AU700630B3 - A motorized drive assembly for a trolley - Google Patents

Description

A MOTORIZED DRIVE ASSEMBLY FOR A TROLLEY This invention relates to a motorized drive assembly which can be releasably attached to a trolley to allow an otherwise manual trolley to be motorized. The invention will be described with reference to a popular type of trolley being a single axle trolley but it should be appreciated that the drive assembly could be attached to other types of trolleys.

Single axle trolleys are very common especially in the furniture removal industry. The single axle trolley has a pair of upwardly extending rail members the upper part of the rail members being grabbable by a person's hands. The lower end of the rail members are attached to a base plate which extends at right angles to the rail members and onto which goods are loaded.

••The lower end of the rail members support an axle and a large ground engageable wheel is attached to each end of the axle. Some of these trolleys are adapted to be "stair-climbing trolleys" whereby the single large wheel is substituted with an arrangement of three spaced apart wheels. It is common for a pair of much smaller idler rollers to be mounted to a smaller axle to support the trolley when the trolley is in the entirely upright position.

.••However, the smaller rollers do not function to take the load of the trolley and therefore such trolleys can still be seen as single axle trolleys as the main load bearing wheels are on a single axle.

While these trolleys are widely used and very versatile, the trolleys are not motorized and therefore it is difficult to safely move heavily loaded trolleys up or down inclines such as along a ramp to the back of the removal truck. Goods are sometimes required to be lifted onto the back of a truck and, to date, trolleys are not able to assist in lifting the goods in this manner. Heavily loaded trolleys (such as trolleys carrying refrigerators and other heavy white goods) are hazardous when maneuvered along inclined surfaces and great care must be taken in order to maintain proper control over the trolley.

It is known to provide some trolleys with brakes, but this provides a measure of control only along downhill inclines but provides no assistance at all in pulling or pushing a trolley up an incline.

The present invention is directed to a robust drive assembly which can be attached to an otherwise conventional trolley and which can be used to convert a conventional trolley into a motorized unit. When not in use, the motorized drive assembly can either be decoupled from the trolley, or can be kept on the trolley but swung out of the way such that the trolley can be used as a normal manual trolley.

It is an object of the invention to provide a motorized drive assembly which may overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

In one form, the invention resides in a motorized drive assembly attachable to a single axle trolley, the assembly comprising: attachment means to attach the drive assembly to a rear portion of the trolley; a chassis assembly hingedly coupled relative to the attachment 15 means and having; a ground engagable endless drive belt; at least one drive member to drive the belt; and motor to drive the drive means.

The drive assembly is attachable to an otherwise conventional 20 trolley and may be attached in a releasable manner, although it is possible to permanently attach the drive assembly to the trolley if it is considered that the trolley will always require driving assistance.

One commercial application of the invention will be to attach the drive assembly to a single axle trolley of the type described above, as these trolleys are very popular and well used in the ferrying of goods. The precise arrangement and type of trolley need not be important to the invention, and it is considered that various types of commercially available trolleys may be suitable. Some trolleys of extremely light weight or simple construction may not be suitable to support the motorized drive assembly, but it is considered that a person skilled in the art will be able to understand what type of trolley will be able to support the motorized drive assembly.

The motorized drive assembly has some form of attachment means to attach the drive assembly to the trolley. As the trolley has a forwardly extending base plate, the motorized drive assembly is typically positioned adjacent a rear portion of the trolley. The attachment means can vary depending on the type of trolley including the type, shape and size of the rail members, and the type and size of the motorized drive assembly.

In one form, the attachment means consists of a pair of elongate steel plates which attach to each of the rail members by suitable fasteners such as bolts. If the drive assembly is to be permanently attached, the attachment means may be welded, riveted, or otherwise permanently attached to the rail members. The steel plates should be sufficiently robust and strong to support the weight of the remaining components of the motorized drive assembly.

The drive assembly further contains a chassis assembly. The chassis assembly is hingedly coupled relative to the attachment means. This allows the chassis assembly to move between a drive position and a lifted free position. In the free position, the trolley can be used as a conventional trolley, while in the drive position the trolley can be used as a driven trolley.

The chassis assembly can comprise a framework of elongate 20 members which can comprise steel plates, steel box section, angle iron, or members formed from other materials which are sufficiently robust and strong to support the weight of the remaining components of the drive assembly.

Typically, the chassis contains a pair of spaced apart longitudinal chassis members which are generally in line with the rail members of the trolley, and a number of transverse chassis member which interconnect the longitudinal chassis members. This arrangement provides a rigid strong structure to support the various components of the motorized drive assembly.

The chassis assembly supports a ground engageable endless drive belt. The drive belt provides the drive power to the trolley and therefore should be strong enough to provide a sufficiently long life to the drive belt.

The drive belt may be formed from rubberized materials, plastic materials, composite materials, materials with reinforcement such as steel reinforcement, cord reinforcement and the like. It is preferred that the ground engaging outer surface of the drive belt is profiled to provide anti-slip properties.

In one form, the drive belt has a width which is less than the distance between the load bearing wheels of the trolley such that no part of the drive belt extends outwardly from the load bearing wheels and therefore be susceptible to damage.

The drive belt is driven by at least one drive member and, in one form of the invention, the at least one drive member is a driven cylinder extending along and underneath the belt. The other end of the belt can be supported by one or more idler rollers or, more preferably, by a single elongate idler cylinder. The distance between the cylinders will vary the ground engageable area of the drive belt and therefore the gripping and driving ability of the drive belt. It is considered that for normal single axle trolleys, the spacing between the drive cylinder and the idler cylinder can be between 20 to 100cm. For larger or smaller trolleys, this can vary to suit.

The chassis can support a motor to drive the drive means. The motor is preferably an internal combustion motor such as a petrol motor although an electric motor is envisaged, especially if battery weight and size becomes smaller in the future.

The motorized drive assembly may further include at least one first adjustable ground wheel. This wheel may be pivotable or otherwise moveable between a first ground engaging position where the wheel lifts the belt entirely off the ground, and a second free position where the belt is able to entirely contact the ground.

In the first ground engaging position, the trolley is supported by its conventional pair of load bearing wheels, and the additional first adjustable ground wheels to allow the trolley to be self-supporting in an upright position. This allows a load trolley to be wheeled about much like a four wheeled trolley without the ground engageable belt engaging with the ground. The first adjustable ground wheel can be pivoted away or otherwise moved away to allow the belt to contact the ground.

In a further form, the drive assembly may have a second adjustable ground wheel. The second adjustable ground wheel may be moveable between a first ground engaging position where a portion (but not the entire) belt contacts the ground, and a second free position where the entire belt can contact the ground. It is preferred that the second adjustable ground wheel can have multiple adjustments to allow the amount of belt contact with the ground surface to the varied.

An embodiment of the invention will be described with reference to the following drawings in which Figure 1 illustrates a conventional type of trolley having attached to it a motorized drive assembly according to an embodiment of the invention.

Figure 2 is a side view of the trolley of Figure 1.

•.*.*Figure 3 illustrates the trolley of Figures 1 and 2 in another adjustment position.

~Figure 4 shows the trolley in a collapsed position.

Figure 5 shows some internal workings of the trolley of Figure 4.

Referring to the drawings and initially to Figure 1, there is shown a conventional single axle trolley 10. Trolley 10 is one in commercial use and has a pair of spaced apart looped rail members 11, 12 the rear end of which can be gripped by a person's hands. The lower end of rail members 11, 12 terminate in a base plate 13 which extends at right angles to rail members 11, 12. Base plate 13 need not be formed from solid continuous material and is usually in the form of a substantially U-shaped piece of metal plate which is thick enough to support a load without bending. The top part of rail members 11, 12 may be fitted with plastic tubes 14 which form no part of the invention but which are conventionally used to protect goods against being scratched by the otherwise steel rail members. At a lower part of the trolley is a single axle 15 which rotatably supports a pair of large load bearing wheels 16, 17. These conventional trolleys contains a smaller sub-axle 18 which support a pair of small idler rollers 19, 20 which are not load bearing but function only to keep base plate 13 slightly above the ground level when the trolley is in the fully upright position. Therefore, this type of trolley can be called a "single axle trolley" for the purpose of the invention.

Attached to the trolley is a motorized drive assembly 21.

Motorized drive assembly consists of a number of components. Firstly, an attachment means is provided to attach the drive assembly 21 to a rear portion of the trolley. In the embodiment, the attachment means includes a pair of steel plates 22, 23 with one plate being attached to each rail member 11, 12 and between the upper and lower loops of the rail members. The steel plates are fairly long and extend from a position adjacent the load bearing wheels 16, 17 up to adjacent an upper cross bar 24 on the trolley. The steel plates are therefore long enough to properly support the remainder of the drive assembly without bending or twisting. Of course, the attachment means need not be limited to the steel plates 22, 23 and other forms of attachment means are envisaged.

A chassis assembly 25 is coupled relative to the attachment means in a manner such that it can hinge or pivot relative to the trolley. The chassis assembly 25 consists of a number of steel sections and plates welded together to form a rigid rectangular unit. In the embodiment, chassis assembly 25 consists of a pair of spaced apart longitudinal chassis members 26, 27 (chassis member 27 not being visible in Figure 1 but being parallel to and on the other side of chassis member 26). The longitudinal chassis Smembers 26, 27 are interconnected by transverse chassis members 28 (only one transverse member being illustrated in Figure 1 to form a strong rigid box-like unit. The front of the chassis assembly is pinned to or relative to the steel plates 22, 23 such that the chassis member can pivot upwardly towards the steel plates 22, 23 or downwardly towards the ground.

The degree of pivoting movement can be adjusted by an adjustment assembly 30 (better illustrated in Figure Adjustment assembly consists of two telescopic members 31, 32, and in the embodiment, upper telescopic member 31 is a steel tube and lower telescopic member 32 is a steel tube of larger cross-section such that steel tube 31 can slide within steel tube 32. Steel tube 31 is formed with a number of spaced apart round holes (not shown) on one face 33. Steel tube 32 supports a spring biased locking pin 34. Spring biased locking pin can be moved between a forward locking position where locking pin 34 extends in one of the holes on face 33 to lock members 31 and 32 together in a retracted position where telescopic members 32 and 33 can slide relative to each other. Locking pin 34 is moved by handle 35 which is positioned on rail member 12 at a position where is can be comfortably gripped by a person's hand.

Therefore, to adjust the angle between the chassis assembly and the trolley, handle 35 is depressed to retract locking pin 34 and the trolley can be pivoted relative to the chassis 25 to a desired angle after which handle 35 is released to cause locking pin to lock in the next available hole on face 33. Once locked together, further pivoting of the trolley will cause °*o99 chassis 25 to pivot with the trolley as chassis 25 is now locked to the trolley at the desired pivot angle. It should be appreciated that an identical adjustment arrangement 30 is on the other side of the trolley, but not illustrated in the drawings, and both adjustment arrangements are controlled by a single handle 35 (using dual sets of cables 36).

A ground engageable endless drive belt 37 is attached relative the chassis. Belt 37 is more clearly illustrated in Figures 2 to 5. Belt 37 is 9*9* an endless conveyor belt formed from suitable rubberized material to give it long life and robustness. The drive belt has a ground engaging surface 9. which is profiled to provide anti-slip properties and this can be done by providing the drive belt with a plurality of transversely extending ribs or teeth (not shown). Drive belt 37 is driven about a first drive member and a second idler member. The first drive member, in the embodiment, consists of a transversely extending driven cylinder 38, while the second idler member consists of an idler cylinder 39. Drive cylinder 38 and idler cylinder 39 are spaced apart from by approximately 60cm but this can vary to suit. The cylinders 38, 39 are approximately 45cm long and have a diameter of approximately 10cm. The belt 37 has a width of slightly less than the length of the cylinders and the belt thickness is approximately 1cm although this can again vary to suit. The chassis assembly 25 is sized such that it does not exceed the spacing between the load bearing wheels 16, 17 on the trolley.

This means that the belt 37 does not extend past the wheels of the trolley.

Idler cylinder 39 is rotatably mounted to a sliding arm 40 and the sliding arm can be releasably bolted to longitudinal chassis member 26. The function of this is to allow the belt 37 to be tightened when need be.

Referring to Figure 5, there is illustrated a motor to drive the drive means. The motor in the embodiment is a small petrol engine 42.

Engine 42 drives an output cog 43, and which through a series of cogs 44, ultimately drives cylinder 38. In the embodiment, the various cogs are interconnected by drive chains 46.

Figure 5 also illustrates a plurality of spaced apart transverse idler rollers 47 which support the ground engaging portion of belt 37 and •forces belt 37 to properly track and press against the ground surface 48.

Petrol engine 42 can be started by a pull rope or other form of 15 starting mechanism and the power of the engine is controlled by a throttle 49 positioned in an upper portion of the trolley and easily manipulated by a person's hand. Throttle 49 is connected to the engine via a throttle cable **illustrated in Figure 1.

As described above, the chassis assembly 25 and its belt 37 is 20 hinged relative to the remainder of the trolley and can be locked in a •oooo a o.particular hinged position via adjustment arrangement In the embodiment, chassis assembly 25 supports a first adjustable ground wheel 53 which is better illustrated in Figure 3. Wheel 53 is rotatably connected to a supporting strut 54 and strut 54 is pivotally attached to longitudinal chassis member 26 through pivot pin 55. The wheel and strut 53, 54 are pivotally moveable between a first ground engaging position illustrated in Figure 3 and a second free position illustrated in Figures 1 and 4. In the first ground engaging position illustrated in Figure 3, wheel 53 lifts the chassis assembly and belt 37 entirely above the ground surface such that the trolley can be wheeled about through its own load bearing wheel 16, 17 and wheel 53. It should be appreciated that a second identical wheel is pivotally attached through its strut on the other longitudinal chassis member but this is not illustrated. In Figures 1 and 4, wheel 53 has been pivoted away to an extent that belt 37 is in full ground engagement with ground 48.

The drive assembly in the embodiment contains a second pair of adjustable ground wheels 60 with only one wheel being illustrated in the figures it being appreciated that an identical second wheel is positioned on the other side of the chassis assembly. The second adjustable ground wheel is also moveable between a first ground engaging position illustrated in Figures 1 and 2 and a second free position illustrated in Figures 3 and 4. In 10 the first ground engaging position illustrated in Figures 1 and 2, it can be !•°.seen that wheel 60 partially lifts up the chassis assembly such that only a forward portion of belt 37 is in ground engagement. Wheel 60 is height S* adjustable via an arcuate slot arrangement. The adjustability allows wheel to determine the amount of belt contact 37 on the ground surface 48.

15 The motorized drive assembly provides a robust and highly effective mechanism to convert a hand pushed trolley into a motorized unit and where the drive assembly can be detached when not in use. The driven belt 37 can be adjusted to be entirely off the ground (Figure 3) or partially on the ground (Figure 2) to allow the trolley to be extremely versatile. The 20 trolley can be pivoted almost horizontally onto the motorized drive assembly (Figure 4) which will allow heavy loads to be safely moved up or down inclined surfaces with belt 37 providing extremely good traction and grip and therefore safety and stability to the moving trolley.

It is found that belt 37 is strong enough to be tipped upwardly such that the front of the belt engages with the edge of a raised platform which will allow the belt to drive itself up and onto the raised platform without the requirement for an inclined ramp. The reverse is also possible whereby a load on the rear of a truck or ute can initially be tied onto the trolley with the trolley being in the orientation illustrated in Figure 4. The engine 42 can be started and the belt engaged to drive the loaded trolley off the back of the truck or ute. If the height of the truck or ute is approximately that of the length of the drive belt, a ramp is not required. Otherwise, a simple ramp can 11 be used to safely drive the loaded trolley onto and off the ute or truck.

It should be appreciated that various other changes or modifications can be made to the embodiment described without departing from the spirit and scope of the invention as claimed.

12 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A motorised drive assembly attachable to a single axle trolley which has a pair of load bearing ground wheels attached to the axle, the drive assembly having: attachment means to attach the drive assembly to a rear portion of the trolley, a chassis assembly hingedly coupled to the attachment means and having a ground engageable endless drive belt, and at least one drive member to drive the belt, 10 a motor to drive the drive member, the chassis assembly being hingeable between a substantially horizontal first position where drive belt is ground engageable and the trolley is substantially upright, and a second position where the trolley overlies the O chassis.

2. The motorized drive assembly of claim 1 substantially as hereinbefore described with reference to the accompanying drawings.

DATED this 1 9 th day of November 1998 Harold Douglas HUNTLEY By his Patent Attorneys CULLEN CO.

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