Presses – Automatic or material triggered control – Of actuating means
Reexamination Certificate
1999-01-14
2002-04-09
Gerrity, Stephen F. (Department: 3721)
Presses
Automatic or material triggered control
Of actuating means
C100S052000, C100S099000, C100S22900A, C100S287000, C100S345000
Reexamination Certificate
active
06367377
ABSTRACT:
FIELD OF INVENTION
This invention relates generally to waste compactors, and, in particular, to waste compactors for receiving inputs of waste and periodically compacting those inputs.
BACKGROUND ART
While waste compactors have been known for domestic use, such machines can also be useful in fast food restaurants and shopping malls for compaction of loose garbage. In general, refuse from fast food restaurants such as may be deposited in waste containers has a relatively low density. It is desirable to compact this garbage for several reasons. First, very low density garbage such as paper cups, hamburger containers, tissue napkins, and the like, can fill waste containers in high usage areas in a relatively short period of time. It is inefficient for staff to have to remove full containers more frequently than necessary. Costs associated with large garbage containers, such as may be transported to a dumpsite or emptied into a large truck, tend to vary as the number of times they are filled. In consequence it is advantageous to compact the garbage to lengthen the time interval between removals, and to reduce the cost of dumping the materials.
The use of such machines in a public or quasi-public space, such as in the relatively large garbage containers used in restaurants and shopping malls poses challenges that may not be as prevalent in the small domestic garbage compactors. First, the overall weight of the compacted mass must be kept to a level that is safe for workers, generally in the range of 35 lbs. Some jurisdictions limit the allowable weight of garbage bags to 25 lbs. In one known unit, a system of hydraulic cylinders is used to compress the waste material. In that known system, a unit having an overall size of 51″ height, 24 ½″ width and 22″ depth accomodates a bin that is 19 ¾″ deep, 18″ wide and 17″ high. This system can, under some conditions, compress more than 100 lbs of garbage in a single load. This is well in excess of what an employee is generally expected, or allowed by law in some jurisdictions, to lift.
In general garbage compactors have a receptacle for receiving garbage, and a compression unit for compacting the garbage after a certain amount has been collected in the receptacle. The compression units generally force a platen to extend into the garbage, causing it to compress. It is important that it be highly improbable, preferably impossible, for the compression unit to operate at any time that a person's hands could be caught in the machinery.
The risk of injury is highest in three instances. The first is when a person is emptying garbage into the input chute of the receptacle. The second is when a person is removing collected garbage or cleaning the inside of the unit. The third is when the compaction machinery is in operation. It is also important that objects not become stuck in the input chute when the compression unit is in the middle of operation, such that it cannot retract. Similarly, it is important to be able to extend the compression unit to permit cleaning, without the risk of having the units retract in the middle of the cleaning operation.
A further problem is the tendency of sticky liquids or gums to build up inside the garbage receptacle. In one known machine a solenoid whose purpose was to lock an input chute door during operation compression became gummed over with sticky materials, and in some instances would not lock the door. Another problem with a known machine was that the compression unit had a hinged pressure plate. On the return stroke the hinged plate had a tendency to flip liquids that collected on top of the plate up into the innards of the machinery space. The machinery space was relatively inaccessible for cleaning.
Whereas a homeowner can explicitly decide when to cause a trash compactor to cycle, it may be advantageous for a machine in a public space, a mall, or a restaurant to operate automatically. On one hand customers may not operate the machine when it is required, and on the other hand, they may not operate it correctly in any event, possibly with unfortunate consequences. Further, a person approaching a public garbage receptacle may be carrying a cafeteria tray. It may be awkward for that person to open the garbage chute with one hand while holding the tray with the other. A person may need both hands to carry the tray, particularly if the user is a child. Alternatively, a person having only one arm may find opening the chute and dumping the tray a difficult task. It would be advantageous to have an input chute that opens automatically. However, once the chute is open, it would not be advantageous to have it close while either a tray or a person's hand was still in the chute.
It is known to use a scissors jack mechanism to drive a compression plate, typically downward, into the garbage. Previous scissors jacks have at times shown a tendency to twist or wander, particularly if the garbage has local discontinuities, that is, it compresses more easily on one side than another. If the wander, or tolerance build-up, is too great, the mechanism may ride against the side of the receptacle or other structure. This can lead to wear and damage to the structure, and is undesirable.
SUMMARY OF THE INVENTION
In a first aspect of the invention there is an apparatus for compacting refuse. It has a compression member moveable to compress refuse collected in a receptacle, a drive connected to move the compression member, a structure to which the drive is mounted, and a sensor for gauging the level of refuse in the receptacle. The drive and the compression member are operable in response to a signal from the sensor.
In an additional feature of the invention, the apparatus includes a housing enclosing the compression member, the drive and the sensor. The housing has an accommodation for the receptacle and an inlet for admitting refuse to the receptacle. The apparatus has an inlet closure member operable to lock the inlet during operation of the compression member.
In another additional feature of that aspect of the invention, the apparatus includes the receptacle. In a still further additional feature of the invention, the compression member is moveable to an inactive position. The apparatus includes a proximity sensor connected to cause the inlet closure member to open when the compression member is in the inactive position and the proximity sensor senses an object near the inlet.
In still another further additional feature of the invention, the apparatus is responsive to resistive loading of the compression member by the refuse. In yet another additional feature of the invention, the compression member is constrained by any one of a load limit and a displacement limit.
In still another additional feature of the invention, the compression member is constrained by a receptacle full limit condition. The apparatus has a signaling device for signalling to an operator that the receptacle full limit condition has been reached. In still yet another additional feature of the invention, the apparatus includes a weight sensor mounted to gauge the amount of refuse in the receptacle and the “receptacle full” limit condition is signalled by the weight sensor.
In another additional feature of the invention, the apparatus further comprises a load sensor for gauging the resistance opposing the drive and a sensor for gauging displacement of the compression member. The “receptacle full” limit condition is determined as a function of signals received from the load sensor and from the sensor for gauging displacement of the compression member.
In yet another additional feature of the invention, the compression member is moveable to engage and disengage the refuse. The apparatus has a wiper mounted to discourage refuse from clinging to the compression member when the compression member is disengaged from the refuse. In another additional feature of the invention, the drive is free of hydraulic elements.
In yet another feature of the invention, the drive includes a scissors mechanism having a p
Gawley James Ernest
May Charlotte Mary-Anne
Rochon Glenn Emile
Compact Waste Systems, Inc.
Gerrity Stephen F.
Lerner, David, Littenberg Krumholz & Mentlik
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