GB2287691A - Tailgates - Google Patents

Abstract

A tipper vehicle (Figure 1) has a wheeled chassis (10), a body (13) pivotally mounted on the chassis at one end thereof, and a tailgate (14) at an open end of the body for discharge of material from the body when it is tipped. At opposite sides of the opening the body is formed with respective columns (16) in which slidable members (18) are disposed, the tailgate being pivotally carried by the slidable members, which are raised, in use, during tipping of the body so that the tailgate is clear of material discharging from the body. The raising of the slidable members can be by respective hydraulic or pneumatic rams in the bottoms of the columns, or by respective wire rope lifting systems associated with the slidable members, each system including a wire rope (27) which is connected between the chassis and a slidable member, passes over pulleys (25, 26: 31: 33: 36), and is tensioned during tipping of the body, to raise a slidable member, and thus the tailgate. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO VEHICLES This invention relates to vehicles, and in particular to improved means for releasing material from a body of a tipper vehicle whilst the body is tipped relative to a chassis of the vehicle.

There are many known forms of tipper trucks, i.e. trucks having a driven, wheeled chassis on which is carried a body which can be tipped relative to the chassis, normally by means of a hydraulic ram operated from the driver's cab. Commonly the body is tipped about an axis at the rear end of the chassis and the body is provided at its rear end with a horizontally hinged tailgate or a pair of vertically hinged doors to allow outflow of material from the body during tipping.

With a pair of such doors at the end of the body, it is known for the sides of the body, and thus the respective mountings for the doors to be deformed outwardiy due to the weight of material carried, so that the respective edges of the doors no longer meet at a straight vertical centre line. Although attempts have been made to overcome this problem, for example by providing additional cam locks and the like between the two doors, the manual opening of the doors by an operator is still unsatisfactory.

With a tailgate, there is generally automatic opening thereof as tipping proceeds, but a problem is the difficulty of moving the tailgate sufficiently clear of the material discharging from the body during tipping so that the tailgate does not impede material flow.

An object of the invention is at least to reduce the above mentioned disadvantages.

According to the present invention a vehicle comprises a wheeled chassis, a body, the body being tippable relative to the chassis for the discharge of material from the body, in use, through an opening at an end or side of the body, at which opening is mounted a closure element, and means for raising the closure element relative to the body.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a fragmentary, schematic part-sectional side-view of a vehicle of the invention with a body thereof shown in an untipped position in full lines, and in a tipped position in phantom, alternative points of rope means connection between the vehicle chassis and the body also being shown in phantom, Figure 2 is a fragmentary, schematic part sectional, part cut-away view of one side of the end of the vehicle shown in Figure 1, the other side being a mirror image thereof, the body being shown in its untipped position and a tailgate not being shown, Figure 3 is a sectional view on line 3-3 of Figure 1, Figure 4 is a sectional view on line 4-4 of Figure 1, Figure 5 is a view corresponding to Figure 1, with the body in its tipped position, and Figure 6 is a view corresponding to Figure 2, but on the line 6-6 of Figure 5, and with the tailgate again not shown.

In Figure 1 there is shown part of an elongated, relatively narrow chassis 10 of a tipper vehicle, such as a dump truck. The chassis has wheels 11, and carries a cab and engine (not shown) in a conventional manner.

Pivotally mounted on the chassis at respectively opposite sides and at the rear end thereof remote from the cab is a base 12 of a body 13. The body is normally in the form of a rectangular, open-topped container having parallel longer side walls upstanding from the base, and a fixed front end wall (not shown) therebetween. As will be described, the open rear end of the body has a tailgate 14 mounted thereat. The one of the side walls of the body illustrated is identified by the reference numeral 15, and as can be seen from Figure 1 the rear end thereof is angled forwardly upwardly, as is the rear end of the other side wall not shown.

Secured to the respective sloping rear ends of the side walls of the body are respective hollow generally upright columns, one of which is shown at 16 in the Figures. The columns are conveniently welded to the side walls, but could be integral with the body. The columns can be interconnected by a square section tube 1 7 across the bottom of the body. Whilst only one side of the end of the vehicle is shown in Figure 2, the other side is a mirror image thereof about the longitudinal centre line '0' of the vehicle.

Slidably received in the columns are respective members of rectangular external cross-section, the one illustrated being identified by reference numeral 18. In this example the members are hollow tubes which are a sliding fit in the columns. As shown in Figures 3 and 4, each column has a self lubricated nylon bearing 19 secured to each of its four inner surfaces near its top end to engage with the member 18 sliding in it, and each member has a similar self lubricated nylon bearing 20 secured to each of its four outer surfaces near its lower end to engage with the column in which it slides. Alternatively the member could be provided with rollers to facilitate its movement in its associated pillar. The members can be suitably prevented from moving out of the pillars during normal operation, if this is likely to occur.The bearing 19 on the interior of the inner facing side of the column can be divided, as shown, for a purpose to be described.

The members constitute support means for the tailgate 14 which has respective hinge parts 21 at its respective opposite upper ends engaged with respective complementary hinge parts 22 at the tops of the members so as to mount the tailgate for swinging movement towards and away from the columns at the rear end of the body.

The provision of the slidable support means, namely the members sliding in the columns, enables the tailgate hinged to said members to be lifted clear of the open rear end of the body, prior to and/or during tipping of the body. Alternatively rather than it being possible to select when the lifting occurs, it can be arranged to be effected solely as a result of the tipping, and thus to occur automatically and simultaneously therewith.

Various ones of these alternatives will now be described.

Firstly it would be possible to use a relatively simple arrangement where rams are provided below the members in the columns to raise, and if necessary, lower, the members, so as to lift the tailgate 14 clear of the end of body defined between the sides. The rams could either merely push on the members, thereby merely cushioning the members when moving in the opposite direction under gravity, or could be physically connected thereto both to push and pull the members. The rams could be controlled from the driver's cab or elsewhere, and could be of hydraulic or pneumatic operation.They could be controlled independently of the tilt of the body, so that the tailgate could be raised before, during or after tipping of the body, but preferably the rams would be automatically actuated, for example by electronic sensor means, as soon as tipping commences, so that the tailgate raises and pivots simultaneously with the tipping of the body, thus ensuring minimum, if any, contact between the tailgate and the material flowing out of the body.

With the alternative arrangement shown by way of example in the Figures, the tipping up or down of the body automatically causes the lifting and lowering respectively of the members, and thus of the tailgate.

This is effected by the connection of wire ropes between the chassis, which is fixed, and the movable body, in the form of the support means for the tailgate.

As shown best in Figure 2, a pair of facing L-section plates 23, 24 respectively are secured to the top of the chassis 10 as mirror images about the vehicle longitudinal centre line '0'. Each plate serves to anchor one end of a wire rope connected, as mentioned above, between the chassis, by means of the plate, and a member slidable in a column.

With the body in its lowered position, received as shown on the chassis, respective rotatable horizontal pulleys 25, 26, are disposed directly above the anchor points, so that the respective wire ropes 27, 28 can pass upwards from their respective anchor points to be received around the pulleys 25, 26 respectively. The pulleys are secured to respective brackets 29, 30, depending from the underside of the base of the body.

A system of wire rope and associated pulley wheels is provided to both sides of the vehicle, but for the sake of clarity only the system at the left hand side will be described, this corresponding to the side at which the system is shown in the drawings. The system at the right hand side is a mirror image and operates identically.

From the pulley 25, the rope 27 continues underneath the body, running parallel to the centre line '0', to reach a vertical pulley 31 on a shaft 32 depending from the underside of the body adjacent the open end thereof. From this pulley, the rope 27 extends through 90" parallel to and behind the tube 17 to a generally horizontal pulley 33 on a shaft 34 mounted at the inwardly facing surface 35 of the lower end of column 16. The rope then turns through 90" around pulley 33 and extends upwards behind surface 35 to a horizontal pulley 36 on a shaft 37 parallel to the shaft of pulley 25. Shaft 37 is carried by spaced parallel lugs of respective brackets 38, 39 secured to the upper end of surface 35.

The surface 35 has a rectangular opening 40 therethrough to receive part of the pulley 36 and rope 27 thereon, and this allows the rope to extend 1800 around the pulley and then to extend downwards between the column 16 and member 18. The rope then passes through an opening 41 in the member 18, which opening has a ring 42 around it on the inner surface of the member. The rope passes through the ring and has an end eyelet 43 secured either by a nut and bolt fixing 44 to a bottom surface of the member, or to a cross-bar 43a (Figures 1 and 5).

Instead of only extending inside the column near the end therefrom, the rope could enter the column adjacent the pulley 36.

Accordingly since the distance between the anchor point on the chassis and the pulley 25 increases as the body moves from its rest or untipped position on the chassis to a position in which it is inclined thereto, the rope is tensioned to exert automatically an upwards pulling force on the member 18 as such tipping occurs. This causes the member to slide upwardly in its column 16. Since the other member is similarly forced to rise synchronously therewith, the resultant upwards movement of the members in the columns raises the tailboard which is pivotally connected to said members. The length of each rope can be chosen to control the amount of lifting, but generally the tailgate is lifted by substantially its own height. Figure 1 shows alternative rope anchor positions and corresponding alternative positions for pulleys 25, 26, for greater amounts of tailgate lift.For example the middle and end alternative positions provide 1.5 and 2 times the lift respectively of the illustrated example. In all cases, the degree of body tilt is approximately 47".

The opposite lower ends of the tailgate are preferably provided with respective projections, which when the tailgate is in its closed state, are received in respective sockets at the lower ends of the columns, thereby to retain the tailgate closed. Projection 45 and socket 46 are shown for one side of the tailgate in Figures 1 and 5. Upon tipping of the body, the swinging and lifting of the tailgate automatically moves the projections clear of the sockets. However in some arrangements the sockets could be sized and shaped to retain the projections even when the tailgate has swung open by a certain, but generally small, angle, in order to release only a small controlled amount of material from the body.

Figures 1 and 2 show the body untipped and the members received almost fully in their columns. Figures 5 and 6 show the body tipped, with the members automatically raised in their columns. As mentioned, means could be provided to prevent the members moving out of their respective columns. The division of one of the bearings 19 allows passage of the rope when the member rises to the extreme upper end of the column.

With the lifting system described, using the ropes, lowering of the body, which like raising is normally controlled by a hydraulic ram operated from the driver's cab, is merely the reverse of lifting in that the pulleys 25, 26 move nearer the plates 23, 24 and the resultant slackening of the ropes allows the downwards movement of the members under gravity, but cushioned by their connection to the ropes.

However in a further convenient example of the invention, a further wire rope and pulley system can be employed so as positively to pull the members downwardly as the body is lowered back onto the chassis after tipping to discharge material. The two systems thus work the reverse way round, the ropes 27, 28 of the lifting system tensioning during tipping, when the ropes of the lowering system slacken, and slackening during lowering, when the ropes of the lowering system tension. The ropes of the lowering system pass over pulleys at the opposite side of the body/chassis pivot from the first pulleys of the ropes of the lifting system.

Thus at one side of the vehicle, a rope of the lowering system has one end fixed to the chassis adjacent the previously described anchor point.

It then passes to two pulleys on the body to turn it through 90 , from where it extends parallel to the tube 1 7 to two further pulleys at the bottom of a column to orientate the rope so that it can then be fixed to the bottom of a member 18 as for ropes 27, 28, but from the opposite direction.

Accordingly as the body tips and the pulleys 25, 26 move away from the anchor point, the two pulleys of the lowering system disposed at the opposite side of the body pivot from the pulleys 25, 26 move nearer the other anchor point to allow the members to be raised by ropes 27, 28.

On lowering the body, the reverse occurs in that the two pulleys of the lowering system move away from the other anchor point and the ropes of the lowering system are tensioned to pull the members down, this now being allowed by the ropes 27, 28 which have slackened.

Thus with this convenient example, both the raising and the lowering of the tailgate by way of the members 18 is directly controlled by the tipping of the body, this being in an effectively counter-balanced manner.

The pulleys can be provided, where appropriate, on plates. The pulley of the lowering system on the chassis could be omitted, with the lowering system fixed anchor point to the chassis being instead at the position of the replaced pulley 23 on the chassis, i.e. at the required side of the body pivot. At the fixed points on the chassis for the four ropes, (or two ropes if lowering system ropes are not provided), a slack adjuster could be provided to alter the tension in the ropes. This is desirable so that should a rope break, its removal is facilitated. The tailgate sockets should preferably be quickly removable to allow tailgate opening to facilitate material discharge should a rope break.

Although the invention has been described and illustrated in relation to a tailgate, it is equally applicable in relation to a sidegate where the body is tipped along one of its sides. Instead of a single gate, a pair of hinged gates should be used to close the opening. Moreover the closure element could be raised by a single central slidable member.

Instead of two rope systems respective to raise and lower the closure element, i.e. a tailgate etc., a pair of rams could be used in the columns in combination with a rope system, with the rams raising the members and the rope system lowering them, or vice versa.

As used herein, the term 'rope' includes all types of cable having sufficient strength to make it suitable for use in the embodiments described, normally without breaking.

Instead of being connected directly to the chassis, the one end of each rope could be connected to a member fixed relative to the chassis, in fact to any member relative to which the body can tip. Instead of being anchored to plates 23,24, the ropes can be led from pulleys 25,26, to the rear of the chassis where they are anchored, for example by tying them over a bar thereat. Rope adjustment is thereby facilitated, as it is no longer necessary to have access from under the chassis to adjust the ropes.

Claims (23)

1. A vehicle comprising a wheeled chassis, a body, the body being tippable relative to the chassis for the discharge of material from the body, in use, through an opening at an end or a side of the body, at which opening is mounted a closure element, and means for raising the closure element relative to the body.

2. A vehicle as claimed in Claim 1, wherein the means for raising the closure element include a pair of slidable members received in respective columns at opposite sides of the opening respectively, the closure element being mounted on said slidable members.

3. A vehicle as claimed in Claim 2, wherein, in use, the slidable members are raised in their respective columns, thereby raising the closure element, by the operation of respective rams in said columns, in use.

4. A vehicle as claimed in Claim 3, wherein the slidable members lower the closure element under gravity, in use.

5. A vehicle as claimed in Claim 3, wherein the slidable members are lowered, in use, by operation of said rams.

6. A vehicle as claimed in any one of the preceding claims, wherein the raising of the closure element occurs, in use, simultaneously with tipping of said body to discharge said material.

7. A vehicle as claimed in Claim 1, wherein the means for raising the closure element includes rope means connected between the chassis and at least one member slidable relative to the body and carrying the closure eiement.

8. A vehicle as claimed in Claim 7, wherein the closure element is carried by a pair of slidable members received in respective columns at respective opposite sides of the opening.

9. A vehicle as claimed in Claim 8, wherein the rope means comprise two wire ropes connected at one of their ends respectively to the chassis, and at the other of their ends respectively to the respective slidable members, each wire rope passing over at least one pulley connected to the body so that it is alternately tensioned and slackened as the body is raised and lowered, or vice versa, with the slidable members, and thus the closure element, being raised as the body is tipped to discharge material, in use.

10. A vehicle as claimed in Claim 9, wherein each wire rope is part of a lifting system for raising one of said slidable members, each system including a plurality of pulleys connected to the body, and the two systems for raising the two slidable members respectively being disposed symmetrically at opposite sides of a longitudinal centre line of the vehicle.

11. A vehicle as claimed in Claim 10, wherein the body is pivotally mounted on the chassis near an end thereof, and each lifting system includes a first pulley on the body at the side of its pivotal connection to the chassis remote from said end of the chassis.

12. A vehicle as claimed in Claim 11, wherein the first pulley is on the underside of the body at a position which is adjacent the connection of the wire rope to the chassis when the body is in its untipped position.

13. A vehicle as claimed in Claim 12, wherein the wire rope passes from a pulley mounted towards the top of the column in which the slidable member is received, through an opening in said column.

14. A vehicle as claimed in Claim 13, wherein after passage into said column, the wire rope passes between respective inner and outer surfaces of the column and slidable member therein before passing through an opening in the slidable member and being secured to a lower end thereof.

15. A vehicle as claimed in Claim 14, wherein from said first pulley the wire rope extends beneath the body to a second pulley at an end of the body, the wire rope extending from said second pulley across said end of the body to a third pulley at the bottom of the column, and thence to said pulley mounted towards the top of the column.

16. A vehicle as claimed in any one of Claims 2 to 6 or 8 to 15, wherein bearing means are provided between each slidable member and its associated column.

17. A vehicle as claimed in Claim 16, wherein each column has bearings on its inner surface adjacent its open upper end, and each slidable member has bearings on its outer surface adjacent its lower end.

18. A vehicle as claimed in any one of Claims 2 to 6 or 8 to 17, wherein the closure element is pivotally mounted at its respective opposite sides to said slidable members.

19. A vehicle as claimed in Claim 18, wherein the closure element is a tailgate.

20. A vehicle as claimed in Claim 18 or Claim 19, wherein the columns and the closure element have respective interengaging retention means which normally hold the closure member closed, but allow automatic pivotal swinging open thereof when the slidable members are raised, in use.

21. A vehicle as claimed in any one of the preceding claims, wherein the closure element is lowered relative to the body, in use, by one or more rams.

22. A vehicle as claimed in any one of Claims 2 to 6 or 8 to 20, wherein the closure element is lowered, in use, relative to the body by a system including rope means and pulley means, the rope means being connected between the chassis and said slidable members and extending over at least one pulley of the pulley means connected to the body, so that the rope means are alternately tensioned and slackened as the body is lowered and raised, or vice versa, thereby effecting lowering of the slidable members when the body is lowered from its tipped state.

23. A vehicle substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.