The present invention relates to hoisting devices. Particularly it pertains to a new lifting device used in conjunction with a ladder for raising construction materials onto the roof of a building.
Construction workers are often called upon to transport construction materials and equipment onto the roof portion of a building. The materials may include roofing shingles, plywood sheets, bricks, ventilation units or even ornamental structures. Various lifting devices have been employed to accomplish this task. Such devices often require multiple persons to operate, have limited safety features and are often quite expensive to purchase and maintain.
Applicant proposes a load lifting system used in conjunction with a ladder to move a load to the roof of a building. The system is comprised of a carriage that rolls along the rails of conventional extension ladders and a self-contained hoisting mechanism for raising a load to the roof surface of a building.
The carriage of Applicant's lifting system includes a dual braking mechanism that reduces the risk of a loaded carriage sliding or rolling down the ladder during a lift or off of the roof once the load is brought to the roof surface. Applicant's lifting system also includes ladder rail adaptors to provide for a smooth transition of the carriage as it rolls along the rails of extension ladders and an eave adaptor to provide for a smooth roll surface between the ladder rails and the roof surface. The proposed lifting system also includes an infinitely adjustable ladder support to provide an intermediate support to the extension ladder.
The present invention provides a hoisting system for use in conjunction with a ladder to lift loads to a roof surface. The device is primarily intended to lift materials to the surface of pitched roofs typically used in residential construction. The device may also be employed to raise loads to flat or substantially flat roofs or to various levels of a wall during its construction and it may be of particular use in the construction of masonry walls.
The hoisting system is comprised of a load-bearing carriage having a roller axle and wheel assembly that allows the loaded carriage to roll up the rails of a ladder on its axels and then roll along a roof surface on the provided wheels to a desired unloading area. A rail guide is provided to maintain alignment of the carriage as it travels on the ladder rails.
A self-contained hoisting means is provided to roll the carriage along the ladder rails and along the roof surface. The hoisting means includes a roof anchor mechanism that adapts to the pitch of the roof in which it is used and thus allows for its employment on roofs having a variety of different roof slopes. The hoisting means is further comprised of a winch mechanism and pull cable arrangement having a support that works in cooperation with the roof anchor mechanism.
The carriage is further provided with a dual breaking mechanism as a safety device. The first breaking mechanism is comprised of a breaking bar that slides over the ladder rungs during a lift up the ladder but provides a positive stop against a ladder rung in the event of an untoward reversal of the carriage during the lift. The second breaking mechanism is comprised of elongated spikes that dig into the roofing surface and serve to hold the carriage on the roof in the event of an untoward reversal of the carriage while it is on a roofing surface.
Adaptors are provided for the ladder rails to allow for a smooth transition of the carriage between ladder rail extensions and from the ladder rails to the roof surface.
An infinitely adjustable ladder support is provided to give support to the extension ladder a point between its ends. This allows the user of the device to reduce the angle of the lift and as a consequence increase the lift capacity of the hoisting device.
Referring now to the drawings and more particularly
The hoisting assembly 14 is comprised of a carriage 12 that rolls along and is supported by the rails 23 and 23A of the ladder assembly. A winch assembly 16 having a winch cable 20 is used, in conjunction with a roof anchor 18 attached to the ridge of the roof 210, to roll the carriage 12 along the ladder 22 to the roof 210.
A carriage deck assembly 27 is supported on the frame 26. The carriage deck assembly 27 has a first deck portion 27A a second deck portion 27B. These deck portions 27A and 27B are pivotally attached to the carriage frame 26 by means of carriage deck hinges 28. To minimize load shifting during a lift the carriage 12 is provided with a deck load support bar 29 adjustably mounted to the frame 26 by means of a load support bar adjustment screw 29A.
The carriage 12 has a carriage load stop 36 which is comprised of a lower load stop frame 38 having tubular lower load stop frame columns 40 and an upper load stop frame 42 having upper load stop columns 44 that slidably fit into the tubular support columns 40 and held in place by means of adjustment screw 48. This arrangement allows for telescopic adjustment of the height of the load stop 36. The load stop 36 has a load stop brace 46 mounted on load stop brace support 46A attached to the upper load stop frame 42. The upper load stop frame 42 may be reversed to position the load support brace 46 atop a load carried on the deck surface 27.
The carriage 12 is provided with a carriage hitch bar 70 mounted to the frame 26 of the carriage 12. The carriage hitch bar 70 has a carriage hitch ring 71 for attachment of the cable 20 from the winch assembly 16.
Referring to
The carriage brake assembly 50 also includes a roof brake assembly 58. The roof brake assembly 58 is comprised of a roof brake claw 60 that is pivotally mounted on the axle 30 between the ladder rung brake bars 52 by means of roof brake bearings 62. Upper and lower carriage ladder support pins 64 attached to the claw 60 impede the full rotation of the roof brake claw 60 on the axle 30. The pins 64 engage the brake bars 52 and allow the carriage brake claw 60 to dig into a roof surface when the carriage 12 rolls down a roof surface.
The carriage brake assembly 50 and roof brake assembly 58 are engaged and disengaged by means of a brake engagement lever 66 that pivots on a brake engagement lever bearing 68 mounted on the roof brake claw assembly 58. When the brake assembly is disengaged the lever 66 is upwardly biased against the carriage hitch bar 70. To engage the braking system prior to making a lift, the engagement lever 66 is pivoted off of the hitch bar 70 to allow the claw 60 of the roof brake assembly 58 and the brake bars 52 of the carriage brake assembly 50 to freely pivot on the axle 30.
The carriage brake assembly 50 and roof brake assembly 58 can also be completely disengaged, as shown in
In
The winch assembly 16 of the hoist assembly 14 is shown in
The roof anchor assembly 18 is shown in
Referring again to
To lower the carriage 12 from the roof surface to 210 and down the extension ladder 22, the break assemblies 50 and 58 are disengaged by means of lifting the deck 27B to expose the brake/carriage deck latch 69 and then lifting the ladder rung brake bar 52 and placing the brake rung stop 56 on the deck latch 69. This procedure will disengage the break assemblies 50 and 58, by holding the bars 52 and the claw 60 above the roof surface 210 and the ladder rungs 24, so that the unloaded carriage 12 may be rolled along the roof 210 and ladder 22.
As can be seen from the illustrations, the carriage 12, in combination with the ladder 22, the roof ridge anchor 18, and the hoist assembly 16, provides for a self-contained hoisting assembly 14. This hoisting assembly 14 allows the winch 60 to be transported to the roof 210 on the carriage 12, detached from the carriage 12, and mounted on the roof anchor 18. The cable 20 may then be attached to the hitch ring 71 of the carriage 12 to allow the carriage 12 to be lowered down the roof and ladder 22. The user never has to manually bring the winch 60 to the roof surface 210 to facilitate a hoisting of a load. Once the carriage 12 is off the roof 210 and on the ground or a truck bed, the deck 27 may be loaded and pulled up the ladder 22 by means of the winch assembly 16. The process may be is repeated as necessary.
The carriage 12 may also be moved on the ladder 22 in the matter described above by placing the anchor stops 84 of the winch support frame 80 on the rungs 24 of the ladder and attaching the cable 20 to the carriage winch ring 71. This will allow loads to move up a ladder positioned against a wall without the use of the anchor assembly 18.
The foregoing is considered illustrative only of the principles of the invention. It may be apparent to those skilled in the art that numerous modifications and changes may be made in such details without departing from the spirit and principles of the invention.
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