GB2065063A - Loading apparatus - Google Patents

Abstract

A loading apparatus comprising a support assembly 14 and a jaw member 130 for engagement or connection with the body to be moved. Member 130 is arranged for longitudinal movement along the support assembly 14 and for controlled movement between a first orientation (as shown) in which the mouth part 139 of the jaw member is at or close to ground level and a support orientation in which the mouth part of the jaw member is directed towards the distal end of the support assembly. <IMAGE>

Description

SPECIFICATION Loading apparatus The present invention relates to loading apparatus i.e. to apparatus for moving a body from a location adjacent the apparatus to a support surface for the body.

According to the present invention, loading apparatus for moving a body from a first location to a second location comprises a support assembly, and, for engagement or connection with the body to be moved, a jaw member arranged for longitudinal movement along the support assembly and mounted for controlled movement between a first orientation in which the mouth of the jaw member is at or close to ground level and a support orientation in which the mouth of the jaw member is directed towards a distal end of the support assembly.

For convenience, the terms "vertical" and "horizontal", etc. have been used through this specification to define and describe the apparatus of the present invention as it would be when supported on a flat horizontal surface and the term "longitudinally" as used above and below then refers to bodily motion of the lifting means (relative to the support assembly) in the vertical plane.

Conveniently, the lifting means is attached to a carriage, arranged to move longitudinally along the support assembly, by one or more arms mounted for limited rotational movement about a horizontal axis.

Conveniently, the controlled movement of the jaw member is achieved by having the one or more arms, or something secured to the one or more arms, form part of a cam arrangement of which the other part is provided by the support assembly or by a mounting structure for the support assembly.

Alternatively, the controlled movement of the jaw member may, for example, be effected by means of one or more hydraulic rams acting on the one or more arms.

Conveniently, the apparatus includes a closure member towards which the upwardly directed jaw member is displaced during operation of the apparatus to close off the mouth of the jaw member.

Conveniently, the apparatus includes holding means mounted on the jaw member and operative to close off the mouth of the jaw member at least until the jaw member has moved to its support orientation.

Conveniently, a latching mechanism is provided to lock the jaw member in its support orientation. Conveniently, when the lifting means is attached to a carriage, then this latching mechanism may be automatically released by the carriage as it reaches a preselected position on its return path down the support assembly.

Embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which Figure 1 is a side view of a loading apparatus according to the present invention; Figure 2 is an elevation of the loading apparatus (when in the position shown in Figure 1) viewed from the rear of a vehicle on which it is mounted; Figure 3(a), 3(b) and 3(c) schematically illustrate different positions of the support assembly; Figure 4 is a side view of the lower part of another loading apparatus according to the present invention;Figure 7 is a back view (in the direction of arrow A); Figure 5 shows, on an enlarged scale, a three-part ram for use in the apparatus of Figure 4; and Figure 6 is a vertical section showing the lifting means of the same apparatus at a different part of its operation cycle to that illustrated in Figure 4.

Thus referring first to Figure 1, a loading apparatus 10 according to the present invention is mounted on a vehicle of which only the rear portion with its support wheels 12 is shown in the Figure.

The support assembly of apparatus 10 is provided by a telescopic mast 14 comprising an inner section 16 nested within an outer section 18. Extension and contraction of the mast is effected by a double-acting hydraulic ram or rams 20 (Figure 2).

The outer section of the mast is pivotally mounted on the vehicle chassis 22 for limited rotation, about a pivot pin 24, under the control of a hydraulic ram 26.

The inner section of the mast is arranged to slide within the outer section from a fully retracted position shown in Figure 3(a) to a fully extended position shown in Figure 3(c). A carriage 28 is supported on rollers 42 and 44 for movement along guide rails (not shown) forming part of the inner section 16.

At its lower end the carriage carries a pair of pivoted arms 30 supporting a jaw member 32. In the situation illustrated in Figure 1, the jaw member is shown engaging an attachment bar 34 of a body 36 which is to be lifted by the apparatus from a first ground location 38 to a load-supporting second location 40 on the vehicle.

The drive for the carriage 28 comprises endless chains (102) passing around sprockets or pulleys 100, 101 at the end of inner section 16, one run ofthe chain being connected to the carriage by attachment 103, and the other to the outer mast section at 104.

The result is that as the mast is extended or contracted by the double-acting hydraulic ram 20, the carriage will move along inner section 16 by an amount equal to the displacement of that section relative to the outer section 18. It follows that if, when the mast is in the fully contracted position shown in Figures 1 and 3(a), the carriage is at the bottom end of the mast 14, it will be at the top end of the mast when this latter is in the fully extended position shown in Figure 3(c).

During normal travel of the vehicle, the ram 26 will of course be in its contracted position so as to hold the mast 14 in the horizontal position indicated at 46 in Figure 1.

To load the body 36 on to the vehicle from the location 38 shown in Figure 1, the mast 14 is tilted to the vertical position (shown in full lines) following which the carriage 28 is moved (if necessary) to bring the jaw member 32 close to the ground. The vehicle is then reversed so that the jaw member engages the lifting bar 34 as shown in the Figure.

Sighting lines on the mast and on the body enable this to be done without the driver leaving his seat.

The ram 20 is now operated to extend the mast and thereby cause the carriage 28 to move upwardly along section 16 under the influence of the chain drive as already described. To avoid dragging the rear of the body along the ground, the vehicle may be allowed to move backwards during this process.

When the jaw member has been raised to about the height of the pivot 24, the mast may conveniently be tilted by ram 26 until the body and the mast lie at substantially the same inclination.

Movement of the carriage is now continued to draw the body further up the mast which is pivoted so that its inclination will at all times remain substantially the same as that of the body.

When the body has reached some preselected "maximum" inclination e.g. typically 25"form body of about 4 metres length, the ram 26 is actuated to return the mast to its horizontal position.

Further movement of carriage 28 along the mast will then be effective to move the body horizontally into place on the load-supporting location 40.

As indicated in the introductory portions of the specification, the lifting means can be one of a number of different designs.

One such design is depicted in Figures 3(a) to 3(c) which shows in more detail the jaw member illustrated in simplified form in Figure 1.

Thus referring first to Figure 3(a), it will be seen that the arms 30 on which the jaw member 32 is supported extend forwardly of the mast to support a cam follower or followers 48. This co-operates with a cam 50 attached to the inner section 16 of the mast.

Alternatively, the cam 50 may be attached to the outer section of the mast at a position similar to that shown in Figure 3(a).

At their other ends, the arms carry a lug or bar member 52 and as the carriage 28 is moved along the mast from the position shown in Figure 3(a), the cam follower 48 will ride up over cam 50 to change the inclination ofthe arms to a position (shown in Figure 3(b)) in which the member 52 will have passed over a latch member 54 pivotally attached to the middle of the carriage to hold the jaw member in place adjacent the under surface of a closure member 56 also mounted on the carriage.

This situation is maintained either until the latch is manually released, e.g. following location of the body on the vehicle, or, alternatively, until the mast is contracted, e.g. from the fully extended position of Figure 3(c), to a position at which an appropriately placed striker (or an equivalent cam surface), indicated diagrammatically at 58 and fixed relative to the inner section 16, is engaged by the end 60 of the latch member to release the latch and free the arms 30 for their return to the position shown in Figure 3(a). This will happen shortly afterthe cam follower 48 has re-engaged cam 50.

Instead of relying upon gravity to swing the arms down to thier initial positions, a spring (not shown) may be fitted for this purpose if desired.

For convenience as shown in Figure 2, the striker 58 may be fitted to the ram cylinder. However, if, as suggested above, the cam 50 is secured to the outer mast section instead of to the inner, then the cam 50 could also be secured to that part if desired.

In a variation (notshown) ofthe illustrated design where a body engagement member is used on the jaw member, the arms 30 carry a link which is operated by a cam or striker secured to the inner or outer section of the mast to open or close the body engagement member as the case may be.

Although the mast has been shown as being vertical in Figures 3(a) to 3(c), this is as a matter of convenience only and generally, as will have been appreciated from the foregoing description, the mast will be inclined to the vertical by varying amounts.

In the embodiment described above, with reference to Figures 3(a) to 3(c), during the first part of the extension until arms 30 are latched, i.e. from i.e.

from Figure 3a to Figure 3b, the load on the lift chains and the hydraulic ram is approximately doublue that during the rest of the extension.

The double loading effect may be avoided in other embodiments of the invention by employing separate hydraulic rams to move the carriage and/orthe arms independently of the extension of the mast. An alternative way of doing this is shown in the embodiment of Figure 4 to 7 which differs from the previously illustrated embodiments in employing a different sequence of movement of the carriage relative to the two parts of the mast to extend and contract the mast and in using a different design of catch mechanism 111 (Figure 4,7 and 5).

Thus referring first to Figures 4,7 and 5, it is to be understood that the interrelationship between the carriage 112, the endless-chain drive 114, the inner and outer mast sections and the piston 119 and cylinder 122 ofthe hydraulic ram 110 is essentially the same as in the embodiment of Figures 1 to 3.

Hence it will not be described again in detail here.

As already indicated, however, the ram 110 of Figure 5 differs from the earlier described ram by having a third part which is in the form of a sleeve 120 which surrounds the lower part of the cylinder 122 producing a two-stage double-acting ram. Reference numeral 124 indicates an annular piston and fluid tight seal assembly secured to the cylinder 122, and reference numeral 125 indicates a cap secured to the sleeve 120 and fitted with a fluid tight seal acting on the cylinder 122. The sleeve 120 is closed at its base whereas the cylinder 122 is open at its lower end.

When fluid is introduced through the pipe 158 and fluid is permitted to flow from pipe 128, the ram will extend in a particular sequence as will be explained below.

The sleeve 120 is attached to the outer part of the mast, e.g. by means of the members which carry the cam 141, and the piston rod 162 is attached to the top of the inner mast. One strand of the lift chains is attached to a member 161 secured to the cylinder 122.

Referring now to Figures 4,7 and 5, the catch mechanism 111 comprises a pair of hook members 130, joined by a cross-bar 131, mounted one on each side of the carriage 112 by a first common pivot 132, and a latch member 134 similarly mounted on one side of the carriage by a second pivot 136.

With the carriage at its lowermost point of travel and the mast vertical and fully contracted, the hook and latch members will assume the attitudes shown in Figure 4with their jaw portions 139,138 lowermost and with their other roller-carrying ends positioned below but in line with respective cam surfaces 141, 142 carried by the outer mast section (144).

To adjust the height of the jaw portions of hook members 130 and to engage them in the lifting bar of the body to be raised, pressurised fluid is introduced into space 146 through pipe 158 to raise the cylinder 122 and with it the piston 119 and its rod 162 and the inner mast to which the rod 162 is attached. Because there is no relative movement between the attachment point of the lift chains and the cylinder, the carriage remains at the bottom of the inner mast and the chains remain free from load. During this stage of the movement the roller (148) of hook member 130 will roll over cam surface 141 to change the inclination of the hook member 130 so thatthejaw portion of this member can raise the lifting bar of the body to move it to the position 150 shown in Figure 6.

During the middle part of this movement, the latch roller (152) will have engaged the lower and central parts of cam surface 142 to deflect the latch member out of the way of an upwardly moving latching surface 154 of hook members 130. However, as the inner mast and carriage continue their upward motion with ram sleeve 122, engagement of roller 152 with the upper sloping part of surface 142 will allow a tension spring 156 (shown only in Figure 6) to return the latch memberto the waiting position in which it will have the same orientation as that illustrated in Figure 4.Further upward movement of the inner mast and carriage will result in the hook-roller 148 moving over the upper sloping part of cam surface 141 to allow the hook member to move in a clockwise direction (as viewed in Figure 6) until the latching surface 154 moves into engagement with the jaw portion 138 of the waiting latch member 134 to lock the jaw member in place. Conveniently in this position the mouth of jaw portion 139 will be closed off by a closure member (not shown) corresponding to member 56 in the first embodiment.

The cylinder 122, at this point, will have reached the limit of its upward movement and additional pressurised fluid introduced (through pipe 158) into the space below the piston 119 will force the piston upwards so as to move the inner mast in relation to the cylinder. Due to the attachment of the chains 114 through part 161 to the cylinder, the carriage will now rise relative to the inner mast by an equal amount as in the embodiment of Figures 1 to 3.

The desired sequence of the movement of the cylinder followed by the piston is achieved by arranging that the ratio of the annular area defined by the bore ofthe sleeve and the bore of the cylinder to the cross sectional area of the piston is greater than that of the forces resisting the upward movement of the cylinder and the movement of the piston relative to the cylinder.

The controlled contraction ofthe mast and the eventual release of the lifting bar 150 will be accomplished by introducing oil through pipe 128 to flow first into the annular space above the piston and subsequently also into the annular space 127 causing the reverse sequence of operations to those above described. Oil is dispelled through pipe 158 during this process. This reverse sequence may be arranged by suitably proportioning the annular areas or preferably by the use of a flow control valve fitted between the space 127 and the pipe 128.

At the beginning of the second stage of the reverse operation when oil begins to flow into space 127, latch member 134 is relieved ofthe load of hook members 130 by the small anticlockwise rotation of members 130 caused by the action of roller 148 coming into contact with the upper part of cam surface 141.

Continued downwards movement of the carriage brings latch roller 152 into contact with cam surface 142 causing member 134 to rotate clockwise into the position shown in Figure 7. On further downwards movement of the carriage, roller 148 follows the lower part of cam surface 141 causing the hook member 130 to swing to the position shown in Figure 4. In the illustrated embodiment this motion of roller 148 is controlled by guide surface 160 (shown only in Figure 6).

In an alternative version (not shown) the lower part of cam surface 142 is omitted and the necessary clockwise rotation of latch member 134 during the upwards movement of the carriage is provided instead by engagement of hook members 130 with jaw portions 138.

If it is required to have a mast with a shorter closed length, for example in order to operate in low buildings orto place a succession of short bodies on the vehicle, a mast having more than two sections may be employed as in known practice with some fork lift trucks.

Variations in the loading cycle are also possible.

For example, after engaging the jaw member with the attachment part of a body resting on the ground, the mast could be tilted to a position where it is at the same angle as the body before the carriage is moved to start drawing the body on to the vehicle.

This may obviate the need for the jaw member to pivot or otherwise clasp the attachment part.

It will also be appreciated that the body to be loaded need not be as long as the body shown (in broken line) in Figure 1. A shorter body or piece of equipment may for example be loaded on to the front of the vehicle's support surface enabling a second body to be loaded (and subsequently unloaded if desired) without disturbing the first body. Alternatively, the second body could be moved forwards on the inclined mast so that the contents of this body can be discharged by gravity into the first body. For the same amount of lift from a ground location, however, a long container will be inclined through a smaller angle to the horizontal than a shorter container, and this may be advantageous in some circumstances.

Where a low loading inclination is especially important, e.g. for animal transport, the rear end of the container may be provided with fixed or retract able legs so that initially the container is inclined oppositely to its loading inclination. This will result in a corresponding reduction in the loading inclination when the front end of the container is raised into place.

As has been explained, the use of a three part hydraulic ram in the embodiment of Figure 4 to 7 enables the inner mast and the carriage carrying the hook members 130 to move together during the first stage of the loading cycle when the hook members swing from the position shown in Figure 4 to that in Figure 6 and are held in this position by the latch member 134. This relieves the lift chains of the higher loads to which they would otherwise be subjected during this stage. However, a similar reduction in the maximum loading in the lift chains and the hydraulic rams, or other actuating means, may be achieved in a modification (not shown) of the first embodiment, in which the cam 50 in Figures 3(a) to 3(c) has been repositioned so as to be engaged by the follower 48 only when the carriage has moved to a zone part way along the mast.This enables the movement of the hook members from the position where they are inclined down towards the bottom of the mast to the position where they are inclined up towards the top of the mast to be delayed until the mast has been inclined at an angle no steeper than 45" (and preferably no steeper than 30 ) to the horizontal so that the work done during this stage in drawing the body forwards along the mast onto the vehicle or other base is substantially reduced. In this latter embodiment, holding means are preferably provided to close off the mouth of the jaw member at least until the jaw member has moved to its support orientation and preferably until it is desired to unload the body from the mast. Suitable holding means are currently available as proprietary items e.g. coupling hooks for a tractor quick hitch arrangement.

In the context of the present invention, one such device for example might comprise an elongate locking element pivotally connected at its centre to the respective hook member and movable between a first position in which a first end of the element closes off the mouth of the hook member and another position in which this mouth is exposed. In operation, the locking element can be locked in its first position by a pawl pivotally connected with the second end of the locking element and springbiassed into one of two over-dead-centre positions.

The locking element can be moved away from the mouth of the hook member by moving the pawl (against the restraining action of the biassing springy to a second over-dead-centre position in which the biassing spring again operates to hold the pawl in position.

It will also be appreciated that the invention extends to the case where the mast 14 is a pivoted fixed-length (i.e. non-telescopic) mast. In these cases, hydraulic rams are conveniently employed to move the carriage and/or the arms.

Some advantages of preferred embodiments of the invention are given below.

There are no restrictions, within practical limits, to the width or height of the body to be handled and additionally the longitudinal movement relative to the load supporting member or mast being handled is close to or greater than the length of that mast.

This makes it possible arrange for the bodyengaging member to extend below the bottom of the mast, when the latter is vertical, and also to draw the body up close to the upper (front) end of the extended load-supportin-g part. The benefits of these features is firstthatwhen working on soil or in dirty conditions the mastmaybe kept clear of the ground and secondlythatthe load;carrying length of an associated vehicle is not significantly reduced by some structure or mechanism extending forward of the body.

Another advantage issthat tlie attachment point of the lifting means with the body is close to the base of the body which leads to economy in body construction and avoids obstructing possible doors in the end of the body.

Additionally, in combination with the above, the mechanism may conveniently serve as a fork lift, hydraulic crane or shovel loader when the mast is within say 45" of the vertical position. The necessary attachments for these duties may be secured directly to the carriage or supported by the body-engaging arm and steadied by contact with the carriage or mast.

In the various embodiments, provision is made for fully or adequately constraining the body attachment bar in the jaw during loading and unloading and this enables the maximum angle of tilt of the body during handling to be kept below that commonly experienced.

The body-handling mechanism may conveniently be used to tip a body for discharging its contents from the rear by gravity.

Claims (10)

1. For moving a body from a first location to a second location, a loading apparatus comprising a support assembly, and, for engagement or connection with the body to be moved, a jaw member arranged for longitudinal movement along the support assembly and controlled movement between a first orientation in which the mouth of the jaw mernber is at or close to ground level and a support orientation in which the mouth ofthejaw member is directed towards a distal end of the support assembly.

2. An apparatus as claimed in Claim 1 in which the lifting means is attached to a carriage, arranged to move longitudinally along the support assembly, by one or more arms mounted for limited rotational movement about a horizontal axis.

3. An apparatus as claimed in Claim 2 in which - the controlled movement of the jaw member is achieved by having the one or more arms, or something secured tothe one or more arms, form part of a cam arrangement of which the other part is provided by the support assembly or by a mounting structure for the support assembly.

4. An apparatus as claimed in Claim 2 in which the controlled movement of the jaw member is effected by means of one or more hydraulic rams acting on the one or more arms.

5. An apparatus as claimed in any preceding claim including a closure member towards which the upwardly directed jaw member is displaced during operation of the apparatus to close off the mouth of the jaw member.

6. An apparatus as claimed in any preceding claim including holding means mounted on the jaw member and operative to close off the mouth of the jaw member at least until the jaw member has moved to its support orientation.

7. An apparatus as claimed in any preceding claim including a latching mechanism to lock the jaw member in its support orientation.

8. An apparatus as claimed in Claim 7 in which the latching mechanism is automatically released by the carriage as it reaches a preselected position on its return path down the support assembly.

9. An apparatus as claimed in Claim 1 substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 3(c) ofthe accompanying drawings.

10. An apparatus as claimed in Claim 1 and substantially as hereinbefore described with reference to, and as illustrated in, Figures 4 to 7 of the accompanying drawings.