Variable-incline ramp system

Information

  • Patent Grant
  • 6739430
  • Patent Number
    6,739,430
  • Date Filed
    Tuesday, February 5, 2002
    22 years ago
  • Date Issued
    Tuesday, May 25, 2004
    20 years ago
  • Inventors
  • Examiners
    • Keenan; James W.
    • Tran; Thuy V.
    Agents
    • Oyen Wiggs Green & Mutala
Abstract
The invention provides a ramp system for transporting objects from a lower site to an upper site and vice versa while keeping the object in a generally horizontal, or upright, orientation when the object is moved up a variable incline. Two rails are provided between the upper and lower site, and a carriage is provided with wheels to allow it to move along the rails. A plurality of cables extend from the carriage to the upper site and to the lower site, the cables passing through pulleys affixed to the carriage, in an arrangement which causes the front portion of the carriage to be cantilevered over the rails, thus keeping a horizontal orientation notwithstanding the incline of the ramp. In a preferred embodiment, the system is implemented in a marine environment between a floating dock and a fixed pier.
Description




TECHNICAL FIELD




The present invention relates to systems for transporting material and people up and down ramps, and more particularly to systems for transporting material and people up and down a variably-inclinable ramp in a carriage configured to maintain a generally horizontal orientation.




BACKGROUND




Ramps are used to transport material between two sites having different elevations. It is well known, for example, to use a ramp to move heavy articles from the ground into a truck.




It is also well known to move people up and down ramps. In particular, ramps are often employed to move people in wheelchairs and other similar devices between two sites having different elevations. Such “wheelchair ramps” are ubiquitous in our society nowadays, and such ramps are indeed often mandated by modern building codes to ease the mobility of those in wheelchairs and generally to assist in the transportation of people using such devices.




Despite the fact that wheelchair ramps and other ramps are now commonplace, however, those in wheelchairs still face difficulties traversing some of these ramps. In some instances, a ramp might be too steep to allow the wheelchair-bound person to push the wheelchair up the ramp alone without assistance. Such assistance might be provided by another person, but it is also common to provide such assistance by means of some motorized system. In many such motorized systems, a carriage is provided which can accept the wheelchair, and which can then be moved from the lower end of the ramp to the upper end (and, of course, vice versa). It is not uncommon for such motorized systems to be constructed to allow a person to remain in their wheelchair, but if this is the case, it is much preferred that the wheelchair maintain a typical, generally horizontal orientation.




While it is relatively straightforward to provide an effective motorized ramp system to transport a wheelchair in a generally horizontal orientation where the degree of incline between a lower site and an upper site is invariable, it is much more difficult to provide a system which will maintain this generally horizontal orientation in a situation where the incline can vary. One very common such situation is that which will be familiar to those who live in marine environments. It is very common to have variably-inclinable ramps extending between the shore (or a fixed dock extending out from the shore) and a floating dock situated upon the surface of the water.




It should be readily understood that the angle of incline of such a ramp, if the ramp is of a fixed length, varies according to the relative elevations between the upper, fixed dock, and the lower, floating dock. The difference in relative elevations, in turn, varies depending upon the water level. In many marine environments (for example, on the ocean), where the action of tides can cause a significant variation in water levels, the degree of inclination of such ramps can pass through a wide range. At low tide, the ramp will be steep, and accordingly difficult for a person in a wheelchair to traverse.




Further, it might be dangerous for the wheelchair-bound person to attempt to traverse a ramp in a marine environment when surrounding environmental conditions are poor. A carriage for securing the wheelchair is therefore desirable.




Attempts have been made to construct systems which can maintain some object in a generally horizontal, or upright, orientation when the object is moved up a variable incline. Indeed, an attempt has been made to describe such a system which might have application in a marine environment. U.S. Pat. No. 6,105,726 discloses a variable-incline ramp system for maintaining a vehicle in a horizontal orientation, and that patent states therein that the system might be employed in a marine environment. This system uses a set of four rails along which are able to move four wheels attached to a platform. It is unlikely that this system would be realistically employed in a marine environment, however. First, it could not be easily retrofitted onto an existing dock. Second, the platform of the system does not permit a wheelchair to be safely contained within a carriage to prevent the wheelchair from slipping off the ramp. Structural limitations of this system also prevent regular, non-wheelchair bound persons from using the ramp in a typical fashion.




What remains necessary, accordingly, is a ramp system for allowing the movement of people and materials through an incline while maintaining them in their generally horizontal or upright orientation, notwithstanding the variable degree of incline. The present invention is directed to such a system.




SUMMARY OF INVENTION




The present invention provides a ramp system for transporting material between a first site and a second site, the first site having a lower elevation than the second site, the system comprising first and second rails extending between the first and second sites, the first and second rails pivotally attached at one end to the second site at first and second lower attachment points respectively, each rail bearing an upwardly extending support member near its opposite end. A carriage is provided for carrying the material, the carriage having a frame comprising a front portion, a lower rear portion and an upper rear portion. A plurality of wheels are attached to the lower rear portion of the carriage for engaging the rails. A first upper pulley is attached to the upper rear portion of the frame on one side thereof, and a second upper pulley is attached to the upper rear portion of the frame on the opposite side thereof. A first lower pulley is attached to the lower rear portion of the frame on one side thereof, and a second lower pulley is attached to the lower rear portion of the frame on the opposite side thereof.




A first cable is attached at one end to a first upper attachment point on the second site, the first upper attachment point located at a higher elevation than the first lower attachment point, and the first cable is attached at an opposite end to the bottom portion of the support member on the first rail. The first cable extends from the first upper attachment point over the first upper pulley and under the first lower pulley. A second cable is attached to a second upper attachment point on the second site, the second upper attachment point located at a higher elevation than the second lower attachment point. The second cable is attached at an opposite end to the bottom portion of the support member on the second rail. The second cable extends from the second upper attachment point over the second upper pulley and under the second lower pulley. Also provided are means for providing motive force to the carriage to move it up and down the rails between the said first and second sites.











BRIEF DESCRIPTION OF DRAWINGS




In drawings which illustrate a specific embodiment of the invention, but which should not be construed as restricting the spirit or scope of the invention in any way:





FIG. 1

is a side perspective view of the ramp system of one embodiment of the present invention, shown in use in a marine environment.





FIG. 2

is a side view of the ramp system shown in FIG.


1


.





FIG. 3

is a close-up cutaway view of the rear portion of the carriage of the system shown in FIG.


1


.











DESCRIPTION




Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.




The present invention is a ramp system for moving material and people up and down a variably-inclinable ramp in a carriage configured to maintain a generally horizontal orientation. While the invention is contemplated to have a wide variety of applications, the inventor believes that it would have particular usefulness in transporting people in wheelchairs up and down ramps, and the figures herein show the invention employed in a marine environment with a carriage for carrying a wheelchair from a dock to a pier. It is of course not necessary that the ramp system be used only between a dock and a pier as shown but the description hereafter shall refer to this marine embodiment of the invention shown in the drawings for the sake of convenience. Furthermore, it is not necessary that the system be used to transport wheel-chairs; references to wheelchairs herein are only for the sake of illustration. Other wheeled devices such as motorized scooters and walkers could also suitably be transported by the inventive system.




Referring first to

FIG. 1

, one embodiment of a ramp system constructed in accordance with the principles of the present invention is denoted generally herein by the numeral “


10


”. Ramp system


10


generally provides a ramp between an upper site such as pier


200


, and a site having a lower elevation than the upper site, such as floating dock


100


.




In the preferred embodiment of the invention, pier


200


extends outwardly from land (not shown) over water


300


and has a fixed elevation, being held up out of the water


300


by a plurality of posts


102


, as is well known in the art. Pier


200


, as is typical, has a deck


105


and may have railings


101


,


103


sitting atop posts


104


,


106


situated at the end of pier


200


. Cross bracing


107


may extend between deck


105


and railings


101


,


103


. In these regards, pier


200


is conventional.




Floating dock


100


, to which a boat (not shown) might be moored, is also conventional. It will be understood that the elevation of dock


100


is not fixed, unlike the elevation of pier


200


, but rather varies according to the level of water


300


. The level of water


300


may change, for example, if water


300


is tidal.




The invention provides a first rail


30


and a second rail


32


which extend between pier


200


and dock


100


. First rail


30


is pivotally attached at one end to pier


200


at a first lower attachment point


34


, which may conveniently be on the lower portion of post


104


, and rail


30


extends downwardly to dock


100


. Similarly, second rail


32


is pivotally attached at one end to pier


200


at a second lower attachment point


36


, which may conveniently be on the lower portion of post


106


, and rail


32


also extends downwardly to dock


100


. The pivotal attachment of rails


30


,


32


allows them to pivot with respect to pier


200


as described in further detail below. Rails


30


,


32


may be secured to dock


100


at their opposite ends either in a fixed fashion, or pivotally, but need not necessarily be secured to the dock.




As shown in the figures, when affixed to pier


200


in this manner, rails


30


,


32


lie generally parallel to one another. Rails


30


,


32


may be provided with decking


38


(shown only in part in

FIG. 1

) extending between them to form a generally conventional ramp between dock


100


and pier


200


which people may traverse in a traditional manner.




The invention further provides a carriage


11


for carrying a wheelchair (not shown) and its occupant up and down the ramp.




In the preferred embodiment, carriage


11


has a frame


12


comprising, generally, a front portion


14


, an upper rear portion


16


(which might be considered to be the upper half and the rear half of the carriage as it sits in its normal, upright orientation) and a lower rear portion


18


. Carriage


11


also has a platform


20


upon which a wheelchair may be maneuvered and secured for transport, and a door


22


hinged to frame


12


at front portion


14


to prevent the wheelchair from sliding out of the carriage. A similar door (not shown) may be hinged to frame


12


at the rear of carriage


11


. Door


22


may be left in an open position when carriage


11


is not in use, so that people may simply walk through carriage


11


from the dock to the pier.




Carriage


11


is provided at its lower rear portion


18


with a plurality of wheels


24


(shown in detail in

FIG. 3

) on which carriage


11


is suited to ride along rails


30


,


32


, and specifically, along upper surfaces


31


,


33


of rails


30


,


32


. In a preferred embodiment, as shown in the figures, there are two wheels


24


, one on each side of carriage


11


.




As further shown in the drawings, a number of cables extend between pier


200


and carriage


11


, and between carriage


11


and dock


100


. It is this arrangement of these cables which is one of the particularly noteworthy aspects of the present invention.




In a preferred embodiment of the invention, carriage


11


is provided with four pulleys: a first upper pulley


40


attached to upper rear portion


16


of frame


12


on one side thereof, a second upper pulley


42


attached to upper rear portion


16


of frame


12


on the opposite side thereof; a first lower pulley


44


attached to lower rear portion


18


of frame


12


on one side thereof, and a second lower pulley


46


attached to lower rear portion


18


of frame


12


on the opposite side thereof.




While pulleys


40


,


42


,


44


,


46


may be placed in a variety of locations with respect to frame


12


to allow the proper practice the invention, in the preferred embodiment, as shown in the drawings, the upper pulleys


40


,


42


are each attached to a corner brace


47


(

FIG. 3

) formed in a respective corner of frame


12


, and extend outwardly from carriage


11


. Further, in the preferred embodiment, lower pulleys


44


,


46


may be attached directly to frame


12


, and, as shown in

FIG. 3

, may also be integrated with wheels


24


, with pulley


44


extending outwardly from frame


12


as the inner part of wheel


24


, as shown in FIG.


3


. Most preferably, the centers of lower pulleys


44


,


46


are located vertically underneath the centers of upper pulleys


40


,


42


when carriage


11


is in a horizontal orientation, as shown in the figures.




Carriage


11


therefore has four pulleys extending outwardly from its rear portion. Associated with each one of these pulleys is at least one cable, and preferably, two cables.




A first cable


50


is attached at one of its ends to a first upper attachment point


60


on pier


200


, preferably located on post


104


. First cable


50


extends downwardly from attachment point


60


to first upper pulley


40


, and passes over the top of it. Cable


50


thereafter passes underneath first lower pulley


44


, as shown in FIG.


3


. First cable


50


is attached at its other end to an attachment point


70


near the end of rail


30


. Attachment point


70


may be on rail


30


itself, as shown in the drawings, or may be on the lower portion of an upwardly extending support member


74


on rail


30


. Again, the specific orientation of first cable


50


at first pulleys


40


,


44


is shown in detail in FIG.


3


.




Preferably, the vertical distance between first upper attachment point


60


and first lower attachment point


34


is such that cable


50


, as it extends from first upper attachment point


60


to first pulley


40


, is approximately parallel to rail


30


, thereby forming a parallelogram between rail


30


, cable


50


, post


104


and the line between the center of pulley


40


and the center of pulley


44


. It will be appreciated that as long as cable


50


is taut, this parallelogram will be maintained notwithstanding the relative position of carriage


11


along rails


30


,


32


, and notwithstanding the degree of inclination of rails


30


,


32


.




Similarly, a second cable


52


, on the opposite side of carriage


11


, is attached at one end to a first upper attachment point


62


on pier


200


, preferably on post


106


. Second


52


extends downwardly from attachment point


62


to second upper pulley


42


, and passes over the top thereof. Passing thereafter underneath second lower pulley


46


, second cable


52


is attached at its other end to an attachment point


72


near the end of rail


32


. Again, attachment point


72


may be on rail


32


, or may be on the lower portion of an upwardly extending support member


76


.




It will be appreciated from this description and from the drawings, accordingly, that first cable


50


and second cable


52


are the two “upper cables” between the carriage


11


and pier


200


as shown in the figures, and the two “lower cables” between carriage


11


and dock


100


. These two cables, when taut, pull on frame


12


of carriage


11


by pulling on pulleys


40


,


42


, and


44


and


46


to cantilever carriage


11


into an upright, horizontal orientation when the upper and lower pulleys are vertically aligned. The inventor has determined that this cable arrangement maintains the carriage


11


in an approximately upright, horizontal orientation no matter how far along rails


30


,


32


carriage


11


is located, and no matter what the degree of incline is between dock


100


and pier


200


.




While it should be clear to those skilled in the art that these two cables alone should be able to maintain carriage


11


in a horizontal orientation, two other cables, cable


54


and


56


, are added to the system in a preferred embodiment for further mechanical support, and to prevent carriage


11


from tipping rearwardly towards pier


200


.




Specifically, cable


54


is attached at one end to post


104


on pier


200


at some elevation point


64


intermediate first lower attachment point


34


and first upper attachment point


60


, and preferably a short vertical distance away from lower attachment point


34


. Cable


54


may be attached at an opposite end to an upper portion of upwardly extending support member


74


on rail


30


. From pier


200


, cable


54


passes underneath pulley


44


, then over pulley


40


, as shown in detail in FIG.


3


. Again, the attachments points of cable


54


should be such as to maintain cable


54


in a generally parallel relation to rail


30


.




A fourth cable


56


similarly passes between pier


200


and rail


32


on the opposite side of carriage


11


, passing under pulley


46


and over pulley


42


, and may be attached to upwardly extending support member


76


on rail


32


at intermediate elevation point


66


.




In one embodiment of the invention, as shown in the figures, at its lower end cable


54


may pass over a series of two pulleys


80


,


82


attached to upwardly extending support member


74


, and have this end attached to a spring


90


which is in turn attached to rail


30


, as shown in FIG.


2


. Pulley


80


may be spring loaded to urge cable


54


upwardly, and may ride within slot


81


in support member


74


. The action of spring


90


and spring-loaded pulley


80


helps to keep cable


54


taut. The same system may be employed for cable


56


, with pulleys


84


,


86


. It will further be recognized that a similar attachment system could be employed at the opposite, pier end, of the ramp. Alternatively, or used concurrently, other means for adjusting the length of the cables may be added to the system. Such adjustment means might be useful, for example, for taking up slack from the cables due to the natural stretching thereof. An example of such means which could be provided would be the addition of turnbuckles (not shown) between the ends of the cables and their respective attachment points.




It will be appreciated that the afore described system allows carriage


11


to be moved between a first, lower position at dock


100


, along rails


30


,


32


to a second, upper position at pier


200


, while maintaining carriage


11


in a generally horizontal orientation. The particular arrangement of the system's pulleys and cables allows the carriage's generally horizontal orientation to be maintained through a wide range of degrees of inclination of the ramp.




While carriage


11


may be moved by hand, the system


10


is preferably provided with motorized motive means for moving carriage


11


along rails


30


,


32


from dock


100


to pier


200


. Specifically, the carriage


11


may be self-propelled, having a motor which turns one or more of pulleys


40


,


42


,


44


or


46


, or may more simply be attached to a winch at pier


200


by a cable.

FIG. 2

shows, in a schematic manner, a winch


202


attached to post


104


, bearing a cable


204


which is attached at one end to carriage


11


. Such a winch could also just as conveniently be incorporated into the carriage


11


. It is accordingly contemplated by the inventor that a wide variety of motive means might be usefully employed in the operation of the system


10


.




In operation, when a wheelchair-bound person wishes to be transported from dock


100


to pier


200


, carriage


11


is moved to its lower position, with platform


20


resting on the surface of dock


100


. This position may indeed be considered the carriage's “default”, or resting position, since in this position it is easy for people to walk through carriage


11


and to traverse the ramp in a traditional fashion on foot. Once carriage is in position, door


22


is opened, and the wheelchair is maneuvered onto platform


20


and secured within the confines of carriage


11


. Once the wheelchair is secured, the carriage


11


is moved by the appropriate motive means upwardly along rails


30


,


32


to an upper position, where platform


20


lies roughly at the same elevation as deck


105


of pier


200


. The rear door (if carriage


11


has one), is opened, and the wheelchair is unsecured from carriage


11


, and the wheelchair user is then able to proceed onto pier


200


. Transporting the wheelchair from pier


200


to dock


100


is simply the reverse of this process.




As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.



Claims
  • 1. A ramp system for transporting material between a first site and a second site, said first site having a lower elevation than said second site, the system comprising:a) first and second rails extending between said first and second sites, said first and second rails pivotally attached at one end to said second site at first and second lower attachment points respectively, each rail bearing an upwardly extending support member near its opposite end; b) a carriage for carrying said material, said carriage having a frame comprising a front portion, a lower rear portion and an upper rear portion; c) a plurality of wheels attached to said lower rear portion of said carriage for engaging said rails; d) a first upper pulley attached to said upper rear portion of said frame on one side thereof, and a second upper pulley attached to said upper rear portion of said frame on the opposite side thereof; e) a first lower pulley attached to said lower rear portion of said frame on one side thereof, and a second lower pulley attached to said lower rear portion of said frame on the opposite side thereof; f) a first cable attached at one end to a first upper attachment point on said second site, said first upper attachment point located at a higher elevation than said first lower attachment point, said first cable attached at an opposite end to the bottom portion of said support member on said first rail, said first cable extending from said first upper attachment point over said first upper pulley and under said first lower pulley; g) a second cable attached to a second upper attachment point on said second site, said second upper attachment point located at a higher elevation than said second lower attachment point, said second cable attached at an opposite end to the bottom portion of said support member on said second rail, said second cable extending from said second upper attachment point over said second upper pulley and under said second lower pulley; and h) means for providing motive force to said carriage to move it up and down said rails between said first and second sites.
  • 2. A ramp system as claimed in claim 1, wherein said motive means comprises a motor associated with a plurality of said wheels.
  • 3. A ramp system as claimed in claim 1 further comprising:a) a third cable attached at one end to said second site at an elevation intermediate said first lower attachment point and said first upper attachment point, and attached at an opposite end to said support member on said first rail; said third cable passing from said second site underneath said first lower pulley and over said first upper pulley; and b) a fourth cable attached at one end to said second site at an elevation intermediate said second lower attachment point and said second upper attachment point, and attached at an opposite end to said support member on said second rail; said fourth cable passing from said second site underneath said second lower pulley and over said second upper pulley.
  • 4. A ramp system as claimed in claim 3, wherein said carriage has two wheels, one on each side thereof, and said lower pulleys are integral with said wheels.
  • 5. A ramp system as claimed in claim 4, wherein said carriage further comprises a door at its front portion, hinged to said frame.
  • 6. A ramp system as claimed in claim 5, further comprising decking passing laterally between said first and second rails to allow people to walk therebetween.
  • 7. A ramp system as claimed in claim 1, wherein said motive means comprises a winch having a cable attached to said carriage.
  • 8. A ramp system as claimed in claim 1, wherein said motive means comprises a motor associated with one of said wheels.
  • 9. A ramp system as claimed in claim 1 further comprising:a) a third cable attached at one end to said second site at an elevation intermediate said first lower attachment point and said first upper attachment point, and attached at an opposite end to said first rail; said third cable passing from said second site underneath said first lower pulley and over said first upper pulley, then over an upper pulley on said support member, then under a lower pulley on said support member; and b) a fourth cable attached at one end to said second site at an elevation intermediate said second lower attachment point and said second upper attachment point, and attached at an opposite end to said support member on said second rail; said fourth cable passing from said second site underneath said second lower pulley and over said second upper pulley, then over an upper pulley on said support member, then under a lower pulley on said support member.
  • 10. A ramp system as claimed in claim 9, wherein said carriage has two wheels, one on each side thereof, and said lower pulleys are integral with said wheels.
Priority Claims (1)
Number Date Country Kind
2367735 Jan 2002 CA
US Referenced Citations (10)
Number Name Date Kind
159233 Walters Jan 1875 A
2563260 Miller Aug 1951 A
2876919 True et al. Mar 1959 A
3168937 Redford Feb 1965 A
3592294 Allen Jul 1971 A
3891062 Geneste Jun 1975 A
4438830 Born Mar 1984 A
4595313 Kotke Jun 1986 A
6105726 Taylor et al. Aug 2000 A
6109854 Thompson et al. Aug 2000 A