. 
     Since the boom extension motor typically runs at a relatively slow speed, the controller  550  can adjust the speed of the belt motor by comparing pulse frequencies from encoders. The speed ratio is known and used to compensate for minor speed variations. The speed of the belt motor may be adjusted only during extension and retraction of the boom length. If the belt motor is run alone (or in other situations where coordination as that sometimes needed with the boom extension motor), then it can be run at full speed. When the belt compensation apparatus is used, the belt motor will feed out the belt when the boom extension motor is extending the boom  520 . Conversely, the belt motor will roll up belt during boom retraction. 
     Thus the improved, modular lifting device shown in connection with embodiments of the present invention provides more universality for applications. A dealer, for example, can order a standard lift model and, using its multi-configurational positioning apparatus, configure the lift to a particular vehicle, mobility device and vehicle mounting position/location (for example, passenger or driver side) without requiring a custom mounting base or other custom components or equipment. A single model of lift also can be transferred from one motor vehicle to another motor vehicle more readily. “Warehouse models” can be provided to improve delivery time. Installation is simplified with the improved mounting base design and reversible head assembly mount. Field service is simpler with embodiments of the modular hoist of the present invention, facilitating substitution of standardized components for several models. 
     The many features and advantages of the present invention are apparent from the written description, and thus, the appended claims are intended to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the present invention is not limited to the exact construction and operation as illustrated and described. Therefore, the described embodiments should be taken as illustrative and not restrictive, and the invention should not be limited to the details given herein but should be defined by the following claims and their full scope of equivalents, whether foreseeable or unforeseeable now or in the future.