GB2372979A - Quick connect implement coupler - Google Patents

Abstract

An implement connector comprises a frame 1 with open ended apertures 3, 4 for connection with pins on an implement and a moving latch portion 5 connected by links 9, 10, 11 with a pivotally mounted hydraulic ram, the arrangement being such that in the latched position, one or more of the links abut against a bar part of the frame so that shocks occurring during use are transmitted through the frame rather than through the hydraulics. Preferably, the rod end of the ram is connected to a bracket 7 and the cylinder is connected to the linkage. The arrangement acts as an over-centre device and minimises the chance that shocks will result in failure of the hydraulics and consequential opening of the latch during use.

Description

Hydro mechanical clamp

This invention relates to an adapter that is conmonly used by heavy construction/excavation equipment for example J. C. B, Komatsu etc It is commonly called a Quick Hitch and its purpose is to allow quick assemble of different types of attachment to the machine There arc different si/. cs of hitch as determined b) the sie of machine me hitch is to be lifted to Quick Hitches fall into two categories Mechanical and Hydraulic for which tins design relates to me hydraulic type Both types of hitch have a fixed locating anm wlich is first located onto the attaclunent location point, The hitch is then manoeuvred in order to bring die hitch and its moving arm into line with the second location point.

The moving arm is then operated manually or hydraulically to lock the moving arm into the location point thus securing the attachment on to the hitch ready to be used Typical types of devices excavator machines use would be Buckets, jackhammers. Grabs etc, all would have location points that a quick hitch could attach to The Hydraulic version falls generally into two categories 1 A hydraulic ram is mounted on to the hitch frame at its base end, and the rod end is attached to a moving arm which moves in an arc about its pivot point when the hydraulic cylinder is actuated to locate and lock on to me attaclunent 2 A hydraulic ram is mounted on to the hitch frame also at its base end. and the rod end is fixed to the moving ann which slides in a linear movement along guides to locate and lock on the attachment Hitches currently on the market require constant hydraulic force acting on the moving ann to ensure location of the Hitch on me attachment In me event of hydraulic failure, me potential energy needs to be contained within the cylinder, otherwise the attaclmlent can free its self from the hitch.

For all hydraulic versions a hydraulic check valve is connected to the base end port of the cylinder.

In the event that there is a hydraulic supply failure the valve will not allow fluid to pass out of the cylinder In the event that the check valve should fail, it is common practise to also install a mechanical means of holding the moving arm, this is a steel rod which is manually inserted behind the moving arm This requires the operator to get out of his cab, and is seen as time consuming A mechanical means of containing potential energy is always deemed to be the best Engineering practice The problems with these two types of system arc ;

1 in operation any shock loads produced by the machine are felt at the attachlllentfhitch and then subsequently into the machines hydraulic system via the hydraulic ram, this can cause a series of failures as follows A Failures in the ram either by seals, check valve failure or mechanical damage B Damage to the Hydraulic pump due to"hydraulic pulsing"i. e. increase of hydraulic pressure in excess of the set pressures, this is caused by sudden shocks produced within) hc system that the unloading safety valves are unable to exhaust into the return circuit 0 C Also due to"pulsulg", failure of the hoses connecting the Hitch to the machines hydraulic systcm All the failures mentioned above will seriously affect the integrity of the Hitch and could result in the moving arm of the hitch relaxing and thus allowing the attacluuent to drop off the hitch 2 Large rams arc needed to provide the force necessary to overcome the loads created b) the attachment in use 3 This invention will resolve most of the issues above by utilising a Hydraulic/mechanical clamp arrangement 4 The feature of this design is that operation of the moving arm involves a hydraulic cylinder that is connected to the moving arm via metal links 5 As the hydraulic cylinder is actuated the metal links cause the arm that engages the attachment to move 6 The mechanical locking is achieved when the moving arm is travelling outwards to engage the mounting points on the attachment 7 The links arc set in such a manner that as me moving arm is fully engaged die set of links arc caused to "toggle over" producing a mechanical locking force on to the moving arm that is engaging die attachment 8 As the links"toggle over"the links come to rest on the frame 9 With die links resting against the frame any forces which try to open me moving arm are felt at this point, and any further effort will act to cause the links to act further against the frame 10 It can therefore be said mat very little force is felt at tile hydraulic cylinder 11 Once"locked out"me moving arm is held mechanically and to prove this the hydraulic cylinder can be disconnected from the hydraulic supply and any actions with the attachment will not cause the moving arm to release the attachment 12 Little effort is required to undo the clamp 13 As the cylinder is now only required as a switch to actuate the mechanical links and not to provide the main holding force against the moving arm it can be very much reduced in size The invention in at least one embodiment is able to produce the following advantages ; A Due to the strong and secure mechanical locking effect of the toggle action, hydraulic check valves may not be needed in the hydraulic cylinder. (Although they can be used as a secondary

safety feature) B most of the shock loads arc fell b) the link on Hie"strike plate" (wluch is the point at which die links come to rest) C all the high forces felt at the hitch arc constrained mostly by the link arrangement and not the hydraulic cylinder, therefore the cylinder can be reduced in size to that which would be expected D the whole system is very small and compact and can be adapted to be used on all sizes of hitch 14 A specific embodiment of the invention will now be described bv way ofcxamplc wilh reference to the accompanying drawings in which ; 15 Drawing (A) shows the frame of a hitch and mounted inside a linkage arrangement with the moving arm in the retracted position This meaning that the attachment can be removed from the device Drawing (B) shows the same view but with the linkage in the extended and locked position The attaclunent would now be"fixed"to the Quick Hitch Drawing (C) shows a plan view of the hitch 16 Referring to the drawing A, the frame 1 is of standard manufacture. The hitch adapts to the

machine via the pinhoies 2 17 Adaptation of the attachments is via fixing points 3 and 4 18 Area 4 will be located on to die lower fixing point of the attachment, and area 3 will be offered up to the top fixing point where the moving arm 5 is moved to secure the hitch to the attachment 19 The mechanism is attached to the swinging ann at point 6. Shown is an adapter which will be welded to die arm but a thread can be utilised at mis point which would provide a means of adjustment 20 The hydraulic cylinder is attached to the frame via bracket 7, which locates the rod end 8, allowing it to pivot at this point 21 The rear of the cylinder is held between two plates 9 and 10, (10 is shown is hidden detail in the side views) 22 The plate 9 is sized to fit through the hole in the frame at point 12 and attach to the links 11, for which there are two in this arrangement 23 The links 11 are then attached to the moving arm via adapter 6

24 The cylinder as it strokes pivots around point 13, which is an existing drilling in the sides of the frame 25 A bar locates the plates 9 and 10 to me frame

26 The point 14 allows the cylinder to pivot between the two plates 9 and 10 27 In drawing"B"the mechanism is shown fully extended, for which the cylinder is retracted 28 The links ha\c gone"over center"and ha\c moved to rest against the frame at point 15 29 The mechanism is now meelianicall) locked, an) forces which will cause die moving arm to open will be felt mainly at point 15 30 If required, secondary locking of the ilion ing ami can be via a rod pushed through me frame behind the moving ann at point 16 31 Connection ports on the cylinder will be on the end face at point 17

Claims (1)

1 Apparatus for use within an apparatus that is conunonly recognised within, die construction industry as a"quick hitch'. The purpose of the apparatus is to provide an alternative means of providing a clamping force to various types of attachment that is required to be used by machines that require to change attachments The apparatus comprises a set of links that is connected at one end to a hydraulic cylinder and al the other end to a moving arm that is part of tile"quick litch" 2 Apparatus according to claim 1 where the hydraulic cylinder is connected to the quick hitch within the frame so as not to impede movement of the hitch as controlled by the machine using the attachment 3 apparatus according to claim 1 or claim 2 in which the hydraulic cylinder can be of any suitable dimension to fit in the hitch

4 apparatus according to claim I claim 2 and claim 3 in which the hydraulic cylinder is double acting, that is can be moved by a hydraulic supply to it either in the retract or extend direction 5 apparatus according to any preceding claim where the hydraulic cylinder will be attached to the frame in such a manner that allows it to pivot about that point 6 apparatus according to any preceding claims where the hydraulic cylinder does not require any means of load holding (i. e. hydraulic check valves) but can be included

7 apparatus according to any preceding claim where die hydraulic cylinder acts agaulsl an arrangement of links 8 apparatus according to claim 6 in which the links arc manufactured from material which is able to withstand the forces being exerted on them 9 apparatus according to claim 5 or claim 6 where the links are connected to the hydraulic cylinder in such a fashion as to allow a rotational movement about its pivot point 10 apparatus according to any preceding claim where the links resists any movement other than in the rotational direction 11 apparatus according to any preceding claim in which the links connecting to the cylinder are also connected to other links

12 apparatus according to claim 10 in which the link is connected to the next set of links in such a manner as to allow rotational movement and is able to resist any other movement 13 apparatus according to claim 11 in which the link is connected to a moving arm 14 apparatus according to any preceding claim in which movement of the hydraulic cylinder caused the moving arm to travel in the direction as dictated by the hydraulic cylinder

15 apparatus according to claim 12 or claim 13 m which the link is cOimected to the moving arm in such a manner as to allow rotational movement and to resist any othei movement 16 apparatus according to any preceding claim in winch adjustment of travel can be effected at this point 17 apparatus according to claim 15 m which the adjustment will cfcct an amount of travel of the moving arm thus increasing or decreasing the distance between the attachment points of the hitch 18 apparatus according to any preceding claim in which the means of adjustment can be by an) suitable method for example by the use of shims or thread 19 apparatus according to any preceding claim in winch the moving arm is mounted on to me liitch 20 apparatus according to claim 19 in which the moving arm can be mounted in any manner which is secure 21 apparatus according to any preceding claim in which the links act against the moving arm as the hydraulic cylinder retracts or extends 22 apparatus according to claim 21 in which the links are set in such manner that as the moving arm is caused to travel in the direction which will lock it on to the attachment. A point is reached during the clamping stage where the relationship between the moving arm and the links causes the links to"toggle"past its centre position 23 apparatus according to claim 21m which the links having travelled past its centre point come to rest agamst the frame of the hitch 24 apparatus according to claim 23 in which the point at which the link comes to rest is the frame or an area which is substantial enough to take the forces that will be exerted on to it 25 apparatus according to any preceding claim in which the frame is part of the clamping process 26 apparatus according to any preceding claim in which the relationship between me link at rest on the frame die moving arm and the hydraulic cylinder is such that any loads exerted on the hitch which will attempt to open the moving arm will result in a force being applied along the link from the moving arm to the point where me link is at rest against the frame 27 apparatus according to claim 26 in which the force being applied at point where the link touches the frame can not over come the resistance being applied by the frame 28 apparatus according to claim 27 in which the angle at which the link touches the frame is such that most of the load is applied at this point 29 apparatus according to any preceding claim in which actuation of the hydraulic cylinder in the opposite direction will easily release the clamping force acting on the moving arm and retract the moving arm 30 apparatus for the use within a"quick lutch"as a means of providing a means of clamping attachments to it, substantially as described herein with reference to and as illustrated in the accompanying drawings