GB2376221A

GB2376221A - A vehicle mounted elevator assembly

Info

Publication number: GB2376221A
Application number: GB0113522A
Authority: GB
Inventors: Kenneth Michael Sparrowhawk
Original assignee: Del Equipment UK Ltd
Current assignee: Del Equipment UK Ltd
Priority date: 2001-06-05
Filing date: 2001-06-05
Publication date: 2002-12-11
Anticipated expiration: 2021-06-05
Also published as: GB0113522D0; GB2376221B

Abstract

A vehicle-mounted elevator assembly (10) comprises a first radius member (12) pivotally secured at one end at a first location (13) that is fixed relative to a vehicle (11). The radius member (12) is pivotable about an horizontal axis (16). At a second location (21) remote from the first location (13) the radius member (12) includes a retainer (22) for releasably securing a lifting aid (23) to the elevator assembly. The apparatus includes a powered, length adjustable actuator (24) that is pivotably secured at one end (26) at a third location that is fixed relative to the said vehicle (11); and at the other end to the radius member (12) such that on powered operation of the actuator (24) the radius member (12) is caused to pivot about the horizontal axis to raise or lower the retainer (22) relative to the vehicle (11).

Description

A VEHICLE MOUNTED ELEVATOR ASSEMBLY This invention relates a vehicle mounted elevator assembly.

Elevators secured to commercial vehicles such as vans and trucks have become increasingly popular in recent years. A well-known example of a vehicle elevator type is the so-called"tail lift" (that is known as a"liftgate" in the USA and Canada).

Typically a tail lift includes a pair of lift posts that extend vertically on either side of the aperture at the rear of a van or truck body.

Each lift post is perforated along its length by an elongate slot, from which protrude respective mounting members that are driveable, by virtue of a mechanism such as a chain drive within each post, vertically up and down the posts.

The mounting members are interconnected by a typically horizontally extending lifting aid such as a platform manufactured from chequer plate (also known as tread plate) or an extrusion.

In prior art vehicle elevator designs the lifting aid is permanently secured to the mounting members. This causes problems in the storage of the lifting aid when the elevator is in a stowed position (eg. while the vehicle is being driven).

In one design of elevator the load platform is pivotable about a horizontal axis, so that in the stowed configuration it lies vertically adjacent the openable rear end of the vehicle body. This is inconvenient since the platform covers part of the open end, including the load bay door.

Consequently it is necessary to actuate and deploy the elevator in order to gain access to the load space of the vehicle.

As an alternative there is known a design of vehicle elevator whose platform is of reduced size compared with the aforementioned platform that covers the vehicle door area. However, of course, a reduced size platform results in a commensurately reduced loading and unloading work rate.

In yet a further prior art design the load platform or other lifting aid stows in a recess beneath the vehicle body. However, this arrangement requires the construction of a chamber for the elevator components. The chamber encroaches into the load space of the vehicle, thereby reducing the vehicle capacity.

Also the elevator mechanism must be capable of generating a complex locus in order to stow the lifting aid. Consequently the elevator is more complicated than it might otherwise be.

There are additional difficulties associated with vehicle elevators that mount at the side of the vehicle body (as opposed to the rear end). Not the least of these difficulties in the fact that vehicle braking and/or drive components under the vehicle body limit the space available for securing and/or stowage of elevator parts.

Consequently there is a need for a vehicle elevator that is more efficient than the prior art arrangements.

According to a first aspect of the invention there is provided a vehicle mounted elevator assembly as defined in Claim 1.

Since the assembly includes a retainer that is capable of releasably securing a lifting aid, stowage of the lifting aid during driving of the vehicle to which the assembly is secured is easier and less inconvenient than in the prior art arrangements.

The arrangement of the radius member and the actuator can be constructed as an advantageously compact assembly, that requires less stowage space than the prior art elevators. Nonetheless the elevator assembly of the invention permits the supporting of a lifting aid in the form of eg. a large load platform. By virtue of its releasable securing the lifting aid may indeed be wider than the vehicle to which the elevator assembly is secured.

Furthermore the arrangement of the invention is advantageously simple to secure either to the rear of a commercial vehicle body; or to the side thereof.

The arrangement defined in Claim I provides for an accurate locus of movement of the retainer, and hence of any lifting aid secured thereto.

However, in preferred embodiments of the invention there is a second radius member pivotally secured at one end at a fourth location that is fixed relative to the vehicle, the second radius member being pivotable about an horizontal axis and being pivotably secured, at a fifth location remote from the fourth location, to a link member that is also pivotably secured to the first radius member whereby the second radius member and the link member constrain the locus of the retainer during operation of the actuator.

More specifically this arrangement constrains the locus of the retainer to eg. a straight line or a gentle curve (depending on the precise lengths and attachment points of the components). Thus it is possible to provide an elevator assembly according to the invention whose action is to lift

vertically a lifting aid secured thereto. Consequently the elevator assembly of the invention is capable of lifting items supported on the lifting aid in an up and down manner.

Conveniently the vehicle includes a body portion that overlies and is spaced vertically from the first and, when present, second radius members, whereby the locus of the retainer lies substantially below the body portion and the locus of the lifting aid secured thereto is spaced laterally from the body portion.

In this way the assembly of the invention is particularly suited for installation on a typical commercial vehicle body. In such an arrangement the lifting aid is nonetheless easily presented clear of the vehicle body both at ground height and at loading deck height.

One preferred form of retainer forming part of the assembly of the invention includes a torsion arm that is fixed relative to the first and, when present, second radius members.

This arrangement is conveniently simple to manufacture, and robust.

Alternatively the retainer may include a torsion arm that is secured to the second radius arm so as to be moveable between stowed and operative positions.

More particularly the torsion arm may be pivotable about a horizontal axis.

This allows stowage of the retainer"inboard"of the radius members. On deployment of the elevator for use the torsion arm is rotatable to a position in which it extends beyond the ends of the radius members, and hence beyond the"envelope"defined by the vehicle body or load deck (if

present).

In particularly preferred embodiments of the invention the torsion arm includes a limit member that engages the first radius member or the link member when the torsion arm occupies its operative position, whereby the torsion arm is in use braced in cantilever fashion from the radius members.

The limit member may be eg. a screw threadedly received in a bore formed' in the torsion arm. When deployed to the operative position of the torsion arm the limit member may engage a plate or functionally similar member formed on the link member or one of the radius members.

In preferred embodiments of the invention the retainer is releasably formlockingly engageable with a lifting aid. This may be achieved eg. by means of a bayonet-type of fitting.

The elevator assembly of the invention may of course include additional and/or alternative fastenings for the lifting aid. The need for such components may derive in part from the nature and mass of the lifting aid and of the articles that it is intended to support.

Conveniently the actuator is selected from the list defined in Claim 9; and the lifting aid is selected from the list defined in Claim 10.

Numerous power sources for the actuator are possible within the scope of the invention. The power sources include but are not limited to electric power (eg. from batteries or as generated by the vehicle to which the elevator assembly is secured); energy storage devices such as springs; hydraulic power; or pneumatic power.

According to a second aspect of the invention there is provided a vehicle having operatively secured thereto an elevator assembly as defined herein.

In preferred embodiments of the invention the vehicle includes two or more elevator assemblies each as defined herein and having secured thereto a lifting aid.

Preferably the lifting aid is a common lifting aid that interconnects the retainers of the respective elevator assemblies. However, in other embodiments it may be desirable to provide a plurality of discrete lifting aids, each operatively securable to a respective elevator assembly as defined herein.

There now follows a description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which: Figure 1 is a side elevational, partly sectioned view of an elevator assembly, according to the invention, in its stowed configuration attached to a vehicle; Figure 2 shows the elevator assembly of Figure 1 deployed in its operative position and having secured thereto a lifting aid that is shown at vehicle deck height; and Figure 3 shows the components of Figure 2 following operation of the elevator assembly to lower the lifting aid to ground level.

Referring to the drawings, there is shown an elevator assembly 10 that is secured to a vehicle 11 such as a truck, van, trailer or similar conveyance.

Elevator assembly 10 includes a first radius member 12 in the form of an elongate square or circular section tube or bar.

As viewed in the drawings the right hand end of radius member 12 is pivotably secured at a first pivot 13, whose location is fixed relative to the remainder of vehicle 11.

In the embodiment shown, pivot 13 is defined by a yoke, constituted by a pair of vertically extending plates 14 one of which is visible in the drawings.

The plates 14 extend parallel to one another and are spaced apart by a distance that is slightly greater than the width of the right hand end of first radius member 12.

A pin 16 interconnects the plates 14 and passes through the end of radius member 12.

In the preferred embodiment radius member 12 is perforated at this location to receive the pin 16. In another embodiment the pin 16 may be rigidly secured to the radius member and may be joumalled at either end in apertures in the respective plates 14.

Regardless of the precise arrangement, pin 16 defines a horizontal pivot axis for the first radius member 12.

The plates 14 are rigidly secured (eg. by welding) to a further, upwardly extending plate 17 whose uppermost end terminates some distance above the uppermost extremities of the plates 14.

Plate 17 is secured eg. by bolting, welding or any equivalent means, to a chassis rail 18 of the vehicle 11.

Chassis rail 18 extends along a part of the vehicle beneath a load deck 19. To all practical purposes it is irrelevant to the functioning of the elevator assembly of the invention whether the chassis rail 18 extends longitudinally or transversely of the vehicle 11.

At a second location that in the preferred embodiment is its free end 21, first radius member 12 has secured thereto a retainer 22 for releasably securing to the elevator assembly a lifting aid such as tapered load platform 23 that is visible in Figures 2 and 3.

A powered, length adjustable actuator that in the embodiment shown is an hydraulic or pneumatic piston and cylinder assembly 24 of per se known design is pivotably secured at its right hand end as shown to an eye or similar pivot attachment 26 protruding from plate 17 on the same side as plates 14. Consequently the eye 26 is fixed relative to the vehicle 11.

At its end 27 that is remote from eye 26. The actuator 24 is pivotably secured to first radius member 12.

As shown end 27 of the rod of actuator 24 is pivotably secured at a location intermediate the ends of first radius member 12. Consequently on extension and retraction of the rod 28 of actuator 24 the radius member 12 is raised and lowered relative to the load deck 19.

In the absence of any other components the radius member 12 would on expansion and contraction of actuator member 24 describe a circular arc.

While this may be desirable in some embodiments of the invention, in other embodiments it is desirable to constrain movement of the retainer 22 to an

essentially vertical locus.

This is achieved in the preferred embodiment by the presence of second radius member 29 that is pivotably secured at its right hand end 31 between the plates 14, in like manner to the pivotable securing of end 13 of first radius member 12.

In other words, a further pin 32 defines a further, horizontal pivot axis about which radius member 29 is pivotable.

The end of second radius member 29 remote from end 31 is pivotably secured, in a similar way to the right hand end 31, to a link member 33 in the form of a short, downwardly extending rod or plate. Link member 33 and radius member 29 are thus connected by a further pivot pin 30.

As shown in the drawings second radius member 29 overlies and is generally parallel to first radius member 12. Consequently the end of link member 33 beneath the adjacent end 34 of radius member 29 lies adjacent the end 21 of radius member 12, and is pivotably secured thereto by means of a pin 35 that is similar to pins 16,32 and 30.

As a result of the presence and pivotable securing of second radius member 29 and link 33, retainer 22 is on extension and retraction of actuator 24 constrained to move essentially vertically.

As previously mentioned, vehicle 11 includes a body portion such as deck 19. The deck 19 may include a plurality of bearers 40. Each bearer 40 is associated with either a rear member 42 or a side rave (not shown), depending on the location of the bearer 40 relative to the deck 19. Side raves are associated with the bearers 40 that extend along the opposed side

edges of the deck 19, whereas a rear member 42 (also known as a rear frame) is associated with the or each bearer 40 that is located between the side edge bearers 40.

As is evident from the drawings, the elevator assembly 10 preferably is secured to the vehicle 11 so that the body portion 19 overlies and is spaced vertically from the first and second radius members 12,29. In other words, the elevator assembly 10 conveniently occupies part of the normal void that exists under a commercial vehicle body.

The lengths of the radius members 12,29 are chosen such that the retainer 22 in its operative position (described in more detail below) extends laterally a short distance beyond the lateral extremity of the body portion 19, whereby the retainer 22 may raise a lifting aid (also described in more detail below) to a position closely adjacent a load deck defined by the body portion 19.

The retainer 22 includes a torsion arm 36 that is pivotably secured, at the left hand end of second radius member 29, by means of the pivot pin 30 by which radius member 29 and link member 33 are pivotably secured together.

Torsion arm 36 includes an essentially L-shaped plate having horizontally protruding therefrom a rectangular section bar 37.

As shown in Figure 1, the torsion arm 36 is pivotable to a retracted position lying beneath the vehicle body portion 19, with the rectangular section bar 37 resting on the second radius member inboard of the link member 33.

In the stowed position of the elevator assembly the retainer member is

safely contained within the"envelope"defined by the lateral extremity of the body portion 19.

To deploy the retainer 22 from the aforesaid retracted position the torsion arm 36 is rotated about pivot pin 30 until a limit member in the form of a bolt, stud, screw, pin or similar component 39 engages eg. the link member 33 or the end of the first radius member 12, to limit the rotation of the torsion arm 36 to a position in which the rectangular section bar 37 is presented ready for attachment of the platform 23 or other lifting aid.

Consequently the torsion arm itself is also braced in cantilever fashion relative to the remainder of the elevator assembly.

Bar 37 is fonn-lockingly receivable, in the manner of a bayonet fitting, in an aperture 38 formed in the underside of platform 23, whereby on deployment of retainer 22 the rectangular section bar 38 provides a cantilever-type support for the platform 23.

As is evident from the drawings, the aperture 38 in the platform 23 fits snugly over the rectangular section bar 37 and provides a rigid yet readily releasable attachment therefor.

In other embodiments of the invention it is possible to employ additional or alternative fastenings for the lifting aid. Such fastenings may be chosen at the option of the manufacturer, independence on the nature and mass of the lifting aid than the loads to be carried thereby.

In another embodiment the retainer 22 is fixed relative to eg. the second radius member (if present). This may be achieved eg. by welding the retainer 22 onto such a component. Such an arrangement is robust, and may

therefore offer advantages in harsh environments.

Regardless of the precise retainer arrangement, in practical embodiments of the invention the vehicle 11 may include eg. a pair of the elevator assemblies each as shown in the drawings. The rectangular section bar 37 may optionally extend rigidly to interconnect the retainers 22 of the respective members of the pair, and the aperture or recess 38 may extend along the width of the platform or other lifting aid 23 to provide a substantial supporting area.

In other embodiments the respective rectangular section bars 37 of the elevator assemblies 10 may be short compared with the width or length of the lifting aid 23, with the lifting aid 23 when attached providing interconnection between the two elevator assemblies as shown.

Regardless of the precise arrangement, the operation of the elevator assembly is as shown in the drawings.

In an initial, retracted position as shown in Figure 1, the torsion arm 36 lies inboard of the link member 33 with the rectangular section bar 37 lying on the second retainer member 29. The actuator 24 is retracted as far as possible, to provide a compact arrangement.

To prepare the elevator assembly for use the torsion arm 36 is rotated to the position shown in Figure 2. At this point the limit member 39 engages the link member 33 to present the rectangular section bar in an upright position as shown.

The load platform 23 or other lifting aid if preferred is then lifted from a storage location eg. inside the vehicle or slung between two chassis rails,

and fitted onto the rectangular section bar as shown.

Subsequent extension of the actuator member 24 under control of eg. a control circuit (not shown) causes the components of the elevator assembly to descend, as illustrated in Figure 3.

When the load platform 23 lies on the ground 41 it is possible readily to place loads on the platform. The actuator 24 may then be retracted, under control of the control circuit, to raise the platform to the level of the load deck 19. Transfer of loads between the platform 23 and load deck 19, and vice versa, may then readily occur as desired.

At the end of operation of the elevator assembly, the load platform or other lifting aid 23 may be lifted off the rectangular section bar 38 and stowed eg. within the vehicle or slung from chassis rails. The elevator assembly 10 is then returned to its stowed configuration as shown in Figure 1, before the vehicle 11 is driven.

As noted herein the lifting aid 23 may take any of a number of possible forms and the attachment to the torsion arm 36 adapted as necessary to suit the precise configuration of the lifting aid.

In addition a variety of sources of power may be employed to operate the actuator 24 or an equivalent device (such as a lead screw and drive nut arrangement or any of a wide range of other mechanical equivalents).

Claims

1. A vehicle-mounted elevator assembly comprising a first radius member pivotally secured at one end at a first location that is fixed relative to a vehicle, the radius member being pivotable about an horizontal axis and including at a second location remote from the first location a retainer for releasably securing a lifting aid; and the apparatus including a powered, length adjustable actuator that is pivotably secured at one end at a third location that is fixed relative to the said vehicle; and at the other end to the radius member such that on powered operation of the actuator the radius member is caused to pivot about the horizontal axis to raise or lower the retainer relative to the vehicle.

2. An elevator assembly according to Claim 1 including a second radius member pivotally secured at one end at a fourth location that is fixed relative to the vehicle, the second radius member being pivotable about an horizontal axis and being pivotably secured, at a fifth location remote from the fourth location, to a link member that is also pivotably secured to the first radius member whereby the second radius member and the link member constrain the locus of the retainer during operation of the actuator.

3. An elevator assembly according to Claim 1 or Claim 2 wherein the vehicle includes a body portion that overlies and is spaced vertically from the first and, when present, second radius members, whereby the locus of the retainer lies substantially below the body portion and the locus of the lifting aid secured thereto is spaced laterally from the body portion.

4. An elevator assembly according to any preceding claim wherein the retainer includes a torsion arm that is fixed relative to the first and, when present, second radius members.

5. An elevator assembly according to Claim 2 or any preceding claim when dependent therefrom, wherein the retainer includes a torsion arm that is secured to the second radius arm so as to be moveable between stowed and operative positions.

6. An elevator assembly according to Claim 5 wherein the torsion arm is pivotable about an horizontal axis.

7. An elevator assembly according to Claim 5 or Claim 6 wherein the torsion arm includes a limit member that engages the first radius member or the link member when the torsion arm occupies its operative position, whereby the torsion arm is in use braced in cantilever fashion from the radius members.

8. An elevator assembly according to any preceding claim wherein the retainer is releasably form-mockingly engageable with a lifting aid.

9. An elevator assembly according to any preceding claim wherein the actuator is selected from: a pulley or winch and cable arrangement; an hydraulic linear actuator; a pneumatic linear actuator; or a powered lead screw and drive nut assembly.

10. An elevator assembly according to any preceding claim wherein the lifting aid is selected from: a platform ; one or more forks; a hook;

a post ; a pulley; or a combination of such elements.

11. A vehicle having operatively secured thereto an elevator assembly according to any preceding claim.

12. A vehicle according to Claim 11 including secured thereto two or more elevator assemblies each according to any of Claims 1 to 10 and having secured thereto a lifting aid.

13. A vehicle according to Claim 12 including a single lifting aid that interconnects the retainers of the respective elevator assemblies.

14. An elevator assembly generally as herein described with reference to and/or as illustrated in the accompanying drawings.

15. A vehicle generally as herein described with reference to and/or as illustrated in the accompanying drawings.