US3844493A

US3844493A - Refuse treatment apparatus

Info

Publication number: US3844493A
Application number: US00338932A
Authority: US
Inventors: C Demenais
Original assignee: SITA
Current assignee: SITA; SOC IND DE TRANSPORTS AUTOMOBILES SITA FR
Priority date: 1972-03-09
Filing date: 1973-03-07
Publication date: 1974-10-29
Anticipated expiration: 1991-10-29
Also published as: NL7303389A; JPS491072A; GB1387111A

Abstract

The invention concerns a trough-like hopper, containing a ram, for mounting on a refuse collecting vessel. The ram has a rotary shaft carrying spaced, claw-like teeth which are angularly reciprocated to entrain, compress and push refuse towards the vessel. The hopper is shaped so that the gap between its inner surface and the pitch circle of the tooth tips progressively narrows from the upper position of the ram to its lower position at the end of its active stroke. A driving mechanism supplies a gradually increasing torque to the ram during its active stroke.

Description

Unite Demenais States atent [4 1 Oct. 29, 1974 1 1 REFUSE TREATMENT APPARATUS [75] lnventor: Claude Lucien Demenais, Breuillet,

France [73] Assignee: Societe lndustrielle De Transports Automobiles S.l1.'ll.A., Paris, France [22] Filed: Mar. 7, 1973 121 Appl. No.: 338,932

[30] Foreign Application Priority Data Mar, 9, 1972 France 72.08189 Mar. 9, 1972 France 72.08190 [52] US. Cl 2411/1911, 214/833, 241/269 [51] Int. Cl. B026 18/04 [58] Field of Search 241/185 R, 186, 189 R, 241/190, 264, 267-269, 277; 214/833 [56] References Cited UNlTED STATES PATENTS 1,440,429 1/1923 Williams 1. 241/190 2,730,255 1/1956 Gibson et a1 214/833 3,062,131 11/1962 Mankki et a1 241/268 X 3,062,394 11/1962 Bowles 214/833 3,232,463 2/1966 Weir 214/833 X 3,499,558 3/1970 Rey 214/833 3,503,531 3/1970 Barbieri 214/833 3,593,930 7/1971 Lautzenheiser 241/190 X 3,763,772 10/1973 Baker 241/267 X Primary Examiner--Roy Lake Assistant ExaminerHoward N. Goldberg Attorney, Agent, or Firm-Karl W. Flocks 5 7 ABSTRACT The invention concerns a trough-like hopper, containing a ram, for mounting on a refuse collecting vessel. The ram has a rotary shaft carrying spaced, claw-like teeth which are angularly reciprocated to entrain, compress and push refuse towards the vessel. The hopper is shaped so that the gap between its inner surface and the pitch circle of the tooth tips progressively narrows from the upper position of the ram to its lower position at the end of its active stroke. A driving mechanism supplies a gradually increasing torque to the ram during its active stroke.

7 Claims, 6 Drawing Figures REFUSE TREATMENT APPARATUS The present invention concerns a collecting hopper provided with a ram for packing refuse into a refuse collecting vessel whether these vessels are installed at a fixed location and periodically removed by vehicles adapted for that purpose, or mounted permanently in the form of a bucket on a truck.

it is known that nowadays urban or industrial refuse is frequently in the form of various types of containers, wrappings and packaging of large apparent bulk associated with great stiffness. Known packing and driving refuse apparatus including hoppers with rams are illsuited for charging with such refuse. The rams are inadequate for possibly crushing dismembering or breaking up the bulks filling the hopper. Moreover, their mode of action sometimes causes a dangerous ejection of a part of its contents to the outside of the hopper.

A hopper of cylindrical trough form is known by the Swiss Pat. No. 268,107, wherein a ram of curved paddle form is pivotally and reciprocably movable around the axis of the cylindrical trough to ram refuse towards a vessel having an opening which communicates with the base of the hopper.

This construction has drawbacks: it is not possible to fill the hopper during operation of the ram because, in its return movement, it would throw the contents of the trough to the outside.

Further, in this known arrangement the driving torque of the ram is constant or hardly varies, and the ram is in a relatively constant position with respect to the hopper. Consequently, in the event of a blockage of the ram by a rigid body of refuse, if this torque is very high, damage to the trough may occur, while if the torque is too weak, the ram may frequently get blocked, which involves a manual operation of rehandling the rammed refuse.

The present invention attempts to remedy these disadvantages.

lt is an object of the invention to the hopper to be charged continuously by the crew emptying the refuse receptacles without risks of the ram in its return movement throwing refuse out of the hopper.

it is a further object to provide a device which ensures crushing of bulky refuse and permits the dismemberment of rigid wrapping and their ramming as dismembered debris into a collecting vessel while nonetheless the risk of the hopper being damaged by a rigid body wedged between the bottom of the hopper and the ram is greatly reduced.

According to the present invention there is provided apparatus for ramming refuse into a collecting vessel, comprising a trough-like hopper for receiving dumped refuse and communicating with the said vessel, a ram mounted on a shaft in the hopper for reciprocating pivotal movement, between an upper and a lower position, the ram having a plurality of claw-like, spaced teeth the profile of each of which is concave towards said vessel and convex on the other side, and means for driving the ram by a driving force which increases gradually from the upper position through an active stroke to the lower position, and back again, the hopper being shaped so that a progressively decreasing gap is formed from the opening of the upper towards the bottom thereof between itself and an imaginary cylinder enveloping the tooth tips during said active stroke.

Thus, owing to the arrangement of the ram in the form of separate teeth, to the convex shape of the backs of these teeth and to the gradual increase in size of the hopper towards its opening, pieces of refuse dumped into the hopper during the period of return of the ram are not thrown back by the ram to the outside of the hopper.

In the course of the ramming movement, owing to their claw shape, the teeth imprison the refuse and, inspite of the gaps separating them, entrain the refuse as one mass towards the collecting receptacle or vessel.

Such claw-like teeth attacking the refuse with the tip of said teeth have a large capability of breaking up and crushing voluminous packaging such as boxes or light metal cans. However, if a rigid body tends to block the movement of the ram and if this incident takes place in the upper part of the hopper, that is to say, in the relatively more fragile part of the hopper, and given that the driving force is then reduced, the ram will be blocked and a manual unblocking will be needed.

The risk of such a blockage diminishes progressively as the wall of the hopper approaches its base and at the same time the driving force of the ram and the rigidity of the base of the hopper are increased which latter is then supported by its connection with the rigid structure of the collecting receptacle or vessel.

Consequently, in case of large rigid refuse body, if the ram is not blocked at once, the body will be progressively crushed and dismembered until being rammed in the collecting vessel.

Preferably, the hopper with the ram is disposed at the base of a vessel (bucket or box) that it is destined to fill, and the axis of the ram has above it a closing wall towards the top of this vessel. This wall may be retracted from the ram when the latter is in its high position, but

this arrangement presents difficulties.

In fact, although the convex shape of the rear surface of the teeth avoids the entrainment of refuse when the ram returns towards the upper position, the entrain ment being then in a direction opposite to the normal progress towards the vessel, a part of the refuse may accumulate in the space between the: shaft of the ram and the said wall.

Preferably, the closure wall of the vessel above the hopper has a baffle joined to the shaft of the ram which has a slot for each tooth.

The two edges of each slot of the baffle may expediently comprise a plane scraper bearing on a face of each claw-like tooth, the edge of each scraper having a predetermined curvature for forming with the clawlike tooth, in each position of the latter, an angle at least equal to such that debris entrained by a tooth in its return movement cannot be wedged between this tooth and the edges of the scrapers and instead falls back into the hopper.

To facilitate the construction and repair, the assembly of the hopper may be constituted by two vertical webs stiffened on their outer faces by sections of supports for the driving mechanism of the ram and which are joined, on the one hand, by an iron plate forming the trough of the hopper and, on the other hand, by a lower cross-beam which stiffens the said plate at the part where the latter supports the maximum thrust of the ram and an upper cross-beam which at least partly constitutes the closure wall of the vessel.

The means for driving the ram with the torque gradually increasing from the top towards the bottom of the hopper may be of any suitable kind.

Preferably, the shaft of the ram comprises a crank on which is articulated one end of a tie-rod which is articulated at its opposite end on an arm pivoting around a fixed shaft, the lever receiving the thrust of a rectilinear jack pivoted at its opposite end.

Provided that the radii or the crank and the arm are diffrent, the inclination of the tie-rod varies during the stroke of the jack which allows a desired variation of the couple acting on the ram to be obtained.

Namely, the crank, tie-rod and arm may be arranged so that, in the upper position, the crank and the tie-rod form an acute angle which increases during the active stroke until the lower position.

The jack need not be articulated on the common axis of the tie-rod and the arm but instead may be pivoted on another point of the arm for amplification of the displacement of the jack and thus of the ram in certain parts of the stroke of the latter.

Since the torque is reduced at the departure from the upper position, with a constant feed of the jack a rapid displacement of the ram is obtained and this torque increases progressively as the end of the stroke is approached in such a manner that the speed of the displacement of the ram also gradually decreases.

The tie-rod is expediently arranged to be in tension during the working stroke of a rod and in compression during the return stroke.

The following description illustrates, with reference to the annexed drawings, preferred embodiments of the invention. In the drawings:

FIG. 1 is a vertical section taken perpendicularly to the axis of the ram of a hopper according to the invention,

FIG 2 is a enlarged section taken on the line II-II of FIG. 1,

FIG 3 is a section taken on the line lll-Ill of FIG. 1,

FIG. 4 shows schematically the shape of a tooth of the ram and its scraper, at various points of their movement,

FIG. 5 shows in elevation and in enlarged detail the ramactuating mechanism, and

FIG. 6 shows graphically the variations of the torque applied to the ram.

Referring to the drawing, in these Figures a box 1 forming a receptacle for refuse is closed at its back by a hopper 2 carried by an upper hinge 2a. This hopper consists of two planar webs 3 which are joined by a bottom 4 constituted by a plate comprising, towards the top, a planar part 4a and towards the bottom a substantially cylindrical part 4b tangentially joined to the part 4a.

The connection between the webs 3 is completed by a lower transverse beam 5 on which is fixed a part 4c of the bottom 4, the part 4c being bent at a right angle from part 4b. An upper box girder 25, described in detail below, also connects the webs 3.

A ram 11 is arranged in the hopper 2 and is carried by a tubular shaft l2 the axis 19 is which is parallel to the bottom 4 and which shaft 12 is journalled in bearings (described below) carried by the webs 3 (FIG. 2).

The shaft 12 of the ram carries a series of clawshaped teeth 21 the profile of each of which has concave and convex faces with radii of curvature increasing from the shaft to the tip of each tooth. Adjacent the ram shaft, the concave and convex faces of the teeth are joined by a substantially cylindrical surface coaxially surrounding the said shaft.

By means described later, in use the teeth 21 are reciprocated according to the double arrow F (FIG. I.) from an upper position 21, (chain-dotted lines) to the lower position 21 (chain-dotted lines), and refuse having been dumped into the hopper; in the course of this movement the concave part of the teeth rams the said refuse into the box 1; on the return stroke, pieces of refuse cannot rest on the rear, convex face of these teeth and will fall back to the bottom of the hopper owing to the splaying out shape of the hopper and, if nevertheless they are raised by the teeth, they cannot remain wedged between the rear wall 28 of the box girder 25 and the convex face of the teeth and fall back again.

The cylindrical part 4b of the bottom 4 has its geometrical axis 18 located above the axis 19 of shaft 12. In this way the space comprised between the imaginary halfcylinder 20 (dotted lines) enveloping the teeth tips of the ram and the inner face of the cylindrical portion 4b narrows progressively in a downward and rearward direction towards the box 1, as viewed in FIG 1. Thus, because the inner face of the hopper is smooth and is polished by use, refuse dumped in the hopper will necessarily be dragged towards the box 1.

Each tooth 21 (FIG. 2) is advantageously formed from two plates 22 welded side-by-side on the shaft 12, the edges of the plates being covered by a steel strip 23, the two ends of this strip being united at the tip 24 of the claw.

The box girder 25 is slotted on its surface facing the hopper for receiving the teeth 21. Thus in the upper position of the ram the teeth are retracted into the box girder; meanwhile the receptacle for the refuse remains perfectly closed to the side of the rear face of the girder owing to the rear wall 27 of this girder.

Along the edges of each of the slots in the girder plates 26 are welded to rear face 27 of the girder and projects forwardly (i.e., to the right in FIG. 1) relative to the front face 28 in a rounded curve 29.

Between two consecutive teeth, the two faces of the box girder are joined by a portion 30 of a casing which is applied against the shaft 12. Finally, above the slots comprising the side face of the girder facing the hopper, the girder is stiffened and closed by a longitudinal plate 40.

The curvature C (FIG. 4) of the convex face of each claw has, as already indicated, a radius increasing from the shaft 12 to its tip 24. Considering successive position C C of the curvature C, when the claw moves upward, the curve 29 of the plate 26 is so arranged that the angle a should be about equal to a right angle and constant over the whole course of the curve C, a being the angle in each successive crosing points between the profile of the convex face of a tooth and the profile 29 of the plate 26. Conversely, the curve C of the tooth may be chosen so that the curve 29 is a simple straight line. The shape of the curve 29 or that of the curve C then approaches an involute curve.

Due to this substantially constant angle, risks of wedging of refuse pieces in the slots receiving in the teeth are reliably avoided. Besides, the side faces of the teeth are scraped by the edges 29 of the plates 26.

FIG. 2 shows in detail the mounting of one of the ends of the tubular shaft 12., the other end being arranged in a similar fashion.

Into this shaft is fitted a plug having two

successive shoulders

31, 35. On the first shoulder 31 a ring 32 is fixed to form a labyrinth seal with the edge of an opening 33 formed in the web 3 for the passage of the shaft. A crank 34 is fixed by welding to this ring 33 for actuating the reciprocating movement of the ram.

The second shoulder 35 supports a rolling bearing 36 the outer race of which is mounted in a ring 37 made rigid with a support 38 secured to the web 3 by means of the casing 39 enclosing the whole of the mechanism (see also FIG. I).

On the axis 40 of the crank 34 a cranked lever 41 is pivoted the other end of which is articulated on a shaft 42 mounted at the end of a piston rod 43 of an hydraulic linear jack 44. The cylinder of each jack 44 is pivoted, towards the top of the girder 25, on a shaft 45. A guiding crank arm 46 pivoting about a fixed axis 47 carried by the web 3 and the casing 39 is also articulated on the shaft 42.

It will be clear that from the position shown in full lines in FIG. 5, the torque exerted on the shaft 12 is initially very weak. In fact, the tie-rod 411 forms a small angle with the axis of the crank 34 and the thrust of the screw jack is nearly perpendicular to this crank.

It will be realized that as the shaft 12 gradually turns in the sense of the arrow F the conditions of action of the jack 44 on the crank 34 by way of the tie-rod 41 will be more and more favourable, such that the torque exerted on this shaft increases progressively. At the end of the movement (

position

34 and 41 the lever pulls the crank perpendicularly to the latter.

Thus one obtains (FIG. 6) a variation of the torque C as a function of the angle of rotation B of the shaft 112, as shown by the curve K. The torque starts with a low value C rises to a maximum which may be limited to an eight to 10-fold increase and then decreases a little. The total angle of rotation B may be slightly more than 180.

Thus, as a result of the weak initial torque, a rigid object grapsed between the tip of a tooth and the planar part of the hopper 4, could block the movement of the ram without causing damage to the hopper. However, owing to the arcuate form of the part 4b of the hopper, the latter is reinforced. Further, this risk of blockage is reduced because of the shapes of the teeth and the bottom 4. In fact at the instant when the torque exerted on the ram is at its maximum rigid objects are dismembered, broken, crushed and then rammed into the box.

The invention is applicable to both industrial and domestic refuse collection with fixed or movable receptacles.

I claim as my invention:

I. Refuse loading apparatus intended for connection with a refuse collecting vessel comprising an upwardly splaying out hopper having a bottom, substantially in the shape of a cylindrical sector, and a communication opening with said vessel at the level of said bottom; a shaft pivotally carried in parallel relationship with the axis of said cylindrical sector carrying a plurality of evenly spaced claw-like teeth each with convex and concave surfaces, said shaft being rotatable and said teeth being reciprocable between an upper position in which said teeth clear said opening; and a lower position in which the concavity of said claw-like teeth face said opening, the gap between said bottom and the portion of circle described by the tip of each tooth during pivotal movement of said shaft decreasing towards said opening, and driving means for pivotally reciprocating said shaft providing a driving force which increases during the stroke between upper and lower positions of the teeth.

2. Apparatus according to claim I in which the radius of curvature of the concave and. convex surfaces of each tooth decreases from the shaft to the tooth tip.

3. Apparatus according to claim I in which a closure wall is provided for the hopper above said shaft and is joined to a cylindrical part of said shaft, and has, for each tooth, a receiving slot defined therein.

4. apparatus according to claim 3, in which each slot has two edges constituting scraping surfaces for the tooth faces.

5. Apparatus according to claim 4 in which the edges of the scraping surfaces are such that, in all positions of the teeth, at the point of their meeting with the profile of a tooth, these edges and the tooth profile form a substantially constant angle at least equal to 6. Apparatus according to claim l in which at least one end of said shaft is provided with a crank and wherein said driving means comprises a linear hydraulic jack, one end of which is pivoted around a fixed axis; an arm articulated around a second fixed axis; an articulated connection between the second end of said jack and said arm; and a tie-rod pivotally connecting said arm and said crank, the angle formed by said crank and tie-rod increasing from an acute angle towards a right angle between the upper and the lower position of said teeth and rotation of said shaft.

7. Apparatus according to claim 6 in which said tierod is pulled by the action of said jack during the movement of said teeth from their high to their low position. =l= l =l=

Claims

1. Refuse loading apparatus intended for connection with a refuse collecting vessel comprising an upwardly splaying out hopper having a bottom, substantially in the shape of a cylindrical sector, and a communication opening with said vessel at the level of said bottom; a shaft pivotally carried in parallel relationship with the axis of said cylindrical sector carrying a plurality of evenly spaced claw-like teeth each with convex and concave surfaces, said shaft being rotatable and said teeth being reciprocable between an upper position in which said teeth clear said opening and a lower position in which the concavity of said claw-like teeth face said opening, the gap between said bottom and the portion of circle described by the tip of each tooth during pivotal movement of said shaft decreasing towards said opening, and driving means for pivotally reciprocating said shaft providing a driving force which increases during the stroke between upper and lower positions of the teeth.

2. Apparatus according to claim 1 in which the radius of curvature of the concave and convex surfaces of each tooth decreases from the shaft to the tooth tip.

3. Apparatus according to claim 1 in which a closure wall is provided for the hopper above said shaft and is joined to a cylindrical part of said shaft, and has, for each tooth, a receiving slot defined therein.

5. Apparatus according to claim 4 in which the edges of the scraping surfaces are such that, in all positions of the teeth, at the point of their meeting with the profile of a tooth, these edges and the tooth profile form a substantially constant angle at least equal to 90*.

6. Apparatus according to claim 1 in which at least one end of said shaft is provided with a crank and wherein said driving means comprises a linear hydraulic jack, one end of which is pivoted around a fixed axis; an arm articulated around a second fixed axis; an articulated connection between the second end of said jack and said arm; and a tie-rod pivotally connecting said arm and said crank, the angle formed by said crank and tie-rod increasing from an acute angle towards a right angle between the upper and the lower position of said teeth and rotation of said shaft.

7. Apparatus acCording to claim 6 in which said tie-rod is pulled by the action of said jack during the movement of said teeth from their high to their low position.