Concrete pulverizer

A concrete pulverizer adapted for mounting on an arm of an excavator including a lower jaw having a first pivot pin mechanism and a crushing surface. The crushing surface on this jaw is formed with concrete waste apertures. An upper jaw has a rear end section connectible to an end of the arm and has crushing teeth mounted on a lower side. This jaw is pivotably connected to the lower jaw by the pivot pin mechanism. The upper jaw is pivotably connected to a hydraulic cylinder actuator on the arm and can be pivoted between an upper position and a crushing closed position. There is a power mechanism for pivoting the lower jaw between a horizontal scooping position and a dumping position and this mechanism can hold the lower jaw in a crushing position while the upper jaw is being pivoted by the hydraulic cylinder actuator.

PRIOR APPLICATION

This application claims priority on the basis of a Canadian Patent Application Number 2,706,174 filed Jun. 2, 2010.

This invention relates to concrete pulverizers for breaking pieces of concrete such as those found at a demolition site and particularly concrete pulverizers adapted for mounting on the end of the arm of a power excavator and this invention further relates to concrete handling machines for picking up and breaking pieces of concrete.

BACKGROUND OF THE INVENTION

The demolition of concrete structures and highway reconstruction can present significant problems in the disposal of large pieces of concrete including reinforced concrete and concrete paving. For example the disposal of large concrete slabs and large reinforced concrete structures can be difficult. One solution to the disposal of such concrete pieces is the use of a crusher or pulverizer which can break large concrete pieces into smaller particle sizes and chunks. By breaking the concrete up, one may be able to reuse the concrete as fill or as an aggregate base for roadways and other construction sites.

Concrete processors used for demolition can be broken into two broad categories of crushing equipment. The first category consists of primary processors which can be good for the demolition of concrete and precast structures. These processors which are designed for controlled demolition are able to deliver force to a small surface area using high pressure which results in clean, precise cracks. Such processors can also be used as a secondary concrete crusher for recycling. The second category of concrete processors is mainly used for secondary breaking of reinforced concrete. These processors can break concrete into further fines for recycling and they can be used to separate concrete from rebar. Such processors are able to deliver force over multiple points and this process causes the concrete to crumble. These processors can be attached to the dipper arm of a power excavator as an attachment which replaces the usual bucket used for digging.

A particular form of concrete pulverizer that can be referred to as a mechanical pulverizer is adapted for attachment to the outer or front end of the dipper arm of an excavator and this pulverizer uses the existing bucket cylinder mounted on the dipper arm to pulverize or crush the concrete piece by means of a jaw or tool connected to the hydraulic cylinder actuator. An advantage of a pulverizer of this type is that it is faster to operate and it can be less expensive than a hydraulically operated pulverizer that employs its own hydraulic cylinder or cylinders for the pulverizing operation.

One known form of mechanical pulverizer is taught in U.S. Pat. No. 6,129,298 issued Oct. 10, 2000 to National Attachments, Inc. This known pulverizer is mounted on the outer end of the dipper arm of an excavator and it includes two jaws confronting and closing on one another and an independent ripper-shank with a ripper tooth. Each jaw includes teeth that serve to engage and fracture concrete slabs. One of the jaws can be pivoted by the large hydraulic cylinder actuator mounted on the front side of the dipper arm or dipper stick. The pulverizer/ripper unit is pivotably attached at 3 points at the end of the dipper stick. Each of the two jaw sections includes multiple projections in the form of upper and lower teeth with a working gap located these two sets of teeth.

There is a need for an improved mechanical-type pulverizer that is better able to pickup chunks of concrete and that is better able to position each large chunk closer to the pivot axis of the jaws of the pulverizer so that a better crushing force can be applied to the concrete piece.

SUMMARY OF THE PRESENT DISCLOSURE

According to one embodiment of the present invention, a concrete pulverizer is adapted for mounting on an outer end of a dipper arm of a power excavator, this dipper arm having a hydraulic cylinder actuator mounted on a front side of the dipper arm. The pulverizer includes a movable lower jaw having a pivot pin mechanism and a crushing surface on which a concrete piece can be received. The crushing surface is formed with concrete waste apertures. A set of forwardly projecting teeth are mounted along a front edge of the lower jar. The pulverizer also has a movable upper jaw having a rear end section adapted for connection to the outer end of the dipper arm and having crushing teeth mounted on a lower side of the upper jaw. This upper jaw is pivotably connected to the lower jaw by the pivot pin mechanism. A further pivot arrangement is provided to pivotably connect the upper jaw to the hydraulic cylinder actuator whereby the upper jaw can be pivoted from an upper open position to a crushing closed position by the hydraulic cylinder actuator. The crushing teeth lie adjacent to the crushing surface in the closed position of the upper jaw. The pulverizer also has a power mechanism for pivoting the lower jaw between a horizontally extending scooping position for picking up the concrete pieces and a dumping position. This power mechanism is adapted to hold the lower jaw in a crushing position while the upper jaw is being pivoted by the hydraulic cylinder actuator for a concrete crushing operation.

In an exemplary version of this pulverizer, the power mechanism is a second hydraulic cylinder actuator connected at one operating end thereof to the lower jaw and connectable at an opposite end of the actuator to a side of the dipper arm.

According to another embodiment of the invention, a concrete pulverizer for breaking pieces of concrete is adapted for mounting on an outer end of a dipper arm of a power excavator, this dipper arm having a hydraulic cylinder actuator mounted on a front side of the arm. The pulverizer includes a movable lower jaw forming a crushing upper surface on which a concrete piece can be received, having a front edge on which a set of teeth are mounted, and having a rearwardly extending, elongate arm rigidly connected to the lower jaw and adapted for orienting the lower jaw. There is also a movable upper jaw having a first pivot mechanism for pivotably connecting a rear end section of the upper jaw to the outer end of the dipper arm, having a mechanism for crushing the concrete piece between the upper jaw and the upper surface of the lower jaw, and having a second pivot mechanism for pivotably connecting the upper jaw to the hydraulic cylinder actuator whereby the upper jaw can be pivoted from an upper opened position to a closed position by the hydraulic cylinder actuator. The crushing mechanism lies adjacent the crushing upper surface in the closed position of the upper jaw. There is a further hydraulic power device connectable to a rear end section of the rearwardly extending arm in order to pivot the lower jaw to a plurality of desired operating positions. During use of the pulverizer on a dipper arm, the lower jaw can be pivoted to a horizontally extending operating position in order to scoop up one or more concrete pieces to be crushed.

In an exemplary version of this pulverizer, the hydraulic power mechanism is a second hydraulic cylinder actuator comprising a hydraulic cylinder and an extendable actuator rod. The hydraulic cylinder is connectable at an upper closed end thereof to a rear side of the dipper arm while the actuator rod is pivotably connectable to the rear end section of the elongate arm. According to yet another embodiment of the invention, a concrete pulverizer for mounting on a movable arm of a power excavator is provided. The arm of the excavator has an extendable hydraulic cylinder actuator mounted on a front side thereof. The pulverizer includes an upper jaw having a rear end section pivotably connectable to one end of the arm and having a front end. The upper jaw is adapted for connection to the hydraulic cylinder actuator for pivotal movement thereby. A first row of forwardly extending pickup teeth are mounted on the front end of the upper jaw. A lower jaw has a rear portion connected to the rear end section of the upper jaw for pivotal movement about a primary pivot axis. The lower jaw forms a crushing surface on an upper side thereof on which a concrete piece can be received and the lower jaw has a front edge. A second row of forwardly extending pickup teeth are mounted on this front edge. There is also an actuator mechanism adapted for mounting on the arm and for connection to the lower jaw, this mechanism during use of a pulverizer being capable of pivoting the lower jaw about the primary pivot axis and between a horizontally extending concrete scooping position and a dumping position. The two rows of pickup teeth are approximately the same perpendicular distance from the primary pivot axis. During use of the pulverizer, the two jaws can be pivoted towards each other to a pickup position where front tips of the teeth in one of the rows are closely adjacent front tips of the teeth in the other of the rows.

While a preferred embodiment is disclosed herein, this is not intended to be limiting. Rather, the general principles set forth herein are considered to be illustrative of the scope of the present invention and it is to be understood that numerous changes may be made without straying from the scope of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT

Referring toFIG. 1, there is shown a concrete handling machine indicated generally at10capable of picking up and breaking pieces of concrete (not shown). This machine includes a mobile construction machine12adapted to carry a machine operator in an operator cab14. It will be understood that the mobile construction machine can be of known construction and can be the same as those commonly available for power excavators having a backhoe type digging attachment with a bucket. The illustrated construction machine is mounted on a standard set of tracks16and it will be understood that there are two tracks that support a central pivot support18on which an upper portion20of the machine is able to pivot about a vertical axis. An elongate boom or boom structure22is mounted on the upper portion of the construction machine and tiltably extends there from to a front end24of the boom. The boom is able to be raised or lowered by means of two hydraulic cylinder actuators26, one on each side of the boom. The rear end of the boom is pivotably mounted to the upper portion of the machine as shown. Mounted on top of the boom is a further hydraulic cylinder actuator28which can be of standard construction. Pivotally mounted on the front end of the boom is an elongate dipper arm30which can also be termed a dipper stick and which is commonly found in a standard power excavator. The dipper arm has a lower or forward end at32on which is mounted a concrete pulverizing attachment constructed in accordance with the present invention, this pulverizing attachment pulverizer indicated generally at34. The dipper arm or dipper stick is pivotally mounted at36to the boom and it will be understood that the hydraulic cylinder actuator28is capable of pivoting the swinging arm about a substantially horizontal axis located at36. In particular a rod38of the actuator has its outer end pivotably connected to the top or rear end of the dipper arm.

Pivotally mounted on the swing arm is an additional hydraulic cylinder actuator40which can be pivotably attached to the dipper arm by a pair of brackets42. The actuator40is provided for the purpose of enabling an upper jaw44of the pulverizing attachment to be pivoted about a substantially horizontal pivot axis at46. It will be understood that a single pivot pin can be provided at46to connect a rear end section of the upper jaw to the forward end32of the swing arm. When the mobile construction machine12ofFIG. 1is not fitted with the concrete pulverizing attachment or pulverizer34, it can be fitted with a standard digging bucket (not shown) and, in this case, the actuator40can be used to operate the digging bucket in a normal fashion.

As illustrated, the extendable rod of the actuator40is pivotably connected to two pairs of links indicated at48and50which again can be of standard construction and are commonly used on the boom of an excavator. The pair of links50pivotably connect the outer end of the actuator rod to a front end section of the dipper stick30while the pair of links48pivotably connect the outer end of the rod to the upper jaw44. Also mounted on the bottom or rear surface of the dipper stick is a three-hole bracket52shown separately inFIG. 10. This bracket can be welded on one side to the dipper stick and it is used to adjustably connect an adapter54described in more detail hereinafter and shown inFIG. 9. Pivotably connected to this adapter by means of a pivot pin56is an additional hydraulic cylinder actuator58which acts as a hydraulic brace for the concrete pulverizer as explained later herein. This actuator has an extendable rod60and, with this rod, the actuator is able to control the orientation of a lower jaw62of the pulverizer.

Turning now toFIG. 2which illustrates an exemplary version of the concrete pulverizer34, its lower movable jaw has a pivot pin mechanism indicated generally at64. The upper jaw44is pivotably connected to the lower jaw by this pivot pin mechanism. The pivot mechanism can include a single pivot pin66extending through holes in upwardly extending legs of L-shaped side plates68. Each pin can extend through a bushing70that is mounted in the side plate68. An elongate wear rail72can be rigidly attached to the plate68along the top of its forwardly extending arm. These wear rails which can be made of hardened, wear resistant steel extend substantially perpendicular to a front edge74of the lower jaw. The lower jaw includes a steel grate (which can also be termed a grizzly plate) in which concrete waste apertures78are formed. These apertures can be arranged in a plurality of rows as shown and, in the illustrated embodiment, the grate has three rows extending in the transverse direction and three or four rows extending in the front to rear direction. The steel grate forms a crushing upper surface of the lower jaw on which a concrete piece can be received initially and then crushed. If desired, an optional row of crushing teeth can be provided in the middle of the grate76as shown. These teeth can be formed from a single steel plate which can be mounted in a vertical plane and can extend in the rear to front direction on the lower jaw. The crushing teeth80can be shaped in the same manner as crushing teeth mounted on the upper jaw which are described hereinafter. The plate forming the teeth80can be welded to the grate76.

A set of forwardly projecting teeth82, which can be described as pickup teeth, are mounted along the front edge74of the lower jaw. The teeth82in an exemplary version of the pulverizer are detachable teeth so that they can be readily replaced. The base of each tooth fits into a respective tooth socket84formed on the front edge of the jaw. The teeth are preferably spaced apart as shown and can be spaced apart a distance equal to the width of one tooth. The teeth, which are made of hardened steel, can have a straight, front edge86so that the teeth as a whole are suitable for scooping up heavy objects such as chunks of concrete. In other words the flat front edges are suitable for insertion between the ground or floor and the concrete piece or slab. It will be appreciated that by a forward movement of the pulverizer (with the jaws in the open position) using the dipper stick of the excavator machine even a large concrete piece can be scooped into the pulverizer so that it rests on the steel grate76.

Other features of the exemplary lower jaw shown include a relatively large, connecting tube88, the ends of which can be inserted through circular holes formed in each of the side plates68and these ends can be welded in the holes thereby forming a rigid connection between the two side plates. Also extending between the two side plates is a solid, generally rectangular front connecting plate90which can be tapered along its forward edge to form the front edge74. Side edge sections of the plate90can extend through respective slots formed at front end sections of the side plates68. As shown, each side edge92of the connecting plate can project a short distance beyond the outer side of the adjacent side plate68.

An exemplary version of the lower jaw62is provided with an elongate, rearwardly extending arm94which can be formed of two spaced-apart, parallel arm plates96. The outer end of the rod60is pivotably connected to a rear end section of the arm94by means of a pivot pin98. The pin hole in each plate96can be extended by means of a short sleeve member100, thereby providing a stronger connection between the pin and the arm. The two arm plates96can be rigidly connected to each other by means of a suitable connecting plate102. Also, an exemplary form of the arm has elongate wear bars104rigidly attached to the bottom edge of the arm plates96.

Turning now to the construction of the upper jaw44, a forward section of the jaw is formed by a rectangular, sloping front plate106and a front edge of this plate forms a front edge of the upper jaw to which a set of forwardly projecting pickup teeth108are connected. Each tooth108can be constructed and mounted in a similar manner as the teeth82on the lower jaw. Again the teeth108are detachable in an exemplary version of the pulverizer in order that they can be replaced from time to time as they become broken or worn. The base of each tooth is mounted in a tooth socket110which in turn is mounted in or on the plate106. As shown, the teeth108are spaced apart from one another and, in the exemplary arrangement, the gap between adjacent teeth is slightly greater than the width of each tooth82. It will be appreciated fromFIGS. 1,2and7that the two rows of pickup teeth, that is the row of teeth82and the row of teeth108are approximately the same perpendicular distance from the primary pivot axis indicated at A and defined by the pivot pin66. During use of the pulverizer, the two jaws can be pivoted towards each other to a pickup position shown inFIG. 7where the front tips of the teeth in one of the rows are closely adjacent the front tips of the teeth in the other of the rows. Thus the present pulverizer is a very good power tool for picking up large pieces of concrete and concrete slabs either to move them to a different location or in order to carry out a crushing operation. Moreover, because of the spacing of the pickup teeth, the set of teeth mounted in one row can mesh with the second set of teeth mounted on the other jaw when the two jaws are pivoted relative to one another to a fully closed position, this position being shown inFIG. 8.

The upper jaw also has a steel, rectangular base plate112which is attached, such as by welding along its front edge to the front plate106. Extending upwardly from the plate112are two, spaced apart connecting plates114and116. Through each of these plates extend two pivot pin holes118and120. The rearward holes118are used to connect a rear end section of the jaw to the outer or bottom end of the dipper arm30. A single pivot pin defines the aforementioned pivot axis at46. The forward holes120accommodate a pivot pin that connects the upper jaw to the two links48. To add to the rigidity of the upper jaw and its connecting plates, a steel connecting plate or bridge122extends between and connects the plates114and116.

The upper jaw is provided with crushing teeth124which are mounted on a lower side of the upper jaw. In particular these teeth can be mounted on the inwardly facing or bottom side of the base plate112. The crushing teeth124are formed by a series of parallel crushing teeth units126, one of which is shown separately inFIGS. 3 and 5. These units are arranged in a side-by-side manner on the upper jaw. In the illustrated crushing teeth unit126ofFIG. 3there are five teeth124of varying height. The forwardmost tooth124′ has the greatest height while the two teeth located at the rearward end128of the plate have the smallest height. These crushing teeth have rounded tips130and each tooth has a convex front surface132and a concave rear surface134. The front and rear surfaces meet at the rounded tip130. The bottom section136located between adjacent teeth can also form a concave surface. By providing the highest crushing teeth along the front of the upper jaw, they are able to assist in the initial grasping of the concrete piece or slab. The curvature of the crushing teeth also helps to pull the concrete piece or slab to the rear of the jaws where the greatest crushing pressure can be applied. The units126forming the crushing teeth are mounted in the upper jaw by using a pin and retainer system indicated generally inFIG. 5by reference140and support pockets and these plates can be replaced readily when required. The rear hole137for the pin is shown inFIG. 3. The forward end of each unit126can be formed with a right angled cutout138.

With reference toFIGS. 4 and 5, each crushing teeth unit126can be constructed from three steel plates that are welded together, these plates being indicated at150,152, and154. The two outer plates150and154have the same size and shape and each is formed with the aforementioned cutout138. The crushing teeth are formed along the bottom edge of each plate while the upper edges of the two outer plates have a straight central portion156. Near the forward end there is an upwardly sloping section158while the rear end of each outer plate is rounded at the top as indicated at160inFIG. 4. The thicker central plate152has a bottom edge which is shaped to form crushing teeth in the same manner as the outer plates. The shape of the central plate152is shown clearly inFIG. 6. The upper surface of the plate152is formed with a number of cavities or pockets162which can vary in depth.

Each unit126is mounted on a rigid, vertically extending support plate164of which there are four shown in the embodiment ofFIG. 4. Each of these plates is welded along a straight upper edge to the rectangular base plate112and each is formed with a pivot pin receiving hole166which can be lined with a suitable bushing. Near the hole166and slightly forward thereof is a smaller hole168which is used to mount a respective one of the crushing teeth units126on the plate164. Formed along the bottom edge of each plate164are several, rounded holding teeth170. These teeth extend into the aforementioned cavities162in the unit126and thus help to hold the unit126in place. A front edge of each plate164is welded to a nose plate172. The nose plate has a series of spaced apart, square notches174formed in its bottom edge and each of these receives a protruding bottom section176of a respective unit126. Formed near the front end of each plate164is a holding cavity180on one side of which is a rearwardly projecting lip182. The central steel plate152is formed with an upwardly and forwardly extending projection at184which fits snugly into the cavity180and the combination of the projection184and the lip182is used to hold the front end of each unit126in place on the jaw.

In the circled area projected fromFIG. 5there is shown the three components which make up the pin and retainer system140. These components include a lock washer190, a short pin192formed with a circumferential groove194and a bushing196. The pin extends through the bushing and the washer and the washer is pressed onto the pin so as to fit into the groove194. Thus the washer acts as a retainer to hold the pin in place once the pin is used to mount the rear end of the unit126. The pin and its bushing are accommodated in their respective hole168. It will be thus be seen that each crushing teeth unit126is detachably connected to a respective one of the support plates164and thus each unit126can be replaced or repaired when required.

Instead of forming the unit126using three steel plates as in the illustrated embodiment, it is also possible to form the crushing teeth unit as an integral casting made of abrasion resistant steel and a unit of this type can be less expensive to manufacture in quantity.

The pulverizer34as illustrated is particularly suitable for separating reinforced rod (rebar) from concrete demolition debris. This is accomplished by an efficient crushing of large concrete pieces or slabs using the replaceable pulverizing teeth124. As the concrete is crushed between the two jaws, smaller pieces of concrete can fall through the apertures78. With the present front end loaded pulverizer, the large dipper arm30of the excavator acts as part of the pulverizing structure and is loaded by the pulverizing cycle.

It will be appreciated that the hydraulic cylinder actuator or hydraulic brace58is provided for adjusting the position or orientation of the lower jaw (which can also be termed a mandible) and this actuator is not normally used for crushing. The actuator58can be retracted to allow scooping from the ground level as the dipper arm30is cast out by the machine operator. The actuator58can be extended to allow scooping in close to the machine with the dipper arm located close to the machine. The actuator58or brace can be extended to help position the jaws in a more vertical position, thereby encouraging concrete pieces to fall in closer to the jaw pivot axis by gravity.

It will be noted that the crushing teeth in the upper jaw oppose a flat, strong steel grate mounted in the lower jaw. Concrete chunks positioned between the two jaws are pulverized by pressure applied by the crushing teeth which have staggered heights. Although smaller chunks of concrete can fall through the waste apertures78of the grate, the grate tends to prevent rebar from falling with these chunks and concrete dust, thereby helping in the effort to separate the rebar from the concrete.

When the pulverizer jaws are mounted in the manner shown inFIG. 1to the dipper arm, the main mounting pins used to connect the rear end section of the upper jaw to the front end of the dipper arm are set at a wider centre distance to maximize the crushing forces produced by the cylinder actuator40. It is also possible to connect the pulverizer to the dipper arm by means of known types of pin-grabber couplers and quick couplers that allow the operator to switch from the pulverizer to a regular bucket and vice versa reasonably quickly and reasonably easily.

The adapter54shown inFIGS. 1 and 9allows the hydraulic cylinder actuator58to be used on an excavator that has been previously equipped with the known three hole bracket52. The adapter is mounted with two pins to the existing three hole bracket welded to the underside of the arm. In the illustrated version ofFIG. 10, a relatively large flat steel pad200can be provided to direct compressive forces up into the arm and thereby prevent the application of excessive torque on the three hole bracket.

The exemplary adapter54shown inFIG. 9includes an elongate steel bar202of rectangular transverse cross-section. Located at a forward end of this bar is a semi-cylindrical recess204which is sized to fit around a connecting pin206. Mid-way along the bar is pin receiving hole208. Mounted on the rear end of the bar are two similar, spaced apart brackets210,212, each of which is welded to a respective side of the steel bar. A pivot pin hole214is formed in each bracket and the perimeter of the hole can be reinforced by an annular rim216. The aforementioned pivot pin56extends through the holes214to attach the hydraulic cylinder actuator58. Details of the three-hole bracket to which the adapter is detachably connected can be seen inFIG. 10. The base of the bracket device is the aforementioned steel pad200which has two parallel longitudinal sides220and, in the exemplary embodiment shown, has end recesses222. Extending from the outer side of the pad are two bracket plates224,226and these are spaced apart a distance sufficient to receive the aforementioned steel bar202of the adapter. Each bracket plate is formed with three pin receiving holes indicated at230to232. If desired, a metal tongue or stop member234can extend upwardly between the bracket plates close to one end of these plates. The connecting pins which join the adapter to the three-hole bracket52can be secured in place by means of bolt and nut combinations240,242. The illustrated adapter ofFIG. 9is only connected to the three-hole bracket by means of two steel connecting pins206and244. It will be appreciated that by using the adapter54, the connecting pin56that extends through the adapter can be located further upwards on or rearwards on the dipper arm, thus allowing the use of a larger hydraulic brace.

While the present invention has been illustrated and described as embodied in an exemplary embodiment, e.g., an embodiment having particular utility in concrete pulverizing operations, it is to be understood that the present invention is not limited to the details shown herein, since it will be understood the various omissions, modifications, substitutions and changes in the forms and details in the disclosed concrete pulverizer and pulverizing machine may be made by those skilled in the art without departing in any way from the spirit and the scope of the present invention. For example, those of ordinary skill in the art will readily adapt the present disclosure for various other applications without departing from the spirit or scope of the present invention.