CA1204616A - Pavement crusher - Google Patents

Abstract

A B S T R A C T

A mobile pavement material crusher is supported on ground engagement members for movement along the ground and has an upwardly and rearwardly inclined pick-up elevator at its front end for picking-up and upwardly displacing pieces of broken pavement material from the ground, primary rolls for receiving and crushing the pavement material, means for segregating the crushed material into oversize pieces and remainder, secondary rolls receiving and crushing the oversize pieces, and an upwardly inclined output elevator for receiving and discharging the crushed pavement material, for example into trucks running alongside the crusher.

Description

;16 MOBILE PAVEMENT CRUSHER
Field of_the Invention The present invention relates to a mobile pavement crusher for crushing pavement material and to a method of crushing such material.
Review of the Prior Art _ The increasing cost of pavement construction and maintenance and the declining purchasing power of public tax revenues, and also the shortage of non-renewable hydrocarbon resources, have made the recycling of pavement material an increasingly desirable objective. This objective is also desirable in order to slow down the depletion of mineral aggregrate resource~. Consequently, efforts have already been made to recycle pavement material, particularly bituminous pavement material A
This has previously been effected by using a bulldozer to rip pavements into oversize pieces or chunks, which are picked up by a front end loader, a bacX hoe or other apparatus and loaded into trucks. After being hauled by the trucks to a central location, the pavement material pieces are stock-piled and subsequently picked up again and fed through a primary crusher and a secondary crusher to produce a final sized material acceptable for a recycled pavement material mix~ It will be evident that this prior method requires repeated handling of the pavement material.
The repeated picking up and handling of this pavement material requires the employment of several pieces of equipment ~2~

and, consequently, results in relatively high equipment and labour costs for the handling of the material.
Definition of the Invention It is accordingly an object of the present invention to provide a novel apparatus and method for crushing pavement material for recycling purposes which substantially reduce the costs involved in handling the material.
This is achieved, according to the present invention, by employing a mobile crusher to pick up the pieces or chunks of pavement material from the ground, to crush these pieces of material and to discharge the crushed material, preferably into a truck travelling with the mobile crusher.
Consequently, the present invention entirely eliminates the need for a front end loader, a back hoe or other equipment for picking up the pieces of pavement material from the ground loading them into a truck, and other equipment for subsequently and picking them up from a stockpile and feeding them to a crusher, and instead enables the material to be discharged directly into a truck, already crushed to the required size suitable for recycling, at the location at which the pavement is ripped up.
More particularly, according to the present invention, there is provided a mobile pavement material crusher, comprising ground engagement members for supporting the crusher for movement along the ground;
a motor drivably connected to said ground engagement members for advancing said crusher along the ground;
pick-up means at ground level at said front end of the

- 2 -~2~4~6 crusher for displacing pieces of broken pavement material from the ground;
upwardly and rearwardly inclined pick-up elevator means at a front end of the crusher for picking-up and upwardly displacing the pieces of broken pavement material from the pick-up means as the crusher advances along the ground;
means for receiving and crushing said pavement material from said pick-up elevator means; and upwardly inclined output elevator means for receiving said crushed material from said crushing means and discharging it from the crusher.
. The present invention further provides a method of breaking and crushing a pavement, comprising the steps of:
advancing a mobile crusher along the ground towards pre-broken pavement material pieces on the ground;
employing a pick-up mechanism at a front end of said crusher to lift said pavement material pieces from the ground, said pick-up mechanism forcing an upwardly and rearwardly inclined pick-up blade beneath said pavement material pieces and conveyir.g said pavement material pieces from the rear of said pick-up blade;
crushing the lifted pavement material pieces in said crusher; and discharging the crushed pavement material from said crusher.
In a preferred embodiment of the invention, a pavement material crusher is equipped with a pair of primary crusher rolls and a pair of secondary crusher rolls for successively .~3

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crushing the bituminous material, with a vibratory screen in the path of the material between the primary crusher rolls and the secondary crusher rolls.
Description of the Drawings The invention will be more readily understood from th~
following description of a preferred e~bodiment thereof given, by way of example~ with reference to the accompanying diagrammatic drawing, in which:-Figure 1 shows a view in side elevation of a pavement crusher embodying the present invention, intended for the crusing of bituminous pavement, parts thereof being omitted and broken away as necessary for clarity of illustration;
Figure 2 is a plan view from above of the machine of Figure l;
Figure 3 is a section taken on the line 3-3 in Figure 4 to show a detail of the connection of a front endless track to the machine chassis and means for steering the said track;
Figure 4 is a side elevation of the said front endless track and adjacent portion of the chassis and a forward pick-up elevator;
Figure 5 is a side elevation of a pick-up blade assembly and the means for effecting vertical pivotal adjustment thereof;
Figure 6 is a plan view from above of pick-up teeth of the pick-up blade assembly to show a detail of the construction thereof;

Figure 7 is a plan view from above of a rear discharge elevator of the machine and means for adjust.ing its poisition and elevation relative to the machine;
Figure 8 is a side elevation corresponding to Figure 7;
Figure 9 i5 a plan view from above to an enlarged scale of a mounting arran~ement for ths said rear elevator;
Figure 10 is a ~ide elevation corresponding to Figure 9; and Figure 11 i5 a hydraulic circuit for the machine for the powering and control of the hydraulic motors thereof~
Description of the_Preferred Embodiment . The mobile crusher of the invention shown in the drawings is intended for the crushing of bituminous pavement mateirial and has a chassis indicated generally by reference 10, which is supported on ground engagement members in the form of endless tracks 11 extending around track wheels 12. An elevator support structure 14 is provided at the front end of the chassis 10, mounted on a front endless track 15 spaced forwardly from the endless tracks 11. The support structure 14 supports an upwardly and rearwardly inclined pick-up elevator indicated generally by reference 17, which extends rearwardly from a pick-up blade assembly indicated ~enerally by reference 18 and located at the front end of the bituminous material crusher, to an upper primary bin or hopper 19.
The pick up elevator 17 has an endless conveyor belt 20 guided over rolls 21, 22 and 23 between upwardly and rearwardly _ ~L2~:!i4~

inclined side walls 25 and 26, the belt 20 being formed, as shown in Figure 2, with perforations or openings 28 of one and a half inch diamet~r and being connected to a pair of parallel drive chains 29. A plurality of slats 30 of two inches height extend transversely of the conveyor belt 20, and the rear of the pick-up blade assembly 18 is formed with a cylindrically curved rear surface 32, which is spaced from the conveyor belt 20 at the adjacent roll 23, so that the outer edges of the slats 30 pass close to the concave surface 32 as the slats 30 pass between the concave surface 32 and the roll 23. The conveyor belt 20 is driven by an hydraulic motor 33 connected to the roll 21.
The hopper 19 is located above a pair of primary crusher rolls 35 and 36 which each have a length of thirty-six inches and a dia~eter of thirty inches. The primary crusher roll 36 is rotatably mounted on shaft 37 journalled, at opposite ends of the primary crusher roll 36, in a pair of fixed pedestals 37, so that the axis of rotation of the primary crusher roll 36 is fixed relative to the chassis 10. The primary crusher roll 35, however, is mounted on a shaft 39 journalled in pedestals 40, which are mounted on a slide 41, which in turn is slidably supported on the chassis 10, and a hydraulic piston and cylinder device 42 is provided for displacing the shaft 39, and therewith the primary crusher roll 35, to and fro in the horizontal direction, as viewed in Figure 1, relative to the primary crusher roll 36 for thereby adjusting the spacing between the primary crusher rolls 35 and 36.

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Below the crusher rolls 35 and 36 there is provided a lower primary bin or hopper 43, which discharges onto an underlying endless conveyor belt 44 running around a pair of conveyor rolls 45 and 46. A pair of upwardly and rearwardly inclined endless conveyors, indicated generally by reference numerals 48 and 49, extend from the roll 46 to a discharge position indicated generally by reference numeral 50, above one end of a downwardly and rearwardly inclined vibrator screen 51,the endless conveyors 48 and 49 being driven by-hydraulic motors 52 and 53 respectively.

The vibratory screen 51 is located above a vibrating screen bin or hopper 55, the lower end of which discharges onto a secondary conveyor belt 57 running around rolls 58 and 59 and driven by an hydraulic motor 60. At the rear of the vibratory screen 51, there is provided an upper secondary funnel 60, which guides material from the vibratory screen 51 into the gap between a pair of secondary crusher rolls 61 and 62. The secondary crusher rolls 61 and 62 each have a length of thirty inches and a diameter of twenty four inches.
The secondary crusher roll 61 is rotatably mounted on a shaft 63 having a fixed axis, while the secondary crusher roll 62 is rotatably mounted on a shaft 64 which can be displaced horizontally to and fro by means of a piston and cylinder device 65, in a manner and arrangement which are similar to that of the primary crusher roll 35 and which are therefore not described in greater detail. A lower secondary bin or hopper 67 is provided ~ J,~, ~2g~

below the secondary crusher rolls ~1 and 62 for receiving crushed material from the secondary crusher rolls 61 and 62 and for discharging the material onto the secondary conveyor belt 57.
An upwardly and rearwardly inclined discharge conveyor, indicated generally by reference 70 is provided at the rear of the crusher, and comprises an endless belt 71 running around conveyor rolls 72 and 73 and driven by an hydraulic motor 74, this discharge conveyor receiving and discharging mater~al from the secondary conveyor 57. As can be seen fxom Figure 2, the discharge conveyor 70 is inclined laterally of ~he longitudinal axis of the crusher.
The rate of discharge of material from the hopper 19 to the primary crusher rolls 35 and 36 may be regulated by means of a part of a rear wall thereof which is pivoted about a pivot 76 to form a flap 77, shown in broken lines in Figure 1. The flap 77 is also ef~ective to break up any clogging of the primary rolls. The flap 77 can be caused to pivot across the interior of the primary hopper 19, by means of an hydraulic piston and cylinder device 78 which is connected to the flap 77 through a pin 79 that is slideable along the rear surface of the flap 77 within the embrace of a retaining bracket 80.
The tracks 15 are pivoted to the support structure 14 pivoted about a vertical axis, and also connected thereto by means of a steering mechanism, for pivoting movement relative to the chassis 10 for steering the tracks 15 and thus for steering the crusher during its advance.

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Thus~ as shown in Figures 3 and 4, the front tracks 15 are mounted on a sub-chassis 90 provided with a :Laterally projecting flange 91, the sub-chassis 90 being pivoted relative to the main chassis 10 and connected thereto by means of a steering hydraulic piston and cylinder device 92, which is pivotally connected at opposite ends thereof to the chassis 10 and sub-chassis 90.
A motor 82 (Figure 2) mounted on the crusher chassis toward the rear is provided for propelling the crusher along the ground by dri~ing the ndless tracks 11. The top surface of the pick-up blade 18 is upwardly and rearwardly inclined, while its rear surface 32 is concave, as can be seen in Figure 1.
The pick-up blade assembly 18 is illustrated in greater detail in Figures S and 6 and has a blade 96 which is pivotally connected to the front of the pick up elevator 17 by means of a horizontal pivot shaft 97, a pair of hydraulic piston and cylinder devices 98, of which only one is shown in Figure 5, being connected between opposite ends of the pick-up blade 96 and the elevator side walls front wall portions 85 and 86 for effecting vertical pivotal adjustment of the pick-up blade 96.
Pick-up teeth 100 are spaced apart horizontally along the pick-up blade 96 and removably secured thereto by respective vertical bolts 101. Each tooth 100 is provided with a replaceable cover 10~, which replaced when worn and for this purpose is removably secured to the respective tooth 100 by a horizontal bolt 103.

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As can best be seen from Figure 2, the pick-up elevator side walls 25 and 26 include forwardly and laterally outwardly inclined front wall portions 85 and 86 extending to opposite sides of the pick-up blade 18 and also extendling downwa~dly to a bottom wall 87 to direct the picked-up materi.al on to the conveyor.
Referring to Figures 1, 7 and 8 a hydraulic piston and cylinder device 88 for vertical adjustment of the elevator 70 is connected between a unversal joint 88a mounted on the rear end of the crusher and a universal joint 88b connected by struts 89 to the elevator 70 for vertical adjustment of the elevator 70.
The pick-up elevator 17 is mounted on the front end of the chassis 10 by a pivot 93 for pivotal movement in a vertical plane, and a further piston and cylinder device 94 is connected between the chassis 10 and the pick-up elevator 17 for adjusting the inclination of the latter.
Referring now to Figures 1 and 7, it will be seen that an hyd.raulic piston and cylinder device 105 is connected between a universal joint 105a, which is mounted on the rear end of the crusher at a position laterally offset from the front end of the elevator 70, and a universal joint 105a, which is mounted on one side o the elevator 70, the hydraulic piston and cylinder device 105 serving to effect pivotal to and fro horizontal adju tment of the elevator 70.
The mounting arrangement illustrated in Figures 9 and 10 is provided to enable the vertical and horizontal pivotal ~ :~ O
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adjustment of the elevator 70, this arrangement connecting the front, lower end of the elevator 70 to the rear end of the crusher~ The arrangement comprises a support member 106 mounted on the rear of the crusher and projecting rearwardly, a pair of vertically spaced projections 107 on the support member 106, and a vertical pivot shaft 108 journalled in the projections 107.
An intermediate member 110 has a rear projection 111 through which the pivot shaft 108 extends, and a pair of rearwardly projecting, horizontally spaced arms 112. A horizontal pivot shaft 113 extends through the arms 112 and through a lower, front end roil 114 of the elevator 70 to allow vertical pivotal movem~nt of the elevator 70 about the axis of the shaft 113.
Thus, this mounting arrangement provides a universal pivot connection between the elevator 70 and the crusher.
lS The hydraulic circuit of the crusher is shown in Figure 11 and is powered by a diesel motor 120, which drives hydraulic pumps 121a through 121i. The~e pumps are connected to the various hydraulic motors and piston and cylinder devices, as described below, through valves ~not shown~ incorporated in a control unit 122, for manual control o the hydraulic circuit by an operator as will be readily apparent to those skilled in the art. The pumps draw their hydraulic fluid from a reservoir 130, the fluid being returned from the motors and cylinders to reservoirs 131 and 132 and thence through return lines 133 and 134 to the reservoir 130.

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The hydraulic pumps 121a - 121i power hydraulic motors and piston and cylinder devices for driving the components of the crusher as follows:-HYDR~UI,IC E~YDRAULIC MOTORS/S COMPO~ENT
MOTOR PISTO~ & CYLINDER
-DEVICE/S
121a Motors 124~ 12S Secondary rolls 61, 62 121b Cylinder 65 Secondary rolls 61, 62 Motor 60 Secondary conveyor 57 121c Motors 126 Tracks 11 121d Motor 74 Conveyor 70 Cylinder 88 Conveyor 70 Cylinder 105 Conveyor 70 121e Motors 52 & 53 Conveyor 50 ~5 Motor 127 Vibratory screen 51 }21f Cylinders 98 Pick-up blade 96 Motor 33 Conveyor 17 Cylinder 92 Track 15 121g Cylinder 94 Conveyor 17 Motor 123 Track 15 121h Cylinder 78 Flap 77 Cylinders 42 Primary rolls 35, 36 121i Motors 128, 129 Primary rolls 35, 36 In operation of the above-described crusher, the entire crusher is advanced forwardly by the driving of the endless tracXs 11, the forward advance being steered by means of the tracX 15.

6~6 A bituminous pavement is pra-ripped into large lumps or pieces by employment of a ripping tooth mounted on a bulldo~er that rips the pavement longitudinally a number of (e.g. four or five) times along parallel lines, these lumps or pieces being picked up from the ground by forcing of the pick-up blade 18 along the interface of the pavement and the granular base course as a result of the forward advance of the crusher. A
cementitious pavement layer would require more vigorous pre breaking, as will be apparent to those skilled-in the art.
The pavement material pieces lifted over the pick-up blade 18 in this way fall, at the rear of the pick-up blade 18, onto the upper run of the endless conveyor belt 20 and are carried upwardly by the slats 30 to be discharged from the pick-up elevator 17 into the upper primary hopper 19. Any granular base material picked-up with the pieces falls through the openings 28 in the conveyor belt 20 to return to the ground, and is thus not included in the final product discharged from the crusher.
The pavement pieces fall from the hopper 19, at a rate determined by the speed of advance of the crusher, between the primary crusher rolls 35 and 35, which are adjusted to provide a spacing between them somewhat smaller than the pavement depth and thereby provide a primary crushing operation. ~he flap 77 is adjusted to restrict the throughput of the material through the hopper, if and as necessary, to avoid clogging of the primary crusher rolls 35 and 36. The primary crusher rolls 35 and 36 are set at the required spacing~ by adjustment of the hydraulic piston and cy1inder device 42, as described above.

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From the primary crusher rolls 35 and 36, the material is directed by the lower primary hopper 43 onto the primary conveyor belt 44, and i5 conveyed thereby and by the conveyors 48 and 49 onto the vibratory screan 51. The vibratory screen 51 5 has 1~1/2 inch openings and an adjustable slope, Consequently, material smaller than 1 1/2 inches passes through the screen and drops through the vibratcry screen hoppPr 55 onto the secondary conveyor belt 57. Ovesize pieces of material, larger than L-1/2 inches, passes over the screen 51 and are deposited into the upper secondary funnel 66 and are discharged thereby to pass between the secondary crusher rolls 61 and 62. The spacing of the secondary crusher rolls 61 and 62 is set as described above so that the material passing therethrough i9 crushed to a size less than l-l/2 inches, and this crushed material is received by the lower secondary hopper 67 arld deposited onto the secondary conveyor belt 57.
The material from the secondary conveyor belt 57 is elevated by the discharge elevator 70 and discharged into a truck (not shown) travelling with the crusher. To facilitate the cooperation of the crusher with the truck, the position of the discharge elevator 70 can be adjusted by means of the hydraulic piston and cylinder devices 88 and 105, as described above. In the case of a bituminous pavement the resultant material is carried by the trucXs to an asphalt plant, where it 25 i5 recycled in hot mixed asphalt pavement material. The material resulting from the crushing of a cementitious pavement can be used as an aggregate in further construction.

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Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A mobile pavement material crusher, comprising:-ground engagement members for supporting the crusher for movement along the ground;
a motor drivably connected to said ground engagement members for advancing said crusher along the ground;
pick-up means at ground level at said front end of the crusher for displacing pieces of broken pavement material from the ground;
upwardly and rearwardly inclined pick-up elevator means at a front end of the crusher for picking-up and upwardly displacing the pieces of broken pavement material from the pick-up means as the crusher advances along the ground;
means for receiving and crushing said pavement material from said pick-up elevator means; and upwardly inclined output elevator means for receiving said crushed material from said crushing means and discharging it from the crusher.

2. A crusher as claimed in claim 1, wherein said ground engagement members comprise first driven ground engagement members supporting said receiving and crushing means from the ground and second ground engagement members spaced forwardly from said first ground engagement members supporting said pick-up elevator means, said second ground engagement members being steerable for steering the crusher.

3. A crusher as claimed in claim 1, wherein said receiving and crushing means comprise a pair of primary crusher rolls and a pair of secondary crusher rolls, the primary crusher rolls receiving and crushing pavement material pieces picked up by said pick-up elevator means into smaller pieces, means receiving said smaller pieces and screening said smaller pieces to separate oversize pieces from the remainder of said smaller pieces, means feeding said remainder directly to said discharge elevator means, and feeding said oversize pieces to the secondary crusher rolls for crushing said oversize pieces.

4. A crusher as claimed in claim 3, including hopper means for receiving said pavement material pieces from said pick-up elevator means, said hopper means being located above said primary crusher rolls and having a bottom opening through which said pavement material pieces fall to said primary crusher rolls, said hopper means including means for adjustably regulating the throughput of said pavement material pieces through said hopper means.

5. A crusher as claimed in claim 4, wherein said regulating means comprise flap means pivotable across the interior of said hopper means and piston and cylinder means for effecting the pivotal movement of said flap means.

6. A method of breaking and crushing a pavement, comprising the steps of:
advancing a mobile crusher along the ground towards pre-broken pavement material pieces on the ground;
employing a pick-up mechanism at a front end of said crusher to lift said pavement material pieces from the ground, said pick-up mechanism forcing an upwardly and rearwardly inclined pick-up blade beneath said pavement material pieces and conveying said pavement material pieces from the rear of said pick-up blade;
crushing the lifted pavement material pieces in said crusher; and discharging the crushed pavement material from said crusher.

7. A method as claimed in claim 6, in which the step of crushing the pavement material pieces comprises primary and secondary crushing thereof.

8. A method as claimed in claim 6, in which the step of discharging the crushed pavement material comprises depositing the material into a truck travelling with said crusher.