WO1991003418A1

WO1991003418A1 - Gripping implement

Info

Publication number: WO1991003418A1
Application number: PCT/NL1990/000127
Authority: WO
Inventors: Cornelis Gijsbertus Klein
Original assignee: C.G. Klein Equipment B.V.
Priority date: 1989-09-06
Filing date: 1990-09-06
Publication date: 1991-03-21
Also published as: AU6430890A; NL8902233A

Abstract

An implement (100), comprising at least one gripping member (3, 4) pivotally mounted on a support member (200), and rotation means (101, 102) for rotatably mounting the support member (200) to a control arm (30), is improved according to the present invention in that the rotation means (101, 102) comprises a cylindrical shaft (103) extending through the support member (200) and in force-transmitting engagement with said support member on the side of said support member proximal to the grip opening and on the side of the support member remote from the grip opening, and that the rotation means (101, 102) further comprises at least two axially spaced rotation bearings (123, 131) for the rotatable coupling of the cylindrical shaft (103) with a corresponding rotation member, such that the implement (100) is capable of being loaded very heavily in a direction perpendicular to the axis of rotation.

Description

GRIPPING IMPLEMENT

The invention relates to an implement, comprising a support member; at least one gripping member pivotally mounted on the support member; and rotation means comprising a first rotation member mounted on the support member and a second rotation member, which members are rotatable relatively to each other; the second rotation member comprising a fastening member for mounting the second rotation member on a control arm so as to permit controlled pivotal movement of the second rotation member and the control arm relatively to each other about a first pivot pin arranged perpendicularly to the axis of rotation; there being further provided means for rotating the first and the second rotation member relatively to each other.

Such an implement is known from U.S. Patent No. 4,257,731.

Hereinafter that position of the implement where the axis of rotation is horizontal will be referred to as the horizontal position, and the position of the implement where the axis of rotation is vertical will be referred to as the vertical position.

The implement described in the publication mentioned comprises two gripping members for gripping objects. It is capable of lifting elongated objects off the ground regardless of their orientation relative to a support of the implement. It is also possible for the implement to approach objects fro a direction other than from directly above, because the implement is adapted to tilt about a horizontal axis (46) . With the known implement, however, tilting is possible to a limited extent only, because the ear portion (44) already abuts the control arm at a relatively small angle of tilt. When it is desirable for the known implement to grip an object from the side, i.e. with the implement in the horizontal position, the control arm must accordingly be fully extended. For this reason alone the range of uses of the known implement is limited. A further disadvantage of the known implement is that it can be loaded only to a limited extent, which further limits the range of uses.

A problem that may occur in the known implement is that in the horizontal position of the implement the weight of an object being gripped by the implement exerts a tilting moment on the implement, which tilting moment must be taken up by the rotation means via the connection of the implement to the rotation means. The forces which are then exerted on the rotation means and the connection mentioned may be of such magnitude that on that account limitations must be imposed on the maximum weight of an object to be gripped so as to avoid damage to the rotation means and the connection mentioned.

One example of a use where it is desirable for the implement to approach the object to be gripped from the side and/or from below and to be able to exert a considerable force is the demolition of houses . Generally a house to be demolished is pulled down or knocked down. The rubble thus formed is then moved to lorries by means of the known grab to be dumped elsewhere.

One disadvantage of this method is that the uncontrolled fall of rubble constitutes a safety hazard, particularly in places such as the centres of cities where buildings are very close to one another.

Another disadvantage is that the rubble constitutes a random mixture of various building materials, such as stone, wood, steel, etc. For various reasons, however, it may be desirable to sort these building materials, which is relatively labour intensive and expensive. One example of such a reason is the wish to reuse certain materials . Environmental considerations may also be a reason to sort construction rubbish before it is dumped. In certain favourable conditions it is possible to remove a particular object from the house to be demolished with the known grapple implement before the house is further knocked down, for instance a steel beam projecting from the wall. In that case the object is pulled until it comes loose, which requires a considerable force to be exerted. This force, which may be a torque and/or a transverse force, must be supplied by the control arm to the implement via the rotation means.

An implement of the above-mentioned type can also be used as a dipper-dredge, for instance for scraping away soil for digging ditches. Then usually one gripping member is provided. During scraping a considerable force is exerted on this gripping member in a direction perpendicular to the axis of rotation of the implement, which force must be supplied by the control arm to the implement via the rotation means.

Accordingly, it is an object of the invention to improve the known implement. In particular it is an object of the invention to provide an implement of the type described hereinabove, which can be loaded more heavily in a direction perpendicular to the axis of rotation of the implement.

It is a further object of the invention to provide an implement of the type described above, adapted to approach an object to be gripped more readily from the side and/or from below.

The invention also aims to provide a solution to the problem that may present itself in practice, namely, that the implement approaches an object to be gripped, for instance a steel truss, somewhat obliquely, so that upon engagement a rotational force is exerted on the implement by the object . This rotational force must be compensated for by the point of support between the control device and the base it rests on. When this rotational force whose magnitude, direction, and time of occurrence will in practice be unknown to an operator, cannot be compensated for by the instantaneous point of support, a dangerous situation may arise. Accordingly, it is a further object of the present invention to construct the rotation means, such that upon engagement the implement is self-adjusting. In this connection "self-adjusting" means that the implement is capable of adjusting its position in the direction of rotation to the position of the object to be gripped without substantial rotational forces being generated in the-process.

In accordance with an important aspect of the invention, the rotation means of the implement of the type described above comprises a cylindrical shaft extending through the support member in force-transmitting engagement with the support member on the side of the support member proximal to the grip opening and on the side of the support member remote from the grip opening, and comprises at least two axially spaced rotation bearings for the rotatable coupling with a corresponding rotation member.

In one embodiment the cylindrical shaft is fixedly mounted on the support member, for instance by welding, so that the cylindrical shaft is part of the first rotation member.

In another embodiment the cylindrical shaft is part of the second rotation member and the at least two bearings are arranged at the side of the support member that is proximal to the grip opening and at the side of the support member that is remote from the grip opening, respectively.

Preferably the cylindrical shaft is solid. In virtue of the above-mentioned features the implement according to the invention is capable of exerting particularly great transverse forces.

In a further preferred embodiment the second rotation member comprises on the side remote from the cylindrical shaft coupling means for coupling with the control arm and for coupling with pivotal drive means, which coupling means are substantially in alignment with the axis of rotation.

Thus the implement according to the invention can be used in many positions .

The implement according to the invention offers the advantage that, for example, materials sorted according to kind can be removed from the house to be demolished in an earlier stage of the demolition because an object to be gripped can be approached from the side and/or from below (see Fig. 4) . Thus a part of an external wall can be gripped, for instance. Via a window the joist framing of a superjacent storey floor can be gripped, or a part of an internal wall, a steel beam, etc. In a further preferred embodiment an implement comprises an operable control device for the controlled rotation of the implement relative to the control shaft, constructed according to the invention such that the control device can be operated in an operative free-running condition where the rotation members of the rotation means can rotate freely relatively to each other.

One preferred embodiment of the implement according to the invention will now be further explained with reference to the accompanying drawings, in which: Fig. 1 is a schematic sectional view of an embodiment of the implement according to the invention; Fig. 2 is a sectional view taken, along the line II-II in Fig. 1;

Fig. 3 is a more detailed schematic perspective view of the second rotation member of the implement of Fig. 1; Fig. 4A schematically illustrates a situation for use of an implement according to the invention;

Fig. 4B schematically illustrates another situation for use of an implement according to the invention;

Fig. 5 shows in greater detail the forces acting on the implement in the situation illustrated in Fig. 4; and

Fig. 6 is a schematic section of an alternative embodiment of the implement according to the invention.

Fig. 1 shows an implement according to the invention, generally indicated by the reference numeral 100. The implement 100 comprises a support member 200 designed as a rigid, box-shaped frame, and two gripping members 3,4 pivotally mounted on the support member 200 by means of respective pivot pins 5,6. Provided in the gripping members 3,4 at the ends of the pivot pins 5,6 are control eyes 7,8 between which a hydraulic grip control means is mounted. Each hydraulic grip control means comprises a piston movable within a cylinder, with the piston being connected to one of the control eyes 7,8 and the cylinder being connected to the other of the control eyes 7,8. When upon the supply of fluid to the cylinders the pistons are forced from the respective cylinders, the gripping members 3,4 will close, as known per se. Since the construction of the hydraulic grip control means is not part of the present invention, they are not shown for the sake of clarity.

The support member 200 is provided with rotation means 101,102 for pivotal connection to a control arm 30 (Fig. 3) . The configuration of the control arm 30 is known per se, and is used for instance in excavators. In the embodiment shown an axially arranged cylindrical bush 101 operating as a first rotation member is fixedly mounted, for instance by welding, on the support member 200 of the implement 100. In a suitable embodiment the inner diameter of the bush is about 20 cm, and the length is about 30 cm. The second rotation member 102 comprises a cylindrical shaft 103 whose diameter is slightly smaller than the diameter of the cylindrical bush 101. At a first end the cylindrical shaft 103 comprises two axially extending plates 104,104', symmetrically arranged on opposite sides of the center line of the cylindrical shaft 103. Provided in the plate 104 are pivot eyes 106 and 107 corresponding with pivot eyes 106' and 107' in the plate 104'. Provided in the control arm 30 is a pivot hole 35 for cooperation with the pivot eyes 106,106' by means of a first pivot pin, not shown, for pivotally mounting the second rotation member directly on the control arm 30. By means of a second pivot pin, not shown either, pivot eyes 107,107' can be coupled with hydraulic pivot control means 110, which in its turn is coupled with the control arm 30 for controlling the pivotal position of the implement 100 relative to the control arm 30. At the second end 120 of the shaft 103 a head flange 121 is mounted, for instance by means of screws 122. This prevents the second rotation member 102 from being withdrawn from the first rotation member 101, which in the absence of the head flange 121 will happen under the influence of a force exerted axially on the implement 100. Arranged about the shaft 103 between the head flange 121 and the first rotation member 101 is a gliding ring 123 for reducing the friction generated as a result of an axial force between the head flange 121 and the first rotation member 101. By welding for instance, a central flange 130 is fixedly mounted on a central portion of the shaft 103. The axial distance between the central flange 130 and the head flange 121 substantially corresponds with the length of the cylindrical bush 101. Mounted between the central flange 130 and the cylindrical bush 101 is a gliding ring 131 whose function is analogous to that of the gliding ring 123. The central flange 130 is of essentially diamond- shaped configuration, as is clear from Fig. 2. At the angles 132, 132' furthest removed from the axis of rotation, holes 133, 133' are provided in the central flange 130.

Diametrically opposite each other engagement members 134, 134' are fixedly mounted on the support member 200, for instance by welding. Provided in the engagement members 134, 134' is a hole 135, 135'. A known per se hydraulic control member 140 is connected with the holes 133 and 135 by means of pins 136, 137, while a likewise known per se hydraulic control member 140' is connected with the holes 133' and 135' by means of pins 136', 137'. By controlling the control members 140, 140' the first rotation member can be rotated relatively to the second rotation member, as a result of which the implement 100 can be rotated relatively to the control arm 30. Further mounted on the central flange 130 and the support member 200 are members 150, 151 forming a stop and defining an extreme rotation position for the first rotation member relative to the second rotation member. The extreme positions are selected such that the path of rotation of the implement 100 relative to the control arm 30 is at least 90°.

Fig. 1 shows the implement 100 in a horizontal position, in the situation where the second rotation member 102 has the second end 120 mounted in the first rotation member 101. When in the grip opening 112 of the implement 100 an object V is disposed (Fig. 4A) , this will cause a tilting moment on the implement 100. Due to a small degree of clearance between the second rotation member 102 and the bush 101 the tilting moment of the implement 100 is substantially transmitted to the shaft 103 at the end of the bush 101, with the forces generated in the process being limited because the points of application of these forces are spaced apart as widely as possible, the distance between them being substantially equal to the length of the bush 101. Here, the contact surfaces between the bush 101 and the shaft 103 function as rotation bearings. It will be clear that separate rotation bearing means such as sliding sleeves may be provided between the bush 101 and the shaft 103. The forces acting in the implement 100 are illustrated in more detail in Fig. 5. Object V exerts a downwardly directed force F._z on the end of the pivoting arm 4, causing a turning moment M_z relative to the pivotal point 107, which might in turn cause a tilting movement of the support member 200 relative to the pivotal point 107. This tilting movement is counteracted by a force F_r exerted by hydraulic pivot control means 110, whereby relatively to the pivotal point 107 a counteractive turning moment M_r on the second rotation member 102 is caused. The second rotation member 102 transmits this counteractive turning moment M_r to the support member 200 by means of an upwardly directed force Fi exerted by the second end 120 of the shaft 103 and a downwardly directed force F₂ exerted by the first end of the shaft 103. The magnitude of the turning moment M_z relative to the pivotal point 107, caused by the force F_z, is defined by the magnitude of the force F_z according to the formula M_z = F_z.d, wherein d is the horizontal distance between the pivotal point 107 and the end of the pivoting arm 4. Since d in the implement according to the invention is as small as possible, the magnitude of the turning moment M_z is as small as possible. Thus the forces Fi and F₂ can be as small as possible, which implies the smallest possible load of the support member 200, or, conversely, with equal loading of the support member 200 a heaviest possible object V can be lifted. By removing the fasteners 122 and the head flange 121 the shaft 103 can be removed from the bush 101. Another support member can now be mounted on the shaft 103, which other support member also comprises a bush 101 for receiving the shaft 103. Thus a quick-detach system is provided, permitting a rapid coupling of a support member 200 of an implement and the control arm 30.

Thus, Fig. 4B illustrates the situation where a support member 200' with one gripping member 204 is mounted on the shaft 103. The gripping member 204 has the shape of a spoon for scraping away soil 400. Here, too, a transversal force F_e is exerted on the end of the gripping member 204, which force is transmitted to the control arm 30 in a manner analogous to that described above.

Fig. 6 illustrates an implement 600 according to the invention, in which the first rotation member comprises a cylindrical shaft 603 fixedly mounted on the support member 620, and in which the second rotation member comprises a cylindrical bush 601 for receiving the cylindrical shaft 603. The second rotation member further comprises a support assembly 621 mounting axially extending plates 604, 604' whose form and function correspond to those of the above described plates 104, 104' .

For the rest the construction of the implement 600 is similar to that of the implement 100 described hereinabove, so that details of this construction will be clear to a person skilled in the art.

Figs . 4A and 4B illustrate situations where the implement 100 according to the invention can be used, but the known gripping implement cannot. With the implement 100 an object V can be approached from the side and/or from below. The control apparatus 300 is so constructed that it has an operative free- running condition. In this operative free-running condition the control members 140 are not energized so that the implement 100 can rotate freely relatively to the control arm 30 so as to prevent the transmission to the control arm 30 of any rotational forces that are generated when the implement 100 engages the object to be gripped. Further, the implement 100 is capable of exerting particularly great transversal forces .

The invention provides an implement which has particularly flexible usability and can be loaded to a high degree. In particular the implement according to the invention is suitable to be used in the demolition of houses in virtue of the fact that the implement is adapted to selectively remove structural parts from the house, for instance a stone wall, a wooden floor, a steel beam, etc.

It will be clear to a skilled person that it is possible to vary or modify the embodiment of the implement according to the invention as described above without departing from the invention or the scope of its protection. Thus, for instance, the cylindrical shaft need not be solid, and the selected dimensions of the cylindrical shaft and the mutual axial distance between the bearings can be adjusted to the intended operational purpose of the implement. Also, the means for rotating the first rotation member relatively to the second rotation member need not be hydraulic control means such as a piston/cylinder combination, but may also be an electric motor/gearwheel combination.

Claims

1. An implement, comprising: a support member; at least one gripping member pivotally mounted on said support member; and rotation means comprising a first rotation member mounted on said support member and a second rotation member, which members are rotatable relatively to each other; said second rotation member comprising a fastening member for mounting said second rotation member on a control arm so as to permit controlled pivotal movement of the second rotation member and the control arm relative to each other about a first pivot pin extending perpendicularly to the axis of rotation; there being further provided means for rotating said first and said second rotation member relatively to each other; characterized by a cylindrical shaft extending through said support member in force-transmitting engagement with said support member on the side of said support member proximal to the grip opening and on the side of the support member remote from the grip opening, and comprising at least two axially spaced rotation bearings for the rotatable coupling with a corresponding rotation member.

2. An implement according to claim 1, characterized in that the cylindrical shaft is fixedly mounted on the support member..

3. An implement according to claim 1, characterized in that the cylindrical shaft is part of the second rotation member, and that said at least two bearings are disposed on the side of the support member proximal to the grip opening and on the side of the support member remote from the grip opening, respectively.

4. A gripping implement according to at least one of claims 1-3, characterized in that the cylindrical shaft is solid.

5. A gripping implement according to at least one of claims 1-4, characterized in that the second rotation member comprises coupling means on the side remote from the cylindrical shaft, for coupling with the control arm and for coupling with pivot drive means, said coupling means being substantially in alignment with the axis of rotation.

6. A gripping implement according to at least one of claims 1-5, characterized in that the rotation members are detachable so as to provide a quick-connect coupling system.

7. A gripping implement according to at least one of claims 1-6, comprising an operable control apparatus for the controlled rotation of the gripping implement relative to the control arm, characterized in that the control apparatus can be operated in an operative free-running condition where the rotation members of the rotation means can rotate freely relatively to each other.

8. A combination of a support member and a first rotation member mounted on said support member, suitable for use in an implement according to at least one of claims 1-7.