Abstract:
An apparatus for carrying loads on inclined surfaces, comprising a support surface adapted to fixedly support a load. An endless track is connected to the support surface and adapted to propel the apparatus on an inclined surface. A power source is provided for actuating the endless track. An anti-roll device is provided for increasing a length of the apparatus beyond the endless track in a direction of movement of the apparatus on the inclined surface to prevent an overturning of the apparatus when transporting loads.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to load-carrying apparatuses and, more specifically, to load-carrying apparatuses used to transport heavy goods on limited-access inclined surfaces, such as staircases.  
         [0003]     2. Background Art  
         [0004]     Various types of load-carrying apparatuses have been developed to carry loads up or down inclined surfaces, that are not readily accessible by larger vehicles such as trucks. For instance, such load-carrying apparatuses are used inside buildings without elevators, or in which elevators cannot accommodate the loads to be carried up. Such apparatuses are used when loads are beyond size and/or weight ranges of human carriers.  
         [0005]     A simple form of a load-carrying apparatus has an endless belt, or track, providing the traction, and a support surface to secure the load to the apparatus. A potential problem with such load-carrying apparatuses occurs when loads of a normegligible height are carried over the inclined surfaces. The center of inertia of the loads is generally related to the height with respect to the ground. Accordingly, loads of normegligible height increase the height of the center of inertia with respect to the inclined surface. As a function of the inclination surface, the gravity can cause the overturning of the load and the load-carrying apparatus. The overturning of the load will not only damage the load, but will also represent a potential danger to people in the surrounding area of the load.  
       SUMMARY OF INVENTION  
       [0006]     It is therefore an aim of the present invention to provide a novel load-carrying apparatus.  
         [0007]     It is a further aim of the present invention to provide a load-carrying apparatus having a mechanism to reduce the risk of overturning.  
         [0008]     It is a still further aim of the present invention to provide a load-carrying apparatus having mechanisms for facilitating the positioning of loads thereon.  
         [0009]     Therefore, in accordance with the present invention, there is provided an apparatus for carrying loads on inclined surfaces, comprising: a support surface adapted to fixedly support a load; an endless track connected to the support surface and adapted to propel the apparatus on an inclined surface; a power source for actuating the endless track; and an anti-roll device for increasing a length of the apparatus beyond the endless track in a direction of movement of the apparatus on the inclined surface to prevent an overturning of the apparatus when transporting loads.  
         [0010]     Further in accordance with the present invention, there is provided an apparatus for carrying loads on inclined surfaces, comprising: a support surface adapted to fixedly support a load; an endless track connected to the support surface and adapted to propel the apparatus on an inclined surface; a power source for actuating the endless track; and a cylindrical roller mounted to the apparatus adjacent to the support surface, for facilitating the positioning of a load onto the support surface. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof and in which:  
         [0012]      FIG. 1  is a perspective view of a load-carrying apparatus in accordance with a preferred embodiment of the present invention, with an endless track removed;  
         [0013]      FIG. 2  is a perspective view of the load-carrying apparatus of  FIG. 1 , with a portion of casing and rollers removed;  
         [0014]      FIG. 3  is a perspective view of the load-carrying apparatus of  FIG. 2 , from a rear point of view;  
         [0015]      FIG. 4  is a side elevation view of the load-carrying apparatus;  
         [0016]      FIG. 5  is a side elevation view of the load-carrying apparatus in accordance with a further embodiment of the present invention;  
         [0017]      FIG. 6  is a side elevation view of the load-carrying apparatus in accordance with a still further embodiment of the present invention  
         [0018]      FIG. 7  is a side elevation view of an endless track for the load-carrying apparatus of the present invention; and  
         [0019]      FIG. 8  is a perspective view of a roller device for the load-carrying apparatus of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     Referring to the drawings, and more particularly to  FIG. 1 , a load-carrying apparatus in accordance with a preferred embodiment of the present invention is generally shown at  10 . The apparatus  10  has a body  12  supporting an endless track system  13 , a power source  14 , and an anti-roll device  15 . Each of these elements will be described in further detail hereinafter.  
         [0021]     The Body  12   
         [0022]     Referring concurrently to  FIGS. 1 and 2 , the body  12  defines the structure of the apparatus  10  and supports the various elements of the apparatus  10 . More specifically, the body  12  has an elongated rectangular cross-section hollow casing  20 , having an upper plate defining a load-supporting surface  21  and a lower plate defining an element-supporting surface  22 . The upper plate and the lower plate are spaced from one another so as to define an inner cavity of the casing  20 , in which various elements of the apparatus  10  will be held. A pair of lateral sides  23  are integrally formed with the upper plate (e.g., a single sheet), and lower plate, as best seen in  FIG. 2 , is fixed to the lateral sides  23  to define therewith the hollow casing  20  ( FIG. 1 ).  
         [0023]     The load-supporting surface  21  and lateral side  23  of the casing  20  are equipped with various connectors in view of the securement of a load on the load-supporting surface  21 . For instance, various slots and holes  24  are illustrated in the lateral side  23  exposed in  FIG. 1  so as to accommodate straps and other similar securement means. Moreover, the upper plate is preferably reinforced (e.g., with transverse beams) so as to sustain the load secured to the load-supporting surface  21 .  
         [0024]     Referring to  FIG. 1 , a back system is optionally provided in order to offer additional support to a load being carried on the load-supporting surface  21 . The system has a back plate  25  that is supported so as to be translatable with respect to a longitudinal direction of the apparatus  10 . More specifically, rails  26  are respectively positioned on the lateral sides  23  to enable the translating motion of the back plate  25  with respect to the casing  20 . Releasable fasteners are used in order to secure the back plate  25  in a given position with respect to the casing  20 . It is pointed out that the releasable fastener provides fastening of sufficient magnitude in order to withstand a portion of the load carried by the apparatus  10  when the apparatus  10  is on an inclined surface. Also, it is contemplated to provide the load-supporting surface  21  with a rubbery surface or the like, to increase the adherence of a load onto the load-supporting surface  21 .  
         [0025]     Referring to  FIGS. 2 and 3 , the lower plate has an undersurface  27  upon which an endless track of the apparatus  10  will slide to provide the apparatus  10  with traction. The undersurface  27  will ensure that the endless track remains in contact against the inclined surface. The undersurface  27  is optionally lubricated or provided with a low-adherence coating.  
         [0026]     A pair of guide bars  28  are provided on the full length of the undersurface  27 , so as to define a channel therebetween. The guide bars  28  will therefore enclose the endless track such that the latter remains centered in the apparatus  10 . The guide bars  28  project beyond the undersurface  27  with curled ends to guide the endless track off/onto the undersurface  27 .  
         [0027]     The Endless Track System  13   
         [0028]     Referring concurrently to  FIGS. 1, 2  and  3 , the endless track system  13  has pairs of front wheels  30 A and back wheels  30 B to actuate the endless track. The front wheels  30 A are the drive wheels, whereas the back wheels  30 B are driven by the endless track, the latter being shown separately as  30 C in  FIG. 7 . The pairs of wheels  30 A and  30 B are respectively interconnected by shafts  31 A and  31 B. The shafts  31 A and  31 B are mounted to the element-supporting surface  22  by brackets  32 A and  32 B, respectively. Longitudinal fingers  33  are provided to engage with complementary fingers  33 B within the endless track  30 C ( FIG. 7 ). The fingers  33 B of the endless track  30 C ( FIG. 7 ) are received between the longitudinal fingers  33  of the front wheels  30 A, whereby the endless track  30 C ( FIG. 7 ) is driven by the front wheels  30 A.  
         [0029]     A pair of driven sprockets  34  are provided at an end of the shaft  31 A so as to receive a drive from a drive source  35  of the endless track system  13 . In a preferred embodiment of the present invention, the drive source  35  is an electric motor equipped with a reducer in order to provide a suitable amount of torque to the front wheels  30 A. As best seen in  FIGS. 2 and 3 , a drive sprocket  36  of the drive source  35  is positioned adjacent to the driven sprockets  34 . A chain is used to transmit motion from the drive sprocket  36  to the driven sprocket  34  of the shaft  31 A. Gears, pulleys and belt and the like could alternatively be used to transmit motion from the drive source  35  to the front wheels  30 A.  
         [0030]     Referring concurrently to  FIGS. 1, 2  and  3 , the guide bars  28  are positioned so as to guide the endless track  30 C ( FIG. 7 ) from the front wheels  30 A to the undersurface  27 , and from the undersurface  27  to the back wheels  30 B. The casing  20  defines a clearance just below the load-supporting surface  21 , through which the endless track  30 C ( FIG. 7 ) will pass. It is pointed out that the brackets  32  and/or the wheels  30 A and  30 B are suitably provided with bearings in order to ensure the efficient rotation of the wheels  30 B and  30 B in the apparatus  10 .  
         [0031]     The endless track is typically made of a polymeric material, and may be provided with treads or like surfacing to ensure suitable traction of the apparatus  10 . Moreover, it is contemplated to provide the endless track with spikes for icy conditions. Moreover, although the apparatus  10  is illustrated as having a single endless track  30  ( FIG. 7 ), it is contemplated to provide the apparatus  10  with a pair of tracks. In an embodiment with a pair of tracks, the drive to the endless tracks has two degrees of actuation and independent drive mechanisms, whereby the tracks may be actuated in opposite directions with respect to one another, to allow the apparatus  10  to rotate. Alternatively, the apparatus  10  may be provided with a peripheral rotating table, so as to rotate the apparatus  10 .  
         [0032]     The Power Source  14   
         [0033]     Referring to  FIGS. 2 and 3 , the power source  14  is illustrated being positioned adjacent to the drive source  35 . More specifically, the power source  14  is a battery that will operate the drive source  35 . Moreover, as will be described hereinafter, the apparatus  10  has other electrically devices that are to be powered by the power source  14 . The drive source  35  is therefore an electric motor that can be readily actuated for forward or reverse motion.  
         [0034]     The Anti-Roll Device  15   
         [0035]     Referring to  FIGS. 1 and 4 , the anti-roll device is generally shown at  15 . The anti-roll device  15  has a pair of arms  50  that project rearwardly from the apparatus  10 . According to a preferred embodiment of the present invention, the arms  50  each have a longitudinal portion  51  generally parallel to a longitudinal axis of the apparatus  10 , and a downwardly-facing end projection  52 , generally perpendicular to the longitudinal portion  51 .  
         [0036]     The arms  50  come into contact with the inclined surface in the event that the apparatus  10 , and its load, tend to overturn. As seen in  FIG. 4 , the end projections  52  are slightly above the undersurface  27 , so as not to impede with the normal displacement of the apparatus  10 , but to come into contact with the inclined surface upon which is the apparatus  10 , as soon as there is motion of the apparatus  10  toward overturning.  
         [0037]     Therefore, the arms  50  increase the length of the apparatus  10  so as to prevent an overturning of the apparatus  10 . Considering that the tendency to overturn is related to the position of center of inertia of the load/apparatus  10  combination, the length of the arm  50  may be decided according to the type of loads that the apparatus  10  is expected to carry. Moreover, although an L-shape is described for the arms  50 , other suitable shapes could be provided. For instance, the end projection  52  lose their efficiency in stair cases between nosings of stairs. Accordingly, it is contemplated to provide another projection that is parallel to the longitudinal portions  51 , and slightly above the undersurface  27  when the apparatus  10  is horizontal.  
         [0038]     It is also contemplated to have the arms  50  release automatically from a tucked position under the upper plate. More specifically, a mercury level trigger, such as that described in U.S. Pat. No. 5,996,767, issued to Misawa on Dec. 7, 1999, could be used in conjunction with the power source  14  to actuate the release of the arms  50  from the tucked position. The mercury level trigger could be adjusted to release the arms  50  for a predetermined incline of the apparatus  10 .  
         [0039]     The automatic release of the arms  50  is preferred in instances where the variation in incline is abrupt. For instance, if the apparatus  10  goes from a horizontal surface to an inclined surface, the arms  50  could impede on the displacement of the apparatus  10 . Therefore, rather than having the hazardous situation in which a person goes behind the loaded apparatus  10  to release the arms  50  after the apparatus  10  has reached the inclined surface, the arms  50  would release automatically upon reaching the inclined surface. Alternatively, the releasing of the arms  50  of the anti-roll device  15  could be performed by a remote controller. As the power source  14  is preferably electrical, linear actuators (as shown at  51  in  FIG. 4 ) or valves can be used to release the arms  50 .  
         [0040]     Roller System  60   
         [0041]     Referring to  FIG. 1 , the apparatus  10  is optionally provided with a secondary roller system  60 . The roller system  60  has rollers  61  positioned at the four corners of the apparatus  10 , and are releasable from a retracted position to be used instead of the endless track system  13 . For instance, the roller system  60  is used when the apparatus  10  is on a flat surface, when traction is not required, and when the loaded apparatus  10  can be pushed around manually.  
         [0042]     The rollers  61  are of the swivel type to facilitate the guiding of the loaded apparatus  10 . Therefore, the rollers  61  each have a swivel mount  62 . As seen in  FIG. 1 , the swivel mounts  62  (two of which are visible) are respectively mounted to a front pivot bar  63 A and a rear pivot bar  63 B. The lateral sides  23  of the casing  20  have arcuate guideways  29 , and the swivel mounts  62  each have a guide pin within a respective guideway  29 , so as to be guided between the retracted position and a deployed position, which is shown in  FIG. 1 .  
         [0043]     Referring to  FIGS. 2 and 3 , a mechanism for actuating a change of position of the rollers  61  is generally shown at  64 , with the rollers being removed from  FIGS. 2 and 3  for clarity purposes. The front pivot bar  63 A and the rear pivot bar  63 B are pivotally mounted to the lower plate so as to be rotatable about their longitudinal axes. The mechanism  64  has levers  65 A and  65 B, respectively mounted to the front pivot bar  63 A and the rear pivot bar  63 B. A link  66  interconnects the levers  65 A and  65 B, so as to define a parallel mechanism therewith. An actuator  67  (e.g., a linear actuator, a hydraulic cylinder), is provided to actuate the displacement of the parallel mechanism formed by the levers  65 A,  65 B and the link  66 . The actuator  67  is sized so as to be adapted to deploy the rollers  61  with the apparatus  10  being loaded.  
         [0044]     The levers  65 A and  65 B each receive a guide pin of the swivel mount  62 , so as to actuate the displacement of the rollers  61  between the retracted position and the deployed position. One of the guide pins is shown at  68  in  FIG. 3 .  
         [0045]     Locking System  70   
         [0046]     Referring to  FIGS. 2 and 3 , the apparatus  10  is optionally provided with a locking system  70  to lock the endless track system  13 . The locking system  70  has a pivot bar  71  and a brake  72 . As best seen in  FIG. 3 , the brake  72  has fingers  73  that will engage with the longitudinal fingers  33  of the front wheels  30 A, so as to prevent the rotation of the front wheels  30 A, and hence of the endless track thereon.  
         [0047]     As an example, the locking system  70  is to be actuated when the loaded apparatus  10 , moving upwardly on an inclined surface, moves downwardly due to a power failure from the power source  14 . In this example, the brake  72  may be of the ratchet type, to enable a unidirectional rotation of the front wheels  30 A.  
         [0048]     However, the apparatus  10  will also be used to carry loads down inclined surfaces, whereby another locking system  70  could be used to prevent the unwanted downward acceleration of the loaded apparatus  10 .  
         [0049]     For instance, the locking system  70  may be manually deployed by a nearby operator through the use of a cable that will release the locking system  70  into engagement with the front wheel  30 A. Alternatively, the locking system  70  could be electrically powered and its release could be triggered using a remote controller.  
         [0050]     Leveling Table  80   
         [0051]     Referring to  FIG. 5 , a leveling table  80  is optionally provided on the apparatus  10 . In instances where loads must be kept horizontal (e.g., a wheel chaired person), the leveling table  80  is used to achieve the leveling. More specifically, an actuator  81  is provided to lift a plate  82  pivotally mounted at a front end to an upper surface of the casing  20 . The actuator  81  must be sized to support a load on the plate  82 .  
         [0052]     Other Features  
         [0053]     Referring to  FIG. 6 , there is shown improvements to the present invention, in which the apparatus  10  has a vertically displaceable load-supporting surface  100 , by way of a scissor mechanism  101  suitably actuated, (e.g., with the power source  14 ). This feature is used to facilitate the reception/removal of a load on/from the load-supporting surface  100 . For instance, the load may be slid onto the load-supporting surface  100  from a transport vehicle (e.g., track). Alternatively, the load-supporting surface  100  may be lifted to slidingly displace a load onto an elevated surface (e.g., track, loading dock).  
         [0054]     Referring to  FIGS. 2 and 3 , a charger is generally shown at  90 , so as to re-charge the power source  14 , in embodiments of the present invention in which the power source  14  is a battery. A power generator is optionally provided to recharge the power source  14 , to confer a greater autonomy to the apparatus  10 .  
         [0055]     It has been discussed that the apparatus  10  is preferably remotely controlled. More specifically, a wireless or wired control pad can be related to the drive source  35  so as to control the displacement of the loaded apparatus  10  from a distance. Moreover, the control pad may have other functions, such as the deployment or retracting of the rollers  61  of the roller system  60  ( FIGS. 1, 2  and  3 ), as well as the leveling of the leveling table  80 . The use of remote distance control is advantageous in that the apparatus  10  carries heavy loads that could cause serious damage and harm if dropped. Therefore, the operator is to be positioned at a safe distance (e.g., upstairs) from the apparatus  10  when the latter carries loads on inclined surfaces.  
         [0056]     As a further suggested feature of the apparatus of the present invention, a buggy (not shown) may be added to the apparatus  10 . For instance, such a buggy can be used to further increase the load-carrying surface associated with the apparatus  10 . It is pointed out that the buggy is not to impede with the action of the anti-roll device  15 .  
         [0057]     It has been discussed previously that the apparatus  10  of the present invention may be provided with a mercury level trigger for releasing the arms  50  of the anti-roll device  15 . Such a level trigger could also be used to indicate that the inclined surface upon which the apparatus  10  operates is too steep for safe operation, or beyond predetermined inclination values.  
         [0058]     Referring to  FIG. 8 , a conveying roller is generally shown at  110 . The conveying roller  110  has a pair of legs  111  each defining a slot  112 . The legs  111  support a cylindrical roller  113 , such that the cylindrical roller  113  is free to rotate about its longitudinal axis. The conveying roller  110  will be used to facilitate the loading of an item onto the load-supporting surface  21 .  
         [0059]     More specifically, referring to  FIG. 1 , the lateral sides  23  of the apparatus  10  are shown having a pair of projecting portions  113  adjacent to a front end of the apparatus  10 . As shown in  FIG. 4 , the conveying roller  110  is positioned onto the apparatus  10  with the projecting portions  113  received in the slots  112  of the legs  111 .  
         [0060]     In order to load the apparatus  10 , an object may be tilted onto the conveying roller  110 , at which point the conveying roller  110  is used to help a person push the object into position on the load-supporting surface  21 . The conveying roller  110  may also be used to discharge an object from the apparatus  10 . The conveying roller  110  is particularly useful in instances where the load is heavy and bulky. For instance, the conveying roller  110  can be used to load and discharge a safe onto/from the apparatus  10 , provided the conveying roller  110  and the projecting portions  113  are sized for such a load.  
         [0061]     The endless track system  13  can be used in combination with the conveying roller  110  to convey the load onto the support surface of load-supporting surface  21 . More specifically, if the rollers  61  of the roller system  60  are deployed, the apparatus  10  does not rest on the endless track  30 C ( FIG. 7 ). Therefore, a load may be tilted on both the exposed portion of the endless track  30 C and the conveying roller  110 , at which point an actuation of the endless track system  13  can entrain the load onto the load-supporting surface  21 .  
         [0062]     Referring to the side elevation views of the apparatus  10 , such as  FIGS. 4 and 5 , it is seen that the front wheel  30 A of the endless track system  13  is well exposed beyond the lateral side  23 , as opposed to the rear wheel  30 B. The exposure of the endless track system  13  at the front end thereof enables the apparatus  10  to climb obstacles, such as stairs. Oppositely, the endless track system  13  is generally concealed within the casing  20 , to prevent having the rear portion of the endless track system  13  as the only point of contact with the inclined surface, in an hazardous situation where the apparatus  10  is tilted toward overturning.  
         [0063]     The various components of the apparatus  10  are principally positioned toward a front end of the apparatus  10 , such that the center of mass of the apparatus  10  is closer to a front end of the apparatus  10  than a rear end thereof. This will further reduce the possibility of an overturn of the loaded apparatus  10 .  
         [0064]     The apparatus  10  is used efficiently to carry loads on unstable ground, such as snow, sand, mud or the like. The endless track system  13  offers sufficient traction to displace the load through unstable ground.  
         [0065]     It is within the ambit of the present invention to cover any obvious modifications of the preferred embodiment described herein, provided such modifications fall within the scope of the appended claims.