US 3914064 A
Control apparatus for a mobile road building machine which is steerable and mounts the road building unit for height adjustment including a dual light sensor unit arranged to sense lateral and height deviations from a beam of laser light to control the steering and the height adjustment.
Description (OCR text may contain errors)
[4 1 Oct. 21, 1975 i United States Patent Gurries 4 mm 4 0m 44 .0 4
Miller am HA 9666 566677 999999 111111 2469 9 1 6 29 7 378992 ,39 1 678246 45750 9 5 233333  Inventor:
Nile C. Byers, Jr. or FirmPaul B. Fihe ABSTRACT Nov. 19, 1973 Appl. No.: 417,421
Related US. Application Data Continuation of Ser. No. 122,586, March 1, abandoned.
. VJ n R e 0 mm T & R 9C E 4, FM Jw T W mm NU fln EQ ma ME GS EG .6 mm 1; AD m mm mm U 0 B My G RG m T m NWL UEE mH MST M U 22 Filed:
arranged to sense lateral and height deviations from a beam of laser light to control the steering and the height adjustment.
References Cited UNITED STATES PATENTS 4 Claims, 7 Drawing Figures U3, Patent Oct.21,1975 Sheet10f4 3,914,064
US. Patent Oct. 21, 1975 Sheet20f4 3,914,064
US. Patent Oct.21, 1975 Sheet 3 of4 3,914,064
US. Patent Oct. 21, 1975 Sheet 4 of4 3,914,064
O mwm ozimmkm EMF-3153 MOUNTING ARRANGEMENT FOR SIDEWALK BUILDING EQUIPMENT OR THE LIKE This is a continuation of application Ser. No. 122,586, filed on Mar. 1, 1971, now abandoned.
FIELD OF THE INVENTION The present invention relates generally to construction equipment utilized for building roads, sidewalks, and the like and, more particularly, to a universal mounting arrangement for various units utilized in such construction.
BACKGROUND OF THE INVENTION While it is, of course, obvious that certain general similarities exist in the construction of highways, roads and sidewalks, the different size of the operations has resulted in considerably different detailed techniques.
In the construction of highways, large-scale earthmoving equipment is initially utilized to create the general path of the highway over an extended distance usually measured in miles. Thereafter base material, in the form of crushed rock or its equivalent, is spread over the area by a spreader or other piece of equipment, again of large capacity. In turn, separate units in the form of heavy rollers are arranged to compress the base material, and graders are utilized to establish the required finished grade and cross-slope thereof. Finally, a paving unit is employed, normally in accordance with current practice, in the form of a slip-form paver which eliminates the need for construction of separate fixed forms for the paving operation. Recently, the spreading, grading, and paving equipment has been automatically controlled from an external reference, such as a grade wire extending along the general path of the highway at one side thereof, or in some cases, on each side, to assure accuracy of the completed highway.
On the other hand, since sidewalks, city streets, and certain other roads are constructed over very limited distances measured in city blocks, it is not economically feasible to utilize the same multiple number of units for the various operations. More particularly, it will be immediately obvious that the capital investment requisite to provide such a multiplicity of individual machines would be prohibitive for the paving of a sidewalk extending one or two blocks in length and having a width of no more than three or four feet. Furthermore, because of the relatively short distances involved, the individual construction units could be employed only at widely-spaced intervals of time. Whereas in the construction of a highway, earthmoving equipment may be operating at one section, while at another section of highway construction, spreaders and graders can be simultaneously utilized, and at yet a third section, spaced one or more miles distant, the paving operation can simultaneously proceed. Since such relatively great distances are not encountered in the paving of sidewalks, the effective simultaneous use of various construction machines cannot be achieved. Finally, even though the machines for sidewalk paving would be scaled down in size from that used on freeways or other highways, the use of automatic controls on each and every machine to which such controls are applicable would also be prohibitive in cost since, even though the machine may be of lesser size, the same basic control elements are requisite regardless of machine size and the total overall cost again becomes excessive.
SUMMARY OF THE INVENTION Accordingly, it is a general objective of the present invention to provide a universal mounting arrangement for a variety of building equipment units for sidewalks, city streets, curbs and gutters or the like including a singlemobile carrier provided with means for alternative attachment thereto of various units required for such construction, such as an earth-moving unit, a spreader unit, a grading unit, a paving unit or, for that matter, any other piece of equipment requisite for a particular trenching, excavating, conveying, spreading, grading,
mixing or paving operation. The mounting arrange-' ment supports the chosen operational unit for adjustment in height, cross-slope, and lateral disposition and, preferably, incorporates automatic control means for actuating the adjustment mechanism so that the particular operational unit mounted thereon follows the required predetermined path.
To best achieve this objective, the mobile carrier preferably takes the form of rather small jeep-like vehicle having its own source of power in the form of an internal combustion engine and which, preferably, is provided with the so-called center-pivot steering wherein both the front and rear sections articulate in response to appropriate steering actuation. The mounting means for an individual unit of construction equipment is preferably mounted at one end of the mobile frame for adjustment in the desired directions and preferably includes a first member which is mounted from one end of the frame for vertical motion, thus to provide height adjustment, a second member which is mounted from the first member for lateral pivotal motion enabling a cross-slope adjustment and this second member can be provided, in accordance with one aspect of the invention, with means for mounting the particular operational unit, such as a grader, paver or the like.
While a conventional manually-actuated steering wheel can be utilized to control the motion of the mobile carrier in one direction during, for example, a grading operation wherein the grader is positioned in advance of the carrier, it can also be operated in the reverse direction when a paving operation is being undertaken so that the paving unit, itself, follows, rather than leads, the mobile carrier.
Automatic control means can be incorporated on the mounting arrangement to control the positioning of the adjustable members. For example, cross-slope can be controlled by a reference in the form of a pendulum control means which automatically adjusts the pivoted cross-slope member in response to any deviations from a desired transverse disposition, and an external wire can be used as a reference for controlling the height of the mounting arrangement and, as a consequence, the operational unit mounted thereby. This same external reference wire can also be utilized as a lateral positional reference for controlling for steering of the mobile carrier so that it will automatically follow the desired path regardless of the particular operation being undertaken.
In accordance with an alternative aspect of the invention, a third adjustable member can be mounted from the second pivoted member for lateral translational motion which can, in turn, be controlled by engagement of an appropriate sensor with the external wire or other reference substantially eliminating any need for automatic steering since this automatic control of the lateral translational position of the third member and an operational unit mounted therefrom will eliminate the need of the driver to follow a precise path.
In some cases, an alternative reference in the form of a laser beam can be utilized, and a light-sensitive sensor means can be mounted on the unit, ultimately to control both height and lateral adjustments, either of the third laterally adjustable member or the steering.
BRIEF DESCRIPTION OF THE DRAWINGS The general objectives of the invention and the manner in which they are achieved, as summarized above, will be more fully understood by reference to the following detailed description of the exemplary structures shown in the accompanying drawing wherein:
FIG. 1 is a front perspective view of a mounting arrangement for a sidewalk building equipment or the like constituting one embodiment of the present invention, portions of the structure being broken away to illustrate details thereof,
FIG. 2 is a front elevational view of the FIG. 1 structure diagrammatically indicating the cross-slope adjustment of the mounting arrangement,
FIG. 3 is a side elevational view of the FIG. 1 structure diagrammatically indicating height adjustment of the mounting arrangement,
FIG. 4 is a horizontal sectional view of a modified mounting arrangement for sidewalk building equipment or the like and diagrammatically indicating lateral translation operations thereof,
FIG. 5 is a diagrammatic view in vertical elevation indicating the modified sensing arrangement for lateral positional control of the mounting arrangement of FIG. 4, substantially as viewed along lines 55 thereof,
FIG. 6 is a fragmentary diagrammatic view, generally similar to FIG. 5 showing a modified laser sensing means, with the associated control circuitry shown in block diagram form, and
FIG. 7 is a further diagrammatic view similar to FIG. 6 showing a modified arrangement for laser control of height and steering.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE INVENTION With initial reference to FIGS. 1, 2, and 3, the first embodiment of the invention includes a mobile carrier arranged to alternatively mount various units of sidewalk building equipment at one end thereof. More particularly, such mobile carrier for the sidewalk building units includes a mobile frame 10 supported on four wheels 12, two or more of which can be driven by a suitable internal combustion engine (not shown) and can be steered through conventional actuation from a steering wheel 14 mounted forwardly of a drivers seat 16. The described structure can take the form of a jeeplike vehicle of relatively small dimensions and having two wheels which can be turned to steer the vehicle or preferably is provided with so-called center pivot steering wherein the frame is centrally articulated to steer the vehicle. Although such center pivot steering is wellknown and thus will not be described in great detail, a diagrammatic visualization thereof will be presented by reference to FIG. 4 and will be briefly described hereinafter.
At the forward endof the mobile frame 10, appearing at the left .in FIGS. 1 and 3, adjustable equipment mounting means, generally indicated at 18, aresupported and are, in turn, arranged to carry the particular unit of sidewalk building equipment for adjustment both in height and in cross-slope relative to the direction of vehicle travel. Such equipment mounting means 18 includes a generally open rectangular frame mem: ber 20 which extends generally transversely of the mo-.
bile frame 10 and mounts at each of its ends outwardly projecting pivot pins 22, which are pivotally joined to a parallel forwardly-projecting pair of links 24, 26 at their forward extremities, the inner ends of the links 24, 26 being, in turn, pivotally secured tothe forward side portions of the mobile frame 10 on similar pivot pins 28. At each side of the rectangular frame member 20, a double-acting hydraulic ram 32 is secured between the mobile frame 10 and the upper link by pivotal connections so that extension of the ram under suitable hydraulic actuation from a hydraulic pump (not shown) driven by the engine under control of the vehicle operator will effect an upward swinging of the links 24, 26 from full line disposition shown in FIG. 3 to the dotted line disposition, thus effecting a height adjustment of the rectangular frame member 20. Although the rectangular frame member 20 also moves rearwardly', the
parallel links 24, 26 maintain the frame member at all.
times during adjustment in the same upright disposition.
To provide cross-slope adjustment for the mounted sidewalk building unit, a second open rectangular frame member 34 is mounted forwardly of the described first frame member 20 in the same general transverse disposition. At the top central portion thereof, the second frame member 34 is secured to the forwardly projecting end of a shaft 36 supported for ro-.
tation in the first frame member 20, thus to provide for pivotal motion of the second frame member 34 relative to the first frame member 20 and about anaxis extending generally longitudinally of the path of. vehicle travel.
In order to effect pivotal adjustment of this second frame member 34, a double-acting hydraulic ram 38 is positioned in general transverse relationship across the central opening of the two rectangular frame members,
as best shown in FIG. 2, one end of the hydraulic ram being pivotally secured to the inner end of the first frame member 20 and the opposite end of the ram being secured pivotally to the opposite end of the second pivoted frame member 34, wherefore extension or retraction of the ram 38 will cause lateral angular or pivotal adjustment of the second frame member about J its mounting shaft 36, for example, from the full line disposition shown in FIG. 2 to the dotted line disposition there illustrated. This hydraulic ram 38 is also connected to the afore-mentioned hydraulic pump through suitable control valves which are preferably automatically actuated in the manner to be described hereinafter.
At the forward side of the pivoted second frame member 34, means 40 are provided for releasably mounting the particular unit of sidewalk building equipment and, to facilitate the mounting of various units, preferably takes the form of a universal mount including four dowel pins projecting forwardly from the four corners of the pivoted frame member 34 for reception in mating openings in the particular construction unit, thus to assure its desired mounted disposition.
In order to control the height of the mounting arrangement and the particular unit of sidewalk building equipment carried thereby, an external reference is utilized in conjunction with sensing means, generally indicated at 41, mounted at one side of the described pivoted cross-slope adjustment member 34. More particularly, the external reference, as shown in FIGS. 1, 2, and 3, takes the form of a grade wire 42 supported in a predetermined disposition parallel to the desired path of vehicle travel on suitably spaced wire hangers 44, preferably of the type described in US. Pat. No. 3,342,446. Cooperating with such external grade wire 42 is a pivoted sensing fork 46 adapted to straddle the grade wire 42 and control a hydraulic valve 48 which is connected between the mentioned hydraulic pump and the described rams 32 connected to the pivoted links 24, 26 that support the height-adjustment member 20. The described sensing fork 46 is arranged for manual vertical adjustment by turning of a hand crank 50 and the details of this entire sensing means 41 are preferably constructed in accordance with the teachings of U.S. Pat. No. 3,142,915.
Functionally, if the mobile frame encounters a depression in its path of travel, the entire structure supported therefrom will also drop relative to the external grade wire 42 which will through the intermediary of the pivoted sensing fork 46 effect actuation of the valve 48 in a manner to produce extension of the hydraulic rams 32 connected to the pivoted links 24, 26 and thus raise the first height adjustment member 20, the crossslope adjustment members 34, and ultimately the sidewalk building unit mounted therefrom, thus to quickly bring the sidewalk building unit once again to the same height as determined by the disposition of the reference grade wire 42.
To control the cross-slope disposition of the sidewalk building unit, a pendulum-controlled, valve-actuating mechanism 52 preferably of the type shown in the US. Pat. No. 3,386,303 is employed, reference being made to such patent for details of its construction and operation. As illustrated, the pendulum-controlled, valveactuating mechanism 52 constitutes a unit that is secured rigidly to the mobile frame 10 substantially centrally of its forward end and can be preset to a deenergized position corresponding to a predetermined cross-slope of the second pivoted adjustment member 34. In accordance with the structural and operational details in the referred-to patent, if the mobile frame 10 encounters a depression at one side so as to laterally tilt, the pendulum, which obviously attempts to maintain a vertical disposition within the unit, will swing so as to open the valve in a fashion to supply hydraulic fluid to one end or another of the hydraulic ram 38 connected to the pivoted adjustment member 34 to effect a pivotal motion thereof with the described pivot shaft 36. From such shaft 36 to the pendulumcontrolled, valve-actuating mechanism 52, a rotary feedback connection 54 is made to de-energize the latter when the desired cross-slope of the pivoted frame and the sidewalk paving unit mounted therefrom has been attained. More particularly, as best shown in FIG. 1, the feedback connection 54 includes several rod sections 56, 58 which are splined for connection by a connecting sleeve 60 to allow extension and retraction of the rod sections in response to the previously described height adjustment and these rod sections are, in turn, connectedto the shaft 36 and to the input shaft of the pendulum-controlled unit 52 by universal joints 62, 64 also to accommodate changes in height disposition of the first mounting member 20.
It will thus be seen that regardless of any variation in the disposition of the mobile frame 10, either in height or in lateral tilt, the described grade wire sensing means 41 and the pendulum-controlled, slope-sensing mechanism 52 will automatically instigate corrections to reestablish the sidewalk building unit at the original desired height and cross-slope. Preferably, the grade wire 42 is also mounted at a lateral position which follows precisely in parallel relation the path of the sidewalk to be constructed and the operator can, by careful obser-' vation of the position of the sensing fork 46 on the grade wire 42, steer the mobile frame 10 quite accurately to perform the particular digging, grading or paving operation.
However, whereas slight lateral deviations of the sidewalk building equipment unit utilized for digging or grading operations does not require extremely precise lateral positioning of the unit, it will be apparent that the .final paving operation, for example, with a small scale slip-form paver unit, does require maximum lateral position accuracy as well as the aforementioned height and cross-slope adjustments and for this purpose, in accordance with one aspect of the invention, an automatic steering control mechanism, generally indicated at 66, can be mounted on the mobileframe 10 in cooperative relationship to the described "external grade wire 42 so that the entire mobile frame will be automatically steered to follow a path in substantial parallelism with such grade wire.
Initially, it will be obvious that the grade wire 42, itself,'lwill be mounted at the required lateralposition and when corners or other curves are encountered, the grade wire can be replaced by a rigid curved reference rod 68, as shown in FIG. 1, which the steering control mechanism 66, to be hereinafter described, will follow to assure appropriate movement of the sidewalk building unit around the curve or corner.
Such steering control mechanism 66 can take the form of a substantially vertically-disposed sensing rod 68 pivoted at its upper end for opening or closing of a hydraulic valve 70 of the same general type discussed hereinabove relative to the height sensing means 41 associated with that same grade wire. More particularly, as shown in FIG. 1, the vertical rod 68 is normally urged outwardly by a suitable counterweight 69 into contact with the adjacent grade wire 42 or rigid rod 68 and is arranged to" control thefdelivery of hydraulic fluid to a hydraulic steering ram 72, as diagrammatically indicated in FIG. 4 and as will be described hereinafter. In its operating details, this automatic steering control mechanisrn'66 is similar to that described with respect to the height sensing means 41 and reference is therefore made to the aforementioned US. Pat. No. 3,142,915 for details of its construction and operation.
Preferably, as best shown in FIGS. 1 and 2, the entire steering control mechanism 66 is mounted alternatively on brackets 74 or 75 located respectively in lateral alignment with the forward or rearward wheels 12 of the vehicle. If the vehicle is to be moved forwardly or to the left, as viewed in FIG. 3, the steering control mechanism 66 will be mounted on the bracket 74 opposite the forward wheels whereas, to the contrary, if
the vehicle is to be moved to the right during the particular sidewalk building operation, the steering control mechanism 66 will be mounted on the second bracket 75 opposite what would normally be the rear wheels but in this operation constitute the forward wheels of the vehicle, thus enabling the vehicle to be steered accurately in parallelism to the external grade wire 42 or rod 68.
The controlled steering arrangement 76, itself, as previously mentioned, preferably takes the form of center-pivot steering as found, for example, on mobile carriers of the type previously mentioned. Diagrammatically, such steering arrangement 76 involves a center post 78 connected to articulated forward and rearward frame sections 80, 82 to which the respective forward and rearward wheels of the mobile frame are mounted so that as the hydraulic steering ram 72 is extended, as viewed in FIG. 4, the vehicle will be turned to the left whereas if the hydraulic ram is retracted, it will, in turn, be turned to the right. Such extension or retraction of the hydraulic ram 72 in this first embodiment of the invention will be obviously controlled by the hydraulic valve 70 associated with the steering control mechanism 66 described hereinabove.
In the operation of the first embodiment of the invention shown in FIGS. 1, 2, and 3, it is, of course, first necessary that the grade wire 42 or rigid ,rod 68 be appropriately positioned along the path of travel of the sidewalk building equipment at the desired height and lateral position. Thereafter a suitable scraping or digging structure can be mounted at the forward end of the mobile carrier for subsequent traverse of the desired path. As the operation continues, the height and cross-slope of the digging or scraping unit is automatically controlled by the external grade reference sensing means 41 and the pendulum-actuated, cross-slope control mechanism 52 and, in turn, the entire vehicle follows the required path in parallelism to the grade wire through appropriate actuation of the steering control mechanism 66. Subsequent spreading or grading operations will thereafter be performed in substantially the same manner after the replacement of the initial digger or scraper unit with the appropriate spreader or grader mechanism. It will be observed that in all these operations, the supporting wheels of the carrier will. ride, on a surface which has already been worked, and as a consequence, relatively little height or cross-slope deviation is encountered during the operation and the requisite automatic adjustments are accordingly minimized.
For purposes of the final paving operation, which, as previously mentioned, preferably would constitute a slip-form paving operation requiring no construction of temporary forms, the direction of machine operation is reversed. For this purpose, as previously mentioned, the steering control mechanism 66 is moved to a position opposite the wheels 12 of the mobile carrier at the right in FIG. 3 and the paving unit, itself, is now mounted at the rearmost end of the vehicle relative to its newdirection of travel. In turn, the wheels 12 move over a previously graded surface so that but little grade or cross-slope deviations are encountered and, in turn, but small adjustments in the automatically-controlled mounting members are requisite.
It will be apparent that various modifications in the details of the mobile frame 10, its steering arrangement 76 and the mounting of the adjustment members 20, 34 can be made without departing from the spirit of the ately prior to the construction of the sidewalk in spaced relationship thereto.
The main structure of the mobile frame 10, the first height-adjustment member 20 and the second crossslope adjustment member 34 can be substantially identical with the structure previously shown and described in connection with the first embodiment of the invention wherefore like reference numerals are applied thereto in FIG. 4 with but an added prime notation and the general operation of such mobile frame and the first two adjustment members is substantially the same.
However, at the forward end of the. cross-slope adjustment member 34', a pair of parallel links 88, are piv- I otally mounted on upright pins 92 to project forwardly from each side of the second pivoted member and are joined at their forward extremities by similar pivot pins 94 to the mentioned third frame member 84which thus is capable of essentially lateral or horizontal pivotal motion between the full line disposition shown in F IG. 4 and the dotted line dispositions.
The laterally-adjustable third member 84 includes a mount for attachment of a particular sidewalk building 1 unit which assures its desired positional support but, at
the same time, enables quick attachment or detachment thereof by use of a single hydraulic clamp. More particularly, the universal mount includes four dowel pins 40' which project from the four corners of the rectangularthird member 84, much in the fashion of those shown in the first embodiment of the invention, and in addition includes an opening through the central upper portion of such third adjustment member 84 that is arranged to receive a mounting pin 1 12 which can be incorporated in each sidewalk building unit. This pin 112 has opposed flats spaced from its projecting end which extends beyond the opening 110 in the lateral adjustment member 84 which flats are arranged for cooperative wedge-like engagement by a fork 114 mounted at the end of a hydraulic ram 116 whose other extremity is secured to the adjustment member 84. When the ram 116 is withdrawn, the pin 112 on the sidewalk building unit can be freely removed from the ram will effect the desired lateral swinging motion of the foremost frame member.
The described hydraulic ram 96 is under control of a position sensing mechanism 98 whichis mounted at one side of the third frame member 84 and if an external grade wire or rod is used, as shown in the first embodiment of the invention, such position sensing mechanism 98 can be substantially equivalent to the steering control mechanism 66 including a substantially vertically disposed rod 100 arranged to be urged against the grade wire, as best illustrated in FIG. 1. Any lateral deviation of the third adjustment member 84 and the operating unit carried thereby will cause a pivotal motion of the dependent rod 100 which, in turn, will control the opening or closing ofa valve 102 to effect appropriate extension or retraction of the hydraulic ram 96 so that the third mounting member will immediately regain its parallel spaced disposition relative to the grade wire. It will be obvious that if this modified embodiment of the invention is employed, no automatic steering of the unit is required so long as the operator generally steers the vehicle along the general path of travel and, in fact, because of the precise sensing of the lateral disposition of the grade wire at the mounting member itself, a very precise path of travel of the operating unit is achieved.
If the previously mentioned curb 86 and gutter 87 construction has been previously installed and it is desired to use this structure as the external reference rather than the grade wire, but slight modification of the lateral position and height sensing mechanisms are required. The lateral position sensing mechanism 98 need only be modified to mount a wheel 104 at the lower end of the rod 100, as clearly shown in FIG. 5, for appropriate lateral engagement with the vertical surface of the installed curb 86 and the sidewalk paving operation will follow this surface in precise parallelism thereto.
in turn, the height sensing means 41' mounted from the second pivoted adjustement member 34' includes rather than the sensing fork 46, described in the first embodiment of the invention, a wheel 106 mounted at the lower end of a pivoted rod 108 for engagement with the horizontal surface of the gutter 87. Except for the slight modifications in the sensing structures, the construction and operation will be precisely the same as discussed in connection with the previous embodiment of the invention and-thus no further details thereof will be recited.
In view of the fact that it is now well-known that a laser beam can be generated to project for considerable distances (measured in miles) in the form of a pencillike beam having a transverse dimension of V4 inch or less, such a beam can be utilized in accordance with another aspect of the present invention as an external reference for controlling both height and lateral adjustments of the mechanical mounting arrangement as described in either of the previous embodiments of the invention. By way of example and with particular reference to FIG. 6, a combined vertical and lateral lightsensitive sensor means, generally indicated at 120, can be mounted at the top of a rod 122 rigidly secured at its lower end to a lateral adjustment member 84" which corresponds quite precisely with the lateral adjustment member 84, described in detail in connection with the second embodiment of the invention.
The sensor means 120 can, more particularly, take the form of a square panel 124 approximately one foot on each side which, in turn, carries a plurality of lightintercepting photocells, photodiodes or other lightsensitive elements 126 of a known commercial type. Preferably, the panel 124 is mounted at an elevation of approximately feet and is arranged to intercept "a laser beam B which is projected along the side of the desired sidewalk or roadway at this elevation and at a predetermined lateral disposition relative to the roadway. The projection of the beam B at this height precludes accidental interception of the beam by personnel working in the area.
The photocells or photodiodes 126 are arranged on the panel in four quadrants 128, 130, 132, 134, the quadrants 128, 130 on the left and right representing the sensing area for any lateral deviation of the sensor from its desired path, and the top and bottom quadrants 132, 134, in turn, representing the areas for sensing any height deviations. When the beam 8 is at the center of the pane 124, the sidewalk building equipment is properly disposed both laterally and horizontally and no error signal will be produced. On the other hand, if the equipment drops, the panel 124 is therefore lowered and the light beam B is then intercepted by one or another photocell 126 above the central position and a vertical error signal will be produced. This vertical error signal is delivered to an amplifier 136, and the amplified signal, in turn, is delivered to an amplidyne generator 138 whose output controls a servo motor 140 that, in turn, physically moves a valve 48' in a fashion to raise the level of the mounting arrangement until the laser beam B, once again, is intercepted at the center of the sensor panel 124 and further vertical adjustment ceases.
If alateral deviation of the equipment is experienced, the sensor means will be displaced laterally relative to the' laser beam B and the resultant lateral error signal is, in turn, fed through another amplifier 142 and amplidyne generator 144 to a lateral servo motor 146 which adjusts a valve 102 to effect lateral motion of the arrangement and, more particularly, the lateral adjustment member 84" until, again, the beam 8 is recentered on the sensor 120.
If both lateral and vertical deviations are encounteredsimultaneously, alternate vertical and lateral adjustrnents will be made as the laser beam B is intercepted by, for example, first a photocell 126 in a vertical quadrant and, then a photocell in a lateral sensing quadrant until in a step by step fashion the position of the beam is, once again, recentered on the sensor means 120.
Preferably, the sensor means 120 is arranged to provide for a proportional adjustment and this can be achieved simply by providing a low output from the photocells 126 closest to the center and a successively higher voltage output from those more remote from the center of the panel 124.
While many modifications in the details of the light sensitive sensor means can be envisioned, it is to be noted that this single sensor means 120, whatever precise form it may take, provides for both vertical and lateral control of the disposition of the sidewalk building unit. Furthermore, because of the permitted disposition of the beam B and the elimination of any external references of a physical nature, accidental displacement of an external wire or other physical reference is avoided.
The discussed advantages of the single light sensor means 120 providing control in two directions can further beextended by a novel arrangement which eliminates the necessity for a separate laterally-adjustable member such as the described member 84 in FIG. 4 together with the associated control mechanism therefor and enables application of the light sensor arrangement to many existent machines, such as the embodiment of the invention of FIGS. 1, 2 and 3 as well as road graders, pavers and the like which provide for height adjust ment butno lateral adjustment of the working tool or other implement.
By way of example, reference is made to FIG. 7 wherein a proportional light sensor means 120' similar in its dual direction sensing is applied to a machine as shown and described hereinabove relateive to FIGS. 1, 2, and 3 to provide height adjustment and steering control, thus to eliminate the need for the specific addition of the laterally-adjustable member 84 as shown in FIG. 4 while at the same time achieving equivalent operational performance. As specifically illustrated in FIG. 7, brackets 148 extend laterally from a vertically adjustable sub-frame in a manner corresponding to the mounting arrangement shown best in FIG. 1 and carry an upright rod 122' which mounts at its upper extremity a light-sensitive sensor means 120' corresponding in its structural arrangement to that shown in FIG. 6and described hereinabove. The outputs of the vertical quadrants are arranged similarly to the arrangement shown in FIG. 6 to pass to an amplifier 136' whose amplified output is delivered to an amplidyne 138' which feeds a servo unit 140 that controls the operation of a valve 48 connected to a ram 32' that raises or lowers the sub-frame 20' in a fashion similar to that of the valve 48 in FIG. 1.
The horizontal quadrants of the light sensor means 120 provide an output when the frame 20' of the machine deviates from its desired transverse disposition and is delivered to an amplifier 150 that feeds another amplidyne 152 which, in turn, actu'ates a steering servo 154 which opens or closes a valve 70' to apply appropriate hydraulic pressure to a hydraulic steering mechanism such as, by way of example, a steering ram 72 which corresponds in its structure and function to the steering ram 72 of FIG. 4. Theentire machine is then appropriately steered to return it and the sensor 120' thereon to its desired central position.
In all embodiments, the hydraulic conduits are not illustrated since they are conventional, but the open rectangular configuration of each adjustment member readily facilitates appropriate connection to the hydraulic rams, valves, and pumps as described.
While relatively small units have been specifically described for the construction of sidewalks, it will be apparent that equally small units can be utilized to mount appropriate curb and/or gutter building equipment, and larger units can be employed in street construction.
It will also be apparent that many other modifications and/or alterations can be made to meet particular conditions without departing from the spirit of the present invention, and, accordingly, the foregoing description of but four embodiments is to be considered as purely exemplary and not in a limiting sense and the actual scope of the invention is to be indicated only by reference to the appended claims.
What is claimed is:
1. Controllable road building equipment or the like which comprises,
a main frame, means mounting said frame for steered movement, steering means for said frame,
means mounting an operational road building unit from said frame including a first frame member mounted for height adjusti ment from said main frame, and
a second frame member mounted from said first frame member for pivotal adjustment relative thereto, means for adjusting the height of said first frame member relative to said main frame, light sensor means mounted from said first frame member adapted to sense lateral deviation thereof from a beam of light for controlling said steering means, and I light sensor means mounted on said first frame member adapted to sense height deviation thereof from the same beam of light for controlling said height adjusting means. 2. Controllable road building equipment or thelike according to claim 1 wherein,
both of said light sensor means constitute a single unit including a plurality of light sensitive elements arranged in four quadrants, two of which lie above and below the quadrant center to sense height deviation, and the other two of which lie on opposite sides of the quadrant center to sense lateral deviation. 3. Controllable road building equipment or the like according to claim 2 wherein,
said single light sensor unit is mounted on said first frame member for the road building unit to vary in height and lateral disposition therewith. 4. Controllable road buildingequipment or the like according to claim 1 wherein,
each of said light sensor means provides an output signal proportional to the amount of deviation.