CROSS-REFERENCE TO RELATED APPLICATION (S)

This patent application claims priority from U.S. provisional patent application No. 61/306,021, filed on February 19, 2010, the specification of which is hereby incorporated by reference.

FIELD OF THE APPLICATION

[0001] The present application relates to elevation platform systems of the type mounted to structures to support a platform in moving up and down the structure .

BACKGROUND ART

[0002] There are numerous ways to climb up structures such as trees, posts, or the like. Numerous vehicles have been devised for such tasks . Cranes and booms are for instance commonly used for such tasks .

[0003] There are however instances in which cranes and booms are not efficient solutions. For instance, in remote locations, and in dense vegetation, cranes and booms are simply not practical. Ladders may also be used, however ladders may prove to be unstable on uneven terrain, and limited in terms of height .

[0004] It is known in the hunting industry to climb trees to hunt from an overlooking standpoint. However, the available systems for climbing up trees require a fair mount of physical strength and ability from the hunter. Numerous accidents have been counted in such circumstances .

SUMMARY OF INVENTION

[0005] It is an aim of the present disclosure to provide a novel modular elevation platform system. [0006] Therefore , in accordance with a first embodiment of the present application, there is provided a modular elevation platform system comprising: at least two rail segments releasably connectable end to end to form a rail unit adapted to be secured against an upstanding portion of a structure; a carriage operatively mounted to the rail unit for translational movement of the carriage along the rail unit; a transmission between the carriage and the rail unit to convert actuation to the translational motion of the carriage along the rail unit; and a frame secured to the carriage and adapted to support a platform.

[0007] Further in accordance with the first embodiment, the rail segments of the modular elevation platform system each have at least one guiding channel portion for receiving a portion of the carriage for translational motion of the carriage relative to rail unit, the at least one guide channel portion forming at least one continuous guide channel in the rail unit.

[0008] Still further in accordance with the first embodiment, the portion of the carriage received in the guide channel of the modular elevation platform system is at least two roller units of the carriage .

[0009] Still further in accordance with the first embodiment, the rail segments of the modular elevation platform system comprise end members at opposite ends, the end members each having a clamping means for gripping to the structure.

[0010] Still further in accordance with the first embodiment , the clamping means of the end members of the modular elevation platform system is a serrated surface adapted to purchase into the structure.

[0011] Still further in accordance with the first embodiment, at least one arm pivotally connected to the each of the end member is provided, the at least one arm adapted to be connected at a free end to a fastener used to fasten the rail segment to the structure .

[0012] Still further in accordance with the first embodiment, at least one arm of the modular elevation platform system has a serrated surface adapted to purchase into the structure.

[0013] Still further in accordance with the first embodiment, a latching mechanism is provided to releasably connect two of the rail segments end to end to form the rail unit .

[0014] Still further in accordance with the first embodiment, end members at opposed ends of each of rail segments are provided, the latching mechanism comprising at least one finger connected to a top one of the end members to move into latching engagement with a bottom one of the end members of end-to-end rail segments.

[0015] Still further in accordance with the first embodiment, at least one finger is provided and is a biased to an engagement position, the at least one finger having a ramp head for engaging with the bottom one of the end members to move against the biasing when rail segments are being positioned end to end, and a catch surface for abutting against the bottom one of the end members for interlocking the rail segments end to end.

[0016] Still further in accordance with the first embodiment, mating engagements means are provided in the top one and the bottom one of the end members for guiding an end to end engagement between the rail segments.

[0017] Still further in accordance with the first embodiment, at least one finger is provided, the at least one finger being positioned and biased on the rail segment to have a portion proj ecting into the guide channel portion when the rai.1 segment not connected to another rail segment at its top end.

[0018] Still further in accordance with the first embodiment, a ratchet mechanism is provided, the ratchet mechanism being operatively connected to a transmission for preventing a downward translational movement of the carriage along the rail unit, the ratchet mechanism having a portion actuatable to selectively allow the downward translational movement of the carriage.

[0019] Still further in accordance with the first embodiment, the transmission comprises a worm rotatably mounted to the carriage .

[0020] Still further in accordance with the first embodiment, worm pins spaced apart in the rail segments are provided, the worm pins being distanced and sized for the operative engagement of the worm in the worm pins .

[0021] Still further in accordance with the first embodiment, the worm pins are each rotatably connected to the rail segments by a bearing.

[0022] Still further in accordance with the first embodiment, a shaft of hexagonal section integral with the worm is provided, the shaft being releasably rotated by a hexagonal head socket .

[0023] Still further in accordance with the first embodiment, a brake system is provided, the brake system comprising a brake pad automatically engaging with the transmission for blocking the translational motion of the carriage along the rail unit.

[0024] Still further in accordance with the first embodiment, the transmission comprises a rotational portion rotating about a single rotational degree of freedom, and a speed limiting device for decelerating a rotational speed of the rotational portion beyond a given threshold.

[0025] Still further in accordance with the first embodiment, a speed limiting device is provided and comprises brake segments rotating with the rotational portion and expanding radially by centrifugal forces, the speed limiting device further comprising a cup for limiting an expansion of the brake segments. [0026] In accordance with a second embodiment of the present application, there is provided a method for moving a carriage along a vertical portion of a structure , comprising: attaching a first rail segment to a vertical portion of a structure, with a carriage operatively mounted to the first rail segment for movement thereon along a translational d direction; latching a second rail segment to the first rail segment such that the first rail segment and the second rail segment are end to end; attaching the second rail segment to the vertical portion of the structure ; and moving the carriage from the first rail segment to the second rail segment along the translational direction.

[0027] Further in accordance with the second embodiment , the latching, the attaching , the moving are repeated for at least a third rail segment.

[0028] Still further in accordance with the second embodiment, attaching the rail segments comprises strapping the rail segments to the vertical portion.

[0029] Still further in accordance with the second embodiment, attaching the rail segments also comprises purchasing the rail segments to the vertical portion.

[0030] Still further in accordance with the second embodiment, moving the carriage comprises moving the carriage with the translational direction being an upstanding translational direction .

[0031] Still further in accordance with the second embodiment, moving the carriage also comprises moving a user platform connected to the carriage.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Fig . 1 is a perspective view of a modular elevation platform system as mounted to a structure in accordance with an embodiment of the present application; [0033] Fig. 2 is a perspective view of a carriage and user platform of the modular elevation platform system of Fig. 1;

[0034] Fig. 3 is a perspective view of a rail segment of the modular elevation platform system of Fig . 1;

[0035] Fig. 4 is an enlarged view of a bottom end of the rail segment of Fig . 3;

[0036] Fig. 5A is an enlarged perspective view of an intersection of two rail segments of Fig. 3 with a clamping device;

[0037] Fig . 5B is an enlarged elevation view of an end one of the rail segment and clamping device;

[0038] Fig . 5C is an enlarged perspective view of pivoting arms of one of the rail segments;

[0039] Fig. 6 is a top plan view of the carriage mounted to the rail segment in the modular elevation platform system of Fig. 1 ;

[0040] Fig. 7 is a perspective view of a worm of the carriage of Fig. 6;

[0041] Fig. 8 is an enlarged perspective view of a ratchet unit of the carriage of Fig. 6;

[0042] Fig. 9 is a perspective view of the carriage of

Fig. 6, with a cover plate covering the worm gear;

[0043] Fig . 10 is a sectional elevation view of an interaction between the worm of the carriage and worm pins of the modular elevation platform system of Fig. 1 ;

[0044] Fig. 11 is an assembly view of components of the carriage in accordance with another embodiment;

[0045] Fig. 12 is an enlarged perspective view of a brake system of the carriage of Fig . 11 ; and

[0046] Fig. 13 is an assembly view of a speed limiting device of the carriage of Fig, 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Referring to the drawings and, more particularly to Fig. 1 , a modular elevation platform system is generally shown at 10 as installed on a structure such as a tree trunk A. The system 10 has a rail unit 11 made of a plurality of rail segments 12. The rail segments 12 are interconnected by clamping devices 13. A carriage 15 moves in translation along the rail unit 11 and supports a user platform 16, thus moving up and down the structure A.

[0048] The rail unit 11 is the base of the system 10 upon which the user platform 16 will be supported.

[0049] The rail segments 12 are the various segments that constitute the rail unit 11. The rai1 segments 12 are assembled end-to-end so as to define a selected height of the rail unit 11.

[0050] The clamping devices 13 lock rail segments 12 in end-to-end assembly such that the rail segments 12 are aligned to define the rail unit 11.

[0051] The carriage 15 is installed in translation on the rail unit 11 and comprises a transmission by which manual or motorized actuation will displace the carriage 15 on the rail unit 11 in vertical displacement. The carriage 15 is also operatively connected to the rail unit 11 to stay at a desired height, unless the user of the system 10 actuates the carriage 15 to move up or down the rail unit 11.

[0052] The user platform 16 is secured to the carriage

15 and supports a user or equipment positioned thereon and mounting up and down the rail unit 11.

[0053] Referring concurrently to Figs. 1, 3 and 4, the rail segments 12 are shown having an elongated body with a pair of guide rail channels 20 on opposed sides thereof . As described hereinafter, the guide rail channels 20 will accommodate parts of the carriage 15 in sliding engagement and will thus form a guide way for the translation of the carriage 15 thereon. The rail segments 12 may also have a single one of the guide rail channels 20, provided the guide rail channel 20 has sufficient structural integrity to support the carriage 15 , the user platform 16 and any load thereon.

[0054] A contact plate 21 is centrally positioned between the guide rail channels 20 and faces away from the structure A (e.g. , the tree trunk) when the rail segment 12 is installed against the structure A. The contact plate 21 is the interface of the rail segment 12 with the transmission of the carriage 15, as described hereinafter .

[0055] A plurality of transverse members interconnect the guide rail channels 20 with the contact plate 21. Some (or all) of the transverse members have claws 22 (i.e. , serrated surface) oriented towards the structure A when the rail segments 12 are against the structure A. The claws 22 purchase into the structure A. Two of the transverse members with the claws 22 are end places 23 , positioned at opposed ends of the rail segments 12. Claws 22 are well suited when the structure A is made of a material allowing the purchase (e.g. , wood) . Other clamping means may be considered, such as vacuum cups , magnets , or the like , depending on the nature of the structure A with which the system 10 will be used .

[0056] The end plates 23 have a pair of rectangular slots 24 , as well as alignment pin holes 25 and strap holes 26. The end plates 23 are configured such that the end-to-end assembly of the rail segments 12 may be performed manually by a single person. Pivoting arms 27 are provided on opposite ends of the end plates 23. The pivoting arms 27 each rotate about an axis that is generally parallel to a longitudinal dimension of the rail segments 12. The pivoting arms 27 may thus embrace the structure A upon which the rail segment 12 will be secured . Hence, the pivoting arms 27 may be clawed as shown in Fig. 5C, or may be provide with other suitable clamping means (e.g. , suction cups , magnets, etc) . Moreover, connection holes 28 may be provided at the free ends of the pivoting arms 27, with a strap, chain, rope, or like fastening element connected {e.g., hooked, attached, tied) at opposed ends to the pair of pivoting arms 27 of a respective end plate 23, to tie the rail segment 12 to the structure A.

[0057] The contact plates 22, or other transverse plates {as shown in the various figures) may also be equipped with pivoting arms 27 although not shown in the figures. Moreover, the fastening elements may be connected directly to the end plates 23, without the pivoting arms 27. It is also considered to secure the rail segments 12 directly to the structure A, for instance by using screws, bolts or like fasteners.

[00S8] Referring concurrently to Figs. 4 and 5A, one of the clamping devices 13 is shown interconnecting a pair of rail segments 12. As observed from Fig. 5A, a single one of the clamping device 13 is required at the junction of a pair of the rail segments 12. The clamping device 13 is typically installed on an upper end of the bottom rail segment 12A to connect to a bottom end of the upper rail segment 12B.

[0059] Although a complete embodiment is described below for the rail segments 12, it is pointed out that the rail segments 12 may have different shapes, different structural elements, etc. For instance, any translational engagement configuration between the rail unit 11 and the carriage 15 may be used. The guide rail channels 20 may for example be on the carriage 15, while rail unit 11 would bear appropriate rollers or guiding or sliding element, etc. The rail segments 12 provide support for the translational movement of the carriage 15, and must be secured to the structure A.

[0060] The clamping device 13 has a pair of clamping fingers 30 pivotally mounted to a support plate. The clamping fingers 30 each have a downwardly orientated catch surface 31 and an upwardly orientated ramp head 32. The clamping fingers 30 are biased away from one another by spring 33 (e.g., coil spring, leaf spring) or any other biasing element (e.g. , gravity based) that pushes the clamping fingers 30 away from one another. Alternatively, any other biasing direction is considered to bias the clamping fingers 30 to an interlocking position between the rail segments 12. In addition, pins 34 are provided to align the rail segments 12 by being threaded through the alignment pin holes 25 of the end plates 23 being positioned end-to-end in the manner shown in Fig . 5A .

[0061] When the rail segments 12 are positioned end- to-end in the manner shown in Figs . 5A and 5C, the rectangular slots 24 of adjacent end plates 23 will be in alignment. Accordingly, by action of ramp head 32 of the clamping fingers 30 against a periphery of the slots 24, the clamping fingers 30 will be pushed toward one another so as to enter into the rectangular slots 24 of the upper rail segment 12B, while the pins 34 allow the rail segments 12 to be in alignment. When the end plates 23 of end- to-end rail segments 12 are against one another, the ramp heads 32 are fully passed the top surface of the end plate 23 of the upper rail segment 12B, whereby the clamping fingers 30 move laterally away from one another such that the catch surface 31 abuts against the top surface of the end plate 23 of the upper rail segment 12B, as shown in Fig. 5A. Therefore, the rail segments 12 are interlocked by the catch surface 31 of the clamping fingers 30.

[0062] In an embodiment, the strap holes 26 may be used to receive strap end, by which the rail segments 12 will be attached to the structure A. Any conventional strap, cord, wire or the like having the structural integrity to support the rail unit 11 may be used to attach the rail segments 12 to the structure A, as set forth above . [0063] In order to disassemble the rail segments 12 , the clamping fingers 30 are brought towards one another against the action of the spring 33 such that the catch surfaces 31 are fully over the rectangular slots 24. At that moment, the upper rail segment 12B may be lifted away from engagement with the bottom rail segment 12A.

[0064] Referring to Fig . 5B, the rectangular slots 24 of the top end plate 23, may be of greater dimension than that of the bottom end plate 23 such that the catch surfaces 31 of the clamping fingers 30 project into the path of the guide rail channels 20 , when the clamping fingers 30 are not used to interconnect rail segments 12 in end- to-end fashion . Accordingly , this represents a safety feature to avoid having the carriage 15 derail out of an uppermost rail segment 12 of the rail unit 11. The clamping fingers 30 would come into contact with brackets 35 (Fig. 11) according to one embodiment.

[0065] The clamping device 13 may have different configurations in addition to that described above. For instance , the clamping device 13 may have a single finger 30. Traditional clamping systems may be used as well, with threaded fasteners, as alternatives to the quick- connection clamping device 13. The clamping device 13 is we11 suited for quick installation, due to its latching nature . Accordingly, latching mechanisms such as the clamping fingers 30 are well suited for the end- to-end interconnection of the rail segments 12.

[0066] Referring concurrently to Figs. 4, 5A and 10, worm pins 40 are shown and are part of the rail segments 12. The worm pins 40 interact with the carriage 15 for the translational movement of the carriage 15 on the rail unit 11. There are a plurality of worm pins 40 spaced apart on the contact plate 21. The worm pins 40 are typically round pins that are supported by bearings 41 , housed in housings 42 in an interior of the contact plates 21. It is observed that the contact plate 21 may have a C-channel configuration as shown in Figs . 4 and 5. The worm pins 40 have a portion thereof projecting through and beyond the contact plate 21, away from the structure A when the rail segments 12 are installed on the structure A. As the worm pins 40 are supported by a bearing 41, they are idle and free to rotate.

[0067] Referring concurrently to Figs . 6, 7 and 10 , the carriage 15 features a frame 50 having a pair of glider units 51. The glider units 51 have an outer shape defined as a function of the inner section of the guide rail channels 20 for a sliding engagement when the frame 50 is mounted to the rail unit 11, while the complementary engagement ensures that the only degree of freedom between the frame 50 and the rail unit 11 is the translational degree of freedom along the rail unit 11. Accordingly, the glider units 51 typically have a low friction surface as do the guide rail channels 20. As an alternative to the glider units 51, rollers 51' may be provided on the frame 50 for engagement into the guide rail channels 20 , as shown in Fig. 11.

[0068] A worm 52 is supported by the frame 50 and is oriented so as to be axially in alignment with a longitudinal dimension of the rail unit 11. The worm 52 may be supported by bearings so as to rotate freely along its longitudinally axis. Other configurations are considered as well, including providing casters with bearings, etc.

[0069] The pitch of the thread of the worm 52 is sized for the worm pins 40 to fit into the thread of the worm 52 as best shown in Fig. 10. Therefore, a rotation of the worm 52 will be converted into a translational movement of the frame 50 of the carriage 15 up and down the rail unit , from the engagement of the worm 52 with the worm pins 40. Although the presence of the bearings 41 is not necessary with the worm pins 40, they will cause the rotation of the worm pins 40 when the worm 52 rotates on itself . Therefore , the combination of the bearing - supported worm pins 40 and worm 52 define a low- friction transmission by which the carriage 15 moves up and down the rail unit 11. Moreover, the worm 52 allows a speed reduction and higher torque during the actuation of the carriage 15.

[0070] Referring to Figs. 6 to 10, a ratchet unit 53 is biased into engagement with a ratchet ring 54 coupled to an end of the worm 52. The ratchet unit 53 is biased by spring 55 that will allow the rotation of the worm 52 in a single direction, namely the direction corresponding to an upward movement of the carriage 15. In order to allow movement in the other direction , the ratchet unit

53 is pulled away from engagement with the ratchet ring

54 by manually pressing against the action of the spring 55. The ratchet unit 53 ensures that the carriage 15 is blocked from moving downwardly by gravity . The ratchet unit 53 may be locked into an opened position, to facilitate the downward movement of the carriage 15. A locking pin or any other blocking device may be used for locking the ratchet unit 53. Also, the ratchet unit 53 may be pivoted away, or disengaged using a pedal.

[0071] A coupler 56 is provided at the end of the worm

52. Accordingly, a drill with a hexagonal head socket may be used to actuate the rotation of the worm 52. Alternatively, as shown in Fig . 1 , a crank 57 may be used for the manual rotation of the worm 52. The platform 16, as shown in Figs . 1 and 2 , may have any suitable configuration, for instance with a seat 61, to support a user seated on the platform 16. Any suitable type of structure may be used to define the platform 16 for instance with a cage or guard railing.

[0072] Referring to Figs . 11 and 12 , a brake system 70 is illustrated. The brake system 70 may be provided to automatically lock the carriage 15 in a position along the rail unit. The brake system 70 has a brake pad 71 that is pivotally mounted to the structure of the carriage 15, The brake pad 71 is biased by biasing element 72 against a friction wheel 73. The friction wheel 73 rotates with the worm 52. In an embodiment of Pig. 13 , the friction wheel 73 may be constituted of a plurality of brake segments 74 engaging with a hexagonal section shaft of the worm 52, although other arrangements are possible. A cup 75, structurally secured to the carriage 15 and hence not rotating with the worm 52, may be used to keep the brake segments 74 together.

[0073] Hence , the brake pad 71 is biased against the. friction wheel 73, whereby friction between the brake pad 71 and the brake segments 74 of the friction wheel 73 will oppose against the rotation of the worm 52.

[0074] Pedal 76 is also pivotally mounted to the structure of the carriage 15, and when the pedal 76 is pressed, the brake pad 71 will move out of engagement with the friction wheel 73, thereby allowing rotation of the worm 52. When the pedal 76 is released, the biasing element 72 will bias the brake pad 71 against the friction wheel 73, for braking action to occur.

[0075] It is also observed that a speed limiting device may be provided, for instance with segments 74 in combination with the cup 75 limiting a rotational speed of the worm 52. More specifically, centrifugal forces resulting from a rotation of the worm 52 will result in a radial expansion of the set of brake segments 74. The brake segments 74 may be sized in such a way that the brake segments 74 will contact the cup 75 when the rotational speed is above a given threshold . The resulting fractional forces will decelerate the rotational speed of the worm 52.

[0076] In order to install the modular elevation platform system 10 to a structure such as a tree A, a first rail segment 12 with the carriage 15 and user platform 16 is secured (e.g., strapped) against the base of the structure A using appropriate straps or cords in the strap holes 26 (Fig. 5A) . A second rail segment 12 is positioned atop the first rail segment 12 , in such a way that the clamping fingers 30 of the clamping device 13 (Fig . 5A) releasably lock the rail segments 12 in end-to- end assembly. By the presence of the pins 34 and alignment pin holes 25, the guide rail channels 20 of the adjacent rail segments 12 are aligned so as to enable the continuous movement of the glider units 51 in the end-to- end guide rail channels 20.

[0077] The second rail segment 12 is then secured

(e.g., strapped) to the structure A, with the claws 22 purchasing into the structure A. At that point, the user platform 16 may be moved upwardly (by actuating the carriage 15) and supported by the uppermost rail segment 12 such that another rail segment 12 may be positioned atop the two first ones. In order to remove the rail segments 12 to disassemble the modular elevation platform system 10, the straps are first removed, and the uppermost rail segments 12 are then removed from the bottommost ones by disengaging the clamping fingers 30 of the clamping device 13 in the matter described previously. It is pointed out that the carriage 15 and thus the user platform 16 must be below the rail segment 12 being removed.

[0078] The transmission using a worm is an efficient solution to convert rotational movement into a translation of the carriage 15. However, other systems are considered as well, such as rack and pinion assemblies. In such a case , gear boxes may be used to allow suitable speed reduction and torque transmission. Moreover, it is considered to provide the system 10 with motors integral with the carriage 15. For instance , electric motors may be used, using appropriate specifications or gear boxes for suitable torque and speed outputs . The inertial of electric motors could be used to limit the rotational speed of the worm 52 as alternatives to the systems described above .