The present invention relates to loading and unloading cargo in a truck or trailer and more particularly, to an elevator delivery system for use in a truck body or trailer.
Trucks have long been used to transport large amounts of cargo of various types. The truck bodies and trailers used to hold the cargo are typically designed to have a high clearance from the ground. Although the cargo can often be loaded easily into the truck bodies and trailers at a loading dock, the cargo is more difficult to load and unload from the ground. The drivers often must climb in and out of the truck to unload the cargo during deliveries. The additional labor required to unload the cargo may result in longer delivery times and more injuries to the delivery person.
Various devices have been used to facilitate unloading the cargo, for example, ramps and hydraulic tailgates added to the rear of the truck or trailer chassis. Although these devices may help to unload the cargo, they often take additional time and labor to operate, for example, to pull out the ramp or to unfold the tailgate platform. Another device, known as the Lang doorway lift, uses a platform to lower or lift the cargo from the truck bed usually in a side door of the truck body. The Lang doorway lift, however, is operated using a single hydraulic cylinder and a complicated cable and pulley system. This cable and pulley system is inefficient and may be dangerous to the operator. Therefore, these existing devices for unloading cargo often do not make the delivery easier.
Some elevator delivery systems include a platform that forms part of the truck bed. Although this type of elevator delivery system is effective, moving a section of the truck bed floor up and down has some disadvantages. When pallets are used, for example, the pallets cannot be positioned on the moving platform that forms part of the truck bed floor. Thus, the truck cannot be filled to capacity.
Accordingly, there is a need for an elevator delivery system for use in a truck body or trailer that provides minimal interference with the cargo loaded on the truck bed.
In accordance with one aspect of the present invention, an elevator delivery system comprises a platform and a drive mechanism for moving the platform at least upward with respect to the truck body. The platform is pivotably coupled to the drive mechanism such that the platform folds into an upright position between walls of the truck body when the platform is in a raised position.
In accordance with another aspect of the present invention, a combination truck body and elevator delivery system comprises an enclosed truck body having a bed, walls around the bed, and a door coupled to at least one of the walls for covering a doorway, and a platform mounted within the doorway such that the platform moves between an upright position between the walls of the truck bed and an extended position extending outward from the doorway. Drive mechanisms are mounted to the truck body on each side of the doorway for moving the platform at least upward with respect to the truck body. A control system controls the drive mechanisms.
According to a further aspect of the present invention, an elevator delivery system comprises a platform and at least two hydraulic cylinder/piston mechanisms for moving the platform upward and downward with respect to the truck body. The hydraulic cylinder/piston mechanisms include at least two pistons mounted respectively on opposite sides of the platform and at least two hydraulic cylinders mounted to the truck body. The pistons move within the cylinders to move the platform relative to the truck body, and the platform pivots with respect to the pistons. A hydraulic control system supplies hydraulic fluid to the hydraulic cylinders to control the upward and downward movement of the platform. An inside switch actuates the hydraulic control system from a location inside of the truck body. The inside switch is located such that an operator of the inside switch is able to stand on the platform while the platform moves upward and downward. An outside switch actuates the hydraulic control system from a location outside of the truck body. The outside switch is located such that the platform is away from an operator of the outside switch.
These and other features and advantages of the present invention will be better understood by reading the following detailed description, taken together with the drawings wherein:
Referring to
Referring to
A hydraulic control system 30, described in greater detail below, controls the supply of fluid to the hydraulic cylinder/piston mechanisms 24a, 24b and thus controls the movement of the platform 20. The hydraulic control system 30 is preferably actuated from both inside and outside the truck body 12. For example, an outside up/down switch 32 is located outside of the truck body 12 to allow the user to raise and/or lower the platform 20 from outside of the truck body 12. The outside switch 32 is preferably in a location that keeps the user away from the platform 20 when it is being lowered. An inside up/down switch 34 is located inside the truck body to allow the user to raise and/or lower the platform 20 from inside the truck body 12, for example, when standing on the platform 20. Although the exemplary embodiment shows the hydraulic control system 30 in a location outside of and below the truck body 12, the hydraulic control system 30 can be located in other locations inside or outside of the truck body 12.
The cylinders 28a, 28b are coupled to the hydraulic control system 30 by way of hydraulic lines 40a, 40b. The hydraulic lines 40a, 40b are preferably in a location that will not interfere with loading and unloading cargo (e.g., under the truck bed 14). The outside switch 32 and the inside switch 34 are connected to the hydraulic control system 30 by way of wires 42, 44, respectively. Other connections between the hydraulic control system 30 and the cylinders 28a, 28b and the switches 32, 34 are also contemplated.
In one preferred embodiment, an edge switch 50 is located around the edge of the underside of the truck body 12 adjacent to the path of the moving platform 20. The edge switch 50 is connected to the hydraulic control system 30 by way of wire 52. The edge switch 50 provides an added safety feature when the platform 20 is being raised. If an object, such as the cargo or the driver's foot, is positioned between the platform 20 and the underside of the truck body 12 when the platform 20 is being raised, the object will actuate the edge switch 50. Actuation of the edge switch 50 causes the hydraulic control system 30 to preferably move the platform 20 downward to avoid damage or injury.
In another preferred embodiment, an audible alarm 54 alerts the operator that the platform 20 is being raised and/or lowered. The audible alarm 54 can be connected to the hydraulic control system 30 and located in any location that permits the alarm to be heard near the elevator delivery system 10.
One embodiment of the truck body 12 preferably includes bracing 60 surrounding the platform region 62, which receives the platform 20 in the raised position. A lower portion 64 of the bracing 60 is preferably tapered such that an object (e.g., the driver's toe) that comes into contact with the tapered lower portion 64 will slide out of the way to avoid damage or injury. In this embodiment, the edge switch 50 is located beneath the tapered lower portion 64 of the bracing 60. A rubber seal (not shown) can be provided along the top portion of the bracing 60 to seal against the platform 20 when raised. One embodiment of the platform 20 includes a ramp surface 66 at one side to allow cargo to be more easily wheeled off of the platform 20.
Referring to
Referring to
In response to signals from the up/down switches 32, 34, the solenoid 74 actuates the pump 72 to pump hydraulic fluid through the lines 40a, 40b to or from the hydraulic cylinders 28a, 28b to lower or raise the platform 20. The flow divider valve 82 evenly distributes the hydraulic fluid pressure between the hydraulic cylinders 28a, 28b to maintain the platform 20 in a substantially level position when a load is being raised or lowered, thereby preventing the hydraulic cylinder/piston mechanisms 24a, 24b from binding. In response to the edge switch 50, the dump valve 76 is actuated causing the platform 20 to drop. In one embodiment, the elevator delivery system 10 at a back door of the truck body is capable of lifting about 2500 lbs. or more and the elevator delivery system 10 at a side door of the truck body is capable of lifting about 1500 lbs. or more, although this is not a limitation of the present invention.
In use, the platform 20 can be raised or lowered using either the outside switch 32 or the inside switch 34. Referring to
Accordingly, the elevator delivery system 10 is relatively easy to operate compared to existing devices and thus facilitates the unloading and loading of cargo into a truck or trailer. The elevator delivery system 10 also has fewer moving parts and thus operates more efficiently and reliably than existing hydraulic tailgate and lift devices. The elevator delivery system 10 further provides a number of additional safety features to avoid injury to the operator. For example, the location of the inside switch and the outside switch 32, the edge switch 50, and the audible alarm 54 all provide safety features that will minimize injuries caused by using the elevator delivery system 10.
Referring to
The platform 120 is coupled to a drive mechanism 124 (
The platform 120 is preferably coupled to the pistons 126 in a manner that allows the platform 120 to pivot between the upright and extended positions, as shown in
In one example, the platform 120 is made of aluminum and is about 44″ by 32″. Other materials and sizes are also contemplated. Where the platform 120 is made of a light-weight material such as aluminum, the drive mechanism 124 preferably moves the platform 120 downward. Where the platform 120 is made of a heavier material, gravity can move the platform 120 downward without being driven by the drive mechanism 124.
The elevator delivery system 110 further includes foldable side rails 130 coupled between sides of the platform 120 and the walls 116 of the truck body, as a safety feature. The foldable side rails 130 include a first folding side bar 132 pivotably coupled to the side of the platform 120 and a second folding side bar 134 pivotably coupled to the first folding side bar 132. The second folding side bar 134 is pivotably coupled to a sliding bar 136. The sliding bar 136 can move freely or can be slidably mounted to the wall 116. In one example, the bars 132, 134 are flat bars made of steel. A chain or other similar structure (not shown) can be coupled between the foldable side rails 130 to provide an additional safety feature across the front of the platform 120.
In the exemplary embodiment, the elevator delivery system 110 is located in a side doorway 118 of a truck body 112, although other locations are contemplated. Because the platform 120 does not form part of the floor of the truck bed 114, the elevator delivery system 110 can be operated without interfering with pallets or other cargo stacked at the doorway.
Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims.
This application is a continuation-in-part of patent application Ser. No. 10/351,812, which claims the benefit of U.S. provisional application Ser. No. 60/376,694 filed May 1, 2002, both of which are fully incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
60376694 | May 2002 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10351812 | Jan 2003 | US |
Child | 10696731 | Oct 2003 | US |