|Publication number||US3231290 A|
|Publication date||Jan 25, 1966|
|Filing date||Dec 31, 1962|
|Priority date||Dec 31, 1962|
|Publication number||US 3231290 A, US 3231290A, US-A-3231290, US3231290 A, US3231290A|
|Inventors||Weyer Paul P|
|Original Assignee||Weyer Paul P|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Referenced by (44), Classifications (11)|
|External Links: USPTO, USPTO Assignment, Espacenet|
P. P. WEYER Jan. 25, 1966 WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL 5 Sheets-Sheet 1 INVENTOR. 841/4 2 WfVf/ AffOFA/fy Filed Dec. 51, 1962 Jan. 25, 1966 P. P. WEYER 3,231,290
WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL Filed Dec. 31, 1962 5 Sheets-Sheet 2 log /07 INVENTOR. PAL/L P. W'Vf/Z Jan. 25, 1966 P. P. WEYER 3,231,290
WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL Filed Dec. 31, 1962 5 Sheets-Sheet 5 INVENTOR. PAUL P. Wei 61E ,4 ffGFA/Z P. P. WEYER Jan. 25, 1966 WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL 5 Sheets-Sheet 4 Filed Dec. 31, 1962 INVENTOR. PAUL P. W575? A ffGP/Vf) Jan. 25, 1966 w Y 3,231,290
WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL Filed Dec. 31, 1962 5 Sheets-Sheet 5 INVENTOR. PAUL P. W'VQ United States Patent 3,231,290 WHEEL CHAIR FOR REGULAR AND IRREGULAR SURFACE TRAVEL Paul P. Weyer, 12345 SE. 160th St., Renton, Wash. Filed Dec. 31, 1962, Ser. No. 248,738 3 Claims. (Cl. 2s0 5.22)
The invention relates to vehicles and more particularly to Wheel chair like vehicles operated by the occupant.
The purpose of the invention is to provide the occupan't, generally an invalid, with a conveyance means which he can conveniently operate to carry himself about his living quarters, working place and/ or community, and when traveling in another conveyance, such as a car or train, he can compact and carry his own personal conveyance means with him.
This invention, briefly described, comprises, in its preferred embodiment, essentially standard wheel chair components supplemented with irregular surface travel components carried in a retracted and non-powered position until needed and then moved and powered for contact with irregular surfaces.
The invention and its purpose will be understood more fully as the complete description of the preferred embodiment is read and references made to the drawings in which:
FIGURE 1 illustrates, schematically, how the wheel chair is moved up and down stairs;
FIGURES 2 and 3, show respectively and schematically, how the wheel chair is unfolded for use and folded for non-use storage or transporting;
FIGURE 4 is a front view of the preferred embodiment of the foldable wheel chair with some rearward portions not shown and others broken away;
FIGURE '5 is a rear view of the foldable wheel chair of FIGURE 4 with some forward portions not shown and others broken away;
FIGURE 6 is a sectional view of the foldable wheel chair taken along line 66 of FIGURE with some portions being broken away; and
FIGURE 7 is an exploded view of some of the running gear and framing components on one side of the foldable wheel chair.
Standard wheel chair components F raming0ccupzmt supp0rtswheels In the preferred embodiment, standard frame tubing and pivoted tubing sections are assembled, being changed only in form and location in certain respects to accommodate the added equipment required for over irregular surface travel. The framing 21 of the illustrated wheel chair 20 has two upright spaced back members 22, 23. At their top, frame members 22, 23 terminate substantially above the seating area in handles 24, 25, and supporting the foldable occupant supporting back material 26 which may be stitched, zipped or laced in place around the upright members 22, 23. At their bottom frame members 22, 23 terminate below in the opposite direction around the axles 27, 28 of the large standard regular surface running Wheels 29, 30, both equipped with hand 3,231,290 Patented Jan. 25, 1966 gripping wheels 31, 32 of slightly less diameter and olfset outwardly from the standard wheels 29, 30, respectively, to accommodate the occupants hands used .in propelling and guiding the illustrated wheel chair 2!).
Additional framing 21, extends forwardly and horizontally from the upright back members 22, 23 forming arm rest supporting sections 33, 34 equipped with like arm rests 35, 36 and thereafter turning downward undergoing a slight offset to receive the forward smaller wheels 38, 39 through pivotal yoke connectors 40, 41.
The framing just described may be considered the outer framing 43. The inner framing 44 primarily is composed of two left and right frame sections 45, 46, pivotally joined along the centerline of the wheel chair 20. These sections 45, 46 support the seat sections 47, 48 on front and rear top cross frame members 49, 50,51 and 52, each composed of two lengths so the left and right inner frame sections and seat sections can be folded reducing the total width of the chair. Directly below the front and rear cross frame members 49, 50, 51, 52 arecomparable bottom cross frame members 53, 54, '55, 56. Their vertical spacing on the centerline is maintained by front and rear vertical frame lengths 57, 58 which are pivotally attached at their ends respectively to these top and bottom cross frame members. The left and right ends of all the cross frame members are pivotally connected through standard pivoting frame inserts 59 to left and right, top and bottom longitudinal frame sections 60, 61, 62, 63. The top and bottom longitudinal frame sections 60, 62 on the left are also joined together by the diagonal forward extending frame member 63. Likewise, the top and bottom longitudinal frame sections 61, 63 on the right are joined together by the diagonal forward extending frame member 69.
At the lower ends of each diagonal frame member 68, 69 are sectional foot rest assemblies 70, 71, each including a fitted frame sleeve 72, pivotal connector 73, partial rotative cylindrical support 74, and foot 'rest section fitted to support 74 which in turn is pivotally connected to the sleeve 72. These left and right assemblies '70, 71 permit the angular and height adjustments of the foot rest sections to meet the comfort requirements of the passenger and also permit their upright positioning upon folding the wheel chair.
The outer framing 43 and inner framing 44 are maintained in a spaced relationship by top transverse rear interconne-ctors on both left and right sides, 64, 65, and lower diagonal transverse front inter-connectors on both left and right sides 66, 67. The spacing of these outer and inner frames 43, 44 is governed by the transverse dimensional requirements of the mounted irregular surface travel running gear arranged in left and right component assemblies 81, 82.
Support of z'rregzclar surface travel running gear I The preferred arrangement construction and mounting of the irregular surface travel running gear 810, arranged in left and right component assemblies 81 and 82, is il-' lustrated in FIGURES 4 through 7. Each running gear assembly is fitted within the spaces between the outer and inner framing 43, 44.
Also each running gear assembly 81, -82 is supported above on its outer side and inner side on a respective large wheel axle 27 or 28 which is directly supported by both the outer and inner framing 43, 44 and more par ticularly at the lower end 83 of an upright framing section 22 or 23 of the outer frame 43 and the turned down rear end 84 of a top longitudinal frame section 60 or 61, of the inner frame 44.
In addition, each irregular surface running gear c0mponent assembly 81 or 82 is supported below on its inner side by the rear end 85 of the bottom longitudinal frame section 62 or 63 of the inner framing 44. Optionally, the running gear assembly 81 or 82 could also be supported below on its outer side by a bottom longitudinal frame section (not shown) added to the outer framing 43.
The left and right irregular surface running gear component assemblies 81 and 82 provide their own framing between these high and low supporting places on the inner and outer frames. On each side of each assembly 81 or 82 are diagonal positioning braces 87 extending downwardly and to the rear. They are maintained in a fixed angular position by their positive attachments above, respectively, to the lower end 83 of the upright framing section 22 or 23 of the outer frame 43 and the turned down rear end 84 of the top longitudinal frame section 60 or 61 of the inner frame 44, and below, respectively, to the rear end 85 of the bottom longitudinal frame section 62 or 63 of the inner frame 44, and optionally to the rear end of a bottom longitudinal frame section (not shown) added to the outer framing 43.
These component assembly diagonal positioning braces 87, once installed, could also be said to be the completing members of the wheel chair framing 21 completing the structural circuits in the longitudinal planes of the respective right and left sections of the inner and outer frames. Carrying this analysis further from still a different viewpoint, these diagonal positioning braces 87 could also be said to be the completing members of the left and right running gear housing frames 38, 89, which thereafter are joined by the pivoting and folding frame sections previously described as pivoting and folding sections of the inner framing 44.
Whichever analysis be undertaken, the Wheel chair framing 21 provides the foldable support for the conventional seating and regular surface running gear in a conventional arrangement and in addition establishes a lower rear mounting position 90 for irregular surface running gear.
Endless belt tracks of irregular surface travel running gear For maintaining satisfactory supporting and propelling contact with irregular surfaces, such as stairs, endless belt track asemblies are arranged preferably in pivotal pairs 92 and 93, pivotal about the lower rear mounting, position 90 and within each irregular surface travel running gear component assembly 81 or 82.
Each individual endless belt track assembly 92 or 93 comprises centered housing structure 94 or 95 including belt guide surfaces 96 or 97 and respective end belt turnin-g wheels, of larger diameter 98 and of smaller diameter 99, rotatably mounted on the center housing structure 94 or 95. The smaller diameter belt turning wheels are mounted for lineal adjustment in slots 100 to acquire satisfactory belt track tension.
Positioning of irregular surface travel running gear Selective pivotal movement of these endless belt track assemblies 92 and 93 about the common axis 104 of their larger belt turning wheels is preferably done by the occupants hand operation of mechanical actuating assemblies 105, 106. These assemblies each include a hand operated revolving means such as a crank 107 or 108 which is directly attached to a threaded rod 109 supported in a slotted housing 110. The housing 110 in turn is secured to the outer framing 43, positioning the cranks 107 or 108 forward of the arm rests 35, 36.
Revolutions of threaded rod 109, depending on the clockwise or counter-clockwise direction of rotation causes up or down movement of a traveling nut 113, restrained from rotating by its integral lateral projections 114 extending forward and rearward through the slots 115. The threads 101 are formed to prevent initial axial forces from turning the nut 113; Attached to each projection 114 of each nut 113 is a control cable 118 which continues on eventually passing through protective and guiding flexible tubing 119, secured to the framing 21, until reaching a selected quadrant 120 or 121 attached to a forward pivotal endless belt track assembly 92 of both the left and right component assemblies 81, 82 or quadrant 122 or 123 attached to a rear pivotal endless belt track assembly 93 of both the left and right component as semblies 81, 82. These control cables 118 are interconnected between the nuts 113 and the quadrants 120, 121, 122, 123 so revolutions of crank 107 to be operated by the occupants left hand will pivot the front pivotal endless belt track assemblies 92, 92 and revolutions of the crank 103 to be operated by the occupants right hand will pivot the rear endless belt track assemblies 93, 93, or vice versa. Upon retraction, cables 118 release retraction spring forces of torsion spring 124 of track assemblies 93 and tension spring 153 of track assemblies 92. The extent of the hand craking to be done will depend on how irregular the surface is which is encountered by the occupant in his travel using this wheel chair. If the terrain to be encountered by the occupant is irregular in multiple directions, the controls could be made more selective by operating each pivotal endless belt track assembly independently (not, shown).
Transmission of power to irregular surface travel running gear Pivotal movement of the irregular surface travel running gear 80 is only undertaken when irregular surfaces are encountered such as the stairs 126 illustrated in FIG- URE 1. While approaching or when leaving the stairs 126 on the higher 127 or lower 128 levels, the irregular surface travel running gear 80 is retracted and not powered. The occupants hand forces turning the larger running wheels 29, 30, on their bearings 37, by contacting hand gripping wheels 31, 32, with the gear 80 retracted, result only in directly powering wheels 29, 30 which are in contact with the substantially regular surface.
When, however, the occupant operates the cranks 107, 108 pivoting the endless belt track assemblies 92, 93 of the left and right component assemblies 81, 82 of the irregular surface travel running gear 80, a clutch cam 130, attached to the centered housing structure 94, lowers with each pivoting front endless belt track assembly 92, as will be noted in FIGURE 7. Thereafter the associated spring 131 loaded clutch assembly 132, on the wheel axle 27 or 28, becomes effective, transmitting any power through its assembly which includes: a positioning sleeve 133; key 134; combination 135 of sleeve 136, follower cam surface flange 137 with laterally intermeshing gear ring 138 and key 139, and a combination 140 of opposed laterally intermeshing gear ring 141, with the upper chain sprocket wheel 142, key (not shown) and attached or integral ratchet wheel 143 of the chain drive 144. Thereafter the transmitted power is conveyed on as the upper sprocket wheel engages and guides the sprocket drive chain 145 along its closed path which is in alignment with the diagonal positioning braces 87. This chain 145 continues the transmission of any applied power for it also is engaged and passed around the lower chain sprocket wheel 147 which is keyed (not shown) to the shaft 143 on the common axis 104 of the larger belt turning wheels 98 and attached to or made integral with the side by side larger diameter belt track turning wheels 98 of both the front and rear pivotal endless belt track assemblies 92, 93.
With the clutch assembly 132 engaged, as the irregular surface travel running gear 80 pivots into contact with an irregular surface such as stair 126 of FIGURE 1, the occupants hand power selectively applied to the hand gripping wheels 31, 32 causes rotation of the regular surface running wheels 29, 30, now raised above the irregular surface. These rotating wheels 29, 30 in turn transmit driving power through: axles 27, 28; clutch assembly 132; and chain drive 144 to move pivotal endless Safety features of irregular surface travel running gear I At all times when the occupant is traveling in this Wheel chair over regular surfaces the safety afforded him matches that available to him in a standard wheel chair. When the occupant travels over irregular, surfaces, the safety afforded him exceeds that available to him in a standard wheel chair, assuming that a standard wheel chair could be used in traveling over some irregular surfaces. Because of the almost universal use of this wheel chair the safety afforded throughout irregular surface travel is necessarily always maintained at the highest level possible to avoid any injury to the occupant caused by any malfunction of the Wheel chair.
Whenever the Wheel chair 20 is traveling over irregular surfaces, such as the stairs 126 shown in FIGURE 1, a motion restraining means 150 is energized. Such a means is a safety assembly 150 composed of the ratchet wheel 143 attached to or made integral with the upper chain sprocket wheel 142, a follower ratchet roller 151, a pivotal ratchet arm 152 supporting the ratchet roller 151 and pivotally secured to the inner framing 44, and a tension spring 153 anchored at its lower end 154 by mounting pin 155 to the centered housing structure 94 of the front endless belt track assembly 92 and at its top end 156 by using selective tensioning detents 157, 158 and 159 spaced along the pivotal ratchet arm 152.
This safety motion restraining assembly 150 is effective in holding the occupied wheel chair stationary on extensive irregular surfaces such as the stairs 126 of FIG- URE 1 without the occupant holding the hand gripping wheels 31, 32. Also, noted previously, non-movement is further insured because the occupant does not have to hold the cranks 107, 108 used to pivot the endless belt track assemblies 92, 93. After these track assemblies 92, 93 are moved to any selected position by the occupant, the friction locked threads 101 are constantly effective in restraining all other forces until the cranks 107, 108 are subsequently and intentionally rotated by the occupant.
Therefore at any time during an otherwise dangerous ascent or descent the occupant using the wheel chair 20 with the irregular surface travel running gear 80 in position knows he may rest with safety while gaining strength to go on with his travels. Even on somewhat regular terrain the occupant may wish to transfer the loaded Weight of the wheel chair to the irregular surface travel running gear 80 to insure non-motion of the wheel chair 20 while he rests.
Operation scope of the wheel chair equipped with the irregular surface travel running gear As already indicated, wheel chair 20 provides the occupant, generally an invalid, with means to travel under his own power and guidance to many places formerly not accessible to him in his wheel chair. He travels over substantially regular surfaces with an efliciency comparable to travel in a standard wheel chair. Then when he encounters irregular surfaces, such as the stairs 126 of FIGURE 1, by his easy pivotal placement of the left and right component assemblies 81, 82 of the irregular surface travel running gear 80, he proceeds up or down the irregular surface safely and conveniently. Only where the irregular surface changes rather abruptly, such as at the top 161 or bottom 162 of stairs 126, must the occupant necessarily restrict his forward motion while positioning the irregular surface travel running gear 80.
Other benefits result from astute placement of the pivotal endless belt track assemblies 92, 93. As previously stated, the occupant may wish to transfer the loaded weight of the wheel chair to the irregular surface running gear 80 to insure non-motion of the wheel chair 20 during his rest period. He may also transfer the loading when he is using the wheel chair while working, perhaps increasing the angular positions of the endless belt track assemblies 92, 93 to raise his seating position at a work table. Moreover, while viewing an athletic contest, a show, or a parade, the occupant may increase his height substantially gaining a better sighting position. In addition, the occupant may increase his seating height prior to receiving the assistance of other persons who will aid him during his entry into another vehicle, such as a car.
, This resume of the new transportation and positioning possiblities made available to the occupant is indicative only, because each user will find other possibilities, all making him more self sutficient than ever before.
1. A rider controlled and propelled chair like vehicle for travel over both substantially level and obstruction like contours comprising: i
(A) essentially standard components of a conventional wheel chair comprising:
(1) a foldable frame supporting a foldable (a) seat;
(b) foot rest; and
(c) back rest; and
(2) a normal speed wheel assembly for travel over substantially level contours comprising:
(a) front swiveled guiding wheels pivotally mounted on the frame; and
(b) rear larger wheels equipped with a hand ring and rotatably mounted on a horizontal axis secured to the frame; and
(B) additional alternate use optional speed belt track assemblies for travel over irregular contours inclusive of stairs and other obstructions, comprising:
(1) a positioning sub framing secured to the foldable frame including axial supports and rotative axles both located below and behind the larger Wheels at a slight distance above the plane of contact of the normal speed wheel assembly;
(2) forward belt track assemblies respectively rotatably positioned on the axial supports;
(3) rear belt track assemblies respectively rotatably positioned on the axial supports;
(4) connecting drive assemblies transmitting rotary motion between the rear larger wheels through cam and spring actuated. clutches to both the forward and rear belt track assemblies; and
(5) rotary positioning mechanism for the belt track assemblies comprising:
(a) left and right hand crank translating nut and threaded guide rod assemblies secured to the foldable frame;
(b) quadrants attached to respective belt track assemblies along the axis of the sub framing axial supports; and
(c) f exible housed control cables having housings secured to both the foldable and sub framing with one set of control cables extending between one translating nut and the forward belt track quadrants and the other set of control cables extending between the opposite side translating nut and the rear belt track quadrants;
(6) adjustable restraining force ratchet assemblies interconnecting the foldable framing and the connecting drive assemblies transmitting rotary motion between the rear larger wheels and the belt track assemblies thereby maintaining a safe braking load during travel over irregular contours; and
(7) cams on the forward belt track assemblies to contact the spring engaged clutches of the connecting drive assemblies upon rotative re- 7 traction of 'the forward belt track assemblies thereby disengaging the entire alternate use optional speed belt track assemblies while traveling over substantially level contours.
2. A rider controlled and propelled chair-like vehicle as claimed in claim 1 wherein the forward and rear belt track assemblies comprise end to end channel belt track frames with end pulley wheels and continuous belts passing through the channels and around the end pulley wheels of the belt tracks.
3. A foldable wheel chair for travel over substantially all surfaces by utilizing both regular and irregular surface running gear alternately depending on the surfaces encountered, comprising:
(A) substantially all essential regular surface occupant hand-powered wheel chair components for seating and framing;
(B) regular surface running gear supported on the framing comprising main wheels "equipped with hand power application auxiliary Wheels, and leading wheels for both stability and stee'rability;
(C) irregular surface running gear including auxiliary framing supported on the framing, comprising endless belt track assemblies mounted for pivotal movement from retracted positions into respective forward and rearward irregular surface contact positions;
(D) adjustment controls on the frame for selectively positioning the endless belt track assemblies;
(E) alternate running gear drive engagement means mounted between the regular and irregular surface running gears to connect the irregular running gear to the hand powered main Wheels only for travel over irregular surfaces; and
(F) adjustable motion restraining force assemblies in-' terconnecting the foldable framing and the alternate running gear drive engagement means transmitting rotary motion between the main Wheels and the belt track assemblies, comprising a ratchet wheel attached to the alternate running gear drive engagement means, a follower ratchet roller, a pivotal ratchet arm supporting the ratchet roller and pivotally secured to the Wheel chair framing and a tension spring anchored at a lower end to the irregular surface running gear and at its upper end at a selective position of several positions along the pivotal ratchet arm, thereby maintaining a safe braking load during travel over irregular contours.
References Cited by the Examiner UNITED STATES PATENTS 2,740,484 4/ 1956 Montana 2805.22 X 2,751,027 6/ 1956 McLaughlin. 3,111,331 11/1963 Locke 280-5.22 3,127,188 3/1964 Greub 2805.22 3,146,841 9/1964 Locke 280-522 FOREIGN PATENTS 541,253 11/1941 Great Britain.
OTHER REFERENCES Brochure: Wanted a Stair-Climbing Wheel Chair, 30 January 1962, National Inventors Council, U.S. Dept. of
BENJAMIN HERSH, Primary Examiner.
ARTHUR L. LA POINT, Examiner.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2740484 *||Aug 26, 1950||Apr 3, 1956||James Montana||Motor driven stair climbing hand truck|
|US2751027 *||May 19, 1952||Jun 19, 1956||Robert B Mclaughlin||Endless track supported invalid chair|
|US3111331 *||Mar 5, 1962||Nov 19, 1963||Burton H Locke||Stair-climbing wheel chair|
|US3127188 *||Apr 23, 1962||Mar 31, 1964||Occupant-controlled|
|US3146841 *||Feb 25, 1963||Sep 1, 1964||Locke Burton H||Stair-climbing wheel chairs|
|GB541253A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3529688 *||Nov 7, 1968||Sep 22, 1970||John W Bruce||Wheelchair|
|US4044850 *||Apr 14, 1975||Aug 30, 1977||Winsor Malcolm C||Wheelchair|
|US4194584 *||Jul 17, 1978||Mar 25, 1980||Delany James F||Variable terrain vehicle|
|US4473234 *||Nov 9, 1981||Sep 25, 1984||Egen David P||Carriage for traversing stairs|
|US4483407 *||Mar 17, 1983||Nov 20, 1984||Hitachi, Ltd.||Variable configuration track laying vehicle|
|US4566551 *||Aug 30, 1983||Jan 28, 1986||Feliz Jack M||Stair-climbing conveyance|
|US4671369 *||Oct 1, 1985||Jun 9, 1987||Gordon W. Rosenberg||Stair-climbing wheelchair with means for cushioning vertical movements thereof|
|US4687068 *||Dec 30, 1985||Aug 18, 1987||Australian Transcenders International Pty. Ltd.||Invalid's wheelchair and like conveyances|
|US5123495 *||Nov 21, 1989||Jun 23, 1992||Quest Technologies, Inc.||Wheelchair stair climbing control system|
|US5248007 *||Nov 1, 1990||Sep 28, 1993||Quest Technologies, Inc.||Electronic control system for stair climbing vehicle|
|US5335741 *||May 21, 1992||Aug 9, 1994||Israel Aircraft Industries Ltd.||Externally mounted track apparatus for a wheel chair|
|US5338048 *||May 10, 1993||Aug 16, 1994||Henry Medina||Collapsible wheelchair|
|US5395129 *||Apr 7, 1993||Mar 7, 1995||Kao; Chin-Hsing||Wheel chair|
|US5423563 *||Jun 27, 1994||Jun 13, 1995||Wild; Franklin J.||Wheelchair having apparatus for climbing stairs|
|US6619414 *||Jan 3, 2002||Sep 16, 2003||Harvey G. Rau||Personal mobility vehicle|
|US6857490 *||Dec 11, 2002||Feb 22, 2005||Robert T. Quigg||Stair-climbing wheelchair|
|US7125022||Mar 14, 2003||Oct 24, 2006||Henry Medina||Collapsible chair|
|US7690738||May 31, 2006||Apr 6, 2010||Wilt H William B||Dynamically changing track support for tracked vehicle|
|US7779940 *||Jan 17, 2007||Aug 24, 2010||Gregory Demetrulias||Vehicles and methods for handling materials|
|US7950673||Mar 13, 2009||May 31, 2011||Monster Medic, Inc.||Stair chair|
|US7988157||Sep 19, 2007||Aug 2, 2011||Steven Rembos||Wheelchair stair assist apparatus|
|US8113304||Jun 13, 2008||Feb 14, 2012||Irobot Corporation||Robotic platform|
|US8333389||Jun 28, 2011||Dec 18, 2012||Steven Rembos||Wheelchair stair assist apparatus|
|US8365848||Jun 17, 2008||Feb 5, 2013||Irobot Corporation||Robotic platform|
|US8763732||Mar 9, 2009||Jul 1, 2014||Irobot Corporation||Robotic platform|
|US9248874||Dec 31, 2008||Feb 2, 2016||Irobot Corporation||Robotic platform|
|US9573638 *||Aug 6, 2007||Feb 21, 2017||Irobot Defense Holdings, Inc.||Robotic platform|
|US20030116927 *||Dec 11, 2002||Jun 26, 2003||Quigg Robert T.||Stair-climbing wheelchair|
|US20080067762 *||Sep 19, 2007||Mar 20, 2008||Steven Rembos||Wheelchair Stair Assist Apparatus|
|US20080143063 *||Aug 6, 2007||Jun 19, 2008||Irobot Corporation||Robotic Platform|
|US20080169135 *||Jan 17, 2007||Jul 17, 2008||Gregory Demetrulias||Vehicles and methods for handling materials|
|US20080211299 *||May 31, 2006||Sep 4, 2008||Wilt H William B||Dynamically Changing Track Support for Tracked Vehicle|
|US20080236907 *||Jun 13, 2008||Oct 2, 2008||Irobot Corporation||Robotic Platform|
|US20090065271 *||Jun 17, 2008||Mar 12, 2009||Irobot Corporation||Robotic Platform|
|US20090107738 *||Dec 31, 2008||Apr 30, 2009||Irobot Corporation||Robotic Platform|
|US20090173553 *||Mar 9, 2009||Jul 9, 2009||Irobot Corporation||Robotic Platform|
|US20090230638 *||Mar 13, 2009||Sep 17, 2009||Monster Medic, Inc.||Stair chair|
|US20140299391 *||Aug 15, 2012||Oct 9, 2014||Ferno-Washington, Inc.||Patient transport devices|
|DE3943260A1 *||Dec 29, 1989||Jul 4, 1991||Kurt Lennartz||Climbing belt attachment to driven vehicles - helps invalid carriages to mount steps|
|DE19748877A1 *||Nov 6, 1997||May 12, 1999||Fritz Conzelmann||Electric wheelchair drive with devices for climbing steps|
|DE19748877C2 *||Nov 6, 1997||Nov 23, 2000||Fritz Conzelmann||Elektrischer Rollstuhlantrieb mit Vorrichtungen für Treppensteigen zum Anbau an Rollstühle normaler Bauart|
|DE19816879A1 *||Apr 17, 1998||Oct 21, 1999||Ernst Wedekind||Motorized universal wheelchair|
|EP0515199A1 *||May 21, 1992||Nov 25, 1992||Israel Aircraft Industries, Ltd.||Wheelchair with apparatus for assisting travel on a surface not suitable for wheeled travel|
|WO2015177625A1 *||May 20, 2015||Nov 26, 2015||Antano Group S.R.L.||Stairlift|
|International Classification||B62D55/075, A61G5/06, A61G5/00, B62D55/00|
|Cooperative Classification||B62D55/075, A61G5/061, A61G5/066|
|European Classification||B62D55/075, A61G5/06C, A61G5/06A|