Crusher

A crusher is provided that can quickly return to the operating state from a shutdown state which occurs due to the incorporation of a foreign object. Provided are a crushing rotor 32, a housing 41 and an anvil 33 supported by the housing to face a crushing chamber 31. A lever 90 is disposed on the side opposite the crushing rotor 32 with respect to the housing 41, pivotably installed with respect to side frames 19, and provided with a holding portion for holding the housing 41 to keep a posture where the anvil 33 faces the crushing chamber 31. An elastic member 93 is for biasing the lever 90 at a set biasing force. When the biasing force is exceeded, the lever 90 turns to permit the anvil 33 to turn and retreat from the crushing chamber 31.

TECHNICAL FIELD

The present invention relates to a crusher for crushing object to be crushed.

BACKGROUND ART

Crushers are used to crush waste materials (to-be-crushed objects) such as waste wood, etc. for the main purpose of recycling of the waste materials and of reducing the volume thereof. One example of such crushers is known that is provided with a crushing apparatus including a crushing rotor arranged with crushing bits (rotating blades) on the outer circumferential portion thereof and an anvil (fixed blade) provided on the outer circumferential side of the crushing rotor.

A crusher of this type is as below for example. A housing provided with an anvil is held by a shear pin, and during the crushing work, when an excessive impactive force is applied to the fixed blade in such a case where foreign object (a metal block, etc.) may mix in to-be-crushed object and may be held between the bit of the crushing rotor and the fixed blade of the housing, the shear pin is broken to retreat the housing. Thus, the crusher (the fixed blade, etc.) is prevented from being damaged. (See patent document 1.)JP, A 2005-319349

DISCLOSURE OF INVENTION

Problem to be Solved by the Invention

However, in the crusher configured to hold the housing by the shear pin, each time the shear pin is broken, the broken shear pin has to be replaced with a new one. This requires great care until the crusher is returned to work.

The present invention has been made in view of the foregoing and aims to provide a crusher that can quickly be returned to work from shutdown state due to the incorporation of a foreign object.

Means for Solving the Problem

(1) To achieve the above object, the present invention provides a crusher including a crusher frame; a crushing rotor rotatably supported by the crusher frame; a housing pivotably mounted to the crusher frame; a fixed blade supported by the housing to face a crushing chamber around the crushing rotor; a lever disposed on a side opposite the crushing rotor with respect to the housing, installed pivotably with respect to the crushing frame, and provided with a holding portion for holding the housing to keep a posture where the fixed blade faces the crushing chamber; and biasing means for biasing the lever at a set biasing force and when a turning force applied to the lever via the holding portion exceeds the set biasing force, turning the lever to permit the fixed blade to turn and retreat from the crushing chamber.

As described above, the holding portion for holding the housing to keep a posture where the fixed blade faces the crushing chamber and the biasing means for biasing the lever at a set biasing force are provided, and when a turning force applied to the lever via the holding portion exceeds the biasing force, the lever is turned to permit the fixed blade to turn and retreat from the crushing chamber. Therefore, even in the event that a bit of the crushing rotor and the fixed blade of the housing hold therebetween a foreign object such as a metal block mixed in to-be-crushed object so that an excessive impactive force (the excessive load) is applied to the fixed blade, the fixed blade is turned and retreated. Thus, it is possible to prevent the bearings of the crushing rotor and the structure from being damaged by the excessive impactive force. In addition, the crusher can quickly be returned to work without the necessity of replacement with a new component part such as when a shear pin is broken.

(2) In the above (1), preferably, a roller is turnably provided at the holding portion of the lever to be abutted against the housing.

With this, when the housing is turned, the roller of the lever rolls on the housing to suppress friction occurring between the housing and the holding portion of the lever.

(3) In the above (1), preferably, the biasing means includes: a rod provided at one end of the lever turnably with respect to the lever and insertably fitted to a support member secured to the crusher frame; and spring means disposed between the lever and the support member so as to receive the rod passed therethrough.

(4) In the above (3), preferably, biasing force adjusting means for adjusting the biasing force of the spring means is provided.

With this, a load to turn and retreat the fixed blade due to the hardness of the to-be-crushed object or the like is adjusted to adjust a frequency where the fixed blade is turned and retreated during the crushing work. Therefore, while preventing the bearings of the crushing rotor and the structure from being broken, the crushing force to crush the object to be crushed is sufficiently ensured so that the crushing work can be carried out efficiently.

(5) In the above (1), preferably, the biasing means is disposed on the side of the housing with respect to the lever.

(6) In the above (1), preferably, the housing is provided with adjusting means for adjusting an amount of engagement with the holding portion of the lever.

With this, a load to turn and retreat the fixed blade due to the hardness of the to-be-crushed object is adjusted to adjust the frequency where the fixed blade is turned and retreated during the crushing work. Therefore, while preventing the bearings of the crushing rotor and the structure from being broken, the crushing force to crush the object to be crushed is sufficiently ensured so that the crushing work can be carried out efficiently.

(7) In the above (6), preferably, the adjusting means includes a latch abutted against the holding portion of the lever and a case secured to the housing to house the latch in such a manner that a portion of the latch is projected toward the holding portion, and the adjusting means adjusts the engaging amount by adjusting a projecting amount of the latch.

(8) In the above (7), preferably, the holding portion of the lever is such that an outer circumferential surface thereof abutted against the adjusting means is formed curved, the adjusting means includes a case secured to the housing and a latch provided in the case to be movable forward and rearward and to have a curved abutment portion against the holding portion, and a contact point between the latch and the holding portion shifts on the outer circumferential portion of the holding portion according to a forward-rearward movement amount of the latch with respect to the case to change the engaging amount between the latch and the holding portion.

(9) In the above (1), preferably, the housing is formed such that a distance from a turning center relative to the crusher frame to the fixed blade is made equal to a distance from the turning center to an abutment portion against the holding portion of the lever.

With this, the load applied to the fixed blade is made equal to the load applied to the holding portion via the housing. Therefore, the biasing force of the biasing means can easily be set accounting for the impactive force to turn and retreat the fixed blade from the crushing chamber.

(10) In the above (1), preferably, the housing is formed such that a distance from a turning center relative to the crusher frame to the abutment portion against the holding portion of the lever is made shorter than a distance from the turning center to the fixed blade.

With this, a range occupied by the housing in the crushing frame can be reduced. Therefore, the flexibility of the arrangement of the members including the housing can be increased.

(11) Further, in the above (1), preferably, the housing is formed such that a distance from a turning center relative to the crusher frame to an abutment portion against the holding portion of the lever is made longer than a distance from the turning center to the fixed blade.

With this, the force needed to hold the housing with respect to the impactive force applied to the blade force to keep a posture where the fixed blade faces the crushing chamber is reduced compared with the case where the distance from the turning center relative to the crushing frame to the fixed blade is equal to the distance from the turning center to the abutment portion against the holding portion of the lever. Therefore, the components such as the lever, the biasing means, etc., relating to the magnitude of the force pressing the housing can be reduced in size.

Advantage of the Invention

According to the present invention, the crusher can quickly be returned work from shutdown state due to the incorporation of a foreign object.

EXPLANATION OF REFERENCE NUMERALS

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1is a lateral view illustrating an overall structure of a self-propelled crusher according to a first embodiment of the present invention.FIG. 2is a plan view ofFIG. 1.FIGS. 3 to 5are perspective lateral views illustrating detailed structures of the vicinity of a crushing apparatus12installed in the self-propelled crusher illustrated inFIG. 1.FIG. 3illustrates a case where a housing lies at a closing position.FIG. 4illustrates a case where the housing is being turning.FIG. 5illustrates a case where the housing lies at an opening position. Incidentally, directions corresponding to the left and right inFIGS. 1 and 2shall be the rear and front, or one and the other, respectively, of the crusher.

Referring toFIGS. 1 and 2, the self-traveling crusher of the present embodiment generally includes: a track body1which allows self-propelling; a crushing function constituting portion2installed on the track body1to crush to-be-crushed object received; a discharge conveyor3which conveys the object crushed by the crushing function constituting portion2and discharges that to the outside; and a power arrangement4(a power unit) equipped with an engine, etc as a power source for devices mounted on the crusher.

The track body1includes: a track frame5; a drive wheel6and a driven wheel7respectively provided at front each end and rear each end of the track frame5; a drive device (traveling hydraulic motor)8having an output shaft connected to the shaft of the drive wheel6; and a crawler belt (endless crawler belt)9wound around the drive wheel6and driven wheel7. A body frame30is mounted on the track frame5and supports the crushing function constituting portion2, the discharge conveyer3, the power arrangement4, etc.

The crushing function constituting portion2includes: a hopper10adapted to receive to-be-crushed object to be fed; a feed conveyer11(seeFIG. 2) as conveying means for the to-be-crushed object received and arranged in the hopper10; the crushing apparatus12(seeFIGS. 3 to 5) for crushing the to-be-crushed object introduced by the feed conveyer11; and a pressing roller device13(seeFIGS. 3 to 5) for pressing the to-be-crushed object to be introduced into the crushing apparatus12against the feed conveyer11before the crushing apparatus12.

The feed conveyor11includes: a sprocket-like drive wheel15provided on the side (on the front side of the crusher) of a crushing rotor32described later; a driven wheel not illustrated provided on the side opposite the drive wheel15(on the rear side of the crusher); and a conveying body (a conveying belt, a chain belt)16composed of a plurality of widthwise lines (e.g., 4 lines, seeFIG. 2) wound between the drive wheel15provided on each end portion of the conveying-direction and the driven wheel.

The driven wheel is supported by bearing18(seeFIG. 1) provided at the rear portion of lateral wall body17(seeFIG. 1) of the hopper10. The drive wheel15is supported by bearing84provided on side frame19(seeFIG. 3) of the crushing apparatus12provided on the front side of the lateral wall body17. In this way, the feed conveyor11is provided to extend generally horizontally from the internal lower portion of the hopper10, i.e., from the inside of the lateral wall body17of the hopper10to the vicinity of a crushing rotor32(described later) and housed and arranged in the hopper10and in the side frames19of the crushing apparatus12.

A rotating shaft20of the drive wheel15of the feed conveyer11is connected, via a coupling or the like, to an output shaft of a drive device (not illustrated) provided widthwise-externally of the bearings. The feed conveyor11is designed to drivingly circulate the conveying body16between the drive wheel15and the driven wheel by allowing a drive device not illustrated to drivingly rotate the drive wheel15.

The pressing roller device13is provided close to the rear side of the crushing rotor32(described later) and above the conveyor11so as to face the conveying surface of the feed conveyor11. While pressing the to-be-crushed object conveyed on the feed conveyor11from above, the pressing roller device13introduces that toward the crushing rotor32. The pressing roller device13has a pivot shaft22journaled above the crushing apparatus12by bearings provided on the side frames19. The pressing roller device13includes: a support member (arm)23turnably supported (vertically swingably inFIG. 3) in a vertical plane; and a pressing roller24provided rotatably with respect to the support member23.

The support member23is provided with the pivot shaft22at one end and with the pressing roller24at the other end (one end on the leading end side). A lower side end face (the end face facing the upper portion of the crushing rotor32) of the support member23is formed to be bent into an arc. A curved plate27constituting part of a crushing chamber31described later is attached to this bending surface. On the other hand, the support member23has a portion which is attached with the pressing roller24, and the portion is formed to be bent into an arc having a diameter smaller than that of the pressing roller24and the outer circumferential surface of the pressing roller24is configured to protrude from the support member23. The pressing roller24is set to have a widthwise (direction perpendicular to the sheet surface ofFIG. 3) size equal to or greater than the width of the conveying surface of the feed conveyor11.

The pressing roller24has a drive device (not illustrated) built in its barrel portion. The pressing roller24is drivingly rotated by this drive device at a circumferential velocity generally equal to the conveying speed of the to-be-crushed object conveyed on the conveying surface of the feed conveyor11. The pressing roller24works with the feed conveyor11to introduce the to-be-crushed object pressed on the feed conveyor11into the crushing chamber31.

A hydraulic cylinder28has a bottom side leading end turnably connected via a pin53to a bracket29secured to the side frames19; and a rod side leading end turnably connected via a pin82to a bracket54provided at a rear side (on the left side inFIG. 3) leading end of the support member23. The extending and contracting movement of the hydraulic cylinder28can turn the pressing roller device13around the pivot shaft22to move it up and down with respect to the feed conveyor11(in other words, to bring it away from or close to the crushing apparatus12).

The crushing apparatus12is located at a generally central portion in the longitudinal direction of the body frame30(seeFIG. 1). As illustrated inFIG. 3, the crushing apparatus12includes: a crushing rotor32rotating at high speeds in the crushing chamber31; an anvil (fixed blade)33provided on the radially outside of the crushing rotor32; and a protection mechanism14for protecting the anvil33, the crushing rotor32, etc. A curved plate27, the anvil33, a curved plate39, screens (sieves)40, etc. are provided around the crushing rotor32from a portion (the portion rearward of the crushing apparatus12) adapted to receive to-be-crushed object supplied thereto by the feed conveyer11and the pressing roller24in the normal-rotational direction of the crushing rotor32(the clockwise direction, in the flowing direction of to-be-crushed object inFIG. 3) so as to surround the crushing rotor32. The crushing chamber31, a cylindrical space, in which crushed pieces go around the crushing rotor32, is defined by these curved plate27, the anvil33, the curved plate39, the screens40, etc.

The crushing rotor32is rotatably supported by bearings (not illustrated) provided on support members not illustrated and provided on the side frames19or on body frame30of the crushing apparatus12. The crushing apparatus32is provided on the outer circumferential portion with a plurality of set constituted by support members34and crushing bits (collision plates, crushing blades or the like)35attached to the front sides, in the normal-rotational direction, of the support members34by means of bolts38. The crushing bit35is disposed such that its blade surface precedes the support member34when the crushing rotor32rotates in the normal-rotational direction. This blade surface strikes the to-be-crushed object. Incidentally,FIGS. 3 to 5typically depict a set constituted by the crushing bit35, the support34and the bolt38.

The anvil33has a collision surface33awith which the to-be-crushed object introduced into the crushing chamber31collides. The anvil33is attached via a support member51to a portion on the upstream side, in the normal-rotational direction, of the crushing rotor32relative to the attachment portion of the curved plate39of the housing41so that the collision surface33amay face the crushed pieces (the to-be-crushed object) circulating in the crushing chamber31along with the rotation of the crushing rotor32. The support member51is attached to the housing41by means of bolts or the like not illustrated.

The housing41holds the anvil33on the side of crushing chamber31. The housing41is pivotably supported in the back and forth direction with a pivot shaft42, serving as a fulcrum, supported by bearings not illustrated provided on the side frames19above the pivot shaft22of the pressing roller device13. In addition, the housing41is provided with an engaging portion46protruded therefrom at its front end portion extending forward as viewed from the pivot shaft42. The housing41is formed so that a distance from the pivot shaft42to the anvil33may be generally equal to a length (distance) from the pivot shaft42to the engaging portion46. Incidentally, the pivot shaft42, anvil33and engaging portion46of the housing41correspond to a fulcrum, a point of effort and a point of load, respectively, in the principle of leverage. Thus, almost the same load as a load applied to the anvil33(the point of effort) is applied to the engaging portion46(the point of load). During the normal time period (during the crushing work), the engaging portion46of the housing41is supported by the holding portion of a protection device14(described later) provided on the inner wall surface of the side frames19. In addition, the anvil33is held at a closing position (the position indicated inFIG. 3) opposed to the to-be-crushed object in the crushing chamber31. During the crushing work, if an excessive load is applied to the anvil33, a load generally equal to such an excessive load is applied to the protection device14to shift the holding portion of the protection device14. This releases the restraint of the housing41(seeFIG. 4). Consequently, the housing41is turned around the pivot shaft42to an opening position (the position indicated inFIG. 5) where the anvil33retreats from the crushing chamber33.

The screens40are provided on the downstream side of the curved plate39in the flowing direction of the to-be-crushed object and on the radially outside of the crushing rotor32, and are arranged almost along with the arc having the same center as the crushing rotor32. In addition, the screens40are provided with a plurality of discharge holes (not illustrated) which pass through the screens40from an inner diameter surface opposed to the crushing rotor32to the opposite surface to discharge the crushed pieces. Crushed pieces each of which has a diameter smaller than the diameter of the discharge hole not illustrated are discharged to the outside of the crusher.

A frame-like screen support member (a screen holder)63holding the screens40on the outer circumferential position of the crushing rotor32is provided below the crushing rotor32. The screen support member63is configured such that its rear end portion is secured via a pivot shaft64to a support member not illustrated or the like provided on the side frames19or on the body frame30so as to vertically turn around the pivot shaft64. On the front end portion of the screen support member63, a link mechanism69adapted to move the screen support member63forward and rearward with respect to the crushing rotor32.

The link mechanism69includes a hydraulic cylinder66, a slider70and an arm72. The hydraulic cylinder66is pivotably connected at a bottom side end portion thereof, via a pin68, to a bracket67secured to the side frames19. The slider70is provided at a rod side end portion of the hydraulic cylinder66so as to be moved forward and rearward along with the extension and contraction of the hydraulic cylinder66. One end of the arm72is pivotably connected to the front end portion of the screen support member63and the other end thereof is pivotably connected to the slider70. The contraction of the cylinder66lowers the screen support member63from the state shown inFIG. 3.

FIG. 3illustrates the state of the crushing apparatus during the crushing work, in which the link mechanism69holds the posture of the screen support member63by the extension of the hydraulic cylinder66. When hydraulic fluid inside the hydraulic cylinder66is pressurized, the other side end of the arm72, i.e., the end on the side of the slider70is parallel shifted in the pressurized direction (rightward inFIG. 3) of the cylinder66together with the slider70to turn downward the screen support member63around the pivot shaft64. In this way, when the screen support member63is lowered, the screen40placed on the screen support member63can laterally be drawn from a cut-away portion (not illustrated) formed on the lower portion of the side frame19. Thus, the screen40can be replaced with ease.

Returning now toFIGS. 1 and 2, the discharge conveyor3has a discharge side (front side) portion suspended and supported by a support member75provided to project from the power arrangement4. In addition, a (rear side) portion opposite the discharge side portion is suspended and supported by the body frame30via a support member36. In this way, the discharge conveyor3is arranged to be passed between below the crushing apparatus12and below the power arrangement4and inclined upward from below the power arrangement4to the front external of the self-propelled crusher. The discharge conveyor3includes a frame77and a conveyor cover78. The conveyor cover78is provided above a conveyor belt (not illustrated) wound between a drive wheel (not illustrated) and a driven wheel (not illustrated) which are provided at both longitudinal ends of the frame77. The drive wheel (not illustrated) of the discharge conveyor3is connected via a coupling or the like to the output shaft of a drive unit (a hydraulic motor for discharge conveyor)79provided widthwise-externally of a bearing. The drive unit79is rotationally driven to drivingly circulate the conveyor belt between the drive wheel and the driven wheel.

The power arrangement4is mounted on the other side end, in the longitudinal direction, of the body frame30via a support member80. A cab seat81is provided in a compartment behind the power unit4and on one side (the lower side inFIG. 2) in the width direction. A control lever85for traveling operation is provided forward of the cab seat81. A control panel83is provided on the lower lateral side of the cab seat81of the self-traveled crusher to perform operation other than the traveling operation, setting, monitoring, etc.

The protection device14described earlier is next detailed with reference toFIGS. 3 to 7.

FIG. 6is a plan view illustrating the protection device14and housing41extracted from the illustration ofFIG. 3along with the peripheral configurations.FIG. 7is a detailed perspective plan view illustrating the housing41and lever90shown inFIG. 6. The left and right directions inFIGS. 6 and 7correspond to the rear and front directions, respectively, of the self-traveled crusher illustrated inFIGS. 1 to 5.

The protection device14includes a lever bracket96, the lever90, a roller95, a rod91, an elastic member93and a shim92. The lever bracket96is provided on a lever support member94disposed along the body-width direction (the vertical direction inFIG. 6) and secured at both ends thereof to the side frames19,19. The lever90is pivotably provided on the lever bracket96via a pin90b. The roller95is turnably provided at one end of the lever90close to the housing41via the pin90a. The rod91is turnably provided at one end of the lever90opposite the housing41via a pin90a. The elastic member93is interposed between the lever90and the stopper support member48through the rod91. The shim92is inserted between the lever support member94and the elastic member93.

The lever support member94is disposed forward of the housing41.

The lever bracket96is provided at the general center of the lever support member94secured at both ends thereof to the side frames19,19, i.e., at a position corresponding to the engaging portion46of the housing41. In addition, the lever bracket96is provided to project from the lever support member94toward the housing41.

The lever90has a converse L-shape bending toward the housing41(leftward inFIG. 3). The lever90is pivotably connected via the pin90bto the lever bracket96at a position where the distance between one end close to the pin90a(close to the rod91) and the pin90bis greater than the distance between one end close to the pin90c(close to the housing41) and the pin90b. A force (turning force) applied in the turning direction to the one end close to the pin90aand corresponding to the point of effort in the principle of leverage becomes a greater force (the turning force) at the one end close to the pin90ccorresponding to the point of load because of passing the pin90bcorresponding to the fulcrum.

A portion of the lever90extending from the pin90bto the side of the pin90cplays a role of a holding portion. This holding portion is provided at one end of the lever90close to the housing41to hold the engaging portion46of the housing41to keep a posture where the anvil33faces the crushing chamber31. The roller95is turnably provided via the pin90cat a contact position of the holding portion with the engaging portion46. When the engaging portion46moves with respect to the holding portion of the lever90, the roller95rolls on the engaging portion46to reduce the friction force occurring between the holding portion and the engaging portion46.

The rod91is pivotably provided via the pin90aat one end of the lever90on the side opposite the housing41and is insertably fitted into the stopper support member48secured to the side frames19,19. The stopper support member48is disposed above the housing41(the upper direction inFIG. 3). The rod91extends from the pin90aof the lever90toward the stopper support member48.

The elastic member93is an elastic member made of e.g. a rubber spring, an urethane spring or the like and is interposed between the lever90and the stopper support member48so as to receive the rod91passed therethrough.

The shim92is inserted between the stopper support member48and the elastic member93and secured with a bolt or the like so as not to drop off. This shim92is biasing force adjusting means for adjusting the biasing force of the elastic member93against the lever90. If the number of the shims92is increased or the shim92is replaced with a thicker shim, the biasing force of the elastic member93against the lever90is increased to thereby increase the holding force of the holding portion of the lever90for the housing41. Reversely, if the number of the shims92is reduced or the shim92is replaced with a thinner shim, the biasing force of the elastic member93against the lever90is reduced to thereby reduce the holding force for the housing41resulting from the holding force of the lever90.

As described above, the rod91and the elastic member93constitute biasing means for biasing the lever at a set biasing force, turnably operating the lever90when the turning force applied to the lever90via the holding portion exceeds the biasing force, to permit the turning retreat of the anvil33from the crushing chamber31. The shim92constitutes biasing force adjusting means for adjusting the biasing force of the elastic member93.

Returning toFIGS. 3 to 5, during the crushing work (in the state illustrated inFIG. 3), the housing41is such that the engaging portion46thereof is fixed and held at a closing position by the holding portion of the lever90of the protection device14mounted to the side frames19, i.e., in the posture where the anvil33is disposed in the vicinity of the rotational trajectory of the crushing bit35. In this case, the roller95provided on the holding portion of the lever90presses rearward the engaging portion46of the housing41by the biasing force of the elastic member93transmitted via the lever90. In the case where the force of the engaging portion46pressing the roller95forward exceeds the biasing force of the elastic member93transmitted to the roller95via the lever90, the lever90is turned to shift forward the roller95provided on the holding portion. As a result, the engaging portion46of the housing41rides across the roller95, thereby permitting the turning of the housing41. With such a configuration, if an excessive impactive force is applied to the anvil33, the lever90of the protection device14is turned in an opening direction (counterclockwise inFIG. 3) to release the restraint of the engaging portion46by the holding portion. The housing41is turned around the pivot shaft42to allow the anvil33to retreat from the crushing chamber31. Thus, components of the crusher including the anvil33can be prevented from being damaged. In this case, even after the anvil33has been retreated from the crushing chamber31by the excessive load in this embodiment as illustrated inFIG. 5, by depressing from above the engaging portion46of the housing41by means of e.g., a cylinder, a manual jack, a hand or the like, the posture of the housing41, i.e., the position of the anvil33with respect to the crushing chamber31can be returned to the state shown inFIG. 3. A stopper50is provided on a stopper support member48secured to the side frames19. This stopper50limits the turning range of the housing41in the opening direction (counterclockwise inFIG. 3) thereof. Thus, the housing41and the other constituent elements can be prevented from interfering with each other.

A description is given of the operation of the present embodiment configured as above.

After to-be-crushed object is fed into the hopper10by a heavy machine (a hydraulic shovel or the like) equipped with an appropriate working tool such as a grapple, the object is put on the conveyor belt16of the feed conveyor11and conveyed toward the crushing apparatus12by the circulating-driving conveyor belt16. When the to-be-crushed object is conveyed to near the pressing roller device13, the pressing roller24runs on the to-be-crushed object. In this state, the to-be-crushed object is pressed against the conveying surface of the feed conveyor11by the pressing roller's own weight. In this way, in the state where the to-be-crushed object is gripped between the pressing roller24and the feed conveyor11, the pressing roller24introduces the to-be-crushed object into the crushing chamber31in cooperation with the feed conveyor11. In this case, the to-be-crushed object projects toward the inside of the crushing chamber31in such a cantilever manner that a portion of the to-be-crushed object gripped between the pressing roller24and the feed conveyor11is made to serve as a fulcrum.

The crushing bits35of the crushing rotor32rotating at high speed collide from below with the to-be-crushed object projecting into the crushing chamber31, thereby roughly crushing it (first crushing). The crushed pieces thus roughly crushed and struck up in the crushing chamber31collide with the anvil33to be more finely crushed by the impactive force. Also thereafter, the crushed pieces go-around in the crushing chamber31along with the rotation of the crushing rotor32and collide with the crushing bits35, the anvil33, the inner wall surface of the crushing chamber31, etc. (secondary crushing). Of the circulating crushed pieces, crushed pieces that are made finer into such a size as to pass through the discharge holes of the screens40sequentially pass through the screens40and are discharged from the crushing chamber31. The crushed pieces discharged from the crushing chamber31drop onto the discharge conveyor3to be conveyed and discharged to the outside of the crusher.

When the secondary crushing mentioned above is carried out during the crushing work as describe above, the crushing bit35and the anvil33may hold therebetween a foreign object such as a stone, metal or the like. In such an event, an excessive load is applied from the crushing bit35to the anvil33and transmitted to the holding portion of the lever90of the protection device14via the engaging portion46of the housing41.

In the event that the excessive impactive force is applied to the anvil33or the like, the lever90of the protection device14is turned in the opening direction (counterclockwise inFIG. 3) to release the restraint of the engaging portion46by the holding portion. Because of the configuration of the protection device14as mentioned above, the housing41and the anvil33are turned around the pivot shaft42with respect to the side frames19to retreat from the crushing chamber31. Thus, components of the crusher including the anvil33are prevented from being damaged.

The hopping impactive force of the housing41encountered when the housing41is turned and retreated is absorbed by the stopper50. In addition, the housing41is returned to the original position (the closing position) by its own weight. However, if a position sensor not illustrated or the like detects the retreat of the housing41, the self-traveled crusher stops the operation for crushing the to-be-crushed object, specifically, the carrying-in of to-be-crushed object by the conveyor11or the like, the rotation of the crushing rotor32, etc.

In the embodiment configured as described above, the engaging portion46is provided opposite the anvil33of the housing41and held by the holding portion of the lever90. In addition, the operation of the engaging portion46is permitted by the biasing means via the lever90. Therefore, even in the event that the crushing bit35and the anvil33hold therebetween a foreign object such as a stone, metal or the like, the biasing means and the lever90are turned to turn the housing41supporting the anvil33, thereby retreating the anvil33from the crushing chamber31. Thus, it is possible to prevent an excessive load from being applied via the crushing bits35to the bearings of the crushing rotor32and the structure including the anvil33. As a result, the bearing of the crushing rotor and the structure can be prevented from being damaged and also the crusher can quickly be returned to work without the necessity of replacement with a new component part such as when a shear pin is broken.

The biasing force adjusting means for adjusting the biasing force of the biasing means against the lever90is provided. Therefore, the frequency of turning-retreat of the housing41during the crushing work can be adjusted by force (hereinafter called the holding force) depending on the hardness of a to-be-crushed object, such a holding force being adapted to hold the holding portion of the lever in the posture of the anvil33facing the crushing chamber31by the holding portion of the lever90holding the engaging portion46of the housing41. For example, in the case of to-be-crushed object having a less possibility of foreign object incorporation and an easily crushing property, the crushing apparatus is less liable to come into an excessive load state. Therefore, the biasing force is adjusted to set the holding force to a large level, which makes it possible to crush the to-be-crushed object more reliably. On the other hand, in the case of to-be-crushed object having a high possibility of foreign object incorporation, such as e.g. mixed waste, the crushing apparatus is likely to come into an excessive load state. Therefore, the biasing force is adjusted to set the holding force at a small level, which makes it easy for the anvil33to retreat, thereby preventing any damage to the crushing apparatus. As described above, the holding force resulting from allowing for both prevention of damage to the bearings of the crushing rotor32and to the structure and ensuring of the crushing force for the to-be-crushed object can be set so that the crushing work can be carried out efficiency.

Further, the housing41is formed such that the distance from the pivot shaft42to the anvil33is made generally equal to the length from the pivot shaft42to the engaging portion46. Therefore, the load applied to the engaging portion46is generally equal to that applied to the anvil33. Thus, it is easy to set the biasing force of the biasing means allowing for the load applied to the anvil33. When an installation space for the housing41and the protection device14is limited, the length (distance) from the pivot shaft42of the housing41to the engaging portion46may be made shorter than the length from the pivot shaft42to the anvil33. In this case, the load greater than the load applied to the anvil33or the point of load is applied to the engaging portion46or the point of effort. However, it is possible to deal with such a greater load by increasing the holding force for holding the engaging portion46of the housing41by changing the installation position of the pin90bof the lever90or a fulcrum, or by adjusting the biasing force of the elastic member93. In contrast, when the installation space for the housing41and the protection device14has room, the length from the pivot shaft42of the housing41to the engaging portion46may be made greater than the length from the pivot shaft42to the anvil33. In this case, the load smaller than the load applied to the anvil33or the point of effort is applied to the engaging portion46or the point of load. Therefore, the protection device14can allow the holding force for holding the engaging portion46of the housing41to have room. Thus, the advantage such as downsizing of the protection device14can be expected.

Incidentally, the present embodiment is described by taking as an example the case where the rubber spring or urethane spring is used as the elastic member93of the protection device14. However, the invention is not limited to this. For example, as illustrated inFIGS. 8 and 9, a coil spring may be used as the elastic member193. Also in this case, the same advantage as that of the embodiment described above can be obtained.

In addition, the present embodiment is described by taking as an example the case in which the single protection device14is used. However, the invention is not limited to this. For example, the protection device14may be provided at each end of the lever support member94.

Further, the biasing force adjusting means for adjusting the biasing force of the elastic member93against the lever90is configured to adjust the biasing force by the number or thickness of the shim. However, the invention is not limited to this. For example, an adjusting screw may be provided and turned to adjust the biasing force. Alternatively, the elastic member93may be replaced with an elastic member having a different elastic force.

A second embodiment of the present invention will be described with reference toFIGS. 10 to 12.

The present embodiment makes use of a protection member214by replacing the protection member14of the crushing apparatus12illustrated in the first embodiment. In the figures, the same members as in the first embodiment are denoted with like reference numerals and their explanations are appropriately omitted.

FIGS. 10 to 12are perspective lateral views illustrating detailed configurations in the vicinity of the crushing apparatus12in the present embodiment.FIG. 10illustrates a case where a housing lies at a closing position.FIG. 11illustrates a case where the housing is being turning.FIG. 12illustrates a case where the housing lies at an opening position. Incidentally, in the following, directions corresponding to the left and right inFIG. 1shall be the rear and front, or one and the other, respectively, of the crusher.

The protection device214includes a lever bracket296, a lever290, a rod91, a roller295, a rod support member248, an elastic member93and a shim92. The lever bracket296is mounted to a lever support member294disposed along the body-width direction (the direction perpendicular to the sheet surface in the figures) and supported at both ends thereof by the side frames19. The lever290is pivotably mounted to the lever bracket296via a pin290b. The rod91is pivotably provided via a pin290aat one end of the lever290opposite the lever bracket296. The roller295is turnably provided at a projecting portion290d, of a barrel portion of the lever290, close to the housing41via a pin290c. A rod support member248disposed along the body-width direction (the direction perpendicular to the sheet surface in the figures) and supported at both ends thereof by the side frames19. The elastic member93is interposed between the lever290and the rod support member248so as to receive the rod91passed therethrough. The shim92is inserted between the rod support member248and the elastic member93.

The lever support member294is located forward of the housing41.

The pin290cof the lever290is disposed so that a distance between one end close to the pin290bprovided with the lever bracket296and the pin290cis shorter than a distance between one end close to the pin290aprovided with the rod91and the pin290c. In this way, force applied to one end close to the pin290aor a point of effort becomes a greater force at the pin290cor a point of load because of the force passing through the pin290bor a fulcrum.

The lever290has a projecting portion290d, at its barrel portion, close to the housing41. The projecting portion290dhas a function of a holding portion for holding an engaging portion46of the housing41to keep a posture where the anvil33faces the crushing chamber31. A roller295is provided at the abutment position of this holding portion290dagainst the engaging portion46so as to be turnable via the pin290c. When the engaging portion46moves relatively to the holding portion290dof the lever290, the roller295rolls on the engaging portion46to reduce the friction force occurring between the holding portion290dand the engaging portion46.

The rod91is pivotably provided via the pin290aat one end of the lever290on the side opposite the lever bracket296and is insertably fitted to the rod support member248secured to the side frames19,19. The rod support member248is disposed forward of the housing41and below (downward inFIG. 10) the lever support member294. The rod91extends from the pin290aof the lever290in the direction of the rod support member248.

During the crushing work (in the state illustrated inFIG. 10), the housing41is such that the engaging portion46is fixed and held at a closing position by the holding portion290dof the lever290of the protection device214mounted to the side frames19, i.e., in the posture where the anvil33is disposed in the vicinity of the rotational trajectory of the crushing bit35. In this case, the roller295provided on the holding portion290dof the lever290presses rearward the engaging portion46of the housing41by the biasing force of the elastic member93transmitted via the lever290. When the force of the engaging portion46pressing the roller295forward exceeds the biasing force of the elastic member93transmitted to the roller295via the lever290, the lever290is turned to shift forward the roller295provided on the holding portion290d. As a result, the engaging portion46of the housing41rides across the roller295to permit the turning of the housing41. With such a configuration, if an excessive impactive force is applied to the anvil33, the lever290of the protection device214is turned in an opening direction (counterclockwise inFIG. 10) to release the restraint of the engaging portion46by the holding portion290d. The housing41is turned around the pivot shaft42to allow the anvil33to retreat from the crushing chamber31. Thus, components of the crusher including the anvil33can be prevented from being damaged. In this case, even after the anvil33has been retreated from the crushing chamber31by the excessive load in this embodiment as illustrated inFIG. 12, by depressing from above the engaging portion46of the housing41by means of e.g., a cylinder, a manual jack, a hand or the like, the posture of the housing41, i.e., the position of the anvil33with respect to the crushing chamber31can be returned to the state shown inFIG. 10. A stopper50is mounted to a stopper support member48secured to the side frames19. This stopper50limits the turning range of the housing41in the opening direction (counterclockwise inFIG. 10) thereof. Thus, the housing41and the other constituent elements can be prevented from interfering with each other.

The other configurations in the present embodiment are the same as those of the first embodiment.

A description is given of the operation of the embodiment configured as above.

During the crushing work, in the event that the crushing bit35and the anvil33hold a foreign object such as a stone, metal or the like, an excessive load is applied from the crushing bit35to the anvil33and transmitted to the holding portion290dof the lever290of the protection device214via the engaging portion46of the housing41.

In the event that the excessive impactive force is applied to the anvil33, the lever290of the protection device214is turned in the opening direction (counterclockwise inFIG. 10) to release the restraint of the engaging portion46by the holding portion290d. Because of the configuration of the protection device14as mentioned above, the housing41and the anvil33are turned around the pivot shaft42with respect to the side frames19to retreat from the crushing chamber31. Thus, components of the crusher including the anvil33are prevented from being damaged.

The hopping impactive force of the housing41encountered when the housing41is turned and retreated is absorbed by the stopper50. In addition, the housing41is returned to the original position (the closing position) by its own weight. However, when a position sensor not illustrated or the like detects the retreat of the housing41, the self-traveled crusher stops the operation for crushing the to-be-crushed object, specifically, the carrying-in of to-be-crushed object by the conveyor11, the rotation of the crushing rotor32, etc.

Also the present embodiment configured as described above can provide the same advantage as that of the first embodiment.

A third embodiment of the present invention is described with reference toFIGS. 13 to 16.

The present embodiment uses the protection device of the crushing apparatus illustrated in the first embodiment applied to a tub-type self-traveled crusher. In the figures, the same members as in the first embodiment are denoted with like reference numerals and their explanations are omitted.

FIG. 13is a lateral view illustrating an overall structure of the self-traveled crusher according to the third embodiment of the present invention.FIG. 14is a plan view ofFIG. 13.FIGS. 15 and 16are perspective views illustrating a detailed structure in the vicinity of a crushing apparatus312installed on the self-traveled crusher illustrated inFIG. 13.FIG. 15illustrates a case where a housing41lies at a closing position.FIG. 16illustrates a case where the housing41lies at an opening position. Incidentally, in the following, directions corresponding to the left and right inFIG. 13shall be the rear and front, or one and the other, respectively, of the crusher.

InFIGS. 13 and 14, the self-traveling crusher of the present embodiment generally includes: a track body301which allows self-propelling; a crushing function constituting portion302installed on the track body301to crush to-be-crushed object received; a discharge conveyor303which conveys the pieces of object crushed by the crushing function constituting portion302and discharges them to the outside; and a power arrangement (a power unit)304equipped with an engine, etc as a power source for devices mounted on the crusher.

The crushing function constituting portion302includes generally cylindrical rotary storing means (rotary tub)99and a crushing apparatus312(seeFIGS. 15 and 16). The storing means99is provided at an upper portion (upward inFIG. 1) of the crusher to receive to-be-crushed object from the generally vertical upside, specifically, from an opening portion provided at the upper portion thereof. The crushing apparatus312is provided below the rotary tub99to crush the to-be-crushed object introduced by the rotary tub99.

The rotary tub99is rotationally driven by a hydraulic motor not illustrated to sequentially introduce a large number of to-be-crushed objects stored therein.

Referring toFIG. 15, the crushing apparatus312includes: a crushing rotor32rotating at high speeds in a crushing chamber331; an anvil (fixed blade)33provided on the radially outside of the crushing rotor32; and a protection mechanism314for protecting the anvil33, the crushing rotor32, etc. The anvil33, a curved plate39, and screens (sieves)40are provided around the crushing rotor32from a portion (the upper portion of the crushing apparatus312) adapted to receive to-be-crushed object supplied thereto by the rotary tub99, in the normal-rotational direction of the crushing rotor32(the clockwise direction, in the flowing direction of to-be-crushed object inFIG. 15) so as to surround the crushing rotor32. The crushing chamber331, a cylindrical space, in which crushed pieces go around the crushing rotor32, is defined by the anvil33, the curved plate39, the screens40, etc.

The housing341holds the anvil33at a position close to the crushing chamber331and is supported pivotably in the back and forth direction at a position below the rotary tub99described earlier with a pivot shaft342, serving as a fulcrum, supported by bearings (not illustrated) provided on side frames319of the self-propelling crusher. In addition, the housing341is provided with a projecting portion46at an end located forward and obliquely downward (in the rightward downward direction) as viewed from the pivot shaft342. During normal time period (during the crushing work), the engaging portion46of the housing341is supported by a holding portion (described later) of a protecting device314(described later) mounted on the inner wall surfaces of the side frames319. In addition, the anvil33is held at the closing position (the position illustrated inFIG. 15) facing to-be-crushed object in the crushing chamber31. During the crushing work, in the event that an excessive load is applied to the anvil33, the holding portion of the protecting device314is shifted to release the restraint of the housing341. The housing341is turned around the pivot shaft342to the opening position (the position illustrated inFIG. 16) where the anvil33retreats from the crushing chamber331.

The protection device314includes a lever bracket96, a lever90, a roller95, a rod support member348, a rod91, an elastic member93and a shim92. The lever bracket96is mounted to a lever support member94disposed along the body-width direction (the direction perpendicular to the sheet surface inFIG. 15) and secured at each end thereof to the side frame319. The lever90is pivotably mounted to the lever bracket96via a pin90b. The roller95is turnably provided at one end of the lever90close to the housing41via a pin90c. The rod support member348is disposed along the body-width direction (the direction perpendicular to the sheet surface inFIG. 15) and secured to the side frames319. The rod91is turnably provided at one end of the lever90opposite the housing341via a pin90a. The elastic member93is interposed between the lever90and the rod support member348so as to receive the rod91passed therethrough. The shim92is inserted between the lever support member94and the elastic member93.

A portion of the lever90extending from the pin90bto the side of the pin90cplays a role of a holding portion. This holding portion is provided at one end close to the housing41to hold the engaging portion46of the housing41to keep a posture where the anvil33faces the crushing chamber31.

The lever support member94is disposed forward and downward (the right downward direction inFIG. 15) of the housing41.

The lever bracket96is provided at the general center of the lever support member94secured at both ends thereof to the side frames319, i.e., at a position corresponding to the engaging portion46of the housing341so as to project upward (the upper direction inFIG. 15) from the lever support member94.

The rod91is pivotably supported via a pin90aat one end of the lever90on the side opposite the housing41and is insertably fitted into the rod support member348secured to the side surfaces319. The rod support member348is disposed on the side opposite the housing341with respect to the lever support member94. The rod91extends from the pin90aof the lever90toward the rod support member348.

The other configurations of the present embodiment are the same as those of the first embodiment.

A description is given of the operation of the present embodiment as described above.

To-be-crushed object is fed into the rotary tub99by the heavy machine (a hydraulic shovel or the like) equipped with the appropriate working tool such as a grapple. A large number of the to-be-crushed objects stored inside the rotary tub99are introduced into the crushing apparatus312by the rotation of the rotary tub99.

The crushing bits35of the crushing rotor32rotating at high speed collide with the to-be-crushed object introduced into the crushing chamber331, thereby roughly crushing that into crushed pieces. The crushed pieces collide with the anvil33to be more finely crushed by the impactive force. Also thereafter, the crushed pieces go-around in the crushing chamber331along with the rotation of the crushing rotor32and collide with and are crushed by the crushing bits35, the anvil33, the inner wall of the crushing chamber31, etc. Of the circulating crushed pieces, crushed pieces that are made finer into such a size as to pass through the discharge holes of the screens40sequentially pass through the screens40and are discharged from the crushing chamber331. The crushed pieces discharged from the crushing chamber331drop onto the discharge conveyor303to be conveyed and discharged to the outside of the crusher.

When the crushing work mentioned above is carried out, the crushing bit35and the anvil33may hold therebetween a foreign object such as a stone, metal or the like. In such an event, an excessive load is applied from the crushing bit35to the anvil33and transmitted to the holding portion of the lever90of the protection device314via the engaging portion46of the housing341.

In the event that the excessive impactive force is applied to the anvil33, the lever90of the protection device314is turned in the opening direction (counterclockwise inFIG. 15) to release the restraint of the engaging portion46by the holding portion. Because of the configuration of the protection device314as mentioned above, the housing341and the anvil33are turned around the turning shaft342with respect to the side frames319to retreat from the crushing chamber331. Thus, components of the crusher including the anvil33are prevented from being damaged.

The hopping impactive force of the housing341encountered when the housing341is turned and retreated is absorbed by the stopper not illustrated. In addition, the housing341is returned to the original position (the closing position) by its own weight. However, when a position sensor not illustrated or the like detects the retreat of the housing341, the self-traveled crusher stops the operation for crushing the to-be-crushed object, specifically, the carrying-in of to-be-crushed object by rotation of the rotary tab99, the rotation of the crushing rotor32, etc.

The present embodiment configured as described above can provide the same advantage as that of the first embodiment.

Incidentally, the present embodiment describes the case where the protection device of the first embodiment is used for the tub-type crusher by way of example. However, the invention is not limited to this. The protection device of the second embodiment may be used. Also such a case can provide the same advantage as that of the first embodiment.

A fourth embodiment of the present invention will be described with reference toFIGS. 17 to 26.

The present embodiment makes use of an engaging portion446and a protection device414in place of the engaging portion46and the protection device14, respectively, illustrated in the first embodiment. An amount of engagement (described later) between the engaging portion446and the protection device414which holds the engaging portion446to keep the posture of the housing441at the closing position is adjusted to adjust a frequency in which a housing441is turned to retreat the anvil33from a crushing chamber31.

The details of the present embodiment are hereinafter described with reference to the drawings. In the figures, the same members as in the first embodiment are denoted with like reference numerals and their explanations are appropriately omitted.

FIGS. 17 to 19are perspective lateral views illustrating a detailed structure in the vicinity of a crushing device12installed in a self-traveled crusher according to the present embodiment.FIG. 17illustrates a case where the housing441lies at a closing position as a position during crushing work.FIG. 18illustrates a case where the housing441is being turning from the closing position to the opening position.FIG. 19illustrates a case where the housing441lies at an opening position as a retreat position of the anvil33. Incidentally, like the first embodiment, directions corresponding to the left and right inFIGS. 1 and 2shall be the rear and front, or one and the other, respectively, of the crusher.

InFIGS. 17 to 19, the housing441holds the anvil33on the side of a crushing chamber31. The housing441is supported above the pivot shaft22of the pressing roller device13described earlier so as to be turnable in the back and forth direction with the pivot shaft42, serving as a fulcrum, supported by bearings not illustrated provided on the side frames19. In addition, the housing41is provided with an engaging portion446(described later) at its front end portion extending forward as viewed from the pivot shaft42. The housing441is formed so that a distance from the pivot shaft42or a fulcrum to the anvil33as a point of effort may be generally equal to a length (distance) from the pivot shaft42to the engaging portion446or a point of load. Thus, the same load as that applied to the anvil33is applied to the engaging portion446. Incidentally, as described in the first embodiment, the length (distance) from the pivot shaft42to the engaging portion446may be increased or reversely reduced compared with the length from the pivot shaft42of the housing441to the anvil33.

During the normal time period (during crushing work), the engaging portion446of the housing441is supported by a holding portion490d(described later) of a protection device414provided on the inner wall surface of the side frames19. In addition, the anvil33is held at a closing position (the position indicated inFIG. 17) opposed to the to-be-crushed object in the crushing chamber31. During the crushing work, if an excessive load is applied to the anvil33, a load generally equal to such an excessive load is applied to the protection device14to shift forward the holding portion490dof the protection device14. This releases the restraint of the engaging portion446of the housing41(seeFIG. 18). Consequently, the housing441is turned around the pivot shaft42to an opening position (the position illustrated inFIG. 19) where the anvil33retreats from the crushing chamber33.

In the following, the forward displacement of the holding portion490drequired to release the restraint of the engaging portion446is referred to as the engaging amount.

A detailed description is now given of the engaging portion446and the protection device414with reference toFIGS. 20 to 26.

FIG. 20is a lateral view extracting and illustrating the housing441lying at the closing position, its engaging portion446, and the protection device414as well as their peripheral configurations.FIG. 21is a plan view extracting and illustrating the housing441and protection device414shown inFIG. 20as well as their peripheral configurations.FIG. 22is a cross-sectional view taken along line A-A shown inFIG. 21. Incidentally, the left and right directions inFIG. 21correspond to the rear and front directions, respectively, of the self-traveled crusher illustrated inFIGS. 1 and 2.

Referring toFIGS. 20 to 22, the engaging portion446includes: a latch447in abutment against the holding portion490dof the protection device414; a case452holding the latch447in a state where its portion abutted against the holding portion490dis projected; and a base portion449adapted to secure the case452to the housing441.

The case452has an opening portion from which the latch447projects toward the protection device414. The case452is arranged as below. The opposite side of the opening portion, i.e., the back side of the opening portion in the case452(hereinafter described as the back side) is oriented in the turning-retreat direction of the housing441. Further, the case452is inclined with respect to the turning-retreat direction so that the opening portion side is located more far away from the pivot shaft42as the turning center of the housing441than the back side. In other words, in the case where the housing441lies at the closing position (seeFIG. 20), the case452is arranged such that the back side is oriented rearward and obliquely upward (leftward and obliquely upward inFIG. 20) and the opening portion side is oriented forward and obliquely downward. Of a wall surface of the case452extending on the opening portion side, a wall surface on the side of the housing441is formed longer than that on the side of the holding portion490d.

The latch447is held along the wall surface on the side of the housing441and of the holding portion490din the case452so as to be slidable in the back direction and in the opening portion direction (movable forward and rearward). An amount of projection of the latch447from the opening portion of the case452is adjusted by sliding the latch447with respect to the case452. One end of the latch447close to the opening portion of the case452is curved from a side of the case452close to the holding portion490dto an end face (the face formed toward the sliding direction) of the case452close to the opening portion.

When the housing441lies at the closing position, the latch447is abutted against the holding portion490dat its horizontal direction with respect to the sliding direction thereof. In addition, the latch447is pressed against the wall surface of the case452close to the housing441. In this case, since a force applied from the holding portion490dto the latch447is vertical to the slidable direction of the latch447, a friction force occurs between the latch447and the wall surface of the case452close to the housing441. This suppresses the sliding of the latch447with respect to the case452resulting from the latch447pressed by the holding portion490d. The contact point between the holding portion490dand the latch447may coincide with the curved portion of the latch447. Also in such a case, a component, vertical to the sliding direction of the latch447, of the force applied from the holding portion490dto the latch447causes a friction force between the latch447and the wall surface of the case452close to the housing441.

The latch447is provided with a bolt hole (not illustrated) at one end on the back side of the case452. This bolt hole is formed with an internal thread portion on the inner circumferential portion. Bolts450provided on the outer circumference of its barrel portion (not illustrated) with an external thread portion threadedly engaged with the corresponding bolt holes are inserted in the direction along the sliding direction of the latch447. In the present embodiment, a plurality of (e.g. three) bolts450are arranged side by side in the left-right direction (the vertical direction inFIG. 21) at one end of the latch447on the back side.

The bolts450are slidably passed through respective through-holes (not illustrated) provided at one end of the case452on the back side. The bolts450are each arranged such that its head450aformed to have a diameter greater than that of the through-hole is located externally of the case452. Thus, the latch447and the bolt450integrally slide with respect to the case452. In addition, the bolt450limits the range where the latch447is slidable in the direction of the opening portion of the case452. Such a range is determined depending on the distance between the head450aof the bolt450and the latch447. In this way, the bolt450is turned to adjust the amount of insertion of the latch447into the bolt hole. Thus, the adjustment is carried out by changing the distance between the head450aof the bolt450and the latch447.

InFIG. 22, a spring451interposed between the case452and the latch447is provided in the case452so as to receive the bolt450passed therethrough. The latch447is biased in the opening portion side of the case452by the spring451and is disposed at one end of the slidable range on the opening portion side.

When the force applied to the latch447from the opening portion side of the case452in the sliding direction of the latch447exceeds the biasing force of the spring451, the latch447is slid in the back side of the case452. As such a case,FIGS. 23 and 24illustrate the case where the housing441is brought (returned) from the opening position to the closing position.FIG. 23illustrates the state where the latch447comes into contact with the holding portion490d.FIG. 24illustrates the state where the housing441is further shifted to the closing position side from the position illustrated inFIG. 23. InFIGS. 23 and 24, as the housing441is shifted from the opening position direction to the closing position direction, the latch447is slid toward the back side of the case452. Thus, the projecting amount of the latch447toward the protection device414is temporarily reduced.

FIG. 25illustrates the case where the latch447is disposed close to the opening portion of the case452with respect to the position (hereinafter, called as the reference position) of the latch447inFIG. 20.FIG. 26illustrates the case where the latch447is disposed on the back side of the case452.

As illustrated inFIG. 25, the distance between the head450aof the bolt450and the latch447is increased to shift the latch447toward the opening portion side of the case452with respect to the reference position. This increases the projecting amount of the latch447toward the protection device414, which increases the engaging amount of the engaging portion446with the holding portion490d. Thus, the force of the holding portion490dholding the latch447is increased. As illustrated inFIG. 26, the distance between the head450aof the bolt450and the latch447is reduced to shift the latch447toward the back side of the case452with respect to the reference position. This reduces the projecting amount of the latch447toward the protection device414, which reduces the engaging amount of the engaging portion446with the holding portion490d. Thus, the force of the holding portion490dholding the latch447is reduced.

The description is returned toFIGS. 17 to 19.

The protection device414includes a lever bracket496, a lever490, a rod91, a roller495, a rod support member448, an elastic member93and a shim92. The lever bracket496is mounted to a lever support member494disposed along the body-width direction (the vertical direction in the figure) and supported at both ends thereof by the side frames19. The lever490is pivotably mounted at one end thereof to the lever bracket496via a490b. The rod91is pivotably provided at one end of the lever90opposite the lever bracket496via a pin490a. The roller495is turnably provided at a projecting portion490d, close to the housing441, of a barrel portion of the lever490via a pin490a. The rod support member448is disposed along the body-width direction (the direction perpendicular to the sheet surface in the figure) and supported at both ends thereof by the side frames19. The elastic member93is interposed between the lever490and the rod support member448to receive the rod91passed therethrough. The shim92is inserted between the rod support member448and the elastic member93.

The lever support member494is disposed forward (on the right side inFIG. 17) of the housing441.

The pin490cof the lever490is disposed so that the distance between the pin490cand one end close to the pin490bat which the lever bracket496is provided is smaller than the distance between the pin490cand one end close to the pin490aat which the rod91is provided. Thus, the force applied to one end close to the pin490aor a point of effort in the turning direction becomes greater at the pin490cor a fulcrum because of passing the pin490cor a point of load.

The lever490has the projecting portion490dat the barrel portion close to the housing441. The projecting portion490dplays a role of a holding portion for holding an engaging portion446of the housing441to keep a posture where the anvil33faces the crushing chamber31. The roller495is turnably provided via the pin490cat an abutment position of the holding portion490dagainst the engaging portion446. When the engaging portion446moves relatively to the holding portion490dof the lever490, the roller495rolls on the engaging portion446to reduce the frictional force occurring between the holding portion490dand the engaging portion446.

The rod91is pivotably provided via the pin490aat one end of the lever490on the side opposite the lever bracket496and is insertably fitted to the rod support member448secured to the side frames19,19. The rod support member448is disposed forward (in the right direction inFIG. 17) of the housing441and above (upside inFIG. 17) the lever support member494. In addition, the rod91extends from the pin490aof the lever490toward the rod support member448.

During the crushing work (in the state illustrated inFIG. 17), the housing441is such that the engaging portion446is fixed and held at a closing position by the holding portion490dof the lever490of the protection device414mounted to the side frames19, i.e., in the posture where the anvil33is disposed in the vicinity of the rotational trajectory of the crushing bit35. In this case, the roller495provided on the holding portion490dof the lever490presses rearward the latch447of the engaging portion446of the housing441by the biasing force of the elastic member93transmitted via the lever490. When the force of the engaging portion446pressing the roller495forward exceeds the biasing force of the elastic member93transmitted to the roller495via the lever490, the lever490is turned to shift forward (in the right direction inFIG. 17) the holding portion490dand the roller495. When the displacement amount of the roller495of the holding portion490dexceeds the engaging amount of the engaging portion446with the holding portion490d, the engaging portion446of the housing441rides across the roller495of the holding portion490dto permit the turning of the housing441. With such a configuration, if an excessive impact force exceeding the reference load of the protection device414predetermined by adjusting the biasing of the elastic member93is applied to the anvil33, the lever490of the protection device414is turned in an opening direction (counterclockwise inFIG. 17) to release the restraint of the engaging portion446by the holding portion490d. The housing441is turned around the pivot shaft42to allow the anvil33to retreat from the crushing chamber31. Thus, components of the crusher can be prevented from being damaged. In this case, even after the anvil33has been retreated from the crushing chamber31by the excessive load in this embodiment as illustrated inFIG. 19, by depressing from above the engaging portion446or the housing441, the state of the anvil33and of the housing441can be returned to the state shown inFIG. 17. A stopper50is mounted to a stopper support member48secured to the side frames19. This stopper50limits the turning range of the housing441in the opening direction (counterclockwise inFIG. 17) thereof. Thus, the housing441and the other constituent elements can be prevented from interfering with each other.

The other configurations of the present embodiment are the same as those of the first embodiment.

A description is given of the operation of the present embodiment configured as described above.

When the crushing work is carried out, the crushing bit35and the anvil33may hold therebetween a foreign object such as a stone, metal or the like. In such an event, an excessive load is applied from the crushing bit35to the anvil33and transmitted to the holding portion490dof the lever490of the protection device414via the engaging portion446of the housing441.

In the event that the impactive load in excess of the reference predetermined by adjusting the biasing force of the elastic member93is applied to the anvil33, the lever490of the protection device414is turned in the opening direction (counterclockwise inFIG. 17) to shift forward the roller495of the holding portion. The latch447of the engaging portion446rides across the roller495of the holding portion to release the restraint of the engaging portion446by the protection device414to permit the turning of the housing441. In this case, as illustrated inFIG. 19, the housing441and the anvil33are turned around the pivot shaft42with respect to the side frames19to retreat from the crushing chamber31. Thus, components of the crusher are prevented from being damaged.

The impactive load as a reference to retreat the anvil33from the crushing chamber31is adjusted by changing the projecting amount of the latch447with respect to the case452. For example, the projecting amount of the latch447is increased to increase the engaging amount of the latch447with the holding portion490d, whereby the force for holding the housing441, of the holding portion490dof the protection device414, is increased. In addition, the projecting amount of the latch447is reduced to reduce the engaging amount of the latch447with the holding portion490d, whereby the force for holding the housing441, of the holding portion490dof the protection device414, is reduced.

The hopping impactive force of the housing441encountered when the housing441is turned and retreated is absorbed by the stopper50. In addition, the housing441is returned to the original position (the closing position) by its own weight. However, if a position sensor not illustrated or the like detects the retreat of the housing441, the self-traveled crusher stops the crushing operation of the to-be-crushed object, specifically, the carrying-in of a to-be-crushed object or the like, the rotation of the crushing rotor32, etc.

When the anvil33is retreated from the crushing chamber31by the excessive load, by depressing from above the engaging portion446or the housing441by means of e.g., a cylinder, a manual jack, a hand or the like, the state of the anvil33and of the housing41is returned to the closing position.

Also the present embodiment described above can provide the same advantage as that of the first embodiment.

The engaging portion446of the housing441is provided with the latch447, whose position is adjusted to adjust the engaging amount with the holding portion490d. With such a configuration, a load as a reference to pivotally retreat the housing441can be adjusted without replacing the shim92and elastic member93of the protection device414.

Further, when the housing441is shifted from the opening position to the closing position, i.e., when the anvil33is returned from the retreat position to the crushing position, the latch447is pressed and slid by the holding portion490dto temporarily reduce the amount of projection from the case452. With such a configuration, the position of the anvil33can be restored by the smaller force.

Incidentally, in the embodiments described above take as an example, the case where the rubber spring or urethane spring is used as the elastic member of the protection device. However, the present invention is not limited to this. For example, as illustrated inFIGS. 8 and 9, the coil spring may be used as the elastic member. Additionally, the description is given by taking as an example the case where the single protection device is used. However, the invention is not limited to this. For example, the protection device may be provided at both ends of the lever support member. Further, the biasing force adjusting means for adjusting the biasing force of the elastic member against the lever is configured to adjust the biasing force by the number or thickness of the shim. However, the invention is not limited to this. For example, the biasing force adjusting means may be configured such that an adjusting screw is provided and turned to adjust the biasing force. Alternatively, the elastic member is replaced with another one having a different elastic force.