Cargo lifting device for a ladder

A cargo lifting apparatus for use with a ladder includes a lift track coupled to each ladder side rail. Each lift track includes first and second adjacent channels, the first channel defining a longitudinal slot. The apparatus includes a carrier assembly having a back portion, a pair of support members extending perpendicularly and forwardly from the back portion, opposed mounting members configured to be received in a respective first channel slot, and rollers attached to the back portion configured to bear against respective ladder side rails. A motor/brake combination is coupled to a lower rung of the ladder. A pulley assembly includes a lower sprocket operatively coupled to the motor, an upper sprocket, and a cord extending between the sprockets and coupled to the carrier assembly for selectively raising and lowering the carrier assembly when the motor is activated or deactivated.

BACKGROUND OF THE INVENTION

This invention relates generally to cargo lifting devices and, more particularly, to a cargo lifting device for use with a ladder of the type having parallel rails and a plurality of rungs extending between rails.

Ladders are typically utilized by roofers, painters, or the like to bring shingles, paint, or other materials to the roof of a structure or other heightened location for use. Carrying heavy materials like shingles up a ladder is a dangerous proposition in that carrying such materials may require the use of both hands, leaving little ability of the workman to hang on to the rungs or rails of the ladder. In addition, manually carrying multiple packages of shingles, tools, or perhaps beverages is likely to require multiple trips up and down the ladder, increasing the dangerousness of the task.

Although various devices having been proposed in the art for lifting cargo in cooperation with a ladder, the existing devices do not provide a cargo assembly slidably operated on a pulley assembly controlled by a combination motor/brake and with a backup inertia reel safety device.

Therefore, it would be desirable to have a cargo lifting apparatus that overcomes the limitations of the prior art and provides a safe and user friendly apparatus for transporting cargo between a ground surface and upward structure such as the roof of a house.

SUMMARY OF THE INVENTION

A cargo lifting apparatus for use with a ladder according to a preferred embodiment of the present invention includes a life track coupled to each ladder side rail. Each lift track includes first and second adjacent channels, the first channel defining a longitudinal slot. The apparatus includes a carrier assembly having a back portion, a pair of support members extending perpendicularly and forwardly from the back portion, opposed mounting members configured to be received in a respective first channel slot, and rollers attached to the back portion configured to bear against respective ladder side rails. A motor/brake combination is coupled to a lower rung of the ladder. A pulley assembly includes a lower sprocket operatively coupled to the motor, an upper sprocket, and a cord extending between the sprockets and coupled to the carrier assembly for selectively raising and lowering the carrier assembly when the motor is activated or deactivated, respectively.

Therefore, a general object of this invention is to provide a cargo lifting apparatus for use with a ladder that is configured to selectively hoist construction materials up or down the ladder.

Another object of this invention is to provide a cargo lifting apparatus, as aforesaid, that utilizes a pulley assembly and motor to selectively actuate movement of a carrier assembly to move up or down the rails of the ladder.

Still another object of this invention is to provide a cargo lifting apparatus, as aforesaid, having a lift track coupled to each ladder rail having first and second channels, one of which defines a slot.

Yet another object of this invention is to provide a cargo lifting apparatus, as aforesaid, that includes a cargo carrier assembly having mounting members received in the channel slot for slidable movement therealong when the motor is activated, thereby raising or lowering cargo that is supported on the carrier assembly.

A further object of this invention is to provide a cargo lifting apparatus, as aforesaid, having a safety reel configured to prevent the carrier assembly from falling in the event of a failure of the motor/brake unit.

A still further object of this invention is to provide a cargo lifting apparatus, that is easy to use and economical to manufacture.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A cargo lifting apparatus10for use with a ladder2of a type having opposed parallel rails4and a plurality of rungs8connecting the ladder rails4will now be described with reference toFIGS. 1 to 12of the accompanying drawings. The lifting apparatus10includes a pair of lift tracks12, first14and second16channels in each lift track12, a carrier assembly20operatively coupled to respective lift tracks12for movement therealong, a motor/brake60combination coupled to the ladder2, and a pulley assembly connecting the motor/brake60with the carrier assembly20.

As shown inFIGS. 4ato4c, each lift track12is coupled to an outer surface6of a respective side rail4of the ladder2. It is understood that the outer surface6of a side rail may have a generally planar configuration to which an inner surface of a lift track12is complementary. More particularly, each lift track12includes first14and second16channels situated adjacent one another. Each channel includes a tubular configuration defining an interior space and open bottom and top ends such cords from a pulley assembly90may extend therethrough as will be discussed in more detail later.

Preferably, a pair of guide members18are positioned in the interior area of each first channel14although it may possible for only a single guide member18to be used. Each guide member18is configured to be movable along the inside of the first channel14as will be understood below. Preferably, the guide members18are constructed of a hard plastic or composite material and may include filleted edges so as to minimize friction when slidably moved within the interior areas of the channels.

The carrier assembly20includes a back portion22. At least one support member30is coupled to the back portion22adjacent a lower edge28thereof and extends forwardly away from the back portion22(FIG. 8a). Preferably, the at least one support member30is generally perpendicular to the back portion22. The support member30may include a lip32extending upwardly from a distal end36relative to the back portion22that is configured to prevent cargo supported on the support member30from sliding off the support member30. The lip32, therefore, may be generally parallel to and displaced from the back portion22of the carrier assembly20. The at least one support member30may be a platform. Alternatively, the at least one support member30may be two or more support members30opposed to or otherwise spaced apart from one another (FIG. 8a). Each support member30may define a plurality of spaced apart apertures34configured to enable accessories, such as tools or other materials, to be tied or otherwise coupled to the support member30.

The carrier assembly20includes at least one mounting member40configured to attach slidably to a lift track12. Preferably, however, the carrier assembly20includes a pair of mounting members40. Each mounting member40may be attached to a side edge26of the back portion22and configured to be received in the slot15of a respective first channel14. Each mounting member40may be construed as having “feet” configured to be inserted into a respective first channel slot15. The foot or mounting member40is coupled to a respective slidable guide member18that is positioned in a first channel (FIG. 7b). Therefore, each carrier assembly20is operatively coupled to the pulley assembly90by connection to a respective mounting member40and slidable guide member18.

At least a pair of rollers42is attached to the back portion22of the carrier assembly20and configured to bear against a respective ladder rail4when the mounting members40are received in respective first channel slots15, the rollers being configured to enable the carrier assembly to roll smoothly along the ladder rails.

With reference again to the back portion22, the back portion22may be a plate having a generally planar configuration that is generally perpendicular to the support member(s). Alternatively to the back portion22including a planar plate, the back portion22may include a pair of upstanding mounting rails44and a scissor mechanism46operatively coupled between the pair of mounting rails. The mounting rails44are configured for movement between collapsed and expanded configurations such that a distance between the mounting rails is increased when the scissor mechanism is moved toward the expanded configuration and is decreased when the scissor mechanism is moved toward the collapsed configuration.

The pulley assembly90includes a lower sprocket68rotatably coupled to a respective ladder side rail4below a respective lift track12and operatively connected to the motor/brake60. As shown inFIG. 5c, the lower sprocket68may be connected to a motor output shaft62with a gear train64having one or more gears and a gear train chain69configured such that operation of the motor/brake60operates the output shaft62, gear train64, and lower sprocket68. The lower sprocket68is positioned below a lower end of the lift track12.

A chain70is operatively coupled to the lower sprocket68and includes a first end72extending upwardly into the interior area of the first channel14and a second end74extending upwardly into the interior area of the second channel16. The pulley assembly90includes an upper sprocket66rotatably coupled to the same ladder side rail4as is coupled to the lower sprocket68. The upper sprocket66is positioned above the respective lift track12connected to that side rail4. The pulley assembly90includes a cable80operatively coupled for movement about the upper sprocket66that includes a cable first end82extending downwardly into the interior area of the first channel14and a cable second end84extending downwardly into the interior area of the second channel16.

The chain first end72is coupled to a guide member18situated in the first channel14and that is coupled to a mounting member40of the carrier assembly20(FIG. 7b). The cable first end82may be coupled to another guide member18situated in the first channel14and which is operatively connected to the carrier assembly20. Therefore, coordinated movement of the chain70and cable80cause the carrier assembly20to move upwardly or downwardly along the lift tracks12as respective guide members18are slidably moved within the lift tracks12. It is understood that the chain70and cable80may together be referred to as a cord. In addition, a tensioning device86may be situated intermediate the cable second end84and chain second end74so as to maintain cord alignment and sprocket engagement.

The combination motor/brake60may be attached to a lower rung9of the ladder2. The motor/brake60includes an output shaft62operatively connected to the pulley assembly90by way of the gear train64and gear train chain69described above. It is understood that when the motor/brake60is electrically activated, the lower sprocket68is rotated causing movement of the chain70and consequent movement of the carrier assembly20. The brake component of the motor60is configured to stop free spinning of the motor when the motor is electrically deactivated such that movement of the pulley assembly90and carrier assembly20are also halted from any further movement.

The cargo lifting apparatus10may include a pair of length adjustable brace member50although a single brace member50may work. Each (or a single) brace member50may include a first shaft telescopically received in another, said shafts defining holes into which a fastener may be inserted to maintain a desired position (FIGS. 11ato11d). The brace member50includes a first end52(i.e. upper end) configured to be releasably coupled to a ladder rung8, such as a clamp54or the like (FIG. 11b). The brace member50includes a second end56(i.e. lower end) configured to bear against a ground surface and may include a non-slip surface or an angle adjustable plate (FIG. 11d). The brace member50is configured to extend rearwardly and downwardly away from the ladder2at an angle different than the angle of the ladder2so as to brace and support a load on the carrier assembly20.

Further, the cargo lifting apparatus10includes shields covering the upper66and lower68sprockets. More particularly, a lower shield69is removably coupled to a side rail4and configured to cover the lower sprocket68(FIG. 4c). Similarly, an upper shield67is removably coupled to a side rail4and configured to cover the upper sprocket66(FIG. 4b).

The cargo lifting apparatus10includes an inertia reel100mounted adjacent an upper end of the ladder2, such as being coupled to an upper rung or to its own mounting framework (FIGS. 5aand5b). The inertia reel100includes a strap102that is movable from a retracted configuration within the reel100and an extended configuration extending downwardly away from the reel100. The strap102includes a distal end away from the reel100that is coupled to a flange24of the carrier assembly back portion22. The inertia reel100is configured to immediately halt extension of the strap102if extension of the strap102is sensed to be greater than at a predetermined speed, inertia, or velocity. In other words, the inertia reel100is configured to stop the carrier assembly20from falling should the motor/brake60fail to stop the downward movement thereof.

The motor/brake60may be in communication with a remote control110(also referred to herein as a controller). The controller42may be a handheld device that is electrically connected to the motor/brake via a data cable112or include a signal transmitter (not shown), in which case the motor/brake60includes a receiver (not shown). Preferably, the controller42is configured to start or stop operation of the motor/brake60. When the motor is stopped or deactivated, the brake automatically engages to stop free wheeling movement of the motor. When deactivated, the pulley assembly90is not able to move and the carrier assembly20is safely held in position along the rails4of the ladder2.

In use, the carrier assembly20may be loaded with cargo when it is at a lowered position on the ladder2. The cargo may be positioned on the support members30, the back portion22and support member lip32contributing to the stability of the load. Using the controller42, the motor/brake60may be actuated, causing engagement of the pulley assembly90as described above. Particularly, coordinated movement of the chain70and cable80that are coupled to the guide members18in the first channel14and mounting members40of the carrier assembly20, the carrier assembly20is urged in a desired direction. The length adjustable brace member50enhances the stability of the entire ladder. If the motor/brake60fails, the inertia reel100will instantly lock such that the carrier assembly20full of cargo will not slide downwardly out of control and potentially cause injury.