GB2429192A

GB2429192A - Load carrying apparatus

Info

Publication number: GB2429192A
Application number: GB0516833A
Authority: GB
Inventors: Daniel Magennis
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-17
Filing date: 2005-08-17
Publication date: 2007-02-21
Also published as: GB0516833D0

Abstract

This device enables one person to transport heavy loads up and down stairs 60. It does this by using a combined drive system which consists of a pneumatic rear wheel 18 connected to a set of toothed belts 46, 48. The rear wheel is driven by a low geared worm and wheel type of electric motor 34, which is battery powered. The wheels at the front are a triple rotatable assembly commonly known as a spider 22 are freewheeling and mounted in a castor frame. At the bottom of the stairs, only the rear wheel and spider wheels are in action (figure 3). Halfway up the stairs the rear wheel, belts and spider wheels are in action and at the top of the stairs (figure 4) only the rear wheel and belts act. Should the battery fail or the operator let go, the drive will lock due to the worm driven motor and will remain stationary and stable even on the slope of a stair. The apparatus may be fitted with a suitable mechanically operated load lifting platform to enable it to carry a payload. On level ground the drive may be disconnected and the apparatus may be used as a conventional horizontal trolley.

Description

Load Carrying Apparatus The present invention relates to a load carrying

apparatus. The invention relares particularly to an apparatus for carrying loads up or down steps or stairs.

The invention provides a load carrying apparatus comprising at least one rear wheel, at least one tront wheel, at least one, endless track assembly at least carc of which is located between the front and rear wheels, and means for drivLng at least one of said at feast one front wheel, at least one rear wheel and at least one track.

Normally, the apparatus also includes a load carryLng platform carried by a frame or support that carries the front and rear wheels.

Preferably, said at least one front wheel takes the form of at least one wheel assembly comprising two or more wheels carried rotatably on a support, the support being rotatabJ.e about an axis subsrantiaLLy parallel with the respective axes of rotation of the wheels. In the preferred embodiment, the, or each, wheel assembly comprises three wheels arranged in a generally triangular formation. The support is preferably pvotable, or rotatable, about an axis that is, in use, substantially perpendicular with the ground when the apparatus is located on level ground.

Preferably, said at least one track assembly includes an endless track having a plurality of projections formed in its outer surface. The projections are preferably spaced apart in a direction substantially parallel with the direction of movement of the apparatus during normal use.

In the preferred embodiment, the in use level of the track(s) is spaced apart from the level of the, in use, lowest portions of the front and rear wheels. The preferred spacing is such that when the apparatus is on the incline of a typical flight of stairs, the track(s) (and in particular the projections) can engage with the leading edges of the steps when the rear wheel 18 and/or the front wheel(s) are in contact with the stairs.

In one embodiment, the apparatus comprises two spaced apart arms, each arm being associated with a respective endless track assembly, a single rear wheel being located between the arms, and a respective front wheel assembly being provided at the end of each arm.

The drive means, which may conveniently comprise a motor, is preferably arranged to drive the rear wheel(s) and the track(s). The front wheel(s) are preferably freely rotatable, or undriven. In the preferred embodiment, the rear wheel(s) is mounted on an axle, the axle being connected or coupled to at least one pulley that carries the at]east one track, the drive means being connected or coupled to the axLe in order to drive both the rear wheel(s) arid track(s).

The drive means may conveniently comprise a motor coupled to the rear wheel by any suitable means, e.g. a drive belt.

Further advantageous aspects of:he invention will become apparent o tnose ordinarily skilled in the art upon review of the foli.owing description of a specific embodiment and with reference to the accompanying drawings in which: Figure 1. is a perspective v-jew of a load carrying apparatus embodying the invention; Figure 2 is a side view of the apparatus of Figure 1 shown on a flat surface; FLgure 3 is a side view of the apparatus of Figure 1 shown ascending a flight of stairs Ln a first mode of use; and Figure 4 shows a side view of the apparatus of Figure 1 shown ascending a flight of stairs in a second mode of use.

Referring now to the drawings, there is shown, generally indica:ed as 10, a load carrying apparatus eimbodying the invention. The apparatus 10 comprises a frame 12 including first arid second spaced apart, and substantially parallel, arms 14, 16. A maIn wheel 18, which in use serves as a rear wheel, is located between the arms 14, 16 and is carried by an axle 20 that is rotatably coupled to a respective arm 14, 16 at either end, the axis of rotation of the axle 20, and therefore of the wheel 18, being substantially perpendicular with the direction in which the arms 14, 16 extend.

Conveniently, the wheel 18 is positioned so that the ends of the axle 20 are coupled to the respective arms 14, 16 adjacent one end. rrhe wheel 18 preferabrv includes a pneumatic tyre, the tyre advantageously being provided with tyre tread. Preferably, the tyre is a pneumatic:yre or a balloon type tyre with relatively deep tread, for example of the type found on quad type vehicles or golf buggies.

The respective other end of each arm 14, 16 carries a respective wheel assembly 22 which, in use, serve as rear wheel assemblies, and respective supporting sub-- frame 24. Each wheel assembly 22 preferably Includes a plurality of wheels 26 in a co-planar arrangement and with their respective rotational axes being substantially parallel. In the preferred embodiment, each wheel assembly 22 comprises three wheeLs 26 arranged in a generally triangular formation such that their respective rotational axes are generally triangularLy spaced-apart. Each wheel 26 is rotatably mounted between a pair of support plates 28 and is freely rotatable about its respective axis. The plates 28, or other support members, are, preferably, rotatably mounted to a respective further support member in the preferred form off a fork 30 (in the drawings, the wheel assemblies 22 are otatably mounted between the prongs of the fork 30) . The fork 30, or other support:, is advantageously pivotably or rotatably mounted to the sub-frame 24 for rotation about an axis that is substantially perpendicular with the rotational axes of the wheels 26 and with the plane that is common to both arms 14, 16. The fork 30 is freely pivotable with respect to the sub- frame 24. Hence, the wheel assemblies 22 may pivot or rotate with respect to the sub-frame 24 and so act as castors that allow the apparatus 10 to be steered during use. Wheel assemblies of the type sometimes knawn as "spider wheels" are TO suitable for use as the wheel assemblies 22. As the apparatus 10 moves forward to climb stairs, tie wheel assemblies 22 engage, in use, with the front face of a step or stair, and are caused to rotate about their connection to the respective fork 30 and this heLps to climb, and to descend, the stairs. Preferably, the diameter of each of the wheels 26 on the wheel assemblies 22 is approximately two thirds the height of the riser of the stairs that are intended to be climbed.

The frame 12 further includes a support portion 32 extending between the arms 14, 16. A motor 34 is carried by the support portion 32. The motor 34 is advantageousLy a battery powered motor, e.g. a 24V motor, and is preferably a worm geared motor. The motor 34 is coupled to the main wheeL 18 in order to impart rotational motion to the wheel 18. In the illustrated embodiment, this is achieved by means of a drive chain or belt 36 mounted on sprockets or gear wheels 38, 40, each gear wheel 38, 40 eing coupled to the main wheel 18 and the motor 34 respectively.

A respective pulley 42, 43 is connected or coupled to the axle 20, one on either side of the main wheel 18, each pulley 42, 43 rotating, in use, wi:h the axle 20.

Conveniently, the pulleys 42, 43 are positioned in register with the arms 14, 16, i.e. at the interconnection between the arms 14, 16 and the axles 20. A respective corresponding pulley 44, 45 is spaced apart from each puLley 42, 43 in a direction substantially perpendicular to the axis of the axle 20.

In the preferred embodiment, the puLleys 44, 45 are provided at the respective opposite end of each arm 14, 16. A respective endless track or belt 46, 48 is mounted on each pair of pulleys 42, 44 and 43, 45. The tracks 46, 48 and pulloys 42, 43, 44, 45 may nrer- engage in any convenient manner. The outer surface of each track 46, 48 is preferably provided with grip formations 50, e.g. ribs, teeth or other projections, for engagement with steps or stairs during use. As may best be seen from Eigure 4, the formations 50 are preferably spaced-apart and dimensioned such that the leading edge of a typical stair or step may be located between adjacent formations 50.

As may best he seen from Figure 2, the level of the tracks 46, 48 is raised with respect to the level of the ground engaging portions of the main wheel 18 and wheel assemblies 22. This clearance distance could, for example, be approximately two to three inches.

Moreover, the preferred arrangement is such that the lengths of tracks 46, 48 running betwn the pulleys are substantially parallel with the ground when the apparatus 10 Is on a flat surface.

During use, the main wheel 18 and the tracks 46, 48 may each be driven by the motor 34.

A handle 51 is connected to the frame 12 at the end that carries the main wheel 18. The handle 51 may be connected to the frame 12 in any convenienL manner. For example, in the illustrated embodiment, a fixed cross- piece 53 may be provided between the arms 14, 16 and a U-shaded bracket 55 may be fixed to the cross-piece 53 over the wheel 18, the handle 51 being fixed to the bracket 55. DurLng use, the apparatus 10 may be steered by a user (not shown) exerting a twisting action, Left or right, on the handle 51. This causes the forks 30, and therefore the wheel assemblies 22, to pivot to effect movement i.n the desired direction.

Figure 2 shows that apparatus 10 in use on a flat surface 52. In this mode of operation, the wheel 18 and wheel assemblies 22 engage with the ground 52.

Preferably, the motor 34 may be disengaged from the wheel 18 such that the main wheel 18 may freely rotate when the apparatus 10 is pushed by a user. This may be achLeved in any suitable manner, e.g. by providing a clutch mechanism between the motor 34 and its gear wheel 40. This is particularly advantageous when pushing the apparatus 10 on level ground as it saves battery power and obviates the need to provide a variable speed gearbox.

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When ascending (or descending) a flight of steps or stairs 60, various combinations of the mai.n wheel 18, wheel assemblies 22 and tracks 46, 48 may engage with the stairs 60. For example, in Figure 3, the apparatus is shown near the beginning of the stairs 60. In this situation, the wheel assemblies 22 engage with the stairs while the main wheel 18 remains in contact with the Level ground at the foot of the stairs 60.

When The apparatus 10 is completely on the stairs, the main wheel 18 and the wheel assemblies 22 are in contact with the stairs and, in the preferred embodiment, so too are the tracks 46, 48. To this end, the preferred spacing or clearance between the tracks 46, 48 and the, in use, level of the ground engaging portions of the wheels 18, 22 is such that, when the apparatus 10 is on the incline of a typical blight of stairs, the tracks 46, 48 (and in particular the projections 50) can engage with the leading edges of the steps when the main wheel 18 and/or the wheel assemblies are in contact with the stairs. In a preferred embodiment, the arrangement is such that, when a leading edge of a step is located between two wheels of the wheel assemblies 22(as shown in Figure 3), the tracks 46, 48 can engage with the leading edge o a lower step. Hence, the tracks can help to drive the apparatus 18 up the stairs.

Figure 4 shows the apparatus 10 in a fourth mode of use in which it has reached the top of a [light of stairs.

It will be seen that the wheel assemblies 22 do not engage with the stairs or the landingbut that the tracks 46, 48 engage with the leading. edge of one or more steps to propel tne apparatus 10 to the top of the stairs.

A load carrying platform (not shown) is also provided on the apparatus 10. The platform may take any convenient form and may be mounted on the frame 12 in any convenient manner. In a preferred embodiment, the platform is mounted on the frame by means of an extension mechanism (not shown) that can raise and Lower the platform with respect to the frame. The extension mechanism may for example.Lnclude an extendible lattice or scissors mechanism comprising one or more sets of two bars pivotably connected at their midpoints. OptionaLiy, the extension mechanism may be arranged to cause the platform to pivot such that it is inclined with respect to the plane in which the arms 14, 16 lie. This enables the platform to be maintained in a horLzontal position even when the rest of the apparatus is inclined with respect to horizontal. In the preferred embodiment however, the platform is arranged to maintained a parallel disposition with respect to the arms 14, 16 as it is raised ad lowered.

An actuator, such as a ram or jack, may be provided to raise and lower the p].atform. The actuator may be electrically, hydraulically or pneumatically powered and, to this end, appropriate electrical, hydraulic or pneumatic circuitry may be provided in any suitable conventional manner.

In an alternative embodiment, the whe1 assemblies 22' may be replaced by a respective single wheel.

In a further alternative embodiment, there may only be a single track and/or single arm. For example, tiere may be a single track on a single arm, with two wheels at the rear of the apparatus, one on either side of the track, the wheels and track all being driven by the motor via a common or linked drive shaft(s).

Alternatively, there may be tree or more tracks and/or a rms The invention is not limited to the embodiment described herein which may be modified or varied without departing from tha scope of the invention.

Claims

1 An apparatus which enables one person to transport a heavy load up and down stairs.

2 An apparatus according to claim 1 which utilizes a combination of electric battery powered low geared drive wheel and drive belts to ascend and descend stairs.

3 According to claim 2 the apparatus uses the driven wheel or the toothed belts or a combination of both to ascend or descend according to the particular section of the staircase upon which it is ascending or descending.

4 According to claim 3 the apparatus uses the driven wheel to push itself and the toothed belts to pull itself up a staircase depending on the particular section of the staircase upon which it is acting.

The apparatus can be fitted with a lifting platform and supports which may be raised or lowered by mechanical means in order to lower the centre of gravity of the load and apparatus for optimum stability when stair climbing.

6 The apparatus is inherently stable on a staircase in that it will not move tilt or roll backward even if power is removed or the operator lets go of the apparatus due to the worm and gear type drive motor.

7 When on level ground the drive may be disconnected from the wheels and toothed belts allowing the apparatus to be used as a conventional trolley in order to maximize battery life and to obviate the need for a two speed gearing system.