NZ242353A - Trailer: deck pivotable with respect to wheels to lower tray to ground level for loading and unloading - Google Patents

Description

242353 Patents Form No. 5 Our Ref: AA691124 NEW ZEALAND PATENTS ACT 1953 Complete After Provisional No. 242353 Filed: 17 September 1993 COMPLETE SPECIFICATION TRAILER LOADING MECHANISM I, JOHN WYMA, a citizen of New Zealand of Wyma Engineering, West Melton, RD 6, Christchurch, New Zealand hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement: f!3t m PT0507878 Vy^'% SJ - 2 242353 This invention relates to trailers and in particular to the type of trailer in which a rear of the trailer is supported by ground wheels and a draw bar at a forward end of the trailer is attached by a connection to the tow bar of a towing vehicle.

The loading and unloading of conventional trailers is dften hampered by the fact that the trailer deck is raised above ground level. Access for loading would be improved if the rear end of a trailer deck could be lowered to ground level, and loading would be even easier, especially for materials such as sand or rubble or heavy objects, if the front end of the trailer deck could also be lowered to keep the deck horizontal.

Another limitation of conventional trailers is that the weight of a load should be evenly distributed in the trailer deck to ensure stability of the trailer; a factor which may further hamper loading.

A primary object of the present invention is to provide an improved trailer which incorporates a means of raising, lowering and/or levelling a trailer deck to facilitate loading and unloading of the trailer, and to compensate for unevenly distributed loads.

According to the present invention there is provided a trailer incorporating a mechanism for lowering, raising or adjusting a trailer deck, the trailer comprising at least: a frame and a deck, a front end of the deck being connected by pivotal members to the frame, an independent wheel mounting pivotally connecting each wheel to the deck, and a control assembly capable of controlling movement of each wheel mounting separately, and thereby lowering, raising or adjusting^he deck.

Q . vr "2 . ■% „ // 242353 In one preferred form, the control assembly comprises a hydraulic, mechanical or pneumatic mechanism associated with each wheel mounting, and a control means for control of each hydraulic, mechanical or pneumatic mechanism. The control means may be adapted to provide separate control of the hydraulic, mechanical or pneumatic mechanisms on each side of the trailer. For example, the control means may include separate switches controlling the amount of hydraulic pressure to each cylinder of the hydraulic mechanism. Independent control of each hydraulic mechanism enables the deck to be kept horizontal even when load distribution is uneven.

In another preferred form of the invention, there are provided removable pins for locking each side of the trailer deck in a deck-raised position. One set of removable pins may be located at the front end of the deck, locking the front end of the deck to the frame. A second set of removable pins may be located on the wheel mountings, one pin to lock each wheel mounting in the deck-raised position.

In a preferred form, the wheel mounting comprises a hub plate for attaching a wheel or a stub axle, a bell-crank connected to the hub plate at one end, a connecting block at the other end and pivotally connected at a mid-portion to the deck of the trailer and, optionally, a wheel guard.

In the preferred form of the invention incorporating a hydraulic mechanism, this mechanism comprises a reservoir, a piston, a cylinder and a return spring or a hydraulic accumulator. One end of the hydraulic mechanism is connected to the frame at the pivotal member and the other end is connected to the connecting block of the wheel mounting. The control means for the hydraulic mechanism may include a hand operated pump or an electric or other type of powered pump. 242353 In a further preferred form of the invention, when the wheel mounting is in the deck-lowered position, the front end of the deck can be adjusted via the pivotal members to allow the deck to be substantially parallel to the ground upon which it rests.

Further aspects of the invention which should be considered in all its novel aspects will become apparent from the following description which is given by way of example only.

An example of the invention will be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a trailer with the mechanism fitted thereto; Figure 2 is a side view of part of the trailer in its deck-raised or road position; Figure 3 is a perspective view of the draw bar and part of a hydraulic system for the mechanism; Figure 4 is a close up view of the hydraulic system on the draw bar; Figure 5 is a close up view from above, of a cylinder, spring, piston and wheel mounting on one side of the trailer; Figure 6 is a side view of the trailer with the deck in its deck-lowered position; Figure 7 is a side view from one side showing the wheel mounting in a deck-lowered position; Figure 8 is from the other side the wheel mounting in its deck-lowered position with the wheel removed; and Figure 9 is a diagrammatic side view of the loading mechanism in operation, with the deck in its deck-raised or road position (Figure 9aHB^cl^n: its deck-lowered position (Figure 9b) $ vw JJ 242353 The drawings show an articulated trailer by way of example only and it is to be appreciated that other types of trailer systems may be readily adapted for use with the system of this invention. In the drawings the trailer is shown with a coupling 1 attachable to a tow bar (not shown) of the towing vehicle (not shown). Referring to Figures 1 and 2, draw bar 2 Extends from the coupling 1 to lie parallel with the trailer deck 3 such that it constitutes a frame 4 of the trailer. The frame 4 may pivot relative to the trailer deck 3 about connection 5. In the deck-raised or road position the frame 4 is kept in place by means of pins 6 positioned on either side of the trailer deck. On either side of the trailer the frame 4 has attached a pivotal member 7 to which is connected a cylinder 12, one of which is illustrated in Figures 5 & 6.

The hydraulics for each cylinder 12, best seen in Figures 3 and 4, consist of a hydraulic fluid reservoir or accumulator 8, control switches 9, a hydraulic pump 10, and hoses 11 which distribute the hydraulic fluid to the cylinder 12 (shown in Figures 5 and 6). The examples shown in Figures 1 and 3 have a hand operated pump 10 as an alternative to an electric or other type of powered pump.

Referring to Figures 5 and 6, the cylinder 12 has extending from it a ram 13 coaxial with which is a suspension spring 14 which may be a heavy suspension spring. The ram 13 is connected by a connecting block 15 to a wheel mounting 21, best seen in Figure 8.

Figures 7 and 8 show the wheel mounting 21, which includes stub axle 16, hub plate 17, bell-crank 18, removable pin 19 and a connecting block 15.

Referring now to Figure 9, when the removable pin 19 of the wheel mounting 2 (shown in a fixed position 19a and released position 19b) is * withdrawn and the hydraulic mechanism 11 is activated, hydraulic pressure is applied to the cylinder 12 causing the piston or ram 13 to 6 242353 cylinder 12. The movement of the piston or ram 13 rotates the wheel mounting 21 about a mid-portion 22 of the bell-crank 18 in the direction of the arrows 20. This causes the trailer deck 3 to move slowly down towards the ground, from the deck-raised position shown in Figure 9a to the deck-lowered position shown in Figure 9b.

As the deck 3 of the trailer may not be quite parallel with the ground upon which it is to rest the removable pin 6 (shown in a fixed position 6a and a released position 6b) which connects the frame 4 to the trailer deck 3 may be removed to allow the deck 3 to rest in a position which is approximately parallel with the ground.

Reverse operation of the ram 13 rotates the wheel mounting in the opposite direction to the arrows 20 to raise the deck 3 off the ground enabling the removable pins 6 and 19 to be re-engaged in holes in the chassis of the deck 3 so that the trailer can be used normally.

In the example shown dual control switches 9 are used although it is to be appreciated that a number of control switches may be used without departing from the scope thereof.

In use, the operator, by means of the control switches 9, can control the amount of hydraulic pressure to the cylinders 12 of the hydraulics on either side of the deck 3 thereby controlling the extension/retraction of the rams or pistons 13 into and out of the cylinders 12. This operational control is particularly important where load distribution on the deck 3 is uneven. By means of the controls the operator can regulate the amount of downward or upward movement of the deck 3 to compensate for uneven loading or unloading so that the deck 3 is or remains substantially horizontal. 1 2JJAtii39s ■v '' L 7 2423 The frame 4 of the trailer unit is held in position relative to the trailer deck 3 when the deck of the trailer is in the deck-raised or road position by the removable pins 6.

In an alternative embodiment of this invention (not shown) it is envisaged that the spring 14 fitted to the outside of the cylinder 12 can be removed. In place of the spring 14 can be hydraulic accumulator which operates in conjunction with the hydraulic mechanism.

For a tandem type trailer (not shown) it is envisaged that a similar mechanism can be used to enable the operator to raise or lower the deck of the trailer with respect to its wheels.

In this example each wheel has a similar wheel mounting.

The front, wheel mounting and rear wheel mounting on each side of the trailer are connected to each other by a piston and ram cylinder, such that the front and rear wheel mountings are operated in unison.

This adaptation is particularly important where the trailer has more than one set of wheels, as it greatly increases the load bearing capability of the trailer unit.

Thus by this invention there is provided a raising and lowering mechanism for a trailer to assist in unloading and loading purposes.

Although the invention has been described by way of example, and with particular reference to various embodiments thereof, it should be appreciated that variations and modifications may be made thereto, without departing from the scope thereof, as defined in the appended claims. -'vsv-v-;^

Claims (15)

4 242353 WHAT I CLAIM IS:

1. A trailer incorporating a mechanism for lowering, raising or adjusting a trailer deck, the trailer comprising at least: a frame and a deck, a front end of the deck being connected by pivotal members to the frame, an independent wheel mounting pivotally connecting each wheel to the deck, and a control assembly capable of controlling movement of each wheel mounting separately, and thereby lowering, raising or adjusting the deck.

2. A trailer according to claim 1 in which the control assembly comprises: a hydraulic, mechanical or pneumatic mechanism associated with each wheel mounting, and a control means for control of each hydraulic, mechanical or pneumatic mechanism.

3. A trailer according to claim 2 in which the control means enables separate control of each hydraulic, mechanical or pneumatic mechanism.

4. A trailer according to either claims 2 or 3 in which each wheel mounting comprises a hub plate for attaching a wheel on a stub axle and a bell-crank, one end of the bell crank being connected to the hub plate, the other end of the bell-crank being connected to a connecting block and the midpoint of the bell-crank being pivotally connected to the deck of the trailer.

5. A trailer according to any one of claims 2 to 4 in which each wheel mounting further comprises a removable rear pin for locking the wheel mounting in a deck-raised position.

6. A trailer according to any one of claims 2 to 5 fur • * - 9 - 242353 removable front pins for locking each side of the front end of the deck, in the deck-raised position, to the frame.

7. A trailer according to any one of claims 4 to 6 in which the bell-crank further comprises a wheel guard.

8. A trailer according to any one of claims 4 to 7 in which the hydraulic, mechanical or pneumatic mechanism of the control assembly comprises a hydraulic mechanism, which comprises a reservoir, a piston, a cylinder and a return spring or a hydraulic accumulator, one end of the hydraulic mechanism being connected to the frame at the pivotal member and the other end being connected to the connecting block of the wheel mounting, so that, in use, the mechanism effects horizontal movement of the connecting block, which in turn effects rotation of the wheel mounting about its mid portion, with a resulting upwards or downwards movement of the deck.

9. A trailer according to claim 8 in which the control means for the hydraulic mechanism includes a hand operated pump.

10. A trailer according to claim 8 in which the control means for the hydraulic mechanism includes an electric or other type of powered pump.

11. A trailer according to any one of claims 8 to 10 in which the hydraulic mechanism comprises a reservoir, a piston, a cylinder and a hydraulic accumulator, the hydraulic accumulator operating in conjunction with the hydraulic mechanism.

12. A trailer according to any one of the preceding claims in which, when each wheel mounting is in the deck-lowered position, the front end of the deck can be adjusted via the pivotal member to allow the deck to be substantially parallel to the ground upon which it rests.

13. A trailer according to any one of claims 8 to 12 in which the control means comprises separate switches for each hydraulic mechanism, each 242353 switch controlling the amount of hydraulic pressure to one cylinder and thus the extension/retraction of the corresponding piston; independent control of each hydraulic mechanism enabling the deck to be kept horizontal even when load distribution is uneven.

14. A trailer according to any one of claims 1 to 13 in'which the trailer incorporates more than one pair of wheel mountings, the wheel mountings on any one side of the trailer being connected to each other by a piston and ram cylinder such that they operate in unison.

15. A trailer substantially as herein described with reference to the accompanying Drawings. JOHN WYMA By His Attorneys BALDWIN. SON & CAREY cv/holdback/ASPEC25365 AA691124 JA^^9S £/) t v E