Improvements in or relating to compactor containers

Abstract

 A container (1) has a hinged door (2) held closed by means of latching means (3). The latching means include a hook (4) controlled by a toggle mechanism comprising cranked levers (7) pivotally connected to the hook (4) by a pivot pin (8) slideable in slots (9). The cranked levers are pivotally connected to arms (11) fixed to a rotatable shaft t (12). Also fixed to the shaft (12) is an arm (27) pivotally connected to a piston rod (15) carrying a piston (17) slideable in a cylinder (14). Holes (19) are provided in the crown of the piston and are covered by a washer (20) so that rapid acceleration of the shaft (12) in the direction necessary to release the hook (4) is prevented.

Description

[0001] This invention relates to compactor containers which are used to facilitate the transport of waste material.

[0002] Normally the container is a longitudinally extending structure having a generally rectangular cross section, and the rear of the container is provided with a door which is held closed by latching means. The door normally has a rectangular orifice through which the material is fed by means of a packer. The material is packed into the container under considerable pressure, and the orifice may be closed, for example, by means of a sliding cover.

[0003] When the container is to be emptied, it is necessary to release the latching means and open the door at the rear of the container. Because of the pressure of the material against the inside of the door, great care has to be taken when releasing the latching means since there is a considerable force applied by the door to the latch so that, at the instant when the door and latch disengage, the latch is liable to move away from the door at high speed and accordingly may constitute a danger to anyone operating the latch.

[0004] Because of the above-mentioned danger it has been normal to provide a turnbuckle to move the latching means from the open position to the closed position, and vice versa. Since the operation of the turnbuckle involved a considerable number of rotations, and accordingly occupied an appreciable amount of time, they were frequently removed from the containers and the latches were operated by a simple lever system. The operating lever in such a case represented a hazard to the operator.

[0005] It is an object of the present invention to provide a latching system which does not suffer from the disadvantages of the known turnbuckle system but which at the same time' is safe to use.

[0006] The invention consists in a compactor container having a door hingedly mounted at one end thereof, wherein latching means are provided to lock said door in the closed position, and wherein said latching means comprise a hook slideably mounted on said container so that it is manually movable between a first position in which it holds said door closed and a second position in which it releases said door, wherein said movement of said hook is controlled by a toggle mechanism including a lever fixed to a rotatable shaft, said lever constituting, or being movable with, a manual operating member, and wherein damping means are provided to limit the speed of rotation of said shaft in the direction necessary to cause movement of said hook from said first position to said second position without restricting rotation of said shaft in the opposite direction.

[0007] Preferably said toggle mechanism includes a cranked lever pivotally connected at one end to said hook, and at the other end to the first-mentioned lever which constitutes, or is movable with, the manual operating member. In this case the pivotal connection between the hook and the cranked lever is constrained to move along a path parallel to the longitudinal axis of the container.

[0008] Preferably the damping means comprises a piston slideable in a cylinder, the piston being pivotally connected to an arm fixed to said rotatable shaft and the cylinder being pivotally mounted on the container. The cylinder contains oil and the crown of the piston is provided with a number of holes which can be covered by a washer urged against the piston by a spring. The arrangement is such that, if the shaft is rotated in the direction necessary to cause, movement of the hook from the first position to the second position, the .washer closes the holes in the piston so that the piston can only move by displacing oil through its clearance in the cylinder, whereas, if the shaft is rotated in the opposite direction, the washer is lifted from the holes so that oil can pass through the holes.

[0009] One method of performing the invention will now be described with reference to the accompanying diagrammatic drawings, in which:-

Figure 1 is a plan view of a container in accordance with the invention;

Figure 2 is a plan view on a larger scale of the latching means of the container illustrated in Figure 1 in the open position;

Figure 3 is a side view of the latching means illustrated in Figure 2 in the closed position;

Figure 4 is a plan view of the latching means illustrated in Figures 2 and 3 in the closed position; and

Figure 5 is a plan view on a larger scale of the damping means used in the latching means illustrated in Figures 2, 3 and 4.

[0010] The container illustrated in Figure 1 is a longitudinally extending structure 1 having a door 2 hingedly mounted to close one end of the structure. The door may be held in the closed position as shown by means of latching means generally illustrated at 3.

[0011] The latching means are shown on an enlarged scale in the open position in Figure 2. It will be seen that the latching means include a hook 4, one end of which is designed to engage a locking plate 5 secured to one side of the door 2. The hook 4 passes through a guide 6 mounted on the container wall, and its lefthand end, as shown in Figure 2, is pivotally connected to one end of a pair of cranked levers 7. A pivot pin 8 constituting the pivotal connection between the hook 4 and the cranked levers 7 is constrained to move in slots 9 formed in plates 10 attached to the side wall of the container.

[0012] The lefthand ends of the cranked levers 7, as shown in Figure 2, are pivotally connected to a pair of arms 11 fixed to a rotatable shaft 12. An operating member 13 is welded at one end to the arms 11.

[0013] It will be seen that, when the operating member 13 is moved in a clockwise direction, the pivot pin 8 is caused to slide to the left from the position shown in Figure 2 to that shown in Figure 4. This movement causes the hook 4 to engage the lock plate 5 and urge the door 2 in a clockwise direction about its hinge axis. Continuing clockwise movement of the operating member 13 secures the door firmly against the container structure, and eventually the toggle mechanism passes over top dead centre and the latching mechanism is held in the closed position.

[0014] When it is desired to open the door 2, the operating member 13 is moved in an anticlockwise direction from the position shown in Figure 4 towards the position shown in Figure 2. This movement causes the pivot pin 8 to slide to the right, and the hook 4 thus also moves to the right. The pressure of the compacted material within the container urges the door 2 in an anticlockwise direction and thus the locking plate 5 applies a force to the hook 4. This force can be quite considerable and without the damping means of the present invention the operating member 13 could be caused to accelerate rapidly as soon as the toggle mechanism has passed through the top dead centre position. This rapid acceleration could be dangerous to the operator.

[0015] In order to prevent the danger referred to, damping means are connected to the shaft 12 to prevent the rapid acceleration of the operating member 13. As shown, the damping means comprise a cylinder 14 and a piston rod 15. The cylinder 14 is pivotally mounted on the container wall as shown at 16, while the outer end of the piston rod 15 is pivotally connected to an arm 17 (best seen in Figure 3) fixed to the shaft 12. The damping means is arranged so that the piston rod 15 can be rapidly moved into the cylinder 14 without hindrance, whereas there is considerable resistance to movement of the piston rod 15 out of the cylinder 14.

[0016] The damping means are shown in more detail in Figure 5. It will be seen that there is a piston 17 secured by means of a pin 18 to the inner end of the piston rod 15. The crown of the piston is provided with a plurality of drillings 19 providing communication between the righthand and lefthand sides of the piston as seen in Figure 5. These drillings 19 are covered by a flexible washer 20 which is urged against the top of the piston by means of a spring 21. The cylinder 14 is filled with hydraulic fluid, and it will be seen that, if an attempt is made to withdraw the piston rod from the cylinder, the washer 20 is forced by the oil against the drillings 19. Thus the piston 17 can only be moved to the right, as seen in Figure 5, by displacing the hydraulic fluid through the clearance between itself and the internal wall of the cylinder 14. This clearance is made relatively small so that the piston rod 15 can only be withdrawn slowly from the cylinder 14. On the other hand, if an attempt is made to move the piston rod 15 into the cylinder 14, the hydraulic fluid will lift the washer 20 from the drillings 19 against the action of the spring 21. Thus the piston 17 can be moved to the left in the cylinder by displacing the hydraulic fluid through the drillings 19. The total cross-sectional area of these drillings is relatively large so that it is relatively easy to move the piston rod 15 into the cylinder 14.

Claims

1. A compactor container having a door hingedly mounted at one end thereof, wherein latching means are provided to lock said door in the closed position, and wherein said latching means comprise a hook slideably mounted on said container so that it is manually movable between a first position in which it holds said door closed and a second position in which it releases said door, wherein said movement of said hook is controlled by a toggle mechanism including a lever fixed to a rotatable shaft, said lever constituting, or being movable with, a manual operating member, and wherein damping means are provided to limit the speed of rotation of said shaft in the direction necessary to cause movement of said hook from said first position to said second position without restricting rotation of said shaft in the opposite direction.

2. A container according to Claim 1, wherein said toggle mechanism includes a cranked lever pivotally connected at one end to said hook and at the other end to said first-mentioned lever.

3. A container according to Claim 2, wherein the pivotal connection between the hook and the cranked lever is constrained to move along a path parallel to the longitudinal axis of the container.

4. A container according to any of the preceding Claims, wherein the damping means comprises a piston slideable in a cylinder containing hydraulic fluid, the arrangement being such that, if the shaft is rotated in the direction necessary to cause movement of the hook from the first position to the second position, the piston can only be moved by displacing hydraulic fluid through the clearance of the piston in the cylinder, whereas, if the shaft is rotated in the opposite direction, the piston can be moved by displacing hydraulic fluid through holes provided in the piston.

5. A container according to Claim 4, wherein the crown of the piston is provided with a plurality of holes and wherein a washer is urged against the piston by a spring to cover said holes, the arrangement being such that, if the shaft is rotated in the direction necessary to cause movement of the hook from the first position to the second position, the washer closes the holes in the piston, whereas, if the shaft is rotated in the opposite direction, the washer is lifted from the holes.

6. A container according to Claim 4 or Claim 5, wherein the piston is pivotally connected to an arm fixed to said rotatable shaft and the cylinder is pivotally mounted on the container.

7. A compactor container having a door hingedly mounted on one end thereof, wherein latching means are provided to lock said door in the closed position, said latching means being substantially as hereinbefore described with reference to, and as illustrated in, the accompanying diagrammatic drawings.

Drawing