CA1147241A - Hydraulic system for material compacting apparatus - Google Patents
Hydraulic system for material compacting apparatusInfo
- Publication number
- CA1147241A CA1147241A CA000350565A CA350565A CA1147241A CA 1147241 A CA1147241 A CA 1147241A CA 000350565 A CA000350565 A CA 000350565A CA 350565 A CA350565 A CA 350565A CA 1147241 A CA1147241 A CA 1147241A
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- Canada
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- ram
- motor
- arm
- valve
- hydraulic
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Abstract
Abstract of the Disclosure The invention comprises an entirely hydraulic control and operating system for material compacting apparatus, consist-ing of a hopper, a compacting ram inside the hopper, and a hydraulic motor for moving the ram in opposite compacting and retracting movements. The system includes a pressure detector valve detecting pressure build-up in the motor when the ram reaches its maximum compacting position, and a manual control valve for moving the ram in either direction. The detector and the manual control supply a shuttle valve which in turn feeds a pilot valve to retract the ram either automatically by the detector, or manually by the manual valve. The system as applied to a self-propelled refuse compacting vehicle also includes means for disabllng loading arm motors while the ram motor is operative and until the ram reaches its fully ret-tracted position.
Description
~L~ 47'~41 HYDRAULIC SYSTEM FO~ MATERIAL COMPACTING APPARATUS
_ . _ Field of the Invention .
The present invention is concerned with improvements in or relating to hydraulic systems for material compacting apparatus, and especially but not exclusively, to such system~
for self-propelled refuse compacting vehicles.
Review of the Prior Art Material compacting apparatus, and particularly refuse-compacting vehicles are now a well-established part of many large-size industrial material handling systems. Such a vehicle usually consists of a truck mounting a compactor apparatus on its chassis, and having at its front end a pair of controllable lifting and tilting arms that are engaged by the operator with a free-standing container. Thereafter the arms are lifted and tilted to discharge the container contents into a compactor hopper, and to return the container to its original position.
A compacting ram within the hopper is then operated either while the truck is stationary or while it is moving to the next pick-up point to compact the material into the space at the rear of the hopper. When the hopper is sufficiently full a rear door is opened and the ram operated to discharge the compacted contents. The control and operating system for such a vehicle must be readily operable by relatively unskilled personnel, also bearing in mind that some operations are carried out while the truck is being driven, and must permit foolproof control of powerful equipment that can cause extensive damage if malfunction occurs. Although I am aware that electrical-hydraulic ~ystems and mechanical-hydraulic systems have ~47~41 previously been employed, to my knowledge an entirely hydraulic system has not been proposed or used hitherto.
Definition of the Invention It is therefore an object of the invention to provide an entirely hydraulic control and operating system for material compacting apparatus.
It is a more specific object to provide such a system for refuse compacting vehicles.
In accordance with the present invention there is provided a hydraulic control and operating system for material compacting apparatus mounted on a self-propelled vehicle, wherein the apparatus comprises:
a hopper for receiving the material, the hopper having an inlet thereto for uncompacted material, an outlet therefrom for compacted material, and a wall member against which the received material is compacted, a ram member mounted in the hopper for compacting movement toward the wall member and opposite retracting movement away from the wall member, hydraulic ram motor means connected to the hopper and the ram means and operative to move the ram means in the said opposite compacting and retracting movements, arm means for engagement with a container and for moving the container to discharge the contents of the container into the hopper, hydraulic arm motor means for moving the said arms, and 7;2~1 pump means for supplying operating liquid under pressure to the hydraulic ram motor means and the hydraulic arm motor means under control of the system, the system comprising:
manually-operated arm motor valve means for controlling the supply of operating liquid to the arm motor means, ram motor valve means controlling the supply of operating liquid to the ram motor means to cause either of the said opposite movements of the ram means, and ram relay valve means having an operating plunger engaged by the ram member in nits fully retracted position, the ram relay valve means when its plunger is so engaged permitting supply of operating liquid under control of the said manually-operated arm motor valve means for the said hydraulic arm motor means, and when nits plunger is not so engaged preventing supply of operating liquid under control of the said manually-operating arm motor valve means to the said hydraulic arm motor means so that the arms cannot be actuated unless the ram member is in its fully retracted position.
Preferably the said arm means includes:-fork means pivotally mounted on the arm means and for engagement with a container to be lifted by the arm means, hydraulic fork motor means connected between the arm means and the fork means and for moving the fork means relative 5 to the arm means, and manually-operated fork motor valve means for controlling the supply of operating liquid to the fork motor means, ~724~
wherein the said arm motor valve means and fork motor valve means comprise a single joystick type proportional valve operable in a first direction for control of the arm motor means and in a second direction transverse to the first direction for control of the fork motor means, and wherein the said ram relay valve means when its plunger is not engaged by the ram member prevents supply of operating liquid to the joystick valve so that both the arm motor valve means and the fork motor valve means are disabled.
Description of the Drawings A hydraulic system for a refuse compacting vehicle that is a particular preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawing wherein:
FIGURE 1 is a side elevation of a typical vehicle employing the system, and FIGUR~ 2 is a schematic diagram of the hydraulic system.
- 3a -~1~7;~41 Description of the Preferred Embodiments Since the speci~ic structure of the vehicle is not part of this invention the construction as illustrated by Figure 1 has been considerably simplified to omit inessential details~
Thus, the vehicle is shown as consisting of a chassis 10 on which is mounted a driver's cab 12 and a hopper container 14. The hopper is provided with a top door 16 pivoted at 18 and having connecting operating linkages 19, each with a cam follower 20, this door closing a respective loading opening. A rear door 22 i8 pivoted at 24 and closes a respective discharge opening. The door 22 is controlled in its pivoting opening and closing movement by a pair of hydraulic piston and cylinder motors 26 (only one is seen in Figure 1). A compacting ram 28 as shown in broken lines i8 mounted within the hopper for movement from the front to the rear, and vice versa, under the control of a high-extension, multi-cylinder hydraulic motor 30. A bifurcated arm structure 32 is pivoted in front of the hopper 14 and reaches over the cab 12 in the travelling and container-engaging positions, the front ends of the arm structure carrying a fork structure 36 pivoted thereto at 38. Novement of the arm structure relative to the chassis is controlled by a pair of hydraulic motors 40, while the movement of the fork structure 36 relative to the arm structure 32 is controlled by a pair of hydraulic motors 42~ The door 16 is opened automatically in known manner upon movement of the arm structure 32 to a container discharge position above the hopper~
when cam fo71Owers are engaged by respective cams 43 on the arm structure thereby causing operation of the linkage~ 19 to 7~41 open the door. The door closes again automatically upon return movement of the arm structure.
The mode of operation of such a vehicle is now extremely well known. The driver engages the fork structure 36 with a free-standing refuse container, and then operates the motors 40 to lift and tilt the container until it can be emptied into the front end of the hopper, the cams 43 and linkages 19 opening the door 16 before the container reaches its tilted emptying position. The container is then returned to the ground while the door 16 closes, the fork structure 36 is disengaged therefrom, and returned to an elevated travelling position, and the vehicle is driven to the next pick-up location while the ram motor 30 is operated to compact the waste to the rear of the hopper against the door 20. Side shields 44 and 46 are provided to prevent spilling of waste as the container is emptied. A side inspection hatch 48 is also provided.
Referring now to Figure 2 the truck engine 50 is employed in conventional manner to drive a two stage hydraulic pump; the reason for employing such a pump will be explained below. The pump is operated either in a single stage low delivery mode, or a two stage high delivery mode under control of a manual switch 53 located in the cab 120 This pump draws operating liquid from a resérvoir 54 via a strainer 56 and shut off valve 58 and delivers it under pressure to the circuit via a check valve 60 that sets the minimum pressure for the system, to ensure that there is ~ufficient pressure for operation of the valves of the system; in a typical ~ystem this valve operates ~47;~1 at about 7 Kg/sq.cm. ~100 p.s.i.). A pressure relief valve 61 operative at about 21 Kg/sq.cm. (300 p.s.i.) ensures that this system operating pressure cannot rise above its present value, the excess liquid being returned to the reservoir. A second pressure relief valve 62 ensures tha~ the pressure of the operating liquid supplied to the various motors cannot rise above a safe value, e.g. about 123 Kg/sq.cm. (1,750 p.s.i.). The excess liquid from the relief valves 61 and ~2 passes to the reservoir via a filter 64, shut-off valve 66 and strainer 68.
The system comprises a plurality of manually operated valves disposed for easy access by the driver, and a plurality of relay valves arranged to provide the desired sequence of operations automatically. A proportional hydraulic pressure reducing valve 70 is provided and is positioned by the driver to lS give the desired liquid flow, and therefore the corresponding motor operating speed, to the pilot valves which it supplies, namely valves 72 and 74, controlling respectively the motors 40 and 42. The valve 70 is of the "joystick" type so that the two sets of motors can be operated simultaneously and at different speeds. A manually-operated directional valve 76 is used to control pilot valve 78 which in turn controls tailgate motors 26 A manual "emergency stop" valve 80 when operated by-passes the entire hydraulic control system and returns the liquid directly to the reservoir 54 to stop all the motors in the positions ifi which they stand when the stop valve is actuatedO
~7~241 The ram is usually ope~ated during the collection of refuse while the vehicle is bein~ drl~en and it~ operation i~
therefore as automatic as po~sible. A two stage pump 52 is used and in a typical embodiment the pump will supply either 55 or 260 litres per minute at a shaft speed of 1200 r.p~m. The higher delivery rate is normally used while the vehicle is standing for the fastest possible operation, while the lower rate is used at other times, when much slower operation is completely adequate; this avoids the overheating and need for auxiliary coolers that might otherwise occur if the pump must always operate a a con~tant high rate. The pump may be left connected to the truck engine at all times and power is there-fore always available for operation of the system: this is not usually possible with a system employing a mechanical power take-off. As the vehicle moves away from the ~ite of the pick-up,manual ram control valve 82 is actuated and cause~ flow of liquid to pilot valve 84 to shift this valve and also to enable this valve to feed liquid to a spring-centered ram pilot valve 86, which in turn feeds liqu~d to the ram motor 30 causing extension of the cylinder and movement of the ram toward the rear of the hopper. In its foremost position the ram 28 is in contact with the plunger of a directional control valve 88; after a small movement of the ram (e.g. about 2-3 cm) the ram disengages from the valve plunger, and that valve now operates to maintain the liquid flow to the valve~ 84 and 86. Moreover, the joystick ~alve 70 is now by-pas~ed and cannot cause operation of the arm motor~, even if manipulated, 80 that tho~e motor~ are disabled.
7 _ 72~1 Pilot valve 84 i~ of the type in wh,.ch the spool is detented in both directions so that it will re.main in the control position in which it was last placed until positi.vely moved therefrom; the ram will therefore continue its compacting movement to the rear. When the deposited material is compacted as tightly as possible the ram will come to a stop and pressure will now build up in the Yystem. This pressure is applied to a sequencing valve 90 which previously ha~ been set in the position illustrated in Figure 2, in which it connects one side of a shuttle valve 92 back to the reservoir, the other side of the ~huttle valve being connected to the ram control valve 82. When the ram motor pressure applied to the valve 90 has risen to a suitable value the shuttle valve 92 is shifted and the high pressure is applied to the v.alve 84 to shift it, whereupon pilot valve is also ~hifted and the motor 30 operates to retract the ram. The detent of valve 84 holds it in the "ram retract" position despite the loss of the elevated pressure through the shuttle valve 92.
Upon return of the ram to the fully retracted position it engages the plunger of valve 88, which is then operative to restore flow to the joystick valve 70 and diverts flow from the valve 84 the flow to pilot valve 86 then stops and this valve centres under control cf its centering spring~ It is possible for the operator at any ti~e to reverse the ram movement by reverse manual operation of the valve 82~ whereupon an excess of pressure goes to the shuttle valve 92~ which transmits thi~
pressure as an operating pressure to the pilot valve 84; the valve shifts as described above and shifts valve 86 to retract the ram~
., , 8 -- .
7~41 The function of the shuttle val~e 92 is therefore highl~ important in permitting the control of the ram operation both automatically and manually, by accepting an excess pressure ~rom the two possible sources and applying this excess pressure as a control pressure to the pilot valve 84, without interference of the two sources with one another and therefore withtheir Reparate function~.
The circuit is provided in known manner at appropriate locations with relief valves 94, 96 and 98, which are ~et at the pre~sures neces~ary to protect their associated component~, and with check va~ves 100, 102 and 104 to prevent reverse liquid flows. A pilot operated unloading valve 106 is operative when the pressure of the liquid supplied to the motor 30 drop3 upon the ram retraction and permits fast dumping of the liquid in the ram motor 30 back to the reservoir 54~ increasing the speed at which the ram can be retracted~
It will be seen therefore that we have provided an entirely hydraulic control and operating ~ystem that provides the desired manual and automatic control, without the need for electrical relays and/or mechanical link connections between valve~.
Although the system has been de~cribed in relation to a truck mounted arrangement, it will be apparent to those skilled in the art that it is equally applicable to a stationary system, such as would be required by an apartment building or a shopping centre, in ~hich for example the ram operation is initiated at predetermined times by a timing device, ~ith the option of manual control when required.
~7~41 It is found in practice that a completely hydraulic system with a permanently operating pump as described permits much faster system operation than prior systems using a mechanical power take off. For example, with such a prior system the operator must stop the vehicle before the container, engage the p.t.o.
and lower the arm structure, disengage the p.t.o. and move the vehicle to engage the arms with the container, engage the p.t.o.
and empty the container, and so on, it not being possible to move both the vehicle and the arm structure simultaneously. With the system of this invention the operator is able to adjust the positions of the arm and fork ~tructures while approaching the container, and can return them to their travelling position while leavinq the pick up site, minimizing the time required for each pick up.
Among the advantageY of a completely hydraulic system is its relative freedom ~rom service problems as compared with mechanical or electrical systems, bearing in mind that these systems are expected to operate under extremely arduous conditions.
For example, it is found wit~ mechanical system~ that the moving parts have a tendency to bind after a while~ and to become frozen 20 ~ during cold weather, while with electrical systems ~here is a tendency toward failure3 due to the common electrical fault~, such a-~ broken wire~ and corroded con nection~.
_ . _ Field of the Invention .
The present invention is concerned with improvements in or relating to hydraulic systems for material compacting apparatus, and especially but not exclusively, to such system~
for self-propelled refuse compacting vehicles.
Review of the Prior Art Material compacting apparatus, and particularly refuse-compacting vehicles are now a well-established part of many large-size industrial material handling systems. Such a vehicle usually consists of a truck mounting a compactor apparatus on its chassis, and having at its front end a pair of controllable lifting and tilting arms that are engaged by the operator with a free-standing container. Thereafter the arms are lifted and tilted to discharge the container contents into a compactor hopper, and to return the container to its original position.
A compacting ram within the hopper is then operated either while the truck is stationary or while it is moving to the next pick-up point to compact the material into the space at the rear of the hopper. When the hopper is sufficiently full a rear door is opened and the ram operated to discharge the compacted contents. The control and operating system for such a vehicle must be readily operable by relatively unskilled personnel, also bearing in mind that some operations are carried out while the truck is being driven, and must permit foolproof control of powerful equipment that can cause extensive damage if malfunction occurs. Although I am aware that electrical-hydraulic ~ystems and mechanical-hydraulic systems have ~47~41 previously been employed, to my knowledge an entirely hydraulic system has not been proposed or used hitherto.
Definition of the Invention It is therefore an object of the invention to provide an entirely hydraulic control and operating system for material compacting apparatus.
It is a more specific object to provide such a system for refuse compacting vehicles.
In accordance with the present invention there is provided a hydraulic control and operating system for material compacting apparatus mounted on a self-propelled vehicle, wherein the apparatus comprises:
a hopper for receiving the material, the hopper having an inlet thereto for uncompacted material, an outlet therefrom for compacted material, and a wall member against which the received material is compacted, a ram member mounted in the hopper for compacting movement toward the wall member and opposite retracting movement away from the wall member, hydraulic ram motor means connected to the hopper and the ram means and operative to move the ram means in the said opposite compacting and retracting movements, arm means for engagement with a container and for moving the container to discharge the contents of the container into the hopper, hydraulic arm motor means for moving the said arms, and 7;2~1 pump means for supplying operating liquid under pressure to the hydraulic ram motor means and the hydraulic arm motor means under control of the system, the system comprising:
manually-operated arm motor valve means for controlling the supply of operating liquid to the arm motor means, ram motor valve means controlling the supply of operating liquid to the ram motor means to cause either of the said opposite movements of the ram means, and ram relay valve means having an operating plunger engaged by the ram member in nits fully retracted position, the ram relay valve means when its plunger is so engaged permitting supply of operating liquid under control of the said manually-operated arm motor valve means for the said hydraulic arm motor means, and when nits plunger is not so engaged preventing supply of operating liquid under control of the said manually-operating arm motor valve means to the said hydraulic arm motor means so that the arms cannot be actuated unless the ram member is in its fully retracted position.
Preferably the said arm means includes:-fork means pivotally mounted on the arm means and for engagement with a container to be lifted by the arm means, hydraulic fork motor means connected between the arm means and the fork means and for moving the fork means relative 5 to the arm means, and manually-operated fork motor valve means for controlling the supply of operating liquid to the fork motor means, ~724~
wherein the said arm motor valve means and fork motor valve means comprise a single joystick type proportional valve operable in a first direction for control of the arm motor means and in a second direction transverse to the first direction for control of the fork motor means, and wherein the said ram relay valve means when its plunger is not engaged by the ram member prevents supply of operating liquid to the joystick valve so that both the arm motor valve means and the fork motor valve means are disabled.
Description of the Drawings A hydraulic system for a refuse compacting vehicle that is a particular preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawing wherein:
FIGURE 1 is a side elevation of a typical vehicle employing the system, and FIGUR~ 2 is a schematic diagram of the hydraulic system.
- 3a -~1~7;~41 Description of the Preferred Embodiments Since the speci~ic structure of the vehicle is not part of this invention the construction as illustrated by Figure 1 has been considerably simplified to omit inessential details~
Thus, the vehicle is shown as consisting of a chassis 10 on which is mounted a driver's cab 12 and a hopper container 14. The hopper is provided with a top door 16 pivoted at 18 and having connecting operating linkages 19, each with a cam follower 20, this door closing a respective loading opening. A rear door 22 i8 pivoted at 24 and closes a respective discharge opening. The door 22 is controlled in its pivoting opening and closing movement by a pair of hydraulic piston and cylinder motors 26 (only one is seen in Figure 1). A compacting ram 28 as shown in broken lines i8 mounted within the hopper for movement from the front to the rear, and vice versa, under the control of a high-extension, multi-cylinder hydraulic motor 30. A bifurcated arm structure 32 is pivoted in front of the hopper 14 and reaches over the cab 12 in the travelling and container-engaging positions, the front ends of the arm structure carrying a fork structure 36 pivoted thereto at 38. Novement of the arm structure relative to the chassis is controlled by a pair of hydraulic motors 40, while the movement of the fork structure 36 relative to the arm structure 32 is controlled by a pair of hydraulic motors 42~ The door 16 is opened automatically in known manner upon movement of the arm structure 32 to a container discharge position above the hopper~
when cam fo71Owers are engaged by respective cams 43 on the arm structure thereby causing operation of the linkage~ 19 to 7~41 open the door. The door closes again automatically upon return movement of the arm structure.
The mode of operation of such a vehicle is now extremely well known. The driver engages the fork structure 36 with a free-standing refuse container, and then operates the motors 40 to lift and tilt the container until it can be emptied into the front end of the hopper, the cams 43 and linkages 19 opening the door 16 before the container reaches its tilted emptying position. The container is then returned to the ground while the door 16 closes, the fork structure 36 is disengaged therefrom, and returned to an elevated travelling position, and the vehicle is driven to the next pick-up location while the ram motor 30 is operated to compact the waste to the rear of the hopper against the door 20. Side shields 44 and 46 are provided to prevent spilling of waste as the container is emptied. A side inspection hatch 48 is also provided.
Referring now to Figure 2 the truck engine 50 is employed in conventional manner to drive a two stage hydraulic pump; the reason for employing such a pump will be explained below. The pump is operated either in a single stage low delivery mode, or a two stage high delivery mode under control of a manual switch 53 located in the cab 120 This pump draws operating liquid from a resérvoir 54 via a strainer 56 and shut off valve 58 and delivers it under pressure to the circuit via a check valve 60 that sets the minimum pressure for the system, to ensure that there is ~ufficient pressure for operation of the valves of the system; in a typical ~ystem this valve operates ~47;~1 at about 7 Kg/sq.cm. ~100 p.s.i.). A pressure relief valve 61 operative at about 21 Kg/sq.cm. (300 p.s.i.) ensures that this system operating pressure cannot rise above its present value, the excess liquid being returned to the reservoir. A second pressure relief valve 62 ensures tha~ the pressure of the operating liquid supplied to the various motors cannot rise above a safe value, e.g. about 123 Kg/sq.cm. (1,750 p.s.i.). The excess liquid from the relief valves 61 and ~2 passes to the reservoir via a filter 64, shut-off valve 66 and strainer 68.
The system comprises a plurality of manually operated valves disposed for easy access by the driver, and a plurality of relay valves arranged to provide the desired sequence of operations automatically. A proportional hydraulic pressure reducing valve 70 is provided and is positioned by the driver to lS give the desired liquid flow, and therefore the corresponding motor operating speed, to the pilot valves which it supplies, namely valves 72 and 74, controlling respectively the motors 40 and 42. The valve 70 is of the "joystick" type so that the two sets of motors can be operated simultaneously and at different speeds. A manually-operated directional valve 76 is used to control pilot valve 78 which in turn controls tailgate motors 26 A manual "emergency stop" valve 80 when operated by-passes the entire hydraulic control system and returns the liquid directly to the reservoir 54 to stop all the motors in the positions ifi which they stand when the stop valve is actuatedO
~7~241 The ram is usually ope~ated during the collection of refuse while the vehicle is bein~ drl~en and it~ operation i~
therefore as automatic as po~sible. A two stage pump 52 is used and in a typical embodiment the pump will supply either 55 or 260 litres per minute at a shaft speed of 1200 r.p~m. The higher delivery rate is normally used while the vehicle is standing for the fastest possible operation, while the lower rate is used at other times, when much slower operation is completely adequate; this avoids the overheating and need for auxiliary coolers that might otherwise occur if the pump must always operate a a con~tant high rate. The pump may be left connected to the truck engine at all times and power is there-fore always available for operation of the system: this is not usually possible with a system employing a mechanical power take-off. As the vehicle moves away from the ~ite of the pick-up,manual ram control valve 82 is actuated and cause~ flow of liquid to pilot valve 84 to shift this valve and also to enable this valve to feed liquid to a spring-centered ram pilot valve 86, which in turn feeds liqu~d to the ram motor 30 causing extension of the cylinder and movement of the ram toward the rear of the hopper. In its foremost position the ram 28 is in contact with the plunger of a directional control valve 88; after a small movement of the ram (e.g. about 2-3 cm) the ram disengages from the valve plunger, and that valve now operates to maintain the liquid flow to the valve~ 84 and 86. Moreover, the joystick ~alve 70 is now by-pas~ed and cannot cause operation of the arm motor~, even if manipulated, 80 that tho~e motor~ are disabled.
7 _ 72~1 Pilot valve 84 i~ of the type in wh,.ch the spool is detented in both directions so that it will re.main in the control position in which it was last placed until positi.vely moved therefrom; the ram will therefore continue its compacting movement to the rear. When the deposited material is compacted as tightly as possible the ram will come to a stop and pressure will now build up in the Yystem. This pressure is applied to a sequencing valve 90 which previously ha~ been set in the position illustrated in Figure 2, in which it connects one side of a shuttle valve 92 back to the reservoir, the other side of the ~huttle valve being connected to the ram control valve 82. When the ram motor pressure applied to the valve 90 has risen to a suitable value the shuttle valve 92 is shifted and the high pressure is applied to the v.alve 84 to shift it, whereupon pilot valve is also ~hifted and the motor 30 operates to retract the ram. The detent of valve 84 holds it in the "ram retract" position despite the loss of the elevated pressure through the shuttle valve 92.
Upon return of the ram to the fully retracted position it engages the plunger of valve 88, which is then operative to restore flow to the joystick valve 70 and diverts flow from the valve 84 the flow to pilot valve 86 then stops and this valve centres under control cf its centering spring~ It is possible for the operator at any ti~e to reverse the ram movement by reverse manual operation of the valve 82~ whereupon an excess of pressure goes to the shuttle valve 92~ which transmits thi~
pressure as an operating pressure to the pilot valve 84; the valve shifts as described above and shifts valve 86 to retract the ram~
., , 8 -- .
7~41 The function of the shuttle val~e 92 is therefore highl~ important in permitting the control of the ram operation both automatically and manually, by accepting an excess pressure ~rom the two possible sources and applying this excess pressure as a control pressure to the pilot valve 84, without interference of the two sources with one another and therefore withtheir Reparate function~.
The circuit is provided in known manner at appropriate locations with relief valves 94, 96 and 98, which are ~et at the pre~sures neces~ary to protect their associated component~, and with check va~ves 100, 102 and 104 to prevent reverse liquid flows. A pilot operated unloading valve 106 is operative when the pressure of the liquid supplied to the motor 30 drop3 upon the ram retraction and permits fast dumping of the liquid in the ram motor 30 back to the reservoir 54~ increasing the speed at which the ram can be retracted~
It will be seen therefore that we have provided an entirely hydraulic control and operating ~ystem that provides the desired manual and automatic control, without the need for electrical relays and/or mechanical link connections between valve~.
Although the system has been de~cribed in relation to a truck mounted arrangement, it will be apparent to those skilled in the art that it is equally applicable to a stationary system, such as would be required by an apartment building or a shopping centre, in ~hich for example the ram operation is initiated at predetermined times by a timing device, ~ith the option of manual control when required.
~7~41 It is found in practice that a completely hydraulic system with a permanently operating pump as described permits much faster system operation than prior systems using a mechanical power take off. For example, with such a prior system the operator must stop the vehicle before the container, engage the p.t.o.
and lower the arm structure, disengage the p.t.o. and move the vehicle to engage the arms with the container, engage the p.t.o.
and empty the container, and so on, it not being possible to move both the vehicle and the arm structure simultaneously. With the system of this invention the operator is able to adjust the positions of the arm and fork ~tructures while approaching the container, and can return them to their travelling position while leavinq the pick up site, minimizing the time required for each pick up.
Among the advantageY of a completely hydraulic system is its relative freedom ~rom service problems as compared with mechanical or electrical systems, bearing in mind that these systems are expected to operate under extremely arduous conditions.
For example, it is found wit~ mechanical system~ that the moving parts have a tendency to bind after a while~ and to become frozen 20 ~ during cold weather, while with electrical systems ~here is a tendency toward failure3 due to the common electrical fault~, such a-~ broken wire~ and corroded con nection~.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A hydraulic control and operating system for material compacting apparatus mounted on a self-propelled vehicle, wherein the apparatus comprises:
a hopper for receiving the material, the hopper having an inlet thereto for uncompacted material, an outlet therefrom for compacted material, and a wall member against which the received material is compacted, a ram member mounted in the hopper for compacting movement toward the wall member and opposite retracting movement away from the wall member, hydraulic ram motor means connected to the hopper and the ram means and operative to move the ram means in the said opposite compacting and retracting movements, arm means for engagement with a container and for moving the container to discharge the contents of the container into the hopper, hydraulic arm motor means for moving the said arms, and pump means for supplying operating liquid under pressure to the hydraulic ram motor means and the hydraulic arm motor means under control of the system, the system comprising:
manually-operated arm motor valve means for controlling the supply of operating liquid to the arm motor means, ram motor valve means controlling the supply of operating liquid to the ram motor means to cause either of the said opposite movements of the ram means, and ram relay valve means having an operating plunger engaged by the ram member in its fully retracted position, the ram relay valve means when its plunger is so engaged permitting supply of operating liquid under control of the said manually-operated arm motor valve means for operation of the said hydraulic arm motor means, and when its plunger is not so engaged preventing supply of operating liquid under control of the said manually-operated arm motor valve means to the said hydraulic arm motor means so that the arms cannot be actuated unless the ram member is in its fully retracted position.
a hopper for receiving the material, the hopper having an inlet thereto for uncompacted material, an outlet therefrom for compacted material, and a wall member against which the received material is compacted, a ram member mounted in the hopper for compacting movement toward the wall member and opposite retracting movement away from the wall member, hydraulic ram motor means connected to the hopper and the ram means and operative to move the ram means in the said opposite compacting and retracting movements, arm means for engagement with a container and for moving the container to discharge the contents of the container into the hopper, hydraulic arm motor means for moving the said arms, and pump means for supplying operating liquid under pressure to the hydraulic ram motor means and the hydraulic arm motor means under control of the system, the system comprising:
manually-operated arm motor valve means for controlling the supply of operating liquid to the arm motor means, ram motor valve means controlling the supply of operating liquid to the ram motor means to cause either of the said opposite movements of the ram means, and ram relay valve means having an operating plunger engaged by the ram member in its fully retracted position, the ram relay valve means when its plunger is so engaged permitting supply of operating liquid under control of the said manually-operated arm motor valve means for operation of the said hydraulic arm motor means, and when its plunger is not so engaged preventing supply of operating liquid under control of the said manually-operated arm motor valve means to the said hydraulic arm motor means so that the arms cannot be actuated unless the ram member is in its fully retracted position.
2. A system as claimed in claim 1, wherein the said arm means includes:
fork means pivotally mounted on the arm means and for engagement with a container to be lifted by the arm means, hydraulic fork motor means connected between the arm means and the fork means and for moving the fork means relative to the arm means, and manually-operated fork motor valve means for controlling the supply of operating liquid to the fork motor means, wherein the said arm motor valve means and fork motor valve means comprise a single joys-tick type proportional valve operable in a first direction for control of the arm motor means and in a second direction transverse to the first direction for control of the fork motor means, and wherein the said ram relay valve means when its plunger is not engaged by the ram member prevents supply of operating liquid to the joystick valve so that both the arm motor valve means and the fork motor valve means are disabled.
fork means pivotally mounted on the arm means and for engagement with a container to be lifted by the arm means, hydraulic fork motor means connected between the arm means and the fork means and for moving the fork means relative to the arm means, and manually-operated fork motor valve means for controlling the supply of operating liquid to the fork motor means, wherein the said arm motor valve means and fork motor valve means comprise a single joys-tick type proportional valve operable in a first direction for control of the arm motor means and in a second direction transverse to the first direction for control of the fork motor means, and wherein the said ram relay valve means when its plunger is not engaged by the ram member prevents supply of operating liquid to the joystick valve so that both the arm motor valve means and the fork motor valve means are disabled.
3. A system as claimed in claim 1 or 2, including a two stage pump means driven by the vehicle engine and for supplying the operating liquid to the system either at a lower delivery rate while the vehicle is moving or at a higher delivery rate while the vehicle is stationary, and operator controlled switch means for determining the delivery rate of the pump means.
4. A system as claimed in claim 1 or 2, including a two stagae pump means driven by the vehicle engine and for supplying the operating liquid to the system either at a lower delivery rate while the vehicle is moving or at a higher delivery rate while the vehicle is stationary, and operator controlled switch means for determining the delivery rate of the pump means, wherein the pump is permanently connectable to the engine of the vehicle for operation thereby as long as the engine is operative.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US5901379A | 1979-07-19 | 1979-07-19 | |
| US59,013 | 1979-07-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1147241A true CA1147241A (en) | 1983-05-31 |
Family
ID=22020262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000350565A Expired CA1147241A (en) | 1979-07-19 | 1980-04-24 | Hydraulic system for material compacting apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1147241A (en) |
-
1980
- 1980-04-24 CA CA000350565A patent/CA1147241A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |