Description:
BACKGROUND OF THE INVENTION
This invention relates generally to refuse compacting devices and more specifically, to apparatus for the clearance of jammed material in a refuse compacting device.
Ram type refuse compacting devices generally fall into two categroies. The first utilizes a ram to compact refuse into a closed chamber wherein a bale of refuse is ejected from the chamber after compaction, by forward movement of the ram into the chamber. The second type ejects a continuous mass of compacted refuse by moving a ram to force refuse through a funnel shaped opening. The pressure of the ram forces the refuse through the funnel causing compaction and ejection through the smaller end of the funnel. A device of this type is disclosed in the Boje et al. U.S. Pat. No. 3,384,007, issued May 21, 1968. Machines of this type are utilized for intermittent, unattended operation. A common usage is in residential apartments where trash and waste are deposited by tenants into chutes which deposit the trash into a bin which feeds the waste compactor. All types of normal waste material, including cartons and irregular shaped objects are deposited in the compactor. The non-uniformity of material results in varying amounts of pressure required to compact the material and force it through the funnel. Occasionally material will jam, resulting in excessive pressure build-up, causing the ram to stall or go through repeated cycling to break up the jam. In the prior art, devices such as the Boje et al patent cited above, smaller auxiliary ram concentrically located in the center of the main ram has been used. The main ram is driven forward by a hydraulic cylinder and, upon occurrence of a jam, the small auxiliary ram is forced forward through a separate hydraulic system in an attempt to break up the jam ahead of the main ram. Devices of this type have been successful, however, they increase the cost of the compactor unit, in that they utilize separate hydraulic cylinders for each ram. The Boje et al. U.S. Pat. No. 3,384,007, for example, utilizes three separate hydraulic cylinders.
Refuse compaction devices which pack refuse into a closed chamber are conventionally referred to as stationary packers. Packers of this type normally use a ram which may be of any configuration, such as cylindrical or rectangular. The refuse is loaded into a compaction chamber and the ram moves into or through the compaction chamber to compress the refuse into the shape of the compaction chamber. Even though there is not the continual emission of compacted refuse, but, rather, the intermittent ejection of compacted bales of refuse, the rams can and do encounter high back pressure as a result of the refuse jamming ahead of the ram. The machine is either recycled to break up the jam or the jam must be broken down by some other means to allow completion of the compaction cycle so that the final bale of refuse may be ejected. A jam clearing ram or auxiliary ram is usable in this situation in the same manner as that describeed for the funnel type compaction device. Here again, it is a distinct advantage to have the auxiliary ram and the main compaction ram operated from a single hydraulic cylinder.
The present invention eliminates the need for separate hydraulic cylinders for each ram while, at the same time, maintaining the operation and function of each ram. On hydraulic cylinder can be used to drive both the main ram for compaction purposes and the auxiliary ram for jam relieving purposes.
Conventional packers of the type disclosed in the Boje et al. U.S. Pat. No. 3,384,007 maintain pressure on the main ram head while the auxiliary head is advanced to clear jams. The present invention removes the pressure from the main head after a jam has occurred and applies the full force of the hydraulic system to the auxiliary or jam clearing ram. The main ram is free to slide rearward relieving pressure on the refuse mass. In this way, the maximum force available is utilized to increase the pressure at the auxiliary ram head to break up the jam.
SUMMARY OF THE INVENTION
It is an object of this invention, to improve ram type refuse compaction devices by reducing the complexity of the mechanical equipment.
It is also an object of this invention to drive a compaction ram and a jam clearing ram in refuse compactors from a single hydraulic cylinder.
It is also an object of this invention to eliminate jams in a refuse compacting device.
These, and other objects of this invention, are attained by means of a hydraulic main ram head mounted in a compaction device and having an auxiliary ram, both of which are operated from a single hydraulic cylinder. The main ram and the auxiliary ram are constructed so that the auxiliary ram is hydraulically driven and is releasably coupled to the main ram. The auxiliary ram drives the main ram through a hydraulic latch and releases the main ram when a refuse jam occurs so that the force available can be used to drive the auxiliary ram into the jammed refuse.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be hereinafter more fully described with reference to the accompanying drawings in which:
FIG. 1 is an isometric view of a funnel type refuse compacting device with portions broken away to show internal structure;
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1 showing the hydraulic latch mechanism;
FIG. 3 is a schematic sectional view of a funnel type refuse compacting device embodying the present invention, with the main ram and auxiliary ram in the fully retracted positions;
FIG. 4 is a schematic sectional view of a funnel type refuse compacting device embodying the present invention, with the main ram in the fully extended position;
FIG. 5 is a schematic sectional view of a funnel type refuse compacting device embodying the present invention, with the main ram and the auxiliary ram in their fully extended positions;
FIG. 6 is a diagramatic representation of a hydraulic system usable with the present invention;
FIG. 7 is a diagramatic representation of an electrical circuit usable with the present invention; and
FIG. 8 is a diagramatic representation of a hydraulic system for an alternate embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 1 through 5 of the drawings depict a funnel refuse compacting device, however, the present invention is equally useful with a stationary compactor of the type wherein a ram is used to compress refuse material into an enclosed chamber. In this latter case, an auxiliary ram of any particular configuration would be mounted internally of the main ram much in the manner disclosed in the FIGS. 1 through 5. It is not necessary that the axuiliary ram be mounted in any particular position relative to the main ram. The location of the auxiliary ram in the funnel type device is normally placed concentric with the main ram so that extension of the auxiliary ram will be aligned with the center of the funnel portion of the compacting device. In the stationary packer the auxiliary ram could be located at any point relative to the main ram wherein it is found that best jam freeing characteristics are obtained.
Referring to FIGS. 1 through 5, a refuse hopper or loading chute 2 is designed to receive and accumulate refuse prior to compaction and empties into a compaction chamber 4. Waste material in the chamber 4 is ejected through a discharge opening 6 into a compaction funnel 8 and conduit 10. Refuse forced through the funnel 8 is compacted and emerges into a conduit 10. Continued compaction of the material and ejection through funnel 8 causes the compacted material to be continually ejected from the end of the conduit 10. Material exiting conduit 10 can be captured in rigid containers or flexible bags.
A casing or shell 12 extends rearwardly of the compaction chamber 4 and the loading chute 2. Within the shell 12 there is mounted a main compaction head 14 of a main compaction ram 15. The ram 15 is mounted for sliding movement through the compaction chamber 4 and has a cylindrically shaped body portion 16 extending rearwardly into the casing 12. An auxiliary ram 18 having a head 20 is concentrically mounted in the center of the main head 14. The auxiliary ram 18 extends rearwardly from the face of the main ram and is mounted on a piston rod 22 of a hydraulic cylinder 24. In the retracted position the face of the auxiliary ram 18 is substantially flush with the face of the main ram head 14 to prevent refuse from depositing on the auxiliary ram and limiting the capacity of the chamber 4.
Secured to the inside of the main ram body 16 there is a hydraulic latch mechanism generally designated 26. The latching mechanism 26 is shown in detail in FIGS. 1 and 2 and consists of a hydraulic cylinder body 28 and a lever 32 mounted on the head 14 of the main compaction ram. An actuating ram 30 extends out of the cylinder 28 as an extension of the piston rod of the hydraulic piston in the cylinder 28. The actuating lever 32 is pivotally secured to the rear side of the main ram head 14 and pivotally connected to the actuating arm 30. Movement of the hydraulic cylinder 28 causes linear movement of the actuating arm 30 and pivotal movement of the lever 32 about point 34 between two positions as shown by the solid and dotted lines in FIG. 2. The lever 32 is of a length sufficient to extend downward into a slotted opening 36 in the auxiliary ram body in interference relationship with the path of travel of the auxiliary ram. This position is shown by the solid lines in FIG. 2. Actuation of the hydraulic cylinder 28 drives the actuating arm 30 forward pivoting the lever 32 about point 34 to the dotted line position shown in FIG. 2. In this position the lever 32 is in non-interfering relationship with the path of travel of the auxiliary ram 18 as shown by the dotted lines in FIG. 2.
The design at the latch mechanism may be varied to suit the needs of the particular compacting mechanism. For example, commercially available linear actuating latches or toggle type of mechanisms may be used to suit particular operational requirements.
An annular stop member 38 is also connected to the inside wall of the main ram body 16 and has a center opening sufficient to accommodate passage of the auxiliary ram 18. The outside surface of the auxiliary ram 18 also has a stop member 40 extending outwardly sufficient to engage the annular stop member 38 on the main ram. The purpose of the two members 39 and 40 is to provide the return movement of the main ram when the auxiliary ram is moved in a rearward direction. The two members 38 and 40 may be of any shape and configuration desired so long as they are in interference relationship during the return stroke of the auxiliary ram and the main ram. The position of the two members on their respective ram bodies is determined so that the lever 32 of the latch mechanism 26 is directly above the slotted opening 36 in the auxiliary ram at the end of the return stroke, whereby actuation of the latching member 26 will move the lever 32 downward into engaging relationship with the body of the auxiliary ram.
Hydraulic fluid is provided to the drive cylinder 24 through fluid line 62 to force the piston rod 22 and the auxiliary ram and the main ram forward through a compaction cycle. At the forward end of the stroke the fluid pressure is then provided to the hydraulic cylinder 24 through a line 61 which drives the piston rod 22 and the auxiliary ram 18 in a rearward direction or a return stroke. A hydraulic fluid line 70 extends from the head end of the cylinder 24 to the head end of the cylinder 28 of the latching member 26. The fluid line 78 extends between the rod end of the cylinder 24 to the rod end of the cylinder 28. A sequence valve 50 is positioned in the line 70 to allow passage of fluid through line 70 to the latching member 26 only upon the detection of the predetermined pressure within the line 70. The operation and description of the sequence valve 50 and the latching member 26 will be more fully described below with reference to the hydraulic circuit shown in FIG. 6.
Operational positions of the auxiliary ram and the main ram can be seen in the schematic sectional views of FIGS. 3, 4 and 5. In FIG. 3 the main ram and the auxiliary ram are shown in their retracted positions wherein the piston rod 22 is in its extreme rearwardly position within the hydraulic cylinder 24. The annular stop 40 is in engagement with the stop 38 on the main ram; the auxiliary ram 18 is withdrawn inside the main ram 15 so that the face of the heat 20 is essentially flush with the face of the main compaction ram head 14 and the lever 32 of latch 26 is positioned in slot 36. Refuse from the loading hopper 2 falls by gravity into compaction chamber 4 and is relatively loosely packed.
Upon operation of the hydraulic cylinder 24 the piston rod 22 moves forward carrying with it the auxiliary ram 18 and main ram 15 to the position shown in FIG. 4. Continued forward movement of the main ram 15 is prevented by actuation of limit switch SW-2 at the discharge opening 6. Actuation of switch SW-2 either energizes a solenoid valve 76 which allows fluid under pressure to pass to the head end of cylinder 28 of hydraulic latch 26, as seen in FIG. 8, or energizes a solenoid SOL-1 which actuates spool valve 54 to return the main ram to its starting position. Actuation of cylinder 28 disengages the lever 32 from slot 36 uncoupling the auxiliary ram 18 from the main ram 15. The full fluid press from cylinder 24 is then acting on the auxiliary driving it forward into funnel 8 to position shown in FIG. 5. In this position the refuse is packed into the funnel by the main ram head and forced into the cylindrical tube by the auxiliary ram.
OPERATION
The operation of the compactor shown in FIGS. 1-5 will be described with reference to the hydraulic system and the electrical circuitry shown in FIGS. 6 through 8. The head end and the rod end of the hydraulic cylinder 24 are connected to a fluid pump 52 through a four-way hydraulic spool valve 54. The pump 52 is driven by a motor 56 and pumps fluid from a reservoir 58 through line 60 to the four-way valve 54. A hydraulic line 62 connects the four-way valve to the rod end of the hydraulic cylinder 24 and a hydraulic line 61 connects the four-way valve to the head end of the hydraulic cylinder 24.
A spring 64 holds the four-way valve in a straight through position wherein the pump 52 pumps fluid through the line 60, through the four-way valve to the line leading to the rod end of the cylinder 24. In this position fluid is free to move under the action of the piston head 66 through line 61, through the four-way valve 54 back to the reservoir 58. A solenoid SOL-1 has its plunger connected to the four-way valve to actuate the valve to a position wherein fluid from the pump 52 will pass through the line 60 to the four-way valve, through thr four-way valve to line 61 leading to the head end of the cylinder 24. Hydraulic fluid in the rod end of the cylinder 24 is free to move under the action of the piston 66 through the line 62, through the four-way valve 54 back to the reservoir 58. A pressure switch 68 is mounted in line 60 to respond to excess pressure in the system to disconnect solenoid SOL-1, allowing the spring 64 to reverse the position of the four-way valve.
As the fluid pressure from the pump 52 through the four-way valve 54 to the head end of the cylinder 24 drives the piston 66 forward, the main compaction ram 15 compresses refuse in the hopper 4 into the funnel 8. As compaction builds up the pressure on the front of the main ram head 14 increases and the fluid pressure in the head end of the cylinder 24 increases. A pressure sequence valve 50 is positioned in a line 70 between the head end of the cylinder 24 and the head end of the cylinder 28 of the latch 26. The sequence valve 50 is set so that fluid in the line 70 does not pass to the cylinder 28 until a predetermined pressure is reached. The valve 50 senses the pressure in the line 70 through bleed off line 72 and upon the predetermined pressure being reached the valve 50 is actuated opening the line 70 to the head end of the cylinder 28. When a jam occurs in the compaction chamber 4 preventing forward movement or further compaction of the refuse material by the compaction head 14 the pressure in the line 70 will rise to a point above the predetermined setting of valve 50. Fluid from the head end of the cylinder 24 then passes to the head end of the cylinder 28 driving the actuating arm 30 forward releasing lever 32 from the slot 36 in the axuiliary ram 18. Under this condition the driving force on the main ram 15 is completely removed and the total operating force available from the cylinder 24 is concentrated on driving the auxiliary ram 18 forward into the mass of refuse. Applying the total force of the hydraulic cylinder 24 to the smaller surface area of the head of auxiliary ram 18 drives the center of the refuse material forward into the funnel 8 and conduit 10.
In the normal operation, when a jam of refuse material does not occur, the main ram 15 continues forward to the end of the compaction chamber 4, at which point it actuates switch SW-2. At this point there are two possible modes of operation. The main ram may be returned with the auxiliary ram to its original position to again recycle and compress further refuse material. In this case the switch SW-2 is a normally closed switch which controls actuation of the spool valve 54. In another mode of operation, the auxiliary ram 18 may be advanced forward into the funnel 8 forcing the compacted refuse into the cylindrical tube 10 when the main ram has completed its travel through the compaction chamber. The position of the main ram and the auxiliary ram in this mode of operation are shown in FIG. 5. In this mode of operation, the switch SW-2 is a normally open switch which energizes a solenoid SOL-2, shown in dotted lines in the circuit diagram, FIG. 7, and the hydraulic circuitry of which is shown in FIG. 8. The solenoid sol-2 actuates a bypass valve 76 in line 74 bypassing the sequence valve 50 to the head end of this piston 28. Pressure from the head end of the cylinder 24 actuates the hydraulic latch 26 releasing the auxiliary ram 18. The ram 18 then continues moving foward out of the main ram 15 forcing refuse in the funnel 8 into the conduit 10. When the auxiliary ram is extended to its forwardmost position, a switch SW-3 on the inside of the body 16 of the main ram is actuated by the stop member 40 to energize the solenoid SOL-1, reversing the spool valve 54.
This second mode of operation is essentially the same as that which occurs when a jam occurs ahead of the main ram 15 prior to traversal of the main ram through the compaction chamber. Release of latch 26 allows the auxiliary ram 18 to move forward until the stop member 40 actuates the switch SW-3, reversing the spool valve 54.
With the spool valve 54 in reverse position hydraulic fluid from pump 52 passes to the rod end of cylinder 24 reversing the direction of movement of the auxiliary ram 18 and allowing the pressure to drop in the head end of the cylinder 24. The pressure drop in the head end of the cylinder 24 releases the sequence valve 50 so that fluid from the head end of the cylinder 28 is discharged to the reservoir 58 under the action of the hydraulic latch piston. The high pressure fluid passing through line 62 to the head end of the cylinder 24 moves the piston 66 in the rearward direction and also allows fluid to pass through line 78 to the rod end of the cylinder 28 of the hydraulic latch. The reverse direction of the piston in the cylinder 28 causes the lever 32 to be moved downward towards the locking or engaging position. As the auxiliary ram 18 moves in the rearward direction, the stop 40 releases switch sw-3 and engages the stop 38 on the main ram 15 and carries the main ram back through the compaction chamber to its original position. When the stop 40 has engaged the stop 38 the slot 36 is in a position to receive the lever 32 to re-engage the auxiliary ram 18 to the main ram 15. At the end of the stroke the body 16 of the main ram 15 contacts switch SW-1 cutting off power to the motor 56 in the pump 52. The compactor is in position to be recycled for further compaction of refuse.
Referring now to the electrical circuit diagram, FIG. 6, a light or sonic sensing switch 80, mounted in the hopper 2 to detect the presence of refuse in the hopper, has contacts SW-2 mounted in the main power line to the compactor. When the light or sonic beam is broken, the contacts SW-S close, energizing the compacting circuit. A master switch SW-M1 is also mounted in the main power line to the compactor so that the entire compactor may be shut down to prevent operation at any time. The master switch SW-M1 must be closed prior to operation of the compactor. A manual switch SW-M-2 is mounted in the compactor circuit in parallel with the contacts SW-s of the sensing switch 80, to allow manual operation of the compactor. In the event there is insufficient refuse in the hopper 2 to actuate the sensing switch 80, the compactor may be manually operated by closing the switch SW-M2.
Closing of the contacts of the sensing switch SW-s or the manual switch SW-M2, energizes the circuit and provides power through a counter 82 to a relay R1. The relay R1 has a set of normally open contacts R1-1 which are in parallel with the contacts of the sensing switch SW-s and the manual switch SW-M2. The contacts R1-1 provide a holding circuit for the relay R1 and continued energization of the entire circuit after release of the manual switch SW-M2 or sensing switch 80. Operation of the compactor allows the refuse in the hopper 2 to be depleted and the beam of switch 80 to be restored. The holding circuit and the contacts R1-1 mantain power to the circuit throughout the cycle of operation. The counter 82 can be set to allow a predetermined number of cycles of operation prior to de-energizing relay R1 to shut down the compactor. The counter 82 is pulsed by a set of contacts to switch SW-1. The switch SW-1 is a limit switch located on the inside of the casing 12 at a position to be actuated by the return movement of the main ram 15. If, for example, it is determined that the hopper 2 and the compaction chamer 4 hold approximately five times the volume of the compaction chamber, then the counter would be set to operate five cycles each time the sensing switch 80 is interrupted. Each time that the main ram 15 returns to its retracted position, it would actuate SW-1 pulsing the counter 82.
Closing of the sensing switch SW-s also energizes the motor 56 and provides power to a second relay R2 through a second set of contacts to switch SW-1. The line to relay R2 also has a set of normally closed contacts for another limit switch SW3 mounted in parallel to the contacts of limit switch SW-1. The limit switch SW3 is mounted inside the body 16 of main ram 15 and is actuated by the stop 40 on the auxiliary ram at the end of the full compaction cycle. In the mode of operation wherein the auxiliary ram is not advanced at the end of each cycle the normally closed contacts of switch SW-2 are also mounted in series with contacts of switch SW3. The switch SW-2 is located at the end of the stroke of the main ram to be actuated by the main ram during a full cycle when a jam has not occurred.
Relay R2 has two sets of contacts, the first set R2-1 being normally open and mounted in the line to relay R2 parallel to contacts of switch SW-1. Contacts R2-1 provide a holding circuit for the relay R2. A second set of contacts R2-2 for the relay R2 are also normally open and control the power to the solenoid SOL-1.
In the mode of operation where the auxiliary ram is to be actuated at the end of each cycle the contacts for limit switch SW-2 are normally open and are located in series with a solenoid SOL-2, shown in dotted lines in the circuit of FIG. 7. The limit switch SW-2 is located in the compaction chamber 4 in a position to be actuated by the main ram head at the end of the compaction stroke. Actuation of the switch SW-2 closes contact SW-2, energizing solenoid sol-2 which, in turn, opens the valve 76 in the line 70 to the hydraulic latch cylinder 28. As described above, operation of the valve 76 releases the latch mechanism from its ram engaging position, and allows the auxiliary ram to advance ahead of the main ram.
Prior to operation, main ram 15 is in the retracted position shown in FIGS. 1 and 3 and the switch SW-1 is held in a closed position by contact with the main ram body. when refuse is accumulated in the hopper 2, the circuit to the switch 54 is interrupted and the normally open contacts SW-S are closed energizing relay R1 and providing the holding circuiting through contacts R1-1. The motor 56 is energized, driving pump 52 to provide high pressure fluid to the system from reservoir 58. With the switch SW1 in a closed position, the relay R2 is energized, closing the holding circuit through contacts R2-1 and the circuit to solenoid SOL-1 through contacts R2-2. With the solenoid energized, the four-way valve 54 is moved to the position wherein high pressure hydraulic fluid is supplied to the head end of the hydraulic cylinder 24. Movement of the hydraulic cylinder 24 causes the auxiliary ram 19 to advance carrying the main ram by means of hydraulic latch 26. Forward movement of the main ram 15 releases the switch SW1, allowing the contacts for SW1 to return to their normally open position. The solenoid SOL-1 continues to be energized by means of power through contacts SW2 and R2-1 to relay R2 and through contacts R2-2 to the solenoid SOL-1. When the main ram 15 advances through the compaction cycle to the position shown in FIG. 4, the switch SW2 is actuated and the normally open contacts SW2 are closed, energizing relay SOL-2.
Energization of the relay SOL-2 releases the latch mechanism 26 allowing the auxiliary ram 18 to advance ahead of the main ram 15 to complete the compaction cycle by forcing the refuse in the funnel 8 into the cylinder 10. The forward movement of the auxiliary ram carries the stop member 40 into engagement with limit switch SW-3 which de-energizes a circuit to relay R2 which, in turn, releases solenoid SOL-1. Release of the solenoid SOL-1 allows the spool valve 54 to revert to the position wherein the high pressure fluid is applied to the rod end of the hydraulic cylinder 24. The hydraulic cylinder 24 moves in the rearward direction carrying the auxiliary ram back into the body of the main ram until the stop member 40 of the auxiliary ram engages the stop member 38 of the main ram, at which time both the main ram and the auxiliary ram are returned to their normal precompaction positions and the limit switch SW-1 is engaged by the body of the main ram. Contact with the switch SW-1 pulses the counter 82 which either advances the counter or, if the counter is fully advanced, de-energizes the circuit to relay R1 shutting down the compactor. If the counter 82 has not completed its cycle, then the relay R1 is still energized and the contacts R1-1 continue to energize the circuit the that the entire cycle of operation is repeated.
If, during the forward movement of the main ram through the compaction chamber, refuse build-up produces a jamming condition such that the fluid pressure in the hydraulic circuit increases above a predetermined level, the sequence valve 50 will be actuated through the bleeder line 72. Actuation of the sequence valve 50, at that point in the cycle, then provides high pressure fluid to the head end of the latch mechanism cylinder 28 in the same manner that the bypass valve 76 does at the end of the main ram compaction cycle. That is, the release of the latch mechanism 26 allows the auxiliary ram to advance ahead of the main ram head, breaking up the jam until switch SW-3 is actuated by the stop mechanism 40, at which time the relay R2 is released, de-energizing solenoid SOL-1 and the spool valve 54 returns to its end of cycle position and returns the main ram and the auxiliary ram to the precompaction position.
Having thus described the invention relative to the preferred embodiment disclosed, it is understood that various changes may be made by one skilled in the art without departing from the spirit and scope of the invention.