US2901232A

US2901232A - Mobile pavement breaker having leaf spring impact tool accelerating means

Info

Publication number: US2901232A
Application number: US563664A
Authority: US
Inventors: William H Lewis
Original assignee: CUTCRETE Manufacturing CORP
Current assignee: CUTCRETE MANUFACTURING CORP
Priority date: 1956-02-06
Filing date: 1956-02-06
Publication date: 1959-08-25
Anticipated expiration: 1976-08-25

Description

Aug. 25, 1959 W, H Ewls 2,901,232

LMOBILE PAVEMENT BREAKER HAVING LEAF' SPRING IMPACT TOOL ACCELERATING MEANS Filed Feb. 6, 1956 5 Sheets-Sheet l w NN NNN R. m W M w E s e 3N W l $1 .Il Jun m M A m 4 k u. W Y 'v B QW Aug. 25, 1959 W H, LEWls 2,901,232

I MOBILE PAVEMENT BREAKER HAVING LEAF SPRING IMPACT TOOL ACCELERATING MEANS Filed Feb. 6, 1956 5 Sheets-Sheet 2 INVENTOR. W/u mm H ew/5 Aug. 25, 1959 W. H.

MOBILE PAVEMENT BR LEWIS EAKER HAVING LEAF SPRING IMPACT TOOL ACCELERATING MEANS 5 Sheets-Sheet 3 Filed Feb. 6, 1956 R5 0/ W4, W l HM W m ,4

United States Patent() MOBILE PAVEMENT BREAKER LEAF SPRING MACT TOOL ACCELERATING MEANS William H. Lewis, Arcadia, Calif., assignor to `CutcreteV Manufacturing Corp., El Monte, Calif., a corporation off California Application February 6, 1956, Serial No. 563,664

9 Claims. (Cl. 262--18) The present invention relates generally'to thev eldof` road building and' more particularly to a mobile pavement breaker.

In repairing, replacing or` otherwise servicing paved surfaces such as roads, parking areas, airport runways and the like, it is sometimes necessary to break up and remove the existing pavement. Thereafter, such pavement is removed from its original site. Although there exist several types of mobile pavement breaking devices, they are generally expensive to maintain and service. These heretofore-proposed devices generally incorporate a heavy breaking hammer which is reciprocated against the pavement several times a minute. This hammer is either hydraulically or pneumatically urged into contact with the pavement, or alternately it may be raised a sufficient height above the pavement that it will break same upon being dropped from such height. Where the pavement breaking hammer is urged under power into contact' With the pavement, the driving mechanism is subjected to rapid wear because of the severe shocks imparted thereto. Where, on the other hand, the hammer is lifted a suiiicient height above the pavement that it may break same upon being dropped thereagainst, not only must a large and cumbersome structure be provided but additionally the number of blows per unit of time which may be undergone by the hammer -is necessarily limited.

It is a major object of the present invention to provide a novel and improved mobile pavement breaker which eliminates the disadvantages of the existing devices of this nature.

It is a more particular object of the invention to provide a mobile pavement breaker which is inexpensive to construct and maintain as compared to theretoforeproposed pavement breakers.

Another particular object of the invention is to provide a mobile pavement breaker which is compact in size and light of weight as compared to existing machines of this type.

A further object of the invention is to provide a mobile pavement breaker `which delivers a maximum amount of pavement breaking blows per unit of time.

An additional object of the present invention is to provide a mobile pavement breaker of the aforedescribed nature which is mounted upon a self-propelled, steerable, wheeled chassis.

Another object of the invention is to provide a mobile pavement breaker wherein the force with which its pavement breaking hammer is urged into the pavement may be readily controlled by a simple mechanism.

These and other objects and advantages of the present invention will become apparent from the following detailed description, when taken in conjunction with the appended drawings, wherein:

`Figure l is a side elevational view, taken partly in vertical section, showing a preferred form of mobile pavement breaker embodying the present invention;

` Figure 2 is a top'plan view lofs'aidV mobile pavement breaker; p

Figure 3 is an enlarged vertical sectionalview ofthe encircledarea designated` 3 ini Figure. 1";m

Figures 4 and 5 are fragmentaryV enlargedviews showing the operation. of the liftingfrneclianisn for the pavement breaking hariuner;

Figure 6 is a front elevationlviw dfsaid mobile pave`` ment breaker; l p

Figure 7` is an enlarged' vertical` sectional viewA taken' on line 7--7 of. Figure 1;,a"iid`` p v Figure 8 isa horizontal, viewr' taken along line 8-8. of Figure 7. p p p Referring tothe` drawings and particularly Figures 1, 2 and 6 thereof, the preferredformdf, mobile pavement breaker embodying the' present' irive'ritionY includes a wheeled frame FA movable" overl the pavementV P` to be broken. A pavement breakingA hammer'- H is' mounted at the rear portion of the' frame E forV vertical reciprocal movement relative thereto through a distance designated X-l in Figure 6; The hammer H'is corrected to a powerdriven hammer liftingmeans L( by means of a ilexible element, such as a' cable 22; The hammer lifting means L includes a crank arm 24 that is rotated by poweroperated means, such as an internalicornbuston engine. E mounted at the front" portion` of the frame F. After the hammer H has been lifted to' the top of its stroke by the crank arm 24 itispermitted to move downwardly under the influenceof gravity; Spring.` means S areinterposed between the frame F and the hammer H for accelerating the downward motion" of` the latter. The downwardly moving hammer H hits `the pavement P with considerable force so as to.' effect the. breaking thereof. In the preferred form of the mobile pavement breaker, the pavement breaking` hammer H, its lifting.

means L and the spring SV are carried upon an auxiliary frame A, the rear portion of which is caused to undergo pivotal movement in a horizontal plane relative to the main frame F. In this manner, the` hammer H is moved through an arcuate horizontal path relative to the rear portion of the main frame F. Referring to Figure 2, this arcuate motion takes placethrough an angle designated alpha on either side of the' longitudinal center line of the frame F. p C

More particularly, the' main frame F includes a pair of side elements 26 and 28 which are' interconnected at their front end by a cross-brace 30 and at their rear end by a cross-brace 32. A transverse cross-brace 34 interconnects the side members adjacent the4 rear portion ofthe engine E. The fro'nt wheelstare` supported at the outer ends of a rigid front axle 38. These wheels are each carried by a vertical pivot pin 4 0 from the rear end of which extends a steering" lever 42. The" rear ends of the steering levers 42 are pivotally attached" to either side of a transverse steering link 44. An actuating lever 46 extends rearwardly from one side of the steering link 46. The rear portion of this actuating lever 46 is formed with a slot 48 which slidably receivesithe free end of a plunger 50 that is `reciprocally` disposed within a hydraulic steeringV cylinder 52 carried by the' underside of the main frame F. A flexible l'rydraulic` line 54 extends from one end of the steering cylinder 52 tb a pump 56` mounted at the rear portion of the frame-F. Therear wheels 58l are mounted by a pair of rear axles rotatably disposed within a pair of axle housings 60. The* rear axles are connected to` a conventional diiferential 62' that is interposed* are connected to a second set of pulleys 70 keyed to the drive shaft 72 of the engine E by belts 74.

The auxiliary frame A includes an elongated box member.75 that is pivotally secured to. the transverse crossbrace 34 of the mainframe F by a vertical pivot bar 76 at a point adjacent the rear end of the engine E. Referring particularly to Figures 7 and 8, the rear portion of the-lower wall 77 of the box member 75 is formed with a longitudinally extending slot 78. This slot 78 intersects a transversely extending slot 80 formed in the upper wall 82 of the rear cross-brace 32. The rear p0rtion of the box member 75 is slidably connected to the rear cross-brace 32 of the frame F by a connector, generally ldesignated 84. This connector 84 includes a pair of rollers 86 and 88v disposed within the

slots

78 and 80, respectively. These

rollers

86 and 88 are journaled by a vertically extending bolt 90. An upper lretainer 92 is interposed between the head of the bolt 90 and the upper roller 86 and a lower retainer 94 is interposed between the lower roller 88 and a nut 96 secured to the lower end of the bolt 90. With this arrangement, the rear portion of the auxiliary frame F is free to undergo arcuate movement relative to the rear portion of the main frame F about a center corresponding with the center of the pivot bar 76.

The relative motion of the auxiliary frame A relative to the main frame F may be effected by means of a hydraulic cylinder 98 that is affixed to the underside of the box member 75 and a pair of plunger rods 100 and 102 which cooperate with this hydraulic cylinder. The mid-portion of this hydraulic cylinder 98 is formed with an upstanding pivot pin 104. A roller 106 journaled by this pivot pin 104 is slidably disposed within a longitudinally extending slot 108 formed in the lower wall 77 of the box member 75. The pair of plunger rods and 102 extend outwardly from the hydraulic cylinder and their outer ends arepivotally secured to the side elements 26 and 28, respectively, of the main frame F. A pair of flexible hydraulic conduits 110 and 112 extend from the outer ends of the hydraulic cylinder 98 to the pump 56. The rear end of the auxiliary frames box member 75 is formed with a vertically extending guide member 114 for the hammer H. The crank arm 24 is disposed above the guide member 114 and is carried by a horizontal lift- Ing shaft 116. The horizonatl lifting shaft 116 is journaled within an opstanding post 118 formed at the rear portion of the obx member 75, as shown in Figures 3, 4 and 5. The rear end of thisy lifting shaft 116 is keyed to a sprocket 119 and a chain 120 interconnects this sprocket 119 with a second sprocket 122 which is keyed to the output shaft 124 of a reduction gear box 126. The reduction gear box 126 is driven by the engine E through a take-olf shaft 128. A clutch 130 and a pair of univer-y sal joints 132 and 134 are provided for this take-off shaft, as shown in Figures l and 2. The pump 56 is driven through the reduction gear box 126.

Referring again to Figures 3, 4 and 5, a driving element 136 is keyed to the rear end of the lifting shaft 116 by a plurality of bolts 13S. The outer portion of this driving element 136 is formed with a pair of notches 142, one of which is adapted to abut a driving pin 144 extending from the intermediate portion of the crank arm 24. A covered sheave 146 is carried by the outer end of the crank arm 24. This sheave 146 encompasses the upper end of the looped cable 22, the lower end of the latter passing throughythe upper portion of the hammer H, as indicated in Figure 6. Referring to Figure 2, it will be observed that the axis of rotation of the lifting shaft 116 is transversely offset from the vertical center line of the hammer H a distance approximating the length of the crank arm 24.

The spring means S Ywill preferably include a multileaf spring 148 having its mid-portion rigidly affixed by a clamp 150 to a horizontal bar 15,2 disposed within the box member 75 of the auxiliary frame. The bar 152 iS f f "2,901,232y

[L pivotally supported upon a shaft 153 having its ends carried by the sides of the box member 75, as shown in Figure 7. The rear end of the leaf spring 148 is carried by the lower end of a vertically extending adjustment post 154. This adjustment post is engaged with a nut member 156 secured to the upper wall of the box member 75. The adjustment post 154 may be provided with a hand crank 157. The front portion of the leaf spring 148 extends through a vertical slot 158 into the confines of the guide member 114. n The operation of the aforedescribcd mobile pavement breaker is controlled by an operator (not shown) seated Y in a conventional seat or saddle 160 disposed at the rear portion of the box member 75. The operator is pro'- vided with a control panel 162. The device may be driven lto the pavement breaking site under its own power if desired. At this time, the take-off shaft 128 will be declutched from the engine E. When the pavement breaking operation is to begin, the main frame F will be stopped and the clutch 138 will be actuated so a-s to effect rotation of the take-off shaft 128. The rotation of the take-olf shaft 128 will be transferred to the lifting shaft 116 by means of the

sprockets

119 and 122 and the chain 128. Rotation of the lifting shaft 116 will be transferred to the crank arm 24 by means of the driving element 136, as indicated in Figures 4 and 5. When the crank arm 24 reaches a position approximating that of Figure 5, the hammer H will have been lifted to the top of its vertical travel. Thereafter, the hammer will be free to fall under the inuenec of gravity. The downward motion of the hammer H at this time will be accelerated considerably by the spring 148. Accordingly, by the time the lower end of the hammer H contacts the pavement P it will be travelling at considerable speed so as to deliver a powerful blow against the pavement. As the hammer H undergoes vertical reciprocation relative to the pavement P, the rear end of the auxiliary frame A will undergo concurrent pivotal movement relative to the rear portion of the main frame F. In this man. ner the entire pavement area adjacent the rear portion of the main frame F may be broken. The operator will preferably be provided with sufficient controls for adequately `adjusting the speed and force with which the hammer is operated as well as the speed at which the auxiliary frame A moves relative to the main frame F. The entire device may be moved over the surface of the pavement to be broken under its own power. Accordingly, once the pavement adjacent the rear portion of the main frame F has been broken, the device may be moved forward under its own power so as to break the next portion of the pavement. It should be especially noted that neither the cable 22 nor the spring 148 will transfer the impact shock of the hammer H to either of the frames F and A.

While there has been shown and described hereinbefore what is presently considered to be the preferred embodiment of the present invention, it will be apparent that various modifications and changes may be made thereto without departing from the spirit of the invention 0r the scope of the following claims.

1 claim:

1. A mobile pavement breaker, comprising: a Wheeled frame movable over said pavement; a crank mounted upon said frame for rotation in a vertical plane; poweroperated means on said frame for effecting rotation of said crank; a guide member formed on said frame below said crank in approximate vertical alignment therewith; a pavement-breaking hammer slidably carried by said guide member for vertical reciprocal movement relative to said pavement, said hammer being offset from the axis of rotation of said crank; means drivingly connecting said power-operated means and said crank during an upstroke of said crank, said means disconnecting said power-operated means from said crank during a down,

stroke of the latter; a flexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during its upstroke; and a horizontal leaf spring interposed between said frame and said hammer with its free end extending into the coniines of said guide member for abutting said hammer, said spring means being deformed by upward movement of `said hammer and said spring means returning towards its normal configuration during a downstroke of said hammer to thereby accelerate the downward movement of said hammer.

2. A mobile pavement breaker, comprising: a wheeled frame movable over said pavement; a crank mounted upon said frame for rotation in a vertical plane; power-operated means on said frame for effecting rotation of said crank; a guide member formed on said frame below said crank in approximate vertical alignment therewith; a pavement-breaking hammer slidably carried by said guide member for vertical reciprocal movement relative to said pavement, said hammer being olfset from the axis of rotation of said crank; means drivingly connecting said power-operated means and said crank during an upstroke of saidV crank, said means disconnecting said power-operated means from said crank during a downstroke of the latter; a iiexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during its upstroke; a horizontal leaf spring having its intermediate portion pivotally secured to said frame with one of its ends extending into the confines of said guide member so as to abut said hammer, said spring means being deformed by upward movement of said hammer and said spring means returning towards its normal configuration during downward movement of `said hammer to thereby accelerate the downward movement of said hammer; and adjustment means interposed between the opposite end of said leaf spring and said frame for varying the elevation of said opposite end to thereby control the amount of force applied by said spring to said hammer.

3. A mobile pavement breaker, comprising: a wheeled frame movable over said pavement; a power-operated horizontal lifting shaft carried by said frame; a driving element keyed to said shaft; a crank journaled on said shaft; a driving pin formed on the intermediate portion of said crank and engageable with said driving element whereby said driving element will impart rotation to said crank in one direction; a guide member formed on said frame below said crank in approximate vertical alignment therewith; a pavement-breaking hammer slidably earned by said guide member for vertical reciprocal movement relative to said pavement, said hammer being olset from the axis of rotation of said crank; a flexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during its upstroke; and a horizontal leaf spring interposed between said frame and said hammer with its free end extendmg into the confines of said guide member for abutting said hammer, said spring means being deformed by upward movement of said hammer and said spring means returning toward its normal configuration during a downstroke of said hammer to thereby accelerate the downward movement of said hammer.

4. A mobile pavement breaker, comprising: a wheeled frame movable over said pavement; a poweroperated horizontal lifting shaft carried by said frame; a driving element keyed to said shaft; a crank journaled on said shaft; a driving pin formed on the intermediate portion of said crank and engageable with said driving element whereby said driving element will impart rotation to said crank in one direction; a guide member formed on said frame below said crank in approximate vertical alignment therewith; a pavement-breaking hammer slidably carried by said guide member for vertical reciprocal movement relative to said pavement, said `hammer being olfset from the axis of rotation of said crank; a flexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during its upstroke; a horizontal leaf spring having its intermediate portion pivotally secured to said frame with one of its ends extending into the contines of said guide member so as to abut said hammer, said spring means being deformed by upward movement of said hammer and said spring means returning towards its normal configuration during downward movement of said hammer to thereby accelerate the downward movement of said hammer; and adjustment means interposed between the opposite end of said leaf spring and said frame for varying the elevation of said opposite end to thereby control the amount of force applied by said spring to said hammer.

5. A mobile pavement breaker, comprising: a wheeled main frame movable over said pavement; an auxiliary frame pivotally supported upon said main frame so as to undergo movement relative thereto in a horizontal plane; engine means on one of said frames; a crank mounted on said auxiliary frame for rotation in a vertical plane; force-transfer means connected to said engine means; a guide member formed on said auxiliary frame below said crank; a pavement-breaking hammer slidably supported by said guide member for Vertical reciprocal movement relative to said pavement, said hammer being offset from the axis of rotation of said crank; means drivingly connecting said force-transfer means and said crank during an upstroke of said crank, said means disconnecting said force-transfer means from said crank during a downstroke of the latter; a exible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during an upstroke of said crank; a generally horizontally extending leaf spring interposed between said auxiliary frame and said hammer, with one end of said leaf spring extending into the contines of said guide member so as to abut said hammer, said spring being deformed upwardly by upward movement of said hammer and said spring returning towards its normal configuration during a downstroke so as to thereby accelerate the downward movement of said hammer; and second force-transfer means interposed be'- tween said engine means and said frames so as to effet said movement of said auxiliary frame in a horizontal plane concurrent with said vertical movement of said hammer.

6. A mobile pavement breaker, comprising: a wheeled main frame movable longitudinally overI said pavement; an auxiliary frame supported upon said. main frame so as to undergo movement relative thereto in a horizontal plane; engine means on one of said frames; a transversely extending crank mounted on the rear portion of said auxiliary frame for rotation in a vertical plane; force-transfer means operatively connected to said engine means; a guide member formed on the rear portion of said auxiliary frame below and in approximate vertical alignment with said crank; a pavement breaking hammer slidably supported by said guide member for vertical reciprocal movement relative to said pavement, said hammer being transversely olfset from the axis of rotation of said crank; means drivingly connectiing said force-transfer means and said crank during an upstroke of said crank, said means disconnecting said force-transfer means from said crank during a downstroke of the latter; a flexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during an upstroke of said crank; a generally horizontally and longitudinally extending leaf spring interposed between said auxiliary frame and said hammer with the rear end of said leaf spring extending into the confines of said guide member so as to abut said hammer, said spring being deformed upwardly by upward movement of said hammer and said spring returning towards its normalconfiguration during a downstroke of said hammer so as to thereby accelerate the downward movement of said hammer; and said second force-transfer means operatively interposed between said engine means and said frame so as to effect said movement of said auxiliary frame in a horizontal plane concurrent with said vertical movement of said hammer.

7. A mobile pavement breaker, comprising: a Wheeled main frame movable longitudinally over said pavement; an auxiliary frame pivotally supported upon said main frame so as to undergo swinging movement relative thereto in a horizontal plane; engine means on one of said frames; a transversely extending crank mounted on the rear portion of said auxiliary frame for rotation in a vertical plane; force-transfer means operatively connected to said engine means; a vertically extending guide member formed on the rear portion of said auxiliary frame be*- low and in approximate vertical alignment with said crank; a pavement breaking hammer slidably supported by said guide member for vertical reciprocal movement relative to said pavement, said hammer being transversely offset from the axis of rotation of said crank; means drivingly connecting said force-transfer means and s'aid crank during an upstroke of said crank, said means disconnecting said force-transfer means from said crank during'a downstroke of the latter; a fiexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer during an upstroke of said crank; a generally horizontally and longitudinally extending leaf spring having its intermediate portion pivotally secured to said auxiliary frame with its rear end extending into the confines of said guide member so as to abut said hammer, said leaf spring being deformed by upward movement of said hammer and said spring returning towards its normal configuration during downward movement of said hammer to thereby accelerate the downward movement of said hammer; adjustment means interposed between the front end of said leaf spring and said auxiliary frame for varying the elevation of said front end to thereby control the amount of force applied by said spring to said hammer; and second force-transfer means inter- .posed between said engine means and said frames so as to effect said swinging movement of said auxiliary frame concurrent with said vertical movement of said hammer.

8. A mobile pavement breaker, comprising: a wheeled main frame movable longitudinally over said pavement; an auxiliary frame pivotally supported upon said main frame so as to undergo swinging movement relative thereto in a horizontal plane; engine means on one of said frames; a longitudinally and horizontally extending lifting shaft rotatably carried by said auxiliary frame; a driving element keyed to said shaft; a transversely extending crank journaled on said lifting shaft; a driving pin formed on the intermediate portion of said crank and engageable with said driving element whereby said driving element will impart rotation to said crank in one direction; force-transfer means connecting said engine means to said lifting shaft so as to effect rotation of the latter; a flexible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer solely during an upstroke of said crank; a generally horizontally and longitudinally extending leaf spring interposed between said auxiliary frame and said hammer with the rear end of said leaf spring extending into the confines of said guide member so as to abut said hammer, said spring being deformed upwardly by upward movement of said hammer and said spring returning towards its normal configuration during a downstroke of said hammer so as to thereby accelerate the downward movement of said hammer; and second force-transfer means interposed between said engine means and said frames so as to effect said swingingmovement of said auxiliary frame concurrent with said vertical movement of said hammer.

9. A mobile pavement breaker, comprising: a Wheeled main frame movable longitudinally over said pavement; an auxiliary frame pivotally supported upon said main frame so as to undergo swinging movement relative thereto in a horizontal plane; engine means on one of said frames; a longitudinally and horizontally extending lifting shaft carried by said auxiliary frame; a driving element keyed to said shaft; a transversely extending crank journaled on said lifting shaft; a driving pin formed on the intermediate portion of said crank and engageable with said driving element whereby said driving element impart rotation to said crank solely in one direction; `force-transfer means connecting said engine means to said lifting shaft so as to effect rotation of the latter; a exible element interconnecting the free end of said crank and said hammer whereby said crank will raise said hammer solely during an upstroke of said crank; a generally horizontally and longitudinally extending leaf spring having its intermediate portion pivotally secured to said auxiliary frame with its rear end extending into the confines of said guide member so as to abut said hammer, said spring being deformed by upward movement of said hammer and said spring returning towards its normal configuration during downward movement of said hammer to thereby accelerate the downward movement of said hammer; adjustment means interposed between the front end of said leaf spring and said auxiliary frame for varying the elevation of said front end to thereby control the amount of force applied by said spring to said hammer; and second force-transfer means interposed between said engine means and said,

frame so as to effect said swinging movement of said auxiliary frame in a horizontal plane concurrent with said vertical movement of said hammer.

References Cited in the le of this patent UNITED STATES PATENTS