GB2162575A

GB2162575A - Portable waste compactor

Info

Publication number: GB2162575A
Application number: GB08419471A
Authority: GB
Inventors: Kenneth R Ellis
Original assignee: Thetford International Products Ltd
Current assignee: Thetford International Products Ltd
Priority date: 1984-07-31
Filing date: 1984-07-31
Publication date: 1986-02-05
Also published as: GB8419471D0

Abstract

The waste-loading door 12 of a compactor having an essentially upright waste-loading opening is supported on a parallelogram linkage 13, 14 and opens and closes by rising and falling, without substantially altering its attitude relative to the waste-loading opening, as the linkage swings up and down. Preferably the or each such door is spring-biased 18 to an over-centre swinging action, but whilst the springs assist in swinging the closed door open, they need not give any appreciable assistance in swinging the open door shut. Preferably the door has a handle 15 which is elongate and continuous and which spans all or substantially all of the height of the door, and which runs centrally up the door; and the door, when opened, blanks off the controls for the compacting mechanism. <IMAGE>

Description

SPECIFICATION Portable waste compactor Field of the Invention The invention relates to portable waste compactors.

Background to the Invention Portable waste compactors conventionally have a generally box-like body fitted at one end with a waste-loading door and at the opposite end (and/or on top) with a waste-discharge door. A ramoperated compacting mechanism moves a blade to and fro within the waste-loading opening so as to sweep the incoming waste towards and eventually against the normally closed waste-discharge door.

When the compactor is full, it is up-ended and the waste-discharge door opens to discharge the compacted contents.

It is conventional for the waste-loading door or doors (the "door" may be constituted by a set of double-doors) to open outwardly away from the waste-loading opening. The compactor currently manufactured and marketed in the United Kingdom by us under the Trade Mark PORTAPACKER has a set of double-doors which pivot about vertical axes in this manner. Our published UK patent specification No 2 101 680 shows another compactor which we currently market under the Trade Mark RELP and which has double-doors opening in this way. Another of our published UK patent specifications No 2 108424 shows a modified PORTAPACKER in which the waste-loading door opens about a normally horizontal axis but nevertheless still opens outwardly away from the waste-loading opening.

There are drawbacks to compactors in which the door or doors open outwardly in the manner exemplified by these known constructions. The open doors can be easily damaged by wind or by lorries or other vehicles backing into them. If they are so damaged, an expensive hinge needs to be repaired or replaced. The fact that an allowance has to be made for the outward swing of the doors is also inconvenient in situations where room is restricted.

The present invention seeks to overcome these drawbacks of known constructions.

Summary of the Invention According to the invention in its broadest aspect the waste-loading door of a compactor having an essentially upright waste-loading opening is supported on a parallelogram linkage and opens and closes by rising and falling, without substantially altering its attitude relative to the waste-loading opening, as the linkage swings up and down.

With such a construction, there need be hardly any outward swing of the door away from the waste-loading opening. In addition, if the door should be inadvertently damaged, there is only a linkage pivot to repair or replace rather than an expensive hinge. A third advantage is that whoever opens and closes the door need not move backwards and forwards as he would have to with a conventional outward-swinging door and this can be a vital safety factor in certain circumstances.

It is known to spring-bias doors generally so that they have an "over-centre" swing action i.e. the springs tend to swing the door open when the closed door fist begins to open, and to swing the door shut when the open door first begins to close.

With a door constructed in accordance with the present invention, however, the spring-biasing can advantageously be so adjusted that whilst it tends to assist in swinging the closed door open, it need not give any appreciable assistance in swinging the open door shut. Because the door rises and falls essentially vertically, its own weight tends to hold it shut; and anyone subsequently opening it does not have to overcome the initial resistance which a conventional "over-centre" sprung arrangement would exhibit.

Preferably the door has a handle which is elongate and continuous and which spans all or substantially all of the height of the door. A user then need simply "run" the handle through his hands as the door rises or falls, rather than having to bend or stretch unduly.

Advantageously such a handle runs centrally up the door, so that where there are (as there would tend to be in practical embodiments) two parallelogram linkages one supporting either side of the door, then there is the minimum tendency for the doortojam due to an uneven application of opening or closing effort between the two linkages.

When the door is fully open its top edge may lie flush with the top of the compactor body. Similarly when the door is fully open its bottom edge may lie flush with the top edge of the waste-loading opening. In either case the arrangement is not only neat but also essentially safe.

Where controls for the compacting mechanism are mounted (as again they would tend to be in a practical embodiment) adjacent the waste-loading door, the door preferably blanks off the controls when it is opened. Although compactors normally incorporate safety locks which prevent the compacting mechanism from operating when the waste-loading door is open, it is always possible for these to fail or to be jammed or inadvertently tripped. If the door when opened blanks off the controls, the mechanism will remain inoperable even in such situations.

Brief Description of the Drawings In the accompanying drawings: Figure 1 shows the door and door linkage in side elevation; Figure 2 shows the same components in end elevation; Figure 3 shows parts of the spring-biasing mechanism of the linkage.

Description of the Preferred Embodiment The compactor illustrated in Figures 1 and 2 has a generally box-like body and need not be described in detail. Its waste-loading opening 11 is indicated in broken line in Figure 2 and, as Figure 2 shows, that opening is essentially rectangular and spans the full width of the end face of the compactor body.

A rectangular door 12 gives access to the opening when the door is raised, and closes the opening off when the door is shut. The door is supported at each opposite side by links 13, 14 each of which is pivotted at one end to the door and at the other end to the compactor body.

In the embodiment illustrated the distance Y between the two pivots of each link is 30 units of measurement and the distance X between respectively adjacent pivots of the two links is 29 of the same units of measurement. Thus the links 13, 14 and the door do notform a literal parallelogram.

The term "parallelogram linkage" is thus to be interpreted with some leeway. The essential requirement is that when the door is fully shut it bears wholly against the edges of the waste-loading opening 11.

A handle 15 runs centrally up the door and spans the full height of the door. The handle 15 is circular in cross section and straight when viewed as in Figures 1 and 2. It stands proud of the door 12 by an amount which is sufficient for a normal user's hand to be inserted into the gap between the handle and the door.

A contact 16 on the top edge of the door respectively makes and breaks an electronic circuit which when the door is shut, allows the compacting mechanism to operate and when the door is open, prevents that mechanism from operating.

An arm 17 swings about the same compactor body pivot as the link 13. Each link 13 has such an arm 17 associated with it. The link 13 and arm 17 move in unison about that pivot.

A coiled tension spring 18 is fixed at one end to the end of the arm 17 and at the other end to the compactor body. When the door 12 is fully shut, as shown in Figure 1,the spring 18 lies parallel with the arm 17. In a practical embodiment there may be two such springs 18 running alongside one another between each arm 17 and the adjacent side of the compactor body.

Figure 3 shows the dimensions of arm 17 and spring 18 in this particular embodiment. The distance A between the points of attachment of each opposite end of the spring 18 when the door 12 is fully shut is 40 units of measurement. The distance B, measured at right angles to the axis of the arm 17, between the point of attachment of spring 18 to the arm, and the pivot about which the arm moves, is 7 of those same units. The distance C, measured along the arm 17, between the point of attachment of the spring 18 to the arm, and the pivot about which the arm moves, is just under 16 such units.

These dimensions, with a spring of appropriate tension, give a spring-assisting action to the opening of door 12 as links 13,14 swing upwards.

The weight of the door assists its subsequent closing, and the springs 18 are not so unduly strong as to resist this closing unduly. The combined weight of the door 12 and the linkages 13, 14 tends to hold the door fully shut, and the springs 18 in that position are almost but not quite over-centre i.e.

they have the minimum tendency to assist in holding the door shut but neither do they unduly tend to try to swing it open until the opening movement has actually commenced.

In this particular embodiment, the door 12 bears fully against the edges of the waste-loading opening 11 when it is fully shut; and it also lies substantially flat against the end of the compactor body when it is fully open. In that latter position the top edge of the door 12 is essentially level with the top 19 of the compactor body, and the bottom edge of the door is level with the top edge of the waste-loading opening 11.

Although not illustrated in the drawings, rubbing strips may run along the opposite vertical edges of the compactor body for the inside faces of the links 13, 14to bear against. There will inevitably be some side-to-side play in the linkages and it would normally be betterto accommodate this with rubbing strips than to allow the linkages to bear against the sides of the compactor body as such.

Claims

1. A waste compactor having an essentially upright waste-loading opening closed off by a door supported on a parallelogram linkage, characterised in that the door opens and closes by rising and falling, without substantially altering its attitude relative to the waste-loading opening, as the linkage swings up and down.

2. A compactor according to Claim 1, in which the door is spring-biased to have an over-centre swing action, and characterised in that the spring-biasing is so adjusted that whilst it tends to assist in swinging the closed door open, it does not give any appreciable assistance in swinging the open door shut.

3. A compactor according to Claim 1 or Claim 2, characterised in that the door has a handle which is elongate and continuous and which spans all or substantially all of the height of the door.

4. A compactor according to Claim 3, characterised in that the handle runs centrally up the door.

5. A compactor according to Claim 3 or Claim 4, characterised in that the handle is straight.

6. A compactor according to any of Claims 3,4 and 5, characterised in that the handle stands proud of the door by an amount which is sufficient for a normal user's hand to be inserted into the gap between the handle and the door.

7. A compactor according to any of the preceding Claims, characterised in that when the door is fully open, its top edge lies substantially flat against the end of the compactor body.

8. A compactor according to any of the preceding Claims, characterised in that when the door is fully open, its top edge lies flush with the top of the compactor body.

9. A compactor according to any of the preceding Claims, characterised in that when the door is fully shut it bears fully against the edges of the wasteloading opening.

10. A compactor according to any of the preceding Claims, characterised in that when the door is fully open its bottom edge lies flush with the top edge of the waste-loading opening.

11. A compactor according to any of the preceding Claims, in which the compacting mechanism controls are mounted adjacent the waste-loading door, characterised in that the door blanks off the controls when it is fully opened.

12. A compactor having a door and doormounting arrangement substantially as described herein with reference to and as illustrated in the accompanying drawings.