US 3220577 A
Description (OCR text may contain errors)
Nov. 30, 1965 c. H. A. LAVERNE 3,220,577
MATERIAL-HANDLING APPARATUS, ESPECIALLY A REFUSE COLLECTOR Filed Nov. 29, 1963 5 Sheets-Sheet 1 M GU AGENT Nov. 30, 1965 c. H. A. LAVERNE 3,220,577
MATERIAL-HANDLING APPARATUS, ESPECIALLY A REFUSE COLLECTOR I 5 Sheets-Sheet 2 Filed Nov. 29, 1965 CHARLES H A. LAVERNE INVENTOR AGENT Nov. 30, 1965 c. H. A. LAVERNE MATERIAL-HANDLING APPARATUS, ESPECIALLY A REFUSE COLLECTOR Filed Nov. 29, 1965 5 Sheets-Sheet 3 IQA CHARLES H A. LAVERNE INVENTOR Nov. 30, 1965 c. H. A. LAVERNE 3,220,577
MATERIAL-HANDLING APPARATUS, ESPECIALLY A REFUSE COLLECTOR Filed Nov. 29, 1963 s Sheets-Sheet 5 CHARLES H A LAVEPNE INVENTOR United States Patent 3,229,577 MATERIAL-HANDLING APPARATUS, ESPECIAL- LY A REFUSE COLLECTOR Charles H. A. Laverne, Paris, France, assignor to Societe Industrielie de Transports Automobile, S.i.T.A. (Socit anonyrne), Paris, France, a company of France Filed Nov. 29, 1963, Ser. No. 326,705 Claims priority, application France, Dec. 5, 1962, 917,624 13 Claims. (Cl. 214-83.3)
This invention is directed particularly to refuse-collector vehicles although it more broadly relates to apparatus for handling solid materials of any nature in more or less particulate form.
A type of municipal garbage truck or refuse collector vehicle in current use is provided at its rear with a container or bin having a generally semi-circular wall with its open diameter directed forwardly towards the body of the vehicle. A vane-like member is mounted for reciprocatory rotation on a shaft upstanding from the bin, somewhat after the fashion of a ships rudder. Garbage dumped into the bin, as from dustbins or the like, is alternately swept up by the vane member on its alternate strokes rightward and leftward and discharged from the bin into the body of the vehicle. Conveniently the bin is arranged so that its base slopes upward into the vehicle body.
Such an arrangement has proved very convenient in that the large-capacity bin is constantly swept clear of refuse and remains available for the continual dumping of refuse into it. However, serious difficulties are encountered in an attempt to provide an eifective and reliable mechanism for driving the vane member. A problem arises because the loading of the vane member and hence the power to be applied to it varies considerably over each semi-circular sweep or stroke of the vane. During the initial, receding or downward arc of the sweep the vane is but lightly loaded and low torque is needed to rotate it, while in the latter, forward or upward arc, and especially as the vane approaches its lateral end position on each side of its path, it is subject to extremely heavy loading by the heap of rubbish swept ahead of it.
Objects of this invention include the provision of improved mechanism for operating a reciprocating chargingvane member of the kind referred to. In accordance with the invention, this mechanism comprises a pair of fluid ram actuators and a linkage of such inherent geometry as to impart varying torque and varying velocity to the vane in the different stages of its reciprocation as required for maximum sweeping efiiciency; specifically to impart relatively high velocity and low torque during the initial receding phase of the sweep and high torque with lower velocity during the active forward sweep. A consequent object is to permit the use of an oil pump of constant delivery and moderate power rating for powering the vane, which pump can be easily driven from the vehicle engine in idling condition, without requiring an auxiliary motor, and without requiring the vehicle engine to deliver a relatively high output torque when idling in the stationary condition of the vehicle. This in turn has an important advantage in that it makes it possible to provide the vehicular power system with automatic clutch arrangements of the hydraulic, centrifugal, or magneticpower types, this being an extremely desirable feature in the case of municipal refuse collectors subject to repeated starts and stops, and a feature difiicult or impossible to realize where the vehicle engine is required to deliver considerable power while the vehicle is at a standstill for actuating the refuse-charging vane mechanism.
Additional objects of the invention relate to improved constructional features of the refuse-dumping and charging structures provided at the rear of a refuse-collector van.
According to an important aspect of the invention, the charging-vane-reciproeating mechanism comprises two fluid rams or actuators each having one end pivoted to a fixed structure and its other end pivoted to a respective crank arm projecting from the vane-mounting shaft. The relative angular setting between the crank arms and the vane, and the positions of the fixed pivots for the outer ends of the actuators, are so predetermined in relation to one another that each actuator extends substantially at right angles to the associated crank arm as the vane sweeps through a corresponding one of its forwardly directed terminal stroke portions during which the material is being compacted. Thus, maximum torque is applied to the vane during the terminal stage of each stroke. Moreover, the relative arrangement of the actuators and their crank arms is such that each actuator assists the other in crossing its dead-center position. Further, advantage is taken of the differential effective cross sections of each of the actuators on opposite sides of the piston therein, due to the presence of the piston rod on one side, for increasing the velocity of rotation of the vane during its receding or relatively idle arc.
The above and further objects and features of the invention will be made clear from the ensuing description of exemplary embodiments of the invention serving as illustrations but not as limitations of the scope thereof and shown in the accompanying drawing wherein:
FIG. 1 is a side-elevational view of the rear part of a refuse-collector truck provided with refuse-charging structure according to the invention;
FIG. 2 is a section on line 11-11 of FIG. 1;
FIG. 3 is a rear view according to the arrows III-III of FIG. 1;
FIG. 4 is an overhead view in the direction of the arrow IV of FIG. 1, with the cover of the mechanism casing removed, showing one embodiment of two-ram actuator mechanism according to the invention;
FIG. 4a is a view similar to FIG. 4 but on an enlarged scale to show certain additional details of the mechanism;
FIG. 5 is a diagram of one form of hydraulic control system usable with an improved two-ram mechanism according to the invention;
FIGS. 6 and 7 are bottom plan views respectively showing two modified forms of the mechanism; and
FIG. 8 illustrates in plan yet another modification of the dual-ram mechanism of the invention.
With reference to the embodiment shown in FIGS. 1-4, there is illustrated in FIG. 1 the rear part of the frame of a refuse van which is not completely shown since its general construction may be conventional. The body of the van defines a refuse-containing chamber 1. The rear opening of the chamber 1 is provided with a door frame or panel 2 swingable about a horizontal axis on a shaft 3 extending across the top of the van structure, this door frame including side members 13a, 13b as well as bottom and top members 13c, 13d and an intermediate brace 132. In the normal or charging position, the door panel 2 is closed with side members 13a, 13b resting on complementary members of the vehicle frame, as shown in FIG. 1, the side members being held in such position by means of retainer hook members 4 at the lower part of the frame. The panel 2 is formed in its lower part with two apertures separated by a sturdy vertical partition 14, to provide entrances for the refuse in the closed position of the panel 2 as will presently appear. The entire refusecharging system to be described below is supported from the outer or rear side of panel 2 so as to be in operative position when the panel is closed. For unloading or dumping the rubbish from the van, the panel 2 together with the refuse-charging mechanism supported from it is swung bodily upward about the pivot shaft 3, thereby fully uncovering the rear aperture of the collector chamber 1, and the van is then tilted rearwardly about its rear axle in the conventional manner to dump the contents of the van chamber.
A charging bin is secured to and projects rearward from the lower part of the side members or uprights 13a, 13b, the bin 5 being of generally semi-cylindrical shape (thus semi-circular as seen from above) and inclined at a rearward angle, with a frustoconical base 5a as will be clear from FIG. 1. From the top of the panel 2 there projects rearwardly, and at a slant angle similar to that of the bin 5, a mechanism frame or casing 10, a rotatable shaft 7 being journaled in an upper bearing 9 in casing 10 and in a lower thrust bearing 8 on the base 5a of bin 5. A strong steel-strip hooping tightly surrounds the casing 10 and bin 5, see especially FIG. 3. A cross member 12 interconnecting the lateral uprights 13a, 13b extends across an upper diameter of bin 5 and carries a third bearing 11 for journaling an intermediate point of shaft 7. Secured to the lower part of shaft 7 within the bin 5 is a heavy vane member 6 which, on reciprocating rotation of the shaft 7, sweeps over a semi-circular path between end positions 6 6 in the bin as indicated in FIG. 2, thereby to sweep up refuse in the bin and propel it upwards alternately through one and the other of the two entrance passages 13, 13" and into the collector chamber 1. Diagonal braces 16 interconnect the central part of cross member 12, carrying bearing 11, with the sides of casing 10.
With reference to the structure so far described, it may be noted that as the vane 6 reaches each of its transverse end positions 6 6 while pushing a pile of refuse upwards before it, the resulting thrust tends to separate the walls of the particular passage up which the refuse is being pushed, and the vane is in turn subjected to 'a strong reaction force rearward of the vehicle. The cross member 12 and partition 14 serve to impart to each of the refuse passages the requisite strength against the outwardly directed thrust of the pile of refuse being pushed therethrough, while the intermediate bearing 11 carried by cross member 12 provided a strong interconnection between the shaft 7 and the member 12 and therethrough with the sidewalls 13a, 3b, enabling the parts to withstand the high bending and/or torsional strains that may be created e.g. in the case of a hard piece of refuse being jammed between vane 6 and a stationary part of the structure. Moreover the partition 14 serves to guide the pile of refuse positively through the entrance 13, 13" into the chamber 1 and prevents it from backsliding into the bin 5 through the open passage on the other side of the partition. The hooping 15 and diagonal bracing 16 further strengthen the structure and stiffen it against asymmetrical forces developed at each reciprocation of the vane 6.
An inwardly directed flange 17 is preferably provided around the upper rim of bin 5 to oppose the overflow of rubbish from the bin during the movements of vane 6 therein. The inner surfaces of crossbar 12, partition 14 and sidewalls 13a and 13b are, moreover, preferably provided with retaining or anchoring elements directed towards the chamber 1 for opposing the backflow of refuse into the bin 5.
Mechanism according to the invention for reciprocating the vane 6 is housed within the upper casing 10 and acts on the upper end of shaft 7 journaled therein. Location of the vane-reciprocating mechanism at the upper rather than the lower end of shaft 7 as shown in FIGS. 1-5 has a number of advantages. Firstly such arrangement allows the upper rim of the bin 5 to be positioned lower than would otherwise be possible for a similar bin capacity, thereby facilitating the emptying of garbage cans into the bin 5. Moreover, in the raised condition of door panel 2 and the structure supported thereby, the
dead-center point of ram tilting moment exerted by the mechanism assembly 10 about the pivot axis 3 is smaller when said mechanism is positioned in the upper position shown in FIG. 1 than it would be if said mechanism were positioned beneath the bin. Thus the illustrated arrangement diminishes the power requirements for swinging the door to its raised position while also reducing the danger of the vehicle tipping about its rear axle during dumping operations. An
additional advantage of placing the vane-operating mechanism in the upper position shown is that it permits increasing the length of the ram cylinders and cranks as will be later understood.
As shown in FIGS. 4 and 4a, the mechanism of the invention comprises two hydraulic rams including ram cylinders 18A and 18B pivoted at 19A, 19B at their outer ends to the casing 10. The piston rods 20A, 20B of the rams are pivoted at their projecting or inner ends at 30A, 30B to respective arms 21A, 21B of a two-armed or forked crank member 21 secured to the vane shaft 7. In FIGS. 4 and 4a the mechanism is shown in full lines in the position corresponding to the point of the reciprocating cycle of vane 6 in which this vane occupies its righthand end position as shown at 6 It will be noted that the relative setting of the two-armed crank 21 with respect to vane 6 on shaft 7 is such that the two crank arms 21A, 21B of crank member 21 project away from vane 6 and symmetrically on opposite sides of the midplane of the vane. It will also be noted from the geometry of the mechanism as shown that in such end position the direction of action of ram 18A is substantially normal to the associated crank arm 21A, so that it applies a maximum torque to shaft 7, while at the same time the direction of action of the other ram 18B still makes an appreciable angle with its corresponding crank arm 21B, so that it too exerts an appreciable torque on the shaft. Thus when pressure fluid is introduced into the outer compartments 22A, 22B of the two ram cylinders, both rams combine to apply a large torque to the shaft 7, thereby causing the vane 6 to apply a strong force as indicated by arrow F1 to the heap of rubbish and to push the latter upward through the respective entrance passage into chamber 1.
Starting from the end position shown, if pressure fluid is discharged from the outer compartments 22A, 22B of both rams and pressure is applied in the inner compartments 23A, 23B thereof, vane movement is reversed and the vane will start turning clockwise from the position 6 Simultaneously both ram cylinders will start pivoting counterclockwise about their respective fixed pivots 19A, 19B. As ram 18A assumes a position in which its longitudinal axis coincides with the line 25 joining pivot 19A to the axis of shaft 7, the torque exerted by it on the shaft 7 becomes zero, i.e., ram 18A is in a dead-center position. However, since the angle on between the center lines of the two crank arms 821A, 2113 is made different from (and here smaller than) the angle 5 formed between the lines 25, 26 joining the axis of shaft 7 to the respective ram pivot points 19A, 19B, it Will be evident that in the aforedescribed dead-center position of ram 18A the other ram 18B is still active to apply an effective torque to shaft 7 which therefore is positively actuated to move past that dead-center position. If at this time the pressure in ram 18A is again switched from the inner cylinder chamber 23A to the outer chamber 22A thereof, both rams will again be working to rotate shaft 7 with vane 6 clockwise until ram 18B in its turn crosses its dead-center position in which its center line coincides with line 26. Ram 18A now operates to rotate the assembly positively past this position in a manner similar to that described above for the action of ram 22B in rotating the assembly past the 18A. The vane 6 reaches its other end position 6 and the movements are then reversed to take the vane over the return half of its cycle from position 6 back to position 6 It will be seen that the angle [3 is included between the sides 25, 26 of a triangle defined by the axis of shaft 7 and by the fixed fulcra 19A, 19B of the actuators. It will also be seen that the extremities 20A, 20B of the actuators, articulated to crank member 21, are nearly perpendicular to each other in either limiting position of vane 6.
It will be noted that the rams 18A, 18B are of the differential type in which the piston rods 20A, 20B are of appreciable cross-sectional area so that the inner cylinder chambers 23A, 23B are appreciably smaller in effective area than are the rear outer chambers 22A, 22B. The significance of this will presently appear.
In the light of the above, if the operation of the respective rams 18A, 18B during displacement of vane 6 from one to the other of its end positions (e.g., from 6 to 6 is considered in detail, it will be seen that three distinct and successive operating phases can be distinguished. In a first phase, the smaller inner ram compartments 23A, 23B are pressurized in both rams so that both ram pistons are retracting and are applying traction to the respective crank arms 21A, 21B. Then in'a second phase (after ram 18A has crossed its dead-center position) one ram has its smaller inner compartment under pressure and the other has its larger outer compartment under pressure, i.e., one ram piston is retracting and pulling on its crank arm while the other ram piston is expanding and pushing its crank arm. Finally in a third phase (after 18B has crossed dead center) both rams have their larger, outer compartments 22A, 22B pressurized, both pistons are advancing and both are applying pressure to the crank arms.
If the oil pump supplying pressure oil to both rams is operated at a constant-volume flow rate of delivery, then during each of the three phases the sum of linear velocities of the pistons in both rams remains unaltered. During the first phase, when the smaller-area compartments of both rams are being supplied with fluid, both said linear velocities are relatively high and the resulting angular velocity imparted to vane 6 is correspondingly high. Because of the low effective cross-sectional areas in both rams, the torque imparted by the rams to the crank member is low, even though the effective moment arms of both rams at this time are relatively long.
In the second phase, when one smallerand one largerarea ram compartments are under pressure, the sum of the linear piston velocities is smaller; however, the moment arms of the rams are now short, with correspondingly reduced leverage, so that the angular velocity of the vane is mode-rate and the torque is also moderate.
In the third phase both large-area compartments are under pressure and the piston velocities are therefore both small. Moreover, the leverages are large since both rams now extend in directions normal or nearly normal to the respective crank arms. Hence, the angular speed of the vane is a minimum while the torque applied to vane shaft 7 is a maximum.
Of the three phases referred to above as occurring during each 180 rotational stroke of the vane, it will be realized that only the third phase (and to a lesser degree the second) is an active phase in that the vane at this time is sweeping through its terminal rising arc through the bin and pushing before it a heap of refuse. The first phase and also the second phase, at any rate in its first half, are idle return phases, during 'which the vane is not subjected to any substantial resistant torque from the [refuse in the bin. Thus it will be apparent from the foregoing discussion that the dual-ram mechanism of the invention makes it possible to achieve high velocity (with low torque) during the idle downward sweep of the vane, and high torque (with low velocity) during the active upward sweep, and thus provides optimum working conditions through the weeping cycle, while utilizing minimum power at a substantially constant value throughout each sweeping cycle.
With reference to FIGS. 4a and 5, an exemplary hydraulic control system according to the invention will now be described whereby the feed of pressure fluid to the respective rams can be reversed in the desired sequence for obtaining the operating cycle described above. It will be recalled from the foregoing discussion that during each one-way sweep cycle the feed to each of the two rams must be reversed once, as said ram is moving past its dead-center position. Moreover, at the end of the sweep the feed to both rams must be reversed simultaneously.
With each of the rams 18A, 18B there is associated a respective control-valve unit 27A, 27B. In FIG. 5 each control-valve unit is schematically shown in the form of an axially displaceable valve member or spool formed with passage therethrough for establishing variable hydraulic connections between lines externally connected to the respective valve casing (not shown) in which the valve spool is displaceable. The external lines are shown as including two lines 42, 43, which as will later appear can be selectively connected to a pressure line P leading to a suitable hydraulic pump not shown and to an exhaust line B leading to a sump or reservoir; they also include two pairs of cylinder conduits 122A, 123A, and 122B, 123B, Which connect with the respective ram-cylinder compartments, analogously designated 22A, 23A and 22B, 23B in FIG. 4, through any suitable connecting means such as flexible hose or rotatable seal connectors, not shown. In FIG. 4a the two valve units 27A, 27B are shown superposed so as to appear as a single unit.
The valve spool in each unit 27A, 27B is displaceable in one axial direction (upward in FIG. 5, leftward in FIG. 4a) by a cam-follower roller 28A, 28B, engaging the contour of a respective cam 31A, 31B secured to the shaft 7, and is biased in the opposite direction into engagement with its cam by an associated spring 29A, 293. Each of the cams 31A, 31B is in the form of a semicircular member having two arcuate sections of unequal radius, inter-connected by a ramp or incline, respectively designated 38, for cam 31A and 38 for cam 3113. The position of each connecting ramp 38 and 38 on its cam corresponds to alignment with the respective deadcenter axis 25, 26 earlier defined. More specifically, the arrangement is such that when ramp 38 is in engagement with the associated follower roller 28A, the corresponding ram 18A is positioned in alignment with the direction 25, and when ramp 38 is in engagement with its follower roller 28B, the ram 18B is positioned in alignment with direction 26. It will likewise be noted from FIG. 4a that in the full-line position there shown, which is the same as the position shown in FIG. 4 and corresponds to the position 6 of vane 6 at the far right end of its stroke, roller 28A engages the large-radius arc of its cam 38A while roller 28B engage the small-radius arc of its cam 38B.
Each of the valve members 27A, 27B is axially displaceable between three operative positions. For convenience, FIG. 5 shows both members in their intermediate positions even though the two valves do not simultaneously occupy their intermediate positions in the normal operating cycle of the mechanism as will presently be understood. Thus, with reference, e.g., to valve member 27A, in the upper operative position of this member as assumed by it when roller 28A is on the larger-radius arc of cam 31A, valve member 27A establishes connections (through passages 32) between cylinder conduit 123A and line 42 and between cylinder conduit 122A and line 43. In the intermediate position shown, which arises momentarily as roller 28A engages the transition ramp 38 valve member 27A establishes connections (as shown) from both cylinder conduits 122A, 123A by way of a connecting passage 33 to line 42. And in the lowermost position of member 27A, when roller 28A is on the smaller-radius arc of its cam 38A, the connections established are from cylinder line 123A to line 43 and from line 122A to line 42. The conditions are the same for the other valve unit 27B except that the relative positions of the cylinder conduits 1223 and 123B are reversed as compared to the cylinder conduits 122A and 123A, as shown. The aforementioned lines 42 and 43 are connectable with the pressure line P and the exhaust line E in essentially two different manners depending on the position of a third valve unit 36. Like each of valve units 27A, 27B, valve unit 36 is displaceable between three positions, by means later described. In a first position (displaced to the left from the one shown in FIG. valve 36 makes connection from pressure line P to line 43 and from exhaust line E to line 42. In the other end position of valve member 36, these connections are reversed; while in an intermediate and transitory position, shown in FIG. 5, both lines 42 and 43 are directly connected to exhaust line E and are simultaneously also connected to pressure line P by way of a restricted orifice provided in the valve member 36.
In the starting position of the cycle shown in FIGS. 4 and 4a (full lines), i.e., with the vane 6 positioned at 6 rotation-reversing valve member 36 is in the first position just described, so that it establishes connections from pressure line P to branch line 43 and from branch line 42 to exhaust line E. Since in this initial position roller 28A is on the larger-radius arc of cam 38A and roller 28B is on the smaller arc of cam 38B, the following connections are established: From pressure line P through passages in valve 36 to line 43 to inner cylinder compartment 23A (through valve 27A, raised) and to inner cylinder compartment 23B (through valve 273, lowered) and from exhaust line B through valve 36 to line 42 to outer cylinder compartment 22A (through valve 27A) and outer cylinder compartment 22B (through valve 27B). Thus both inner compartments 23A, 23B are under pressure and both outer compartments 22A, 22B are exhausted. Both rams operate jointly to rotate vane 6 clockwise from the position 6 by retracting their piston rods as earlier described.
As ram 18A moves past its dead-center position in conincidence with direction 25, its roller 28A engages ramp 38 and valve member 27A momentarily moves to its intermediate position shown in FIG. 5. Both cylinder compartments 22A and 23A of ram 18A are now momentarily connected by way of connecting passage 33 with line 42 and hence through valve 36 to exhaust E. Meantime the other ram 18B continues to have its inner compartment 23B pressurized since roller 28B still remains in engagement with the small-radius arc of cam 38B, so as to continue its pull on the crank arm 21 and to maintain rotation of vane 6 in the clockwise direction. As soon as the vane 6 has moved past the deadcenter position for ram 18A, roller 28A moves to the small-radius part of cam 38A and valve member 27A moves to its lowermost position in which inner compartment 23A is connected (through valve passage 32, line 42 and valve 36) to exhaust E and outer compartment 22A is connected to pressure source P. Now ram 18A extends its ramrod to push crank arm 21A clockwise while ram 18B continues retracting its ramrod to pull crank arm 21B in the same clockwise direction.
This initiates the second phase of the cycle. During this phase the vane 6 reaches and moves past its lowermost position in the bin directed due aft of the vehicle, and commences its upward sweep. Soon afterwards the ram 18B reaches its dead-center position in coincidence with line 26 and roller 28B moves over transition ramp 38 and then on to the larger-radius arc of cam 38B. This causes valve 27B to operate as earlier described for valve 27A, momentarily connecting both compartments of ram 18B to exhaust and then reversing their connections so that outer compartment 22B is now pressurized and inner compartment 23B exhausted. Ram 18B now extends its rod to continue to propel the vane clockwise, while ram 18A continues unaltered in its previous condition in which its rod advances. Thus in this, the third phase of the movement of the vane, both rams 18A, 18B are operating in an advancing sense as earlier indicated.
The vane 6 is thus ultimately moved to its opposite end position 6 (FIG. 4), at which point its movement must reverse. For this purpose reversal valve member 36 is shifted from its former (left-hand) position to its opposite (right-hand) end position. Valve member 36 is shifted between its end positions by the alternate action of a pair of hydraulic plunger members 39 39 acting on its opposite ends. Plungers 39 39 operate in respective pressure cylinders, not shown, whose outer compartments are connectable through lines 58 and by way of an auxiliary reversing valve member 35A with the pressure and exhaust lines P and E. Auxiliary valve member 35A operates in an auxiliary valve casing 35 (see FIG. 4a) positioned near the shaft 7, the latter carrying a pair of projecting lugs 37;, 37 which are adapted to engage the respective ends of the valve member 35a at each of the two end position 6 6 of the vane 6 so as to shift valve member 35a between its two limiting positions. Thus, at the end of the above-described stroke of vane 6 as the vane reaches position 6 lug 37 acts on the upper end (as viewed in FIG. 4a) of valve member 3511, to shift said member to the position shown in FIG. 5. In this position lines 58 are seen to be so connected with lines P and E that pressure is applied to plunger 39 while plunger 39 is relieved. This shifts main reversing valve 36 from its leftward end position, in which it was previously located, to its rightward end position, thereby reversing the connections between lines 42, 43 and lines P and E. Thus, during the reverse stroke of the vane cycle from position 6 to position 6 the operation of the rams and their control valves will be the same as that described above except that the motions of the two rams 18A and 18B will be interchanged and their directions of action reversed.
During shift of the main reversing valve member 36 between its end positions it will be noted that both lines 42, 43 are momentarily connected in an intermediate position of member 36 through passage 41 with exhaust line B and also through restriction 40 with pressure line P. This not only serves to prevent objectionable back pressure loading on the oil pump during movement reversal, but also completely unloads both cylinder cornpartments of both rams, so that the downward movement of vane 6 from its end position can be initiated by the action of gravity and/or the pressure of refuse acting on the upper surface of the vane, such vane movement being thereafter continued in the same direction by the action of the rams after valve 36 has reached its end position.
In the modified construction of the dual-ram mechanism according to the invention shown in FIG. 6, the vane shaft 7 has two diametrically opposed crank arms 45A, 45B secured thereto instead of the forked crank member of the first embodiment. In this case the mechanism is shown as being mounted underneath the bin 5 rather than in an overhead position, and the ram cylinders 18A, 18B have their outer ends pivoted at 19A, 19B to points near the lower outer corners of the swinging frame or door panel 2. It may be noted that the modification of FIG. 6, and also that of FIG. 7, hereafter described, is advantageous in cases where the mechanism may have to be mounted beneath the bin (rather than in the overhead position shown for the first embodiment) because it takes up less space longitudinally of the vehicle. It will be seen that in this case as in the first embodiment the angle formed between the crank-arm radii, here is different from the angle 5 between the lines joining the axis of shaft 7 to the ram-cylinder pivots 19A, 19B. Thus the system is able to operate in a manner similar to the mechanism first described in enabling each of the rams to help the other ram cross its neutral'position. Moreover, owing to the relative mount ing of the crank arms and the vane 6, and the positioning of ram pivot points 19A, 19B along with the relatively small difference between the two angles at (here 180) and 5, again as in the first embodiment, both rams are able to develop concurrently a torque approximating the maximum possible torque during the upward sweep of the vane towards each of its end positions. The control system associated with the mechanism of FIG. 6 for producing the desired changes in hydraulic connections during each cycle may be generally similar to that described with reference to FIGS. 4a and 5, mutatis mutandis.
The further modification shown in FIG. 7 differs from that of FIG. 6 essentially only in that it is the rods rather than the cylinders of the rams 18A, 1813 that are pivoted to the fixed fulcra 19A, 19B, the cylinders being pivoted to the crank arms 45A, 45B at points 46A, 46B spaced from the ends of said cylinders. The crank arms 45A and 45B are preferably formed as clevises with parallel spaced branches between which the bodies of the respective ram cylinders can pass. This arrangement has an advantage over that of FIG. 6 in that it makes it possible to increase the effective stroke of the rams as well as the leverage of each crank arm. The control system for this modification may again be similar to that described.
The further modification of a two-ram mechanism shown in FIG. 8 includes a pair of single-acting rams 47A, 47B, both arranged exclusively for operation in traction. The ram cylinders are pivoted to stationary points at 48A, 48B, while their piston rods 49A, 498 have flexible linkage elements 50A, 50B attached to their outer ends. The flexible elements may assume .any suitable form, such as chains, cables, steel bands, belts, or the like. Both flexible elements have their free ends attached to an eccentric pin on a common crank arm 52 secured to shaft 7. A tension-adjusting device 51A, 51B is interposed in each flexible link ahead of its attachment to the crankpin. Secured on shaft 7 adjacent to crank arm 52 is a pulley 53 which is adapted to receive in its peripheral groove one or the other of the flexible links 50A, 50B as the shaft 7 rotates towards one or the other of the end positions 6 or 6 respectively, of vane 6.
In the operation of this system, only the inner chamber of each of the ram cylinders 47A, 47B, i.e., the chamber on the same side as the piston rod, is adapted to be connected to pressure and to exhaust. Starting with the end position 6 shown in full lines, ram 47B is connected to exhaust while ram 47A is pressurized. Piston rod 49A is thereby retracted and pulls on the link 50A. Vane 6 is rotated counterclockwise. So long as link 50A remains in engagement with pulley 53 the rotation of the shaft 7 and vane 6 is relatively fast, and it will be noted that the ram cylinder 47A retains a constant angular position about its pivot 48A. As the link 50A leaves the periphery of pulley 53 the ram 47A begins to swing counterclockwise about its pivot 48A and the direction of its line of action progressively approaches a line normal to the direction of crank 52. The angular speed of the crank 52 and vane 6 gradually decreases, while its torque increases. Thus, as the vane sweeps upwardly towards its end position 6 maximum torque is again available for heaping the refuse up into the collector chamber. The ram movements are then reversed, i.e., ram 47A is exhausted and ram 47B pressurized, to send the vane 6 back to its other limiting position. A control mechanism suitable for providing the above operating sequence for the rams will be readily devised in the light of the explanations previously given with reference to FIGS. 4a and and will be considerably simpler than the system there shown in view of the single-acting nature of the rams here used.
Various modifications other than those expressly disclosed may be conceived within the scope of the invention.
The total angular sweep of the vane, here shown as about in all the embodiments, may be smaller or larger than this angle.
In the hydraulic control system disclosed, the various steps of the operating sequence may be performed by means other than those shown. Thus, while the two control valves directly associated with each of the rams are shown as being operated mechanically through cams and the common reversing valve as being operated hydraulically under control of a mechanically operated auxiliary valve, a wide variety of alternative combinations of control means may obviously be provided, including mechanical, hydraulic, pneumatic, electromechanical, electromagnetic, photoelectric and other means. The common movement-reversing valve may be omitted and its functions incorporated in the operation of each of the two control valves associated with the respective rams. The valves may assume various shapes including both axially displaceable and rotary valve members. The cams may be mounted on a separate camshaft coupled with the vane shaft through speed-modifying gearing.
The invention may find various applications other than that specifically referred to, as in the charging of a material processing plant.
What I claim is:
1. In material-handling apparatus comprising a charging container, a vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft supported for reciprocatory rotation relative to the container and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member, the combination therewith of mechanism for operating said vane member comprising: crank-arm means projecting from said shaft; two fluid-pressure-responsive actuators pivotally connected at fixed points to the apparatus and provided with extermities articulated to said crank arm means; said fixed points and the axis of said shaft defining a triangle, said extremities extending generally perpendicularly to each other in two limiting stroke positions of said vane member; and reversible fluid-supply means for said actuators.
2. In material-handling apparatus comprising a charging container, a vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft journaled for reciprocatory rotation relative to the container and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member, the combination therewith of mechanism for operating said vane member comprising a pair of crank arms projecting from said shaft symmetrically on opposite sides of the midplane of the vane member; a pair of rectilinear double-acting fluid-pressure-responsive actuators having inner ends respectively, pivoted to said crank arms and having outer ends pivoted to a part of the apparatus at fixed points disposed substantially symmetrically on opposite sides of said midplane upon said vane member occupying a central position intermediate the ends of its rotational stroke, said points defining a triangle with said shaft axis, the angle between said crank arms being different from the angle included between sides of said triangle extending from the shaft axis to said fixed points whereby each actuator is operable to sweep the other past a dead-center position of alignment of said other actuator with said shaft axis; and control means for aidingly subjecting said actuators to a pressure fluid with reversal of flow in each terminal position of said vane member, said control means including flow-reversing means individual to each actuator and coupled with said shaft for operation in a respective dead-center position.
3. The combination defined in claim 2, wherein said actuators each comprise a cylinder and a piston rod, said piston rods defining in said cylinders chambers of substantially smaller effective area at one end than at the other end of each cylinder, said mechanism further including means for admitting pressure fluid into said other end of each cylinder during said terminal stroke portions of said member and for admitting pressure fluid into said one end of each cylinder during remaining stroke portions of said member, thereby imparting reduced velocity with increased torque to said vane member throughout said terminal stroke portions and increased velocity with reduced torque throughout said remaining stroke portions.
4. In material-handling apparatus comprising a charging container, a vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft journaled for reciprocatory rotation relative to the container and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member, the combination therewith of mechanism for operating said vane member comprising a pair of crank arms projecting from said shaft symmetrically on opposite sides of the midplane of the vane member; a pair of rectilinear double-acting fluid-pressure-responsive actuators having inner ends respectively pivoted to said crank arms and having outer ends pivoted to a part of the apparatus at fixed points disposed substantially symmetrically on opposite sides of said midplane upon said vane member occupying a central position intermediate the ends of its rotational stroke; the relative setting of said crank arms and said vane member and the positioning of said pivoted outer ends being such that each actuator extends substantially at right angles to the respective crank arm as the vane member sweeps through a corresponding one of said terminal stroke portions with exertion of a maximum torque on said member, the angle between said crank arms being different from the angle included between lines extending from the shaft axis to said fixed points whereby each actuator is operable to sweep the other past a dead-center positionof alignment of said other actuator with said shaft axis; and a fluid-control system for said actuators comprising a source of pressure fluid and an exhaust therefor, flow lines defining a fluid circuit connected with each end of each actuator and with said source and exhaust, valve means connected in said circuit for selectively reversing the connections between each end of each actuator and said source and exhaust, and valve-actuating means disposed for operation by said shaft and connected to actuate said valve means so as to reverse the connections from opposite ends of each actuator to said source and exhaust upon said actuator crossing its said dead-center position and to reverse said connections simultaneously in both actuators with concurrent reversal of motion of said vane member upon the latter arriving in a limiting position of its reciprocation.
5. In material-handling apparatus comprising a charging container, a vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft journaled for reciprocatory rotation relative to the container and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member, the combination therewith of mechanism for operating said vane member comprising a pair of crank arms projecting from said shaft symmetrically on opposite sides of the midplane of the vane member; a pair of rectilinear double-acting fiuid-pressure-responsive actuators having inner ends respectively pivoted to said crank arms and having outer ends pivoted to a part of the apparatus at fixed points disposed substantially symmetrically on opposite sides of said midplane upon said vane member occupying a central position intermediate the ends of its rotational stroke; the relative setting of said crank arms and said vane member and the positioning of said pivoted outer ends being such that each actuator extends substantially at right angles to the respective crank arm as the vane member sweeps through a corresponding one of said terminal stroke portions with exertion of a minimum torque on said member, the angle between said crank arms being diiferent from the angle included between lines extending from the shaft axis to said fixed points whereby each actuator is operable to sweep the other past a deadcenter position of alignment of said other actuator with said shaft axis; and a fluid-control system for said actuators comprising a source of pressure fluid and an exhaust therefor, flow lines defining a fluid circuit connected with the ends of both actuators and with said source and exhaust, a first pair of reversible valve means respectively associated with said actuators and connected in said circuit for selectively reversing the connections between each end of a respective actuator and said source and exhaust, third reversible valve means common to both actuators and connected for simultaneeously reversing the connections between each end of both actuators and said source and exhaust, and valve-actuating means disposed for operation by said shaft and connected to actuate said valve means so as to reverse each of said first valve means upon the respective actuator crossing its said dead-center position and to actuate said third valve means so as to reverse same on the vane member in a limiting position of its reciprocatory stroke.
6. The combination defined in claim 5, wherein each of said first valve means includes means for momentarily interconnecting both ends of the respective actuator during reversal thereof.
7. The combination defined in claim 5, wherein said third valve means includes means for momentarily connecting both ends of both actuators to exhaust during reversal thereof.
8. The combination defined in claim 4, wherein said valve-actuating means comprises cam means rotatable with said shaft and cam-follower means engaging said cam means and connected for actuating said valve means.
9. The combination defined in claim 4, wherein said valve-actuating means comprises fluid-pressure means acting on opposite sides of said valve means; an auxiliary valve reversible to reverse the connections between said fluid means and said pressure source and exhaust; and mechanical means operated by said shaft at each end position thereof for reversing the position of said auxiliary valve.
10. In material-handling apparatus comprising a charging container, a vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft journaled for reciprocatory rotation relative to the container and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member, the combination therewith of mechanism for operating said vane member comprising: a crank arm projecting from said shaft; a grooved pulley secured on said shaft adjacent said crank arm; a pair of fluid-pressure-responsive actuators having outer ends pivotally connected to a fixed part of the apparatus; a pair of flexible links each having an end connected to the inner end of a respective actuator and its other end connected to said crank arm; each link being adapted to extend around the groove in the pulley as the other link is stretched taut between the crank arm and the respective actuator; each actuator and its respective link being disposed to assume a position substantially normal to the crank arm upon said vane member reaching the limit of its said terminal stroke portion in a respective direction with exertion of maximum torque upon said member during each terminal stroke portion.
11. Refuse-collecting apparatus comprising a vehicle frame defining a refuse-receiving chamber therein having an opening rearwardly of the vehicle; a bin supported rearwardly of the vehicle and of said opening and having a generally semi-circular wall with an open diameter directed forwardly towards said opening; a vane member rotatable in said bin for sweeping up refuse deposited therein; an upstanding shaft journaled for reciprocatory rotation in said frame and supporting said vane member to sweep up refuse and discharge it from said bin alternately on opposite sides of said shaft during forwardly directed terminal portions of opposite strokes of reciprocating rotation of said member, and mechanism for operating said vane member comprising: crank-arm means projecting from the shaft; two fluid actuators having outer ends pivotally connected at fixed points to said frame and inner ends connected to said crank-arm means, said fixed points defining a triangle with the axis of said shaft; and fluid-supply means for said actuators, said fluid-supply means including flow-reversing means coupled with said shaft for operation in predetermined positions of said vane member.
12. In material-handling apparatus comprising a fixed substantially semi-cylindrical charging container, at vane member rotatable in said container for sweeping particulate material therein, and an upstanding shaft journaled in line with the axis of said container for reciprocatory rotation relative thereto and supporting said vane member to sweep up said material and discharge it from the container during material-compacting terminal portions of opposite strokes of reciprocating rotation of said member through substantially 180, the combination therewith of mechanism for operating said vane member comprising: crank-arm means projecting from said shaft in a position of symmetry with respect to said vane member; two
rectilinear double-acting fiuid-pressure-responsive actuators symmetrically arranged with respect to said container and having outer ends pivotaliy connected to a fixed part of the apparatus and inner ends articulated to said crank-arm means; each actuator being disposed to assume an angular position about its pivoted outer end substantially normal to a radial line extending from the shaft axis to the point of articulation of its inner end to said crank-arm means upon said vane member sweeping over one of its terminal stroke portions in a respective direction; a source of pressure fiuid; and fluid-control means responsive to the position of said vane member for alternately feeding said fluid to said actuators.
13. The combination defined in claim 12 wherein said apparatus is provided with two passages for said material communicating with said container on opposite sides of said shaft, said passages being separated by a plane partition radially extending from said shaft in the midplane of said container.
References Cited by the Examiner UNITED STATES PATENTS 2,252,608 8/ 1941 Ballert 21583.3 2,333,853 11/1943 Fellabaum 280-423 FOREIGN PATENTS 968,489 4/ i1 95 0 France. 1,196,122 11/ 1959 France.
651,156 3/ 1951 Great Britain.
GERALD M. FORLENZA, Primary Examiner.