Abstract:
A passenger standing platform for attachment to a mobility vehicle that provides improved support for the rider, increased weightload, and easy mountability and storage capability, The unit has a paddle shape platform base with 3 fully rotating caster assemblies attached to its underside in a triangular configuration and a non-skid mat attached to its obverse side. The platform base is hingedly attached to a mount plate that connects to the mobility vehicle, and is retained in a non-use generally vertical position off the ground by a pair of spaced coil springs attached at opposite ends to the mount plate and to the platform base.

Description:
FIELD OF THE INVENTION 
     The invention relates to a releasably detachable wheelchair attachment and more particularly to a passenger carrying platform supported by three spaced swivel casters, none of which are connected to any other caster. 
     KNOWN PRIOR ART 
     Andes, U.S. Pat. No. 6,443,252 was issued on Sep. 3, 2002. The device of the only prior art patent known to applicant lacks the sophistication of the instant device. It has only two wheels, mounted on an axle, and as such, the wheelchair occupant must take special care in both making left and right turns, and especially when backing up. The backing up experience either with or without a passenger on the platform is akin to backing up a truck or car with a fixed axle trailer attached. Not for the faint of heart. 
     In addition to Andes, the axle that carries the two wheels is disposed beneath the rear of the platform such that when the platform is occupied, there could arise a warping or deformation of the platform, due to the stress placed on the specific tongue used to attach the trailer-platform 
     BACKGROUND OF THE INVENTION 
     Wheelchairs, particularly self-powered wheelchairs, such as those powered by a battery and a motor are widely used by individuals who have limited mobility. People who are disabled or otherwise immobilized due to disease or injury to one or both legs. A: use either a motorized wheelchair or an electric scooter. The invention of this application may be attached to either of said mobility devices. A motorized wheel chair costs more than a scooter, is commanded directionally by a multi-directional joy stick and is powered generally by two motors that operate together as well as separately. A scooter has handlebars interconnected to a pivot-able single front wheel to control left and right movement and is powered. 
     When a person is walking side by side with a motorized wheelchair operating at full speed, the person walking may have difficulties in keeping up with the speed of the wheelchair, therefore is under a high degree of stress when they have to keep up with the speed of the motorized wheelchair and the distance traveled. 
     There have been previous inventions of a standing platform to be attached to the back of a powered wheelchair, however, such platforms are only equipped with limited number of wheels (two or less). If the rear wheels are poorly positioned at the rear end of the platform and no wheel in the front of the platform, the weight of the standing person would deform the platform and cause a warping or deformation in the rear of the platform and increased weight on the tongue of the platform that connects to the rear of the wheelchair, eventually disabling the mobility of the standing platform. 
     It is therefore an object of the present invention to provide a standing platform for a motorized wheelchair that is equipped with at least three 360 degree swivel wheels mounted to the bottom surface of the platform. 
     DEFINITIONS 
     The term “PSP” as used herein means personal standing platform. 
     The term “motorized vehicle” as used herein, pertains to a motorized wheelchair or a two handled battery powered scooter. 
     The term “towing vehicle” shall be used interchangeably with motorized vehicle. 
     SUMMARY OF THE INVENTION 
     There is disclosed a releasably detachable passenger standing platform that attaches behind a motorized wheelchair or scooter onto the mounting means for the stabilizer wheels. These are the little wheels mandated to prevent the wheelchair or scooter from tipping backward on a hill or for some other reason when the load becomes unbalanced. The platform may be tilted up when not in use The platform has 2 trailing swivel casters and one leading centrally disposed swivel caster mounted to the underside of a rearwardly elongated platform sized to accommodate an adult person. The ability to ride short or long distances on the standing platform permits the companion, spouse, care giver or child of the vehicle operator to maintain the pace of the vehicle operator for extended periods of time. 
     It is a first object therefore to provide a spring loaded passenger platform that attaches semi-permanently to the rear of a motorized wheelchair or scooter. 
     It is a second object to provide a passenger standing platform that has a trio of 360 degree swivel casters, mounted on the underside of a platform. 
     It is a third object to provide a passenger standing platform hereinafter (PSP) that while fully attached to the vehicle, is also spring loaded to move from a first horizontal position to a second vertical position by a gentle foot nudge or even by the finger of a teenager. 
     It is fourth object to provide a PSP that will not buckle under the stress of being towed with a passenger in place, at speeds up 10 mph, by a motorized vehicle. 
     It is a fifth object to provide a “PSP” for a motorized vehicle that permits the operator of the motor vehicle, to maintain his/her operating speed. 
     Other objects of the invention will in part be obvious and will in part appear hereinafter. 
     The invention accordingly comprises the device possessing the features, properties and the relation of components which are exemplified in the following detailed disclosure and the scope of which shall be indicated in the appended claims. 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is rear top perspective view of the device of this invention. 
         FIG. 2  is a side perspective view of the device of this invention, mounted to a motorized vehicle. 
         FIG. 3  is a closeup perspective view of the mounting means of this invention to a towing vehicle. 
         FIG. 4  is a top plan closeup view of the spring loaded components of this device to raise it from a first in use to the second storage position. 
         FIG. 5  is a bottom elevational view of the passenger standing platform of this invention stored in its upright position. 
         FIG. 6  is a side elevational view of the passenger standing platform shown in  FIG. 5 . 
         FIG. 7  is a top perspective view of the platform portion of the device prior to the addition of the non-skid surface. 
         FIG. 8  is a s right side perspective view showing an occupant standing on the passenger standing platform of this invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Let us first turn to  FIG. 1 , where the passenger standing platform, the invention  10  is seen attached to a mobility vehicle  100 , here a motorized wheelchair of a conventional nature. Such chairs are sold by several vendors, the most popular brand of which is Quickee. All elements of the invention will be cast in 2 digit numbers while those of the mobility vehicle will be in the 3 digit series. 
     The device  10  includes a platform base  11  that is configured like a ping pong paddle in that it has a forward narrower section  11 A and a wider elongated section  11 B connected by a trapezoidal intermediate section  11 C. See  FIG. 2 , wherein imaginary lines of demarcation for the intermediate section  11 C are set out by dashed lines  50  and  51 . Rear section  11 B may have square corners, chamfered corners, or tapered corners as shown here and designated  31 R in  FIGS. 1 &amp; 2 . While shown with oblique rounded or chamfered rear corners for the rear section  11 B, the corners need not be so configured. Of course a sharp 90 degree rear corner is to be avoided since a person will be entering and exiting the unit at different frequencies as events unfold. 
     As seen here, the platform base  11  is almost entirely covered with an anti-skid self adhesive mat. The mat  19  is seen to have a main or central section  20 C and a pair of mirror image side sections  20 L,  20 R the latter which are confined to portion  11 B, while the main part of the mat  20 C extends from the elongated section  11 B to the narrower leading section  11 A. See also  FIG. 2  and  FIG. 4 . Each of the segments  20 R and  20 L are separated from the main segment  20 C, by a non nonstick stripe  20 NN the runs from the oblique edge  31  to the rear of the platform base. This stripe is built into the non-skid attachment as purchased from vendor, 3M Company. While the mat  19  has been described as having 3 segments, in point of fact it is two somewhat mirror image segments cut to shape from rectangular stock that has the non nonstick stripe incorporated therein. The line  37  designates the abutment of the two sections of the mat  19  that appears as 3 segments  20 C,  20 L, and  20 R. 
     Platform base  11  has a conventional door hinge half  12  transversely attached via 3 bolts  13  disposed in unnumbered throughbores of the forward or leading section  11 A and aligned un-numbered bores found in the hinge half. The other hinge half is attached in like manner by similar bolts  13  through aligned unnumbered bores in the cover plate  15  and the center segment of the double U mount plate  14 , which plate  14  will be described infra. In essence the forward hinge half  12  is sandwiched between the cover plate  18  and segment F of the double U mount plate. 
     While the mount plate is seen in  FIG. 1 , it is seen better in full in  FIG. 2 . The mount plate is referred to as a Double U mount plate because the segments form two inverted U shape members on the two ends of the plate. Reference should simultaneously be made to  FIGS. 3 and 4  as well. 
     The mount plate which is an integrated unit of equal depth front to back, commences with an upwardly disposed segment  14 A, connected to a first horizontal segment  14 B that overlies a first anti-tip wheel  102 . A segment of substantially the same extension downward,  14 C commences from  14 B&#39;s second end to form a first inverted U. At the lower terminus of  14 C, a second horizontal segment  14 D, extends inwardly toward the middle of the vehicle. At the second terminus of segment  14 D there is a small downward descending segment  14 E, per  FIG. 4 , which at its lower terminus connects to center segment  14 F. 
     Segment  14 G is a mirror image of  14  E, segment  14 H is a mirror of  14 D, and segments  14  I, 14  J and  14  K are mirror images of  14 A, 14 B and  14 C and form the second inverted U overlying the right anti-tip wheel. 
     A pair of spaced coil springs  16  are each attached at one end thereof to a respective stand off  17  disposed on the oblique edge  31 F of the platform base  11 . The other end of the respective coil spring is disposed in a bore  18  in section  14  F. See  FIG. 4  Since the tension pressure of the springs utilized is chosen to be greater than the pressure to keep the hinge open, the platform base stays in the upright non-use position until moved from the generally vertical storage position to the in-use horizontal position by the pressure of one or two fingers of an adult. The mirror image oblique edges  31  define a trapezoidal section  11   c  disposed between the wider and longer section  11 B and the narrower and shorter section  11 A. 
       FIG. 3  is a closeup view of the right side inverted U consisting of segments  14  K,  14 J and  14  J and the adjoining segment  14 H. Bolt  104  is seen extending between segments  14 K and  14 I through unnumbered aligned bores. The bolt  104  is retained by a lock washer  106  and two nuts  105 . The same retention means is also utilized for the opposite inverted U not seen that overlays the left anti-tip wheel  102  of the mobility vehicle. 
     In  FIG. 5 , the underside of the platform base  11  is seen. Here  3  caster assemblies  21 , each of which is not connected to another caster assembly, are seen with one assembly  21  in the leading area and 2 in the trailing part of the platform base. Each caster assembly  21  includes a rectangular flat plate  25  for mounting, to which is rotatably attached conventional housing  26  and wheel  26 W. Each flat plate  25  has a through bore unnumbered in each corner. A set of spaced 4 bolts  27 , are disposed under the mat  19 . All of said bolts pass through a set of bores in platform base  11 , also not seen, and through the corner bores of plate  25 . These 4 bolts are retained by a pair of nuts  28  on each bolt end. Reference is made to  FIG. 7  and the discussion infra. Note that in this FIGURE,  FIG. 5  the passenger standing platform device is disposed in a vertical position in this figure. 
     In  FIG. 6 , the platform base  11 , is shown in the vertical position of  FIG. 5  is seen from the side. The reader&#39;s attention is called to the fact that the platform base tilts forwardly about 30 degrees toward the body of the mobility vehicle  100 , due to the fact that the coil springs when in the relaxed position, retain the platform base pitched forwardly for ease of storage and mobility of the vehicle. The springs eliminate the need for any type of locking mechanism to retain the device in the upward non-use position. 
     In  FIG. 7 , In this FIGURE, the platform base  11  is seen disposed horizontally, that is in the in-use position. Here the bolt heads  27  are seen to be recessed flush with the surface of the platform  11 . All 12 bolt heads are seen in the rectangular pattern corresponding to the locale of each caster assembly  21 . The two caster wheels  26 W of the side by side mounted rear caster assemblies  21  are also visible. 
     The passenger standing platform is elevated approximately 4 inches from ground level, such that a person of any age can easily step on and step off of the device of this invention. In embodiments of the device, the width of section  11 A ranges from 7 to about 9 inches, while the larger section of the platform ranges from about 10 to 13 inches. The overall length from the hinge rearward may vary from 11 to 15 inches. By using high strength aluminum or steel for the platform and heavy duty caster assemblies, the instant device can be constructed to carry persons of up to 400 lbs in weight. Other suitable materials include plastic such as polycarbonate, and resin reinforced glass fibers. The coil springs utilized have about a 7 lb pressure and have 0.5 inch diameter coils. The hinge employed is a variable pressure hinge available from Stanley Tool Works and other vendors. The operating range may be set from 10 to 25 lbs of pressure, and as utilized the pressure is set at 10 lbs. When detached by removing the two bolts  109  that hold the framework to the anti-slip wheels of the mobility vehicle it is seen that the passenger standing platform weighs about 10 pounds, not including the double inverted U mount plate. 
     It has been found that since the center of gravity of the device of this invention is on the rear two caster assemblies, when occupied, there is little or no effect on the speed achievable by the mobility vehicle. Thus speeds of up to 10 MPH for a Quickee Model SE-646 have been recorded when the occupant on the device weighed over 150 lbs. On the other hand when the platform is occupied, depending upon the vehicle employed, speeds constituting a slow crawl of say 2 mph, the speed of foot traffic at Epcot Center in Florida, or 5 th  Ave. In NYC have also been recorded for this same unit. 
     While removal of the mount plate bolts is the easiest way to remove the entire device, the cover plate over the hinge and the removal of the 4 bolts is also a mode of separation of the device from the mobility vehicle. Both are within the skill of the art. 
       FIG. 8  is a side perspective view showing a passenger standing on the device of this invention. Since the device has been fully described, suffice it to say that the platform can be lowered from the position shown in  FIG. 5 , vertical to the in use horizontal position merely by the use of the tip of one&#39;s shoe or by the use of two fingers from a bending position. 
     It is seen that the device of this invention affords a very safe environment for an occupant, as the user is only about 4 inches off the ground and has plenty of room to place both feet firmly on the platform. The device maximizes weight distribution, provides increased load capacity, and provides greater stability for the user, coupled with increased navigational control by the “driver” of the mobility vehicle, especially when backing up with the device down in the in use position, as well as when riding with no occupant. With the present invention, two individuals can comfortably ride together whether through the Atlanta Hartsfield airport, or any theme park, or just for a stroll in the neighborhood after dinner, without the companion fighting to keep up with the speed of the mobility vehicle driver, or the vehicle driver having to slow down to keep up with the walking companion. 
     Clearly both parties, the driver and the rider, are benefited by the use of this invention. 
     While only a motorized wheelchair is featured in the drawings, the device works equally as well with a scooter and is readily mounted thereto by a person possessing minimum skill. 
     Since certain changes may be made in the above device without departing form the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.