US3321250A - Machine for transversely slotting a strip of concrete pavement at different angles - Google Patents

Description

RETE

May 23, 1967 E. M. TRUELOCK MACHINE FOR TRANSVERSELY SLOTTING A STRIP OF CONC PAVEMENT AT DIFFERENT ANGLES 2 Sheets-Sheet Filed Feb. 4, 1965 INVENTOR.

y 23, 1967 E. M. TRUELOCK 3,321,250

MACHINE FOR TRANSVERSELY SLOTTING A STRIP OF CONCRETE PAVEMENT AT DIFFERENT ANGLES Filed Feb. 4, 1965 2 Sheets-Sheet 2 INVENTOR. [6/1/55 M 77051064 51/ HAS A 77'0ZA/fl/5' 4452/5, 1756/4 2055a; iii-0v United States Patent MACHINE FOR TRANSVERSELY SLDTTING A STRIP 0F CONCRETE PAVEMENT AT DIF- FERENT ANGLES Elmer M. Truelock, Albuquerque, N. Mex., assiguor to Concut, Inc., El Monte, Calif, a corporation of California Filed Feb. 4, 1965, Ser. No. 430,353 1 Claim. (Cl. 299-39) The present invention relates in general to a machine for grooving or slotting pavement and, more particularly, to a machine for transversely slotting a strip of concrete pavement at longitudinally spaced points to provide contraction joints at such points.

It is conventional in present-day concrete highway construction to pour the concrete in long strips Without transverse joints. After the concrete of a particular strip of pavement has set sufiiciently, transverse grooves or slots are cut therein at longitudinally spaced points, the depth of out being but a fraction of the thickness of the pavement. Subsequent contraction of the pavement results in controlled transverse cracking of the strip along the transverse slots, thereby providing the necessary contraction joints in a regular pattern.

When a strip of concrete pavement having transverse contraction joints is in use, vehicle wheels crossing the joints impose shock loads on the succeeding slabs, such shock loads being extremely severe in the case of heavy vehicles such as heavy trucks, large aircraft, and the like. In order to reduce the impact of vehicle wheels crossing contraction joints in pavement, it is necessary to form the joints at an angle to the path of vehicles crossing the joints which differs susbtantially from 90. By proper selection of the angle of such a nonperpendicular joint, only one wheel of a pair of laterally-aligned vehicle wheels will cross the joint at a time. Consequently, the impact load produced by a vehicle crossing such a nonperpendicular joint is only half the impact load imposed with a perpendicular joint.

The basic object of the invention is to provide a machine for transversely slotting a strip of pavement having very simple means for obtaining a nonperpendicular slot orientation, or any desired slot orientation.

In general, the invention contemplates a cross slotting machine which includes a wheeled vehicle movable longitudinally of the strip of pavement and having a frame supported by longitudinally-spaced front and rear wheel assemblies, and which includes pavement slotting means,

movable laterally of the frame along a transverse slotting path, for transversely slotting the strip of pavement while the vehicle is stationary.

An important object of the invention is to mount the wheel assemblies on the frame for pivotal movement relative to the frame about upright axes so as to vary the angle of the transverse slotting path relative to the longitudinal path of movement of the vehicle along the strip of pavement. With this construction, any desired cross slot angle relative to the strip of pavement can be achieved merely by correspondingly adjusting the angular positions of the wheel assemblies relative to the frame and then orienting the wheel assemblies parallel to the longitudinal edges of the strip, which is an important feature of the invention.

Another object of the invention is to provide mounting means for the wheel assemblies comprising upper bearing plates on the frame resting on lower bearing plates on the wheel assemblies and pivotally connected thereto by upright pivot pins, the wheel assemblies being pivotable relative to the frame into the desired angular positions about the axes of such pivot pins.

Still another object is to provide means extending 3 ,321,250 Patented May 23, 1967 through the upper and lower bearing plates associated with the respective wheel assemblies for locking such wheel assemblies in the desired angular positions.

Preferably, the frame of the wheeled vehicle is supported by front and rear pairs of laterally or transversely spaced wheel assemblies, the front and rear pairs being spaced apart longitudinally of the vehicle. An object in this connection is to provide the wheel assemblie of one of the pairs, preferably the rear wheel assemblies, with driving wheels, and to provide means for driving such wheels to advance the vehicle longitudinally of the strip of pavement from one cross slotting location to the next.

Another object of the invention is to provide means for rotating the driving Wheels which includes a differential on the frame in a laterally intermediate position, and which includes driving connections between the differential and the driving wheels, such driving connections including universal and slip joints to permit pivoting of the corresponding wheel assemblies relative to the frame.

Another object is to provide means for braking the Wheels of one pair of wheel assemblies, preferably the driving wheels, to lock the vehicle in position at each cross slotting location. A related object is to provide separately-actuable braking means for the wheels of the two brake-equipped wheel assemblies to permit steering of the vehicle along the strip of pavement. Still another object in this connection is to provide a machine wherein the two braking means act on the driving connections between the differential and the wheels of the driving wheel assemblies.

An important advantage of the particular means of the present invention for varying the angle of the transverse slotting path relative to the longitudinal path of movement of the vehicle is that it permits the use of a frame having a longitudinal dimension which is small compared to its lateral dimension. Thus, when the machine is loaded on a trailer, for example, with its longitudinal dimension perpendicular to the longitudinal axis of the trailer, the over-all width of the resulting load is minimized so that the machine can be transported long distances without exceeding maximum width limits. Also, if it is desired to transport the machine of the invention a relatively short distance under its own power, the Wheel assemblies can readily be oriented parallel to the longitudinal axis of the frame to make driving the machine more convenient to the operator. Further, with the wheel assemblies oriented parallel to the longitudinal axis of the frame, the lateral dimension of the frame is minimized to permit passagethrough spaces which would not be wide enough to permit passage if the wheel assemblies were oriented at angles to the longitudinal axis of the frame.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the art to which the invention relates in the light of this disclosure, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIG. 1 is a plan View of a machine of the invention for transversely slotting a strip of pavement, the machine being shown adjusted to cut a nonperpendicular slot in a strip of pavement;

FIG. 2 is a side elevational view showing the lefthand side of the machine of FIG. 1, except that the machine is adjusted to make a perpendicular cut in the strip of pavement;

FIG. 3 is a fragmentary rear elevational view, taken as indicated by the arrowed line 33 of FIG. 2; and

FIGS. 4 and 5 are enlarged, fragmentary sectional views 3 respectively taken along the arrowed lines 4-4 and 5-5 of FIG. 2 of the drawings.

Referring particularly to FIG. 1 of the drawings, the cross slotting machine of the invention is designated generally by the numeral and comprises a wheeled vehicle 12 supported by and movable longitudinally along a strip of concrete pavement 14, the function of the machine being to cut longitudinally spaced, transverse slots 16 in the pavement strip at an angle relative to the longitudinal edges of the strip differing substantially from 90. The wheeled vehicle 12 comprises a frame 18 supported by laterally-spaced front wheel assemblies 20 and laterally-spaced rear wheel assemblies 22, the latter being spaced longitudinally from the front wheel assemblies. The machine 10 further includes pavement slotting means 24 for cutting successive nonperpendicular transverse slots 16 at successive longitudinal positions of the machine along the pavement strip 14. The slotting means 24 is carried by the frame 18 of the wheeled vehicle 12 longitudinally intermediate the front and rear ' wheel assemblies 20 and 22, and is movable laterally of the frame, in a manner to be described, in the course of cutting each transverse slot 16 while the vehicle 12 remains stationary.

As will be described in more detail hereinafter, the wheel assemblies 20 and 22 are pivotable relative to the frame 18 about upright axes to vary the angle between the longitudinal centerline 26 of the frame and the longitudinal edges of the pavement strip 14. Thus, when the wheel assemblies 20 and 22 are oriented parallel to the longitudinal edges of the pavement strip 14, as shown in FIG. 1, the slotting means 24 cuts the transverse slots 16 at a corresponding angle to the longitudinal edges of the pavement strip. If desired, a transverse slot 28, FIG. 2, which is perpendicular to the longitudinal edges of the pavement strip 14 may be produced by pivoting the wheel assemblies 20 and 22 relative to the frame 18 until they are oriented parallel to the longitudinal centerline 26 of the frame, and by reorienting the machine 10 until the wheel assemblies are again oriented parallel to the longitudinal edges of the pavement strip.

Considering the machine 10 in more detail now, the frame 18 is shown as rectangular and as having a longitudinal dimension, in the direction of its longitudinal centerline 26, which is relatively small as compared to its lateral dimension or width, the magnitude of the latter being determined by the width of the pavement strip 14. Except as hereinafter pointed out, the frame 18 may be of any suitable construction so that a detailed description is not necessary.

Considering the pavement slotting means 24, it comprises two laterally spaced slotting units 30 interconnected to move laterally of the frame 18 in unison in cutting one of the transverse slots 16. Each slotting unit 30 is similar to the laterally movable slotting unit of the cross slotting machine of Patent No. 2,791,412, issued May 7, 1957, to Cecil W. Hatcher, attention being directed thereto for a more complete disclosure. Briefly, each slotting unit 30 comprises a carriage 32 supported by rollers 34 movable along tracks 36 extending laterally of and mounted on the frame 18. Each carriage 32 is guided in its lateral movement relative to the frame 18 by a guide rail 38 on the frame.

Each slotting unit 30 includes a motor, preferably an internal combustion engine 40, mounted on the corresponding carriage 32. Also mounted on each carriage 32 are laterally spaced arbors 42 the axes of which are parallel to the longitudinal centerline 26 of the frame 18. The two arbors 42 on each carriage 32 are driven by the corresponding engine 40 through belts 44, respectively. The four arbors 42 of the two slotting units 30 respectively carry four rotary slotting elements 46 arranged in tandem so that they all cooperate to cut a single transverse slot 16 as the carriages 32 are moved laterally along the tracks 36. -It will be understood that the rotary slotting elements 46 on each carriage 32 cut slightly more than one-half the length of each transverse slot 16, there being sufiicient overlap of the movements of the slotting units 30 along their transverse slotting path to insure a cut extending completely across the pavement strip 14.

The manner in which the carriages 32 are moved laterally along the tracks 36, the manner in which the rotary slotting elements 46 are moved into and out of cutting engagement with the pavement strip 14, and the like, are all disclosed in the aforementioned Hatcher patent. Consequently, a further description herein is not required.

The manner in which the front and rear wheel assemblies 20 and 22 are mounted on the frame 18 for pivotal movement relative thereto about upright axes will now be considered. Basically, the mounting means for the front wheel assemblies 20 respectively comprise front upper bearing plates carried by the frame 18 adjacent the front corners thereof and resting on front lower bearing plates 52 forming parts of the front wheel assemblies 20. Each set of upper and lower bearing plates 50 and 52 is pivotally interconnected by an upright pivot pin 54 which permits the desired pivotal movement of the corresponding front wheel assembly 20 to vary the angular orientation thereof relative to the frame 18. Similarly, the rear wheel assemblies 22 are mounted on the frame 18 adjacent the respective rear comers thereof by rear upper bearing plates 56 on the frame, rear lower bearing plates 58 on the rear wheel assemblies, and upright pivot pins 60. With this construction, the front and rear wheel assemblies 20 and 22 may be oriented at any desired angle relative to the longitudinal centerline 26 of the frame 18.

Each of the front and rear wheel assemblies 20 and 22 is preferably locked in its desired angular position rela tive to the frame 18 by clamping the corresponding upper and lower bearing plates together with the correct angular relationship therebetween. Turning to FIG. 4 of the drawings, four clamping bolts 62 are shown as extending through the corresponding front upper bearing plate 50 and through arcuate slots 64 in the corresponding front lower bearing plate 52, such slots being concentric about the axis of the corresponding pivot pin 54. By tightening nuts, not shown, on the four clamping bolts 62, the corresponding front wheel assembly 20 can be locked in position with the desired angular orientation relative to the frame 18. An orienting pin 66 may be used to orient the corresponding front wheel assembly 20 at any of several preselected angles relative to the longitudinal centerline 26 of the frame 18. This orienting pin extends downwardly through the corresponding front upper bearing plate 50 and may be inserted into any one of holes 68, 70, 72, 74 and 76 in the corresponding front lower bearing plate 52. As will be apparent from FIG. 4 of the drawings, if the orienting pin 66 is inserted into the orienting hole 68, the front wheel assembly 20 in question is oriented parallel to the centerline 26 of the frame 18, in which case the slotting means 24 will cut a transverse slot perpendicular to the edges of the pavement strip 14. By inserting the orienting pin 66 in either of the orienting holes 70 and 72, the transverse slot cut by the slotting means 24 will be oriented at an angle a to one side or the other of a perpendicular to the edges of the pavement strip 14. Similarly, inserting the locating pin 66 into either of the orienting holes 74 and 76 will result in a deviation of the transverse slot from the perpendicular by an angle [2.

Turning to FIG. 5, the mounting means for each rear wheel assembly 22 comprises a similar arrangement of clamping bolts 82, arcuate slots 84 in the corresponding rear lower bearing plate 58, orienting pin 86, and orienting holes 88, 90, 92, 94 and 96 in such rear lower bearing plate. As will be apparent, the locating hole 88 produces an orientation for the corresponding rear wheel assembly 22 such as to produce a perpendicular transverse cut. The orienting holes 90 and 92 produce angular orientations forming transverse cuts which are off perpendicular by the angle a. Use of the orienting holes 94 and 96 provides transverse cuts off perpendicular by the angle b.

It will be understood that all of the front and rear wheel assemblies 20 and 22 must be adjusted to the same angular orientation relative to the longitudinal centerline 26 of the frame 18. The transverse slot 16 cut by the slotting means 24 then has the same angular orientation relative to a perpendicular to the edges of the pavement strip 14. Preferably, an angular orientation for the front and rear wheel assemblies 20 and 22 corresponding to one of the angles a and b is used, rather than an angle which would produce a perpendicular slot. However, a slot perpendicular to the longitudinal edges of the pavement strip 14 may be used if desired or required.

In the particular construction illustrated, each front wheel assembly 20 includes dual front wheels 102 and each rear wheel assembly 24 includes dual rear wheels 104. However, it will be understood that the number of wheels in each wheel assembly may be increased or decreased if desired.

The wheels of one of the pairs of wheel assemblies 20 and 22, and preferably the wheels 104 of the rear wheel assemblies 22, are driving wheels for moving the vehicle 12 along the pavement strip 14 from one joint location to the next after cutting a transverse slot 16 at the preceding joint location. An exemplary driving means for the rear wheels 104 is designated generally by the numeral 106.

The driving means 106 is shown as including a differential 108, containing conventional ditferential gearing, mounted on the frame 18 and having driving connections 110 to the respective dual rear wheels 104. The differential 108 may be driven by a hydraulic motor 112 supplied with hydraulic fiuid under pressure by a hydraulic pump, not shown, driven by one of the engines 40. (It will be noted that the rotary slotting elements 46 are not in operation during forward movement of the wheeled vehicle 12. Consequently, the output of one of the engines 40 may be used to produce the desired forward movement of the vehicle 12). Each driving connection 110 includes a shaft 114 carried by the corresponding rear wheel assembly 22 and carrying a sprocket 116 driving a chain 118 trained around a sprocket 120 on an axle 122 carrying the corresponding dual rear wheels 104. The shafts 114 of the respective rear wheel assemblies 22 are connected to opposite sides of the differential 108 through shafts 124 and 126, universal joints 128 and 130, and slip joints 132, FIG. 3. Such combinations of universal and slip joints permit the hereinbefore-discussed pivoting of the rear wheel assemblies 22 relative to the frame 18.

The driving connections 110 between the differential 108 and the two sets of rear wheels 104 incorporate braking devices 136, which may be hydraulically operated in a manner not specifically shown, but well known in the art. The respective braking devices 136 are controlled by foot pedals 1'38 accessible from a drivers seat 140, from which a control console 142 for operating various other components of the machine 10 is also accessible. taneously while making one of the transverse cuts 16, the machine 10 may be held absolutely stationary to insure an accurate cut and to prevent damage to the rotary slotting elements 46. During forward movement of the machine 10 from one slotting location to the next, any steering of the machine which may be required may be accomplished by actuating one or the other of the braking devices 136.

It is thought that the over-all operation of the pavement slotting machine 10 of the invention will be clear from the foregoing. Consequently, a further description is not necessary.

Although an exemplary embodiment of the invention has been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claim which follows:

I claim:

In a machine for transversely slotting a strip of pavement, the combination of:

(a) a wheeled vehicle movable longitudinally of the strip of pavement and including a frame supported by at least three wheel assemblies two of which are spaced apart laterally of said vehicle and are spaced longitudinally of said vehicle from the third wheel assembly;

(b) pavement slotting means, carried by said frame between said front and rear wheel assemblies and movable laterally of said frame along a transverse slotting path, for transversely slotting the strip of pavement while said vehicle is stationary;

(c) said wheel assemblies being pivotable relative to said frame about upright axes to vary the angle of said transverse slotting path relative to the path of said vehicle;

(d) said laterally spaced wheel assemblies including driving wheels;

(e) means for driving said driving wheels, including a differential on said frame between said laterally spaced wheel assemblies, and including driving connections between said differential and said driving wheels; and

(f) said driving connections including universal and slip joints to permit pivoting of said laterally spaced wheel assemblies relative to said frame.

References Cited by the Examiner UNITED STATES PATENTS 2,311,891 2/1943 Tyson 299-39 2,791,412 5/1957 Hatcher 29939 2,845,851 8/1958 Nagin 29939 X ERNEST R. PURSER, Primary Examiner,

By applying the braking devices 136 simul-.

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