APPARATUS FOR MOVING OVER UNEVEN TERRAIN

Abstract: Apparatus (100) for moving over uneven terrain (102) including a support element (17), a pair of cams (5, 5') rotatingly attached to the support element (17), wherein one of the cams (5, 5') is shaped as the mirror-image of the other cam, a pair of runners (1, 1') each having a terrain contacting surface (90) and a cam/runner contacting surface (2, 3), and a pair of lifters (108, 108') each connected to one of the runners (1, 1'), each lifter (108, 108') having a cam/lifter contacting surface (2', 3'), the runners (1, 1') and the lifters (108, 108') being alternatively moved by the cams (5, 5'), wherein when one of the cams (5, 5') contacts the cam/runner contacting surface (2, 3) of one of the runners (1, 1'), the terrain contacting surface (90) of the runner (1, 1') contacts a terrain (102) thereby causing the apparatus to move in a direction of travel, while simultaneously the other cam (5, 5') contacts the cam/lifter contacting surface (2', 3') and lifts the lifter (108, 108') away from the terrain (102), thereby also lifting the other runner (1, 1') away from the terrain (102), and vice versa, such that the runners (1, 1') move along the terrain (102) by alternately contacting the terrain (102).

Description: APPARATUS FOR MOVING OVER UNEVEN TERRAIN FIELD OF THE INVENTION The present invention relates generally to apparatus for moving over uneven terrain and particularly to a pair of runners that are alternately moved by mirror-image cams such that while one runner contacts the terrain the other runner is lifted away from the terrain, the runners advancing along the terrain by an alternating forward motion similar to a walking gait. BACKGROUND OF THE INVENTION Many devices are known for minimizing or eliminating wobble or bumping of moving vehicles, baby carriages or other bodies while traveling over uneven terrain. Some examples found in the patent literature are US Patents 4, 110,429 and 4,962,940, USSR Patents 929487, 1632853, 1654093, 1685436 and 1698116, Great Britain Patent 2191454, French Patent 2609267, Japanese Patent Documents N90/01441 and N3- 14670, and Israel Patent 91344. The devices of the prior art have certain disadvantages, inter alia, inconvenience, difficulty of operation, high cost and complexity of construction, thus making these devices inconvenient for use with baby carriages. SUMMARY OF THE INVENTION The present invention seeks to provide a improved apparatus for moving over uneven terrain that is of simple and inexpensive construction and is very convenient and easy to use. The apparatus is particularly useful for baby carriages, but may also be applied to heavy vehicles. The apparatus includes a pair of runners that are alternately moved by mirror- image cams such that while one runner contacts the terrain the other runner is lifted away from the terrain, the runners advancing along the terrain by an alternating forward motion similar to a walking gait. There is thus provided in accordance with a preferred embodiment of the present invention apparatus for moving over uneven terrain including a support element, a pair of cams rotatingly attached to the support element, wherein one of the cams is shaped as the mirror-image of the other cam, a pair of runners each having a terrain contacting surface and a cam/runner contacting surface, and a pair of lifters each connected to one of the runners, each lifter having a cam/lifter contacting surface, the runners and the lifters being alternately moved by the cams, wherein when one of the cams contacts the cam/runner contacting surface of one of the runners, the terrain contacting surface of the runner contacts a terrain thereby causing the apparatus to move in a direction of travel, while simultaneously the other cam contacts the cam/lifter contacting surface and lifts the lifter away from the terrain, thereby also lifting the other runner away from the terrain, and vice versa, such that the runners move along the terrain by alternately contacting the terrain. In accordance with a preferred embodiment of the present invention the apparatus also includes a pair of biasing devices each connected to one of the runners, wherein for each pair of the biasing device and the runner, the biasing device applies a force to the runner so as to cause the runner to return to a position where the cam initially contacts the cam/runner contacting surface of the runner only when the cam does not- contact the cam/runner contacting surface. Further in accordance with a preferred embodiment of the present invention the cam/runner contacting surface includes a first portion and a second portion, wherein the first portion is distanced further from the terrain than the second portion, such that the cam always contacts the cam/runner contacting surface during roll of the apparatus, roll being defined as rocking motion about an axis along the direction of travel. Additionally in accordance with a preferred embodiment of the present invention each lifter includes a roller and a periphery of the roller is the cam/lifter contacting surface, wherein each roller is rotatably attached to a yoke which is translatably mounted on the support element, each yoke including contact members which contact a cross-bar attached to each runner. The runners may be generally straight or generally arcuately shaped. In accordance with a preferred embodiment of the present invention the apparatus also includes leveling apparatus connected to the body for substantially maintaining the body horizontal during downwardly- sloped movement of the body. Further in accordance with a preferred embodiment of the present invention the apparatus also includes at least one shock absorber connecting between the lifters and the runners. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified left side view illustration of apparatus for moving over uneven terrain constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 2 is a simplified sectional illustration of the apparatus of Fig. 1, taken along lines II-II in Fig. 1 ; Fig. 3 is a simplified right side view illustration of the apparatus of Fig. 1; Figs. 4A and 4B are simplified illustrations of mirror-image cams used in the apparatus of Fig. 1, constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 5 is a simplified illustration of using the apparatus of Fig. 1 to push a baby carriage up a flight of stairs in accordance with a preferred embodiment of the present invention; Fig. 6 is a simplified illustration of using the apparatus of Fig. 1 to push a baby carriage down a flight of stairs, and employing a self-adjusting mechanism for bringing the apparatus of Fig. 1 into contact with the stairs constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 7 is a simplified illustration of leveling apparatus for maintaining the carriage of Fig. 6 substantially horizontal while going downstairs; and Figs. 8 and 9 are simplified illustrations of apparatus for moving over uneven terrain constructed and operative in accordance with another preferred embodiment of the present invention, wherein Figs. 8 and 9 illustrate two different operative positions of shock absorbers used in the apparatus during movement over uneven terrain. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Figs. 1-3 which illustrate apparatus 100 for moving over uneven terrain 102, constructed and operative in accordance with a preferred embodiment of the present invention. Apparatus 100 includes a support element 17 which comprises a transverse portion 17A and an elongate portion 17B (Fig. 2). A pair of cams 5 and 5' are rotatingly attached to support element 17 by means of an axle 9. Cam 5 is shaped as the mirror-image of cam 5'. This can be understood best by referring to Figs. 4A and 4B which illustrate cam 5 and cam 5', respectively. It is seen that cam 5 is the mirror image of cam 5' about a mirror- symmetry axis 77. Cams 5 and 5' respectively contact a pair of runners 1 and 1 '. Runner 1 has a terrain contacting surface 90 and a cam/runner contacting surface which is preferably comprised of a first portion 2 and a second portion 3. Runner 1 ' is similarly constructed with like elements being designated by the same numerals with an added apostrophe. For the sake of simplicity the description will generally follow for the un-apostrophized elements, such as runner 1, it being understood that the same description applies for the apostrophized elements, such as runner 1', mutatis mutandis. Runners 1 and 1' may be generally straight or generally arcuately shaped. Cam 5 is correspondingly shaped with surfaces 6 and 7 that respectively contact first portion 2 and second portion 3. As seen in Fig. 2, first portion 2 is distanced further from terrain 102 than second portion 3. On basically even ground, when surface 6 of cam 5 contacts first portion 2, surface 7 of cam 5 does not contact second portion 3, but rather is distanced from second portion 3 by a tolerance "c", as shown in Fig. 2. The main purpose of constructing cam/runner contacting surface with first portion 2 and second portion 3 and of providing tolerance c, is to provide a structure wherein cam 5 always contacts the cam/runner contacting surface even during roll of apparatus 100. Roll is defined as rocking motion about an axis 104 (Fig. 1) along a direction of travel, roll being designated by arrows 106 in Fig. 2. Referring to Fig. 4A and 4B, it is seen that the outermost contours, i.e., surfaces 7 and 7', of cam 5 and 5' are defined by a radius R 2 and a gap "h" from the outermost contour of the cam to a circumscribed circle of diameter D 2 . The gap h is provided mainly to compensate for very rough terrain. As an example only, h may be about 5 mm and c may be about 1-1.5 mm, and D 2 may be 90 mm and R 2 may be 66 mm. Referring to Fig. 1, the inner contour of cam 5, i.e., surface 6, is defined by a circle of diameter Dι. As an example only, Di may be 50 mm. A pair of lifters 108 and 108' are each connected to runners 1 and 1 ' respectively. Lifter 108 preferably includes a roller 10 which contacts cam 5, i.e., the periphery of roller 10 is the cam/lifter contacting surface. Roller 10 is rotatably attached to a yoke 13 which is translatably mounted on elongate portion 17B of support element 17. Yoke 13 includes contact members, such as end rollers 1 1 and 12, which contact a cross-bar 4 attached to upper extensions 110 of runner 1. In the orientation of Fig. 1, cam 5 has not yet touched roller 10, but rather a gap "a" exists therebetween. Gap a may be chosen in accordance with the other design parameters (c, h, R 2 , etc.) in order to adjust the synchronization of lifting lifter 108 and 108' with respect to the rotation of cams 5 and 5'. Runners 1 and 1 ' and lifters 108 and 108 * are alternately moved by cams 5 and 5', respectively. As cam 5 rotates clockwise in the sense of Fig. 1, cam 5 eventually contacts the cam/runner contacting surface (first and/or second portions 2 and 3) of runner 1, and the terrain contacting surface 90 of runner 1 is pushed against terrain 102, thereby causing apparatus 100 to move in a direction of travel, designated by an arrow K in Fig. 1. Simultaneously cam 5' contacts cam/lifter contacting surface (first and/or second portions 2' and 3') and lifts lifter 108' away from terrain 102, thereby also lifting runner 1' away from terrain 102, and vice versa, this arrangement of cam 5 and 5' being the mirror-image construction mentioned hereinabove. Thus runners 1 and 1 ' move along terrain 102 by alternately contacting terrain 102. A pair of biasing devices 18 and 19 (and 18' and 19') are preferably each connected to one of runners 1 and 1 ', respectively. For example, biasing devices 18 and 19 may be elastic cords or springs. As cam 5 rotates clockwise in the sense of Fig. 1 , biasing device 18 is pulled in tension and biasing device 19 is compressed. Biasing device 18 thus applies a force to runner 1 in a direction indicated by an arrow 112 opposite to the direction of a force applied to runner 1 by cam 5, the biasing device force being less than the cam force. Biasing device 18 causes runner 1 to return to a position (that shown in Fig. 1) where cam 5 initially contacts the cam/runner contacting surface (first and second portions 2 and 3) of runner 1. Biasing device 18 is capable of returning runner 1 to this position only when cam 5 does not contact the cam/runner contacting surface. As mentioned before, biasing device 19 is in compression. If biasing device 19 is an elastic cord, then biasing device 19 simply sags limply. However, if biasing device 19 is a spring, then biasing device 19 may also apply a force to runner 1 to restore runner 1 to the initial position shown in Fig. 1. The force applied by biasing device 19 in this case is opposite to arrow 112. Reference is now made to Figs. 5 and 6 which illustrate using apparatus 100 to move a baby carriage 120 respectively up and down a flight of stairs in accordance with a preferred embodiment of the present invention. Support element 17 is affixed to an underframe 122 of carriage 120 such that runners 1 and 1 ' contact the stairs when wheels 124 of carriage 120 do not touch the stairs. As described hereinabove, when runner 1 is forced against the steps, runner 1 ' is lifted up and does not touch the steps, and vice versa. Carriage 120 is moved up/down the stairs virtually free of any bumping effects because runners 1 and 1 ' maintain contact with the steps and provide a constant, substantially linear movement of carriage 120 along the steps. The relative height of terrain contacting surfaces 90 and 90' of runners 1 and 1 ' with respect to the steps, designated by the letter "s" in Fig. 5, and to the diameter of the wheels of carriage 120, designated by D 3 in Fig. 5, may be suitably selected in accordance with the expected differences in height experienced by the carriage when going up/down the steps. Without the present invention, people normally go down stairs by bumping the rear wheels of the carriage down the steps, all the while maintaining the carriage more or less horizontal. With the present invention, since there is no bumping of the carriage, the carriage need not be held horizontal. However, optionally, leveling apparatus 130 may be provided for maintaining carriage 120 horizontal while going down steps. Reference is now made to Fig. 7 which illustrates leveling apparatus 130 for maintaining carriage 120 horizontal while going down steps. Handle 22 of carriage 120 is normally in the position shown in Fig. 5. Handle 22 is connected to a portion of -a frame 27 of carriage 120 by means of a spring-hinge 23. In the position shown in Fig. 5, frame 27 abuts against an arresting member 24. A pivoting support member 26 is pivotally attached to another portion of carriage 120 about a pivot 25. A stop 21 is provided for checking movement of pivoting support member 26 in the direction of an arrow 132 in Fig. 7. As seen in Fig. 6, when a person wishes to go downstairs, handle 22 is brought in the direction of an arrow 134 to the position shown in Fig. 6. This movement of handle 22 brings arresting member 24 out of contact with frame 27 and the upper portion (i.e., the baby carrying portion) of carriage 120 swings downwards generally in the direction of arrow 132 so that pivoting support member 26 now abuts against frame 27. Fig. 6 shows pivoting support member 26 abutting against frame 27 at a reference point 136. At this point 136, the upper portion of carriage 120 is not yet completely horizontal. Pivoting support member 26 may then slide along frame 27 to a reference point 138, whereupon the upper portion of carriage 120 is substantially horizontal. For going upstairs or for proceeding on level ground, handle 22 is merely returned to the position of Fig. 5 and pivoting support member 26 pivots back to the position shown in Figs. 5 and 7. Reference is now made to Figs. 8 and 9 which are simplified illustrations of apparatus 140 for moving over uneven terrain constructed and operative in accordance with another preferred embodiment of the present invention. Apparatus 140 is substantially identical to apparatus 10, except that shock absorbers 142 are added to provide extra cushioning capability for negotiating very uneven terrain. Figs. 8 and 9 illustrate two different operative positions of shock absorbers 142 while traveling over uneven terrain. Apparatus 140 illustrates the applicability of the present invention not only to baby carriages, but also to heavy duty vehicles as well. It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.

Claims: C L A I M S What is claimed is: 1. Apparatus ( 100) for moving over uneven terrain ( 102) comprising: a support element (17); a pair of cams (5, 5') rotatingly attached to said support element (17), wherein one of said cams (5, 5') is shaped as the mirror-image of the other cam (5, 5'); a pair of runners (1, 1 ') each having a terrain contacting surface (90) and a cam/runner contacting surface (2, 3); and a pair of lifters (108, 108') each connected to one of said runners (1, 1'), each said lifter (108, 108') having a cam/lifter contacting surface (2', 3'), said runners (1, 1 ') and said lifters (108, 108') being alternately moved by said cams (5, 5'), wherein when one of said cams (5, 5') contacts said cam/runner contacting surface (2, 3) of one of said runners (1, 1 '), said terrain contacting surface (90) of said runner (1, 1 ') contacts a terrain (102) thereby causing said apparatus to move in a direction of travel, while simultaneously the other cam (5, 5') contacts said cam/lifter contacting surface (2', 3') and lifts said lifter (108, 108') away from said terrain (102), thereby also lifting said other runner (1, 1 ') away from said terrain (102), and vice versa, such that said runners (1, 1 ') move along said terrain (102) by alternately contacting said terrain (102). 2. Apparatus (100) according to claim 1 and comprising a pair of biasing devices (18, 18', 19, 19') each connected to one of said runners (1, 1 '), wherein for each pair of said biasing device (18, 18', 19, 19') and said runner (1, 1 '), said biasing device (18, 18', 19, 19') applies a force to said runner (1, 1 ') so as to cause said runner (1, 1') to return to a position where said cam (5, 5') initially contacts said cam/runner contacting surface (2, 3) of said runner (1, 1 ') only when said cam (5, 5') does not contact said cam/runner contacting surface (2, 3). 3. Apparatus (100) according to claim 1 and wherein said cam runner contacting surface (2, 3) comprises a first portion (2) and a second portion (3), wherein said first portion (2) is distanced further from said terrain (102) than said second portion (3), such that said cam (5, 5') always contacts said cam/runner contacting surface (2, 3) during roll of said apparatus (100), roll being defined as rocking motion about an axis (104) along said direction of travel. 4. Apparatus (100) according to claim 1 wherein each said lifter (108, 108') comprises a roller (10) and a periphery of said roller (10) is said cam/lifter contacting surface (2', 3'), wherein each said roller (10) is rotatably attached to a yoke (13) which is translatably mounted on said support element (17), each said yoke (13) comprising contact members (11, 12) which contact a cross-bar (4) attached to each said runner (1, 1'). 5. Apparatus (100) according to claim 1 wherein said runners (1, 1') are generally straight. 6. Apparatus (100) according to claim 1 wherein said runners (1, 1') are generally arcuately shaped. 7. Apparatus (100) according to claim 1 and comprising a body (120) connected to said apparatus (100) and further comprising leveling apparatus (130) connected to said body (120) for substantially maintaining said body (120) horizontal during downwardly-sloped movement of said body (120). 8. Apparatus (140) according to claim 1 and comprising at least one shock absorber (142) connecting between said lifters (108, 108') and said runners (1, 1'). AMENDED CLAIMS [received by the International Bureau on 10 March 1999 (10.03.99); original claims 2, 3, 4 cancelled; original claim 1 amended; new claim 6 added; claims 5 - 8 renumbered as claims 2 - 5 (2 pages)] 1. Apparatus (100) for moving over uneven terrain (102) comprising: a support element (17); a pair of cams (5, 5') rotatingly attached to said support element (17), wherein one of said cams (5, 5') is shaped as the miιτor--mage of the other cam (5, 5'); a pair of runners (I, 1') each having a terrain contacting surface (90) and a cam/runner corøactidg surface (2, 3); and a pair of lifters (108, 108') each connected to one of said runners (1, F), each said lifter (108, 108') having a cam/lifter contacting surface (2 3'), characterized by said runners (1, V) and said lifters (108, 108') being alternately moved by said cams (5, 5'), wherein when one of said cams (5, 5') contacts said c-tm/runner contacting surface (2, 3) of one of said runners (1, 1'), said terrain contacting surface (90) of said runner (1, 1') contacts a terrain (102) thereby causing said apparatus to move in a direction of travel, while simultaneously the other cam (5, 5') contacts said cam/lifter contacting surface (2', 3') and lifts said lifter (108, 108') away from said terrain (102), thereby also lifting said other runner (1, 1') away from said terrain (102). and vice versa- such that said runners (1, 1 ') move along said terrain (102) by alternately contacting said terrain (102); further characterized by a pair of biasing devices (18, 18', 19, 19') each connected to one of said runners (1, 1'), wherein for each pair of said biasing device (18, 18', 19, 19') and said runner (1, 1'), said biasing device (18, 18', 19 ; 19') applies a force to said runner (1, 1') so as to cause said runner (1, 1') to return to a position where said cam (5, 5') initially contacts said cam/runner contacting surface (2, 3) of said runner (1, 1') only when said cam (5, 5') does not contact said cam runner co acting surface (2, 3); further characterized in that said cam runner contacting surface (2, 3) comprises a first portion (2) and a second portion (3), wherein said first portion (2) is distanced further from said terrain (102) than said second portion (3), such that said cam (5, 5 " ) always contacts said cam/mnner contacting surface (2, 3) during roll of said apparatus (100), roll being defined as rocking motion about an axis (104) along said direction of travel; and further characterized in that each said lifter (108, 108') comprises a roller (10) and a periphery of said rolier (10) is said cam/lifter contacting surface (2\ 3'), wherein each said roller (10) is rotatably attached to a yoke (13) which is translatably mounted on said support element (17), each said yoke (13) comprising contact members (11, 12) which contact a cross-bar (4) attached to each said runner (1, 1'). 2. Apparatus (100) according to claim 1 wherein said runners (1, 1') are generally straight. s 3. Apparatus (100) according to claim 1 wherein said runners (1, F) are generally arcuately shaped. 4. Apparatus (100) according to claim 1 further comprising a body (120) connected to said apparatus (100) and further comprising leveling apparatus (130) connected to said body (120) for substantially m-dntaining said body (120) horizontal during downwardly- 0 sloped movement of said body (120). 5. Apparatus (140) according to claim 1 further comprising at least one shock absorber (142) connecting between said lifters (108, 108') and said runners (1, F). 6. Apparatus (100) according to claim 4 wherein said leveling apparatus (130) comprises: 5 a handle (22) attached to a frame (27) of said body (120) by means of a spring- hinge (23; an arresting member (24) attached to said body (120); a pivoting support member (26) pivotally attached to another portion of said body (120) about a pivot (25); and 0 a stop (21) attached to said body (120) for checking movement of said pivoting support member (26),

Inventors: DVORKIN VLADIMIR, GAMBURG ROMAN, DVORKIN, VLADIMIR, GAMBURG, ROMAN
Applicants: DVORKIN VLADIMIR, GAMBURG ROMAN, DVORKIN, VLADIMIR, GAMBURG, ROMAN
Application year: 1998
Main classification: B62B5
IPC codes: B62B5, B62D57