Abstract:
A scissor lift platform adapted to attach to an existing skid steer loader provides the functionally of a scissor lift to elevate personnel and equipment. The platform comprises hand rails and a lift control panel supported by a hydraulic scissor lift assembly section. The base of the scissor lift assembly is provided with a box-like frame attachable to a front loader portion of the skid steer loader and equipped with a hydraulic pivoting mechanism to keep the platform level.

Description:
RELATED APPLICATIONS 
     The present invention was first described in and claims the benefit of U.S. Provisional Application No. 61/682,829, filed Aug. 14, 2012, the entire disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a scissor lift assembly having a man platform attached to a tilting assembly configured to be attached to and manipulated by a skid steer assembly. 
     BACKGROUND OF THE INVENTION 
     Scissors lifts, or hydraulically-operated scaffolding, are extremely useful in the construction and maintenance industry fields. They provide a stable elevated work surface that is easy to erect, and most importantly, safe. Unfortunately, such scissors lifts are extremely expensive to own, especially if they are only used occasionally for short periods of time. Renting is not always an option, especially if at a remote location where transportation of the lift is a problem. Furthermore, whether purchased or rented, a scissor lift occupies a large amount of storage space when not being used. While the actual scissors portion of the lift is generally simple, straight forward, and low cost, it is the base of the unit, with its heavy mass, power units, hydraulic pumps, and transportation system, where most of the cost is experienced. Accordingly, there exists a need for a means by which the functionality of a scissors lift can be utilized without the disadvantages as described above. 
     Prior art in this field consists of simple scissor jacks, load leveling devices, or complex portable scissor lifts. Simple scissor jacks incorporate the scissor framework, but lack the necessary hydraulic power and transmission means to hoist heavier loads and hoist to heights achieved by the present invention. Load leveling devices are portable, but are not transportable by devices such as skid loaders. Furthermore, load leveling devices cannot be connected with skid loaders to enable command and control of the load leveler via the skid loader. Both styles of devices lack the means to tilt and oscillate the work platform in such a manner afforded by the present invention. Portable scissor lifts are complex, elaborate machines that are relatively expensive. Such machines lack the utility of being connected to a skid loader and lack the ability of availing the hydraulic power of the skid loader to perform hoisting and tilting functions. It is an object of this invention to provide a scissor lift working platform that avails the hydraulic power of an ancillary vehicle so as to reduce cost and space of the scissor lift hoisting machine. It is a further object of this invention to provide a means to tilt and oscillate the working platform from a control panel of the platform or from the controls of the ancillary vehicle. A beneficial feature of this invention is to provide stabilizers to ensure a level and secure base from which the platform is hoisted. 
     SUMMARY OF THE INVENTION 
     The apparatus comprises a platform positioned on top of a scissor-style hydraulic lifting mechanism. A top surface of the platform is provided with a railing and a control panel. The apparatus is further equipped with a tilt assembly to enable oscillatory motion of the platform and hydraulic lifting mechanisms in order to compensate for uneven ground surfaces, thereby providing a level working surface from which a user stands upon. The tilt assembly attaches to a skid frame of a skid loader, and the hydraulic components of the hydraulic lift and tilt assembly are placed into hydraulic communication with the hydraulic system of the skid loader to facilitate operational control of the lift and tilt through the controls of the skid loader. In addition, the normal actuating, tilting, and oscillation motions of the skid loader further enable a user to maneuver the platform to a desired position and location. The skid loader provides limited lifting and tilting, but a wide range of transportability and maneuverability of the work platform. The control panel provides a wide range of lifting and tilting, but limited transportability and maneuverability of the work platform. Therefore, the skid loader controls, in conjunction with the control panel of the platform, are used to maneuver, lift, tilt, and oscillate the platform to a desired location and position. Additionally, four (4) height-adjustable feet are disposed on the apparatus to serve as stabilizers. 
     The base of the scissor section is provided with a standard universal loading plate, which attaches to almost all types of skid loaders, and is equipped with a pivot joint to keep the platform level at all times. After attaching the platform and tilt assembly to a front portion of a skid loader, the necessary hydraulic hoses are connected to place the platform and tilt assembly in hydraulic communication with the hydraulics of the skid loader. The platform can then be transported by the skid loader to a desired location to perform work. These particular features of the invention allow the platform to lifted a few feet using only the arm of the skid loader, but lifted further using the supplied scissor lift assembly. Many of the expensive components of a conventional scissor lift, such as the power unit, hydraulic pump, transportation system, and the like, are shared with the skid loader making the invention much more feasible, cost effective, and easy to store. The use of the present invention provides for the complete functionality of a scissor lift with reduced costs, floor space usage, and increased simplicity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a side view of a skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention; 
         FIG. 2  is a side cut-out view of a skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention; 
         FIG. 3  is a front view of the skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention; 
         FIG. 4  is a front cut-out view of the skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention; 
         FIG. 5  is an electrical/hydraulic block diagram of the scissor lift assembly portion  46  of the skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention; and, 
         FIG. 6  is an electrical/hydraulic block diagram of the tilt assembly portion  40  of the skid-mounted scissor lift platform  10 , according to a preferred embodiment of the present invention. 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  skid-mounted scissor lift platform 
               20  skid frame 
               21  skid steer plate 
               22  torsion bar 
               24  ear plate 
               26   a  first tilt cylinder 
               26   b  second tilt cylinder 
               26   c  clevis 
               27  loader hydraulic hose 
               28  safety foot 
               29   a  fastener 
               29   b  fastener aperture 
               30  front-to-rear tilt arrow 
               32  hydraulic connector 
               40  tilt assembly 
               42  upper plate 
               43  lower plate 
               44  side-to-side tilt arrow 
               46  scissor lift assembly 
               47  pivot pin 
               48   a  lift cylinder 
               48   b  hydraulic reservoir/pump unit 
               48   c  hydraulic line 
               49  mounting bracket 
               50  man platform 
               51  gate 
               52  lift control panel 
               53  lift switch 
               54  battery/battery box 
               55  battery charging connector 
               56  ladder 
               57  hand rail 
               58  platform floor 
               100  skid steer loader 
               105  implement attachment means 
               110  ground surface 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIGS. 1 through 6 . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The present invention describes a skid-mounted scissor lift platform (herein described as the “apparatus”)  10 , which provides a hydraulically-operated attachment for an existing skid steer loader  100  being capable of elevating a man platform  50  via integration of a scissor lift assembly  46 . The apparatus  10  provides side-to-side tilting of the scissor lift assembly  46  and the man platform  50 . When combined with a front-to-rear tilting capability of the existing skid steer loader  100 , the apparatus  10  provides a means to correct for an uneven ground surface  110  and to position the man platform  50  in a level manner for safe vertical elevation of personnel and equipment. 
     Referring now to  FIGS. 1 ,  2 ,  3 , and  4 , side and front views of the apparatus  10 , according to the preferred embodiment of the present invention, are disclosed. The apparatus  10  comprises a skid frame  20 , a tilt assembly  40 , a scissor lift assembly  46 , and a man platform  50 . 
     The apparatus  10  comprises a box-like skid frame portion  20  which rests upon a ground surface  100  via height-adjustable safety feet  28 , thereby acting as a stable foundation portion of the apparatus  10 . The skid frame  20  further comprises an integral vertical skid steer plate  21  along one (1) side which allows secure interlocking attachment to an implement attachment means  105  of the skid steer loader  100 . Said skid steer plate  21  and implement attachment means  105  are envisioned to be commercially-available equipment commonly sold by manufacturers of skid steer loaders  100 . 
     The apparatus  10  works in conjunction with a standard skid steer loader  100  similar those manufactured by GEHL®, JOHN DEERE®, and others, preferably providing a universal plate-type implement attachment means  105 ; however, other equivalent attachment means my be provided which provide attachment and front-to-rear tilting of the apparatus  10 . 
     The box-like skid frame portion  20  provides containment of, and rotating attachment to a tilt assembly  40  comprising a box-shaped welded structure which provides side-to-side tilting capability to the superjacent scissor lift assembly  46  and attached man platform  50  portions. Said tilting function is enabled by internal portions including an ear plate  24 , a first hydraulic tilt cylinder  26   a , and a second tilt cylinder  26   b , as indicated in  FIG. 3  by side-to-side tilt arrows  44 . 
     The tilt assembly  40  includes a weldment comprising a stationary weldment including a torsion bar  22  and an ear plate  24  being welded to the skid frame  20 . 
     The torsion bar  22  and ear plate  24  work in conjunction with a pair of tilt cylinders  26   a ,  26   b  rotatingly affixed to end portions of said ear plate  24  via respective clevis  26   c  portions. The torsion bar  22  and ear plate  24  form a singular weldment with the torsion bar  22  being welded perpendicularly at an intermediate portion of the ear plate  24 . The end portions of said torsion bar  22  are in turn stationarily welded to opposing inner side surfaces of the skid frame  20 , particularly disposed directly underneath a center of gravity of the scissor lift assembly  46  to ensure balanced tilting thereof. The vertical tilt cylinders  26   a ,  26   b  extend downwardly from respective outer end portions of the ear plate  24  and are connected to a lower plate portion  43  of the tilt assembly  40  via additional clevis&#39;  26   c , thereby acting to tilt said lower plate portion  43  and affixed scissor lift assembly  46 . The tilt assembly  40  further comprises an upper plate  42  welded across an upper surface which in turn provides rigid attachment to the scissor lift assembly  46  and man platform  50  portions. Although the tilt assembly  40  is illustrated here utilizing a stationary torsion bar  22  and ear plate  24  mechanism, it is understood that other methods may be utilized to tilt the tilt assembly  40  with equal benefit, and as such should not be interpreted as a limiting factor of the apparatus  10 . 
     The apparatus  10  comprises a hydraulically-powered folding scissor lift assembly  46 . The scissor lift assembly  46  comprises a plurality of upwardly extending elements being joined by respective pivot pins  47 . The bottommost portion of the scissor lift assembly  46  is in turn affixed to the subjacent horizontal upper plate portion  42  of the tilt assembly  40  via a plurality of mounting brackets  49 . The scissor lift assembly  46  further comprises at least one (1) lift cylinder  48   a  and a hydraulic reservoir/pump unit  48   b . The lift cylinder  48   a  is shown here mounted to adjacent pivotingly connected scissor element portion of the scissor lift assembly  46 ; however, an actual position of at lease one (1) lift cylinder  48   a  may be located at various positions to apply a spreading force to extend the scissor lift assembly  46 , and as such should not be interpreted as a limiting factor of the apparatus  10 . The hydraulic reservoir/pump unit  48   b  is preferably mounted to the upper plate  42  which supplies hydraulic pressure to said lift cylinder  48   a  to enable vertical extension of said scissor lift assembly  46 . The hydraulic reservoir/pump unit  48   b  is envisioned to comprise a commercially-available self-contained unit including conventional and expected components such as, but not limited to: a fluid reservoir, a pump, an electrical solenoid valve, and corresponding electrical and hydraulic connections. Said hydraulic lift cylinder  48   a  and hydraulic reservoir/pump unit  48   b  are interconnected with a plurality of hydraulic lines  48   c  (see  FIG. 5 ). 
     A top portion of the folding scissor lift assembly  46  provides an attachment means to a floor portion of the metal man platform  50  via additional pivoting mounting brackets  49 . The man platform  50  comprises expected features including a platform floor  58 , a hand rail  57  located along a perimeter of the platform floor  58 , a gate  51  located along a side portion of the hand rail  57 , and a lift control panel  52  preferably mounted to the hand rail using appropriate bracketry. The platform  50  may also have a ladder  56  mounted thereon. The lift control panel  52  provides a means for an operator to control vertical motions of the scissor lift assembly  46  while occupying the man platform  50  via manipulation of an integrated lift switch  53  (see  FIG. 5 ). 
     The existing skid steer loader  100  is envisioned to be equipped with standard front-to-rear tilting capability to tilt the apparatus  10  in a front-to-rear direction as indicated by a front-to-rear tilt arrow  30 . The hydraulic lift cylinder  48   a  portion of the tilt assembly  40  are in hydraulic communication with, and controlled by existing hydraulic system portions of the skid steer loader  100 , thereby allowing operation of the tilt assembly  40  in a similar manner as various mountable skid steer loader implements (see  FIG. 6 ). The side-to-side  44  and front-to-rear  30  tilting capabilities of the apparatus  10  work in conjunction with four (4) independent height-adjustable safety feet portions  28  of the skid frame  20  to allow secure placement of the apparatus  10  upon an uneven ground surface  110 . Each safety foot  28  comprises a pair of telescoping structural tubing sections having a pointed bottom end portion. Each safety foot  28  extends downwardly in a telescoping manner, being locked at a desired length using a plurality of through-hole-type fasteners  29   a  such as release pins, and corresponding fastener apertures  29   b.    
     The apparatus  10  is envisioned to meet all applicable local, state, and federal safety regulations for personnel lifting equipment. The features of the apparatus  10  allow the man platform  50  to either be raised slightly above a ground surface  110  using the lifting capabilities of the skid steer loader  100 , or may be raised up to approximately twenty feet (20 ft.) by utilizing the functions of the scissor lift assembly portion  46  of the apparatus  10 . 
     The apparatus  10  provides reduced equipment costs by eliminating a number of expensive hydraulic and control components such transportation features such as wheels and steering equipment, and the like, as compared to the scissor lift unit  46 . By interfacing and utilizing said existing systems which reside upon the skid steer loader  100 , the apparatus  10  is more feasible, cost effective, and easy to store. 
     Referring now to  FIG. 5 , an electrical/hydraulic block diagram of the scissor lift assembly portion  46  of the apparatus  10 , according to a preferred embodiment of the present invention, is disclosed. The scissor lift assembly  46  comprises a lift control panel  52  further comprising a lift switch  53 . The lift switch  53  preferably comprises a three-position, center-return toggle-type switch, or equivalent component, which allows an operator to raise and lower the scissor lift assembly  46  while occupying the man platform  50 . The lift switch  53  is in electrical communication with the aforementioned hydraulic reservoir/pump unit  48   b . Upon receiving an electrical signal from the lift switch  53 , the hydraulic reservoir/pump unit  48   b  supplies hydraulic pressure to the lift cylinder portion  48   a  of the scissor lift assembly  46  to raise or lower the man platform  50 . Electrical power is supplied to the lift switch  53  and hydraulic reservoir/pump unit  48   b  portions via a battery/battery box  54  mounted to the upper plate  42 . It is envisioned that the battery/battery box  54  includes a battery charging connector portion  55  for periodic recharging of the battery. 
     Referring now to  FIG. 6 , an electrical/hydraulic block diagram of the tilt assembly portion  40  of the apparatus  10 , according to a preferred embodiment of the present invention, is disclosed. The hydraulic portions of the tilt assembly  40  are in hydraulic communication with, and controlled by an existing hydraulic system of the skid steer loader  100  via connection of loader hydraulic hose portions  27  of the skid steer loader  100  and a hydraulic connector  32  located upon an outer surface of the skid frame  20 . The apparatus  10  in turn route hydraulic fluid from the hydraulic connector  32  to the tilt cylinders  26   a ,  26   b  via hydraulic lines  48   c  allowing operation of the tilt assembly  40  in a similar manner as various other skid steer loader implements. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention is envisioned to be utilized by a trained equipment operator while requiring minimal additional training. After initial purchase or acquisition of the apparatus  10 , it would be utilized as indicated in  FIGS. 1 and 2 . 
     The method of utilizing the apparatus  10  may be achieved by performing the following steps: procuring the apparatus  10 ; attaching the implement attachment means  105  of the existing skid steer loader  100  to the matching skid steer plate portion  21  of the skid frame  20 ; connecting loader hydraulic hose portions  27  of the skid steer loader  100  to the hydraulic connector portion  32  of the skid frame  20 ; transporting the apparatus  10  to a job site using the skid steer loader  100 ; lowering the skid frame  20  until the safety feet  28  are slightly above a ground surface  110 ; using the front-to-rear tilt capabilities of the skid steer loader  100  to tilt the apparatus  10  until level in a front-to-rear direction; lowering each safety foot  28  until making contact with the ground surface  110 ; locking all safety feet  28  in position by inserting through-bolt fasteners  29   a  through corresponding fastener apertures  29   b ; lowering the apparatus  10  onto the ground surface  110 , using lift controls of the skid steer loader  100  until the weight of the apparatus  10  rests securely upon the ground surface  110  via the safety feet  28 ; using control portions of the skid steer loader  100  to adjust the tilt cylinders  26   a ,  26   b  until the skid frame  20  and man platform  50  are level in a side-to-side direction; occupying the man platform  50 ; utilizing the lift switch portion  53  of the control panel  52  to raise the man platform  50  to a desired height, as needed during the execution of a construction project or similar task; and, benefiting from increased safety and equipment simplicity to lift personnel and equipment afforded a user of the present invention  10 . 
     The use of the apparatus  10  provides the complete functionality of a scissor lift unit  46  with reduced equipment costs, reduced floor space usage, and increased simplicity. 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention and method of use to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teaching. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application, and to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions or substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but is intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.