GB2108424A - Portable waste compactor - Google Patents

Abstract

A portable waste compactor has a generally box-like body (11) fitted at one end with a waste-loading door (14) and at the opposite end with a waste- discharge door (12). A ram-operated compacting mechanism moves a blade (15) so as to sweep the incoming waste towards and eventually against the normally closed waste-discharge door (12). The waste-loading door (14) pivots open about a normally horizontal axis (19) so as to open outwardly away from the compacting mechanism. The door (14) has a step (22) which contacts the outer surface (23) of the compactor loading-end to support the opened loading door in a position in which the inside surface (14a) of the door slopes towards the waste-receiving floor of the compactor to form effectively a waste- loading chute. The door (14) once closed is held shut by a latch (24) which hooks into a slot (26) in the edge of the door and which is not connected to any compacting-mechanism-actuating switch. The leading part of the inside surface (14a) of the loading door is concavely curved and the blade (15) sweeps against it when the door (14) is fully closed. <IMAGE>

Description

SPECIFICATION Portable waste compactor The invention relates to a portable waste compactor of the kind which comprises a generally box-like body fitted at each of its opposite ends with respective waste-loading and waste-discharge doors and which houses, adjacent the waste-loading door, a power-operated compacting mechanism so desinged and positioned as to sweep the incoming waste towards and eventually against the normally closed waste-discharge door; the compactor being so sized and shaped that it can be lifted, when full, and up-ended to discharge its contents through the then-opened waste-discharge door.

Such a compactor is already known and will be referred to as a compactor 'of the kind in question'. It may be fitted on its outside surface with points of attachment for chains orthe like which allow it to be lifted and up-ended by a crane mechanism. The crane mechanism may be incorporated onto a vehicle, and the compactor may be small enough to be carried by the vehicle to a refuse tip before being up-ended, discharged, and returned by the vehicle to the site on which the compactor normally stands to receive waste. Recently there have been introduced so-called 'mini-skip' vehicles which can pick up, discharge, and return specially scaled-down waste skips.These 'mini-skip' units are especially useful where there is not room to accommodate the normal full-sized skip or a corresponding compactor and there is certainly not room to manoeuvre the normal full-sized skip-collecting vehicle into and out of position to receive and return the skip.

The invention is especially applicable to waste compactors which can be made small enough to fit a 'mini-skip' vehicle whilst still being large enough to accommodate sizeable amounts of waste. Any compactor will of course accommodate more waste than a non-compacting skip of similar dimensions, and will thus be more advantageous than the skip.

However, the invention is not restricted solely to compactors which are capable of being handled by these so-called 'mini-skip' vehicles.

According to the invention a compactor of the kind in question is characterised by the features (a) that the waste-loading door opens outwardly away from the compacting mechanism and (b) that when the compactor stands in its normally-intended wastereceiving attitude, and the waste-loading door is fully opened, the inside surface of that door (i.e. the surface facing the compacting mechanism) slopes towards the waste-receiving floor of the compactor to form effectively a waste-loading chute.

It is known for the waste-loading door or doors of a compactor to open outwardly. However such doors usually pivot about vertical axes and have a waste-containing but not a waste-loading function.

The invention lies in the realisation that the inside surface of the opened loading door, hitherto unused during actual loading, can be made use of and will be particularly appreciated by the 'mini-skip' class of user who very probably is not skilled in wasteloading and would likely 'miss' the loading bay of the standard compactor on occasion with consequent untidy results. A compactor embodying the invention offers such a person a positive tangible chute on which to load. It is also much easier to load onto a chute opened at convenient height than to try to load up and over the relatively high sides of a similarly-sized open-topped skip.

The waste-loading door may pivot open, for example about a normaiy horizontal pivot axis running across that end of the compactor, so that the door opens outwardly and downwardly into a fullyopen position in which it is positively supported and projects out from the skin body to offer itself as a loading chute. It is however fully within the scope of the invention for the door to slide out from the compactor body, orto move on an articulated linkage.

The inside surface of the waste-loading door may be concavely curved to assist the passage of waste ioaded on the door into the compactor body.

The inside surface of the waste-loading door may for instance be so curved that, with the door fully closed, part at least of said surface is swept by the compacting mechanism. for example a leading portion of the door's inside surface (i.e. a portion first traversed by the compacting blade during its operating cycle) may be swept and then the blade may move away from said surface so that the portion nearer the waste-receiving floor is not positively swept by the blade. It is always possible for waste to stick to the inside surface of the door after the door has been closed, and if at least part of the inside surface is swept in this way then there is less chance of the connector blade being damaged as it passes over such waste and the compactor is also made more efficient in its operation.

A compactor embodying the invention in commercially saleable form will normally incorporate automatic safety locks into its operating circuits. It is for example desirable to prevent the compacting mechanism from being operated until the wasteloading door has been fully shut. It is known to accomplish this by an electrical or electro-hydraulic switch operated by the movement of the door.

According to a corresponding feature of the invention the waste-loading door, once closed, is held shut by a latching means which is wholly independent of any compacting-mechanism-actuating switch, so that the compacting mechanism once stopped cannot be started by 'tripping' the door latch with the door still open.

According to a further feature of the invention the latching means will not release the door until the compacting blade has completed a full sweep-andreturn operating cycle. Thus the door cannot be opened if the compacting mechanism has stopped in a mid-cycle position, and the risks of the mechanism suddenly starting again to complete its cycle with the door open are avoided.

An effective yet potentially trouble-free door latch fulfiiling all these desirable features comprises a mechanical latch which engages the leading edge of the door and which is lifted out of such engagement by the compacting blade, to release the door, only when the blade reaches its 'beginning-of-an operating-cycle' position. Such a latch could drop into its engaged position under gravity, and be lifted against gravity by the up-coming blade. Alternatively or additionally it could be spring-loaded into engagement.

One compactor embodying the invention is shown by way of example in the accompanying drawings. it will now be described with reference to those drawings, in which; Figure 1 shows the compactor viewed from one side and from its loading end, in perspective; and Figure 2, drawn to an enlarged scale, shows the loading end of the compactor in diagrammatic sectioned side view.

The compactor has a generally box-like rectangular body referenced 11. One end of this body 11 is closed by a waste-discharge door 12 which is normally locked shut but which, when the lock is released, pivots upwardly about an axis 13 running generally horizontally across the compactor body.

The means to keep the waste-discharge door 12 closed, and to release it, can readily be supplied by the skilled reader of this specification and are neither illustrated nor described herein. The door 12, like the body 11, is welded up from prefabricated steel sheet and is suitably braced and reinforced at stressbearing regions. This door 12 extends over substantally the whole of the end-face area of the body 11, so that when the door 12 is opened and is swung fully about its pivot axis 13 there is a substantially uninterrupted waste-discharge passageway from the body 11.

The end of the body 11 opposite the wastedischarge end is fitted with a waste-loading door 14.

A ram-operated compacting mechanism comprises a blade 15 swept, in use, about a fixed horizontal pivot axis 16 by a ram 17 which is connected at one end to the blade and at the other end to the body 11 of the compactor by suitable pivotal bearings.

The compacting mechaism is housed adjacent the waste-loading door 14 inside the body 11 of the compactor. The blade 15 sweeps, in use, down towards the waste-receiving floor of the compactor body (i.e. clockwise when viewed as in Figures 1 and 2), and the lead-in surface 18 of the compactor body down which waste travels towards the body floor is curved so as to be swept by the blade 15 during the latter part of the blade's travel.

Once the blade has reached the end of the lead-in surface 18, it is automatically reversed and swept back along the same arc by the ram 17 until it reaches the 'beginning-of-cycle' position illustrated in Figure 2. Once it reaches that position, the compacting mechanism is automatically stopped since a complete sweep-and-return cycle has taken place.

Because the compacting mechanism is housed in the top region of the compactor body adjacent the loading door 14, and the lead-in surface 18 extends below the door 14, the loading door 14 is much smaller in height than the waste-dischrge door 12.

Like that door 12, however, the door 14 spans substantially the whole of the width of the compactor. It pivots open about a horizontal axis 19. A similarly horizontal bar 21 spans substantially the full width of the door 14, and is spaced upwardly from the outside surface of the door, to act as a handle which can be grasped to swing the door 14 down (i.e. clockwise when viewed as in the drawings).

As Figure 2 shows, the pivot-end of the door 14 exhibits a step 22 which, as the door is swung down, eventually contacts the ouside surface 23 of the compactor body-end to support the door 14 in a position in which the pivot-adjacent portion of its inside surface 14a is substantially horizontal whilst the remaining portion of the inside surface curves concavely up from the horizontal.

In that position, the inside surface 14a of the loading door 14 effectively offers itself as a wasteloading chute. It forms in effect an extension of the lead-in surface 18, and the concavely-curved portion of the surface 1 4a slopes towards the lead-in surface 18 and hence towards the waste-receiving floor of the compactor body 11.

The door 14 may be spring-loaded towards it closed position, but in the illustrated compactor the door opens under gravity and is closed, without spring assistance, solely against the force of gravity.

As shown in Figure 2, the concavely-curved portion of the inside surface 14a of the door, and some of the remaining substantially flat portion of that surface, is positively swept by the compacting blade 15 as the blade travels towards the lead-in surface 18. The remainder of the flat portion of the inside suface 14a (i.e. the portion nearer the wastereceiving floor of the compactor body 11) is not swept, since the arc of the compacting blade 15 travels away from that remaining portion as it approaches the lead-in surface 18.With the compactor standing in its normally-intended wastereceiving attitude, i.e. with its waste-receiving floor standing on substantially horizontal level ground, and the loading door 14 fully shut, then as Figure 2 shows the flat portion of the inside surface 14a of the door slopes towards the waste-receiving floor; and the concavely-curved portion extends even more towards the interior of the compactor.

Thus anywaste tending to stick to the inside surface 14a is highly likely to fall under gravity onto the lead-in surface 18 as the door 14 is fully shut.

Waste which may still stick to the door is then swept offthesurface 14a by the compacting blade 15asthe blade starts its cycle.

A mechanical latch 24 is freely pivotable about a generally horizontal axis 25, within the compactor body 11 and adjacent the end of the compacting blade 15 when the blade is in its 'beginning-of-cycle' position as illustrated in Figure 2. The end of the latch 24 remote from the pivot axis 25 is hooked, and when the blade is other than in its illustrated Figure 2 position the hook of the latch engages a corresponding slot 26 formed in the edge of the loading door 14.

The latch 24 is moved about its pivot 25 solely by the reinforced back edge 15a of the compacting blade 15. This movement is quite independent of any elctrical or electro-hydraulic safety inerlocks which may be built into the compactor to prevent the compacting mechanism from being operated until the door 14 has been fully closed.

A mechanically simple and trouble-free screwedlocknut arrangement 27 enables the latch 24 to be adjusted in such a way that the hook on the end of the latch will not release its hold on the edge of the door 14 until the blade 15 has fully returned to its 'beginning-of-cycle' position illustrated in Figure 2.

Once that position is reached, the door 14 can be opened, but any subsequent adjustment or movement of the latch 24 with the door 14 still open will have no effect whatever in operating the compacting mechanism. The latch 24 is purely a mechanical latch unconnected to any operating circuit of the compactor.

The automatic single-cycle operation of the compacting mechanism is controlled by a two-position four-way electro-hydraulic valve which is referenced 28 in Figure 2 which is already available as a commercially sold unit. The American company Stone Hydraulics Inc. manufacture such a unit under the style 'hydra-shift valve' especially for waste compactors. The unit has a built-in electric limit switch, and in the compactor illustrated the switch is actuated by the reinforced back edge 15a of the blade 15. When the 'stop-start' control knob 29 of the valve 28 is depressed, a sweep-and-return cycle of the blade 15 is automatically initiated if electrical interlocks (not illustrated, but of conventional kind) indicate that the door 14 is in its fully-closed position.If the door is anything other than fully closed, these electrical interlocks, which are not in any way connected to the latch 24, prevent the compacting blade from being moved at all out of its Figure 2 position. When the blade does begin to move, after the door 14 has been fully closed, its reinforced back edge 1 5a allows the spring-loaded electrical limit switch of the valve 28 to move down, and power is supplied to the ram 17 as long as that limit switch remains in its 'down' position.

The limit switch is moved up out of its 'down' position by the back edge 15a of the returning blade 15. This causes the limit switch automatically to cut off the power to the ram 17. The valve 28 itself automatically ensures a reversal of the ram stroke when the blade reaches its end-of-sweep position, and the ram then retracts to bring the blade back along its return path.

It should be emphasised again that the conventional electrical interlocks which indicate to the valve 28 the position of the door 14 are not connected in any way to the latch 24. They are of course so housed within the compactor body adjacent the door that they cannot be 'tripped' ortampered with.

The pump supplying fluid to the ram 17 is driven by an AC motor and this in turn is powered by a mains source of electrical power available adjacent the site where the compactor normally stands. A simple external jack plug, not illustrated, is provided on the compactor for connection of electrical power to the pump-driving motor. The fluid reservoir is carried in the compactor above the compacting mechanism, and again need not be illustrated or described in any detail. Because the compactor has a separate waste-discharge door as well as a wasteloading door, no power-operated mechanism on the compactor is needed during waste-discharge. Thus the compactor need not carry its own elctrical power supply. This feature enables the overall weight of the compactorto be kept within limits which make it capable of handling by a 'mini-skip' vehicle.Also, by using an external AC electrical supply, the compactor can accommodate a motor which is powerful enough to compress the waste effectively: a corresponding DC motor might not necessarily be as powerful and yet would require the relatively heavy accumulator power source to be carried on the compactor itself.

CLAIMS (Filed 20 Nov 1981) 1. A portable waste compactor of the kind in question, charcterised in that the waste-loading door opens outwardly away from the compacting mechanism and in that when the compactor stands in its normally-intended waste-receiving attitude, and the waste-loading door is fully open, the inside surface of that door slopes towards the wastereceiving floor of the compactor to form effectively a waste-loading chute.

2. A compactor according to Claim 1 in which the waste-loading door pivots open about a normally horizontal pivot axis running across that end of the compactor.

3. A compactor according to Claim 1 or Claim 2 in which the inside surface of the waste-loading door is concavely curved to assist the passage of waste loaded on the door into the compactor body.

4. A compactor according to Claim 3 in which the inside surface of the waste-loading door is so curved that, with the door fully closed, part at least of said surface is swept by the compacting mechanism.

5. A compactor according to any of the previous Claims in which the waste-ioading door, once closed, is held shut by a latching means which has no operative connection with any compactingmechanism-actuating switch.

6. A compactor according to Claim 5 in which the latching means will not release the door until the compacting blade has completed a full sweep-andreturn operating cycle.

7. A compactor according to Claim 5 or Claim 6 in which the latching means comprises a mechanical latch which engages the leading edge of the wasteloading door and which is lifted out of such engagement by the compacting blade, to release the door, only when the blade reaches its 'beginning-of-anoperating-cycle' position.

8. A compactor substantially as described herein with reference to and as illustrated in the accompanying drawings.

9. Means, relating to an essential element of the invention, suitable for putting or intended to put into operation the invention defined in any of the preced

Claims (1)

1. ing Claims.