US2973723A - Roadway working apparatus - Google Patents

Description

M. l. HUDIS ETAL ROADWAY WORKING APPARATUS March 7, 1961 9 Sheets-Sheet 1 Filed March 25, 1955 INVENTORS` M ICHHL 1. H0015 /lullllllll Bf, Jacco J. mancano N .ma

March 7, 1961 M. HuDls ETAL RoADwAY WORKING APPARATUS Filed March 25, 1955 9 Sheets-Sheet 2 INVENTORS Murmel. :.Huozs Bt J'Hco J. Manna www March 7, 1961 M. l. HUDls ETAL 2,973,723

ROADWAY WORKING APPARATUS March 7, 1961 Filed March 25, 1955 M. l. HUDIS ET AL ROADWAY WORKING APPARATUS 9 Sheets-Sheet 4 d gg N x v0 U a JI l w 2 P |l un I| j V sa l il* I |I ,11T-:Iii Ill, l l 3 Iil 1 :k l

l. i l@ f N mmfvwfzs 1" Bf, Jncoa Macau-a March 7, 1961 M, l, HuDls ETAL '2,973,723

ROADWAY WORKING -APPARATUS March 7, 1961 M. l. HuDls Erm. 2,973,723

ROADWAY WORKING APPARATUS Filed March 25, 1955 9 Sheets-Sheet 6 INVENToRs MNHN I. H0015 BY .18:03 J. MRRctLLo March 7, 1961 M. l. HuDls ETAL 2,973,723

Y ROADWAY WORKING APPARATUS Filed March 25, 1955 9 Sheets-Sheet 7 INVENTORS MICHRIL :.Hurs BY JRcoB J. MHRCBLLo ttorney March 7, 1961 M. Hunls Erm. 2,973,723

ROADWAY WORKING APPARATUS Filednarch 25. 1955 9 sheets-sneet s INVENTORS MICHIIL I. H0013 BY JHCQB J. MRRCELLQ MMM March 7, 1961 M, HUDIS ETAL 2,973,723

ROADWAY WORKING APRARTUS Filed March 25. 1955 l9 Sheets-Sheet 9 INVENToRs MICHREL i., Hunts MJMQW United States Patent ,i

ROADWAY WORKING APPARATUS Michael I. Hudis and Jacob J. Marcello, Warren, Ohio;

Filed Mal'. 25, 1955, Ser. No. 496,851

2 Claims. (CI. 10S-178) The present invention relates to apparatus adapted to travel along longitudinally extending, transversely spacedapart supporting surfaces which may incline vtoward or away from each other, more particularly to roadway working apparatus adapted to travel along the usual road forms which normally deiine the edges of the intended roadway and which, in certain cases, may be disposed in converging orA diverging relationship, and the principal object of the invention is to provide new and improved apparatus of such character.

Modern highway construction, particularly so-called super-highway construction, dictates the use of gently curving entrance and exit roads which intersect the main road at a tangent to minimize traiiic 4iiow disturbances at these points. Road constructions of this type often vary in width, changing from wide to narrow and vice versa in accordance with intersection requirements, bridges, curves, grades and the like. These width changes generally progress gradually from one to the other and to meet these requirements, the finishing machines and other allied apparatuses which normally ride the forms defining the edges of the intended roadway must be capable of expanding and contracting in width to maintain the road form engaging wheels of the apparatus upon the road forms despite divergence of convergenceof the latter. Y

l In the past, apparatus has been devised wherein roadV form engaging iianged wheels float axially toward and away from each other to accommodate converging ory diverging road forms. In most instances, the wheels on one side of the apparatus which are engageable with onel road form are maintained in axially iixed relation relative to the main body of the apparatus while the wheels on the other side, engageable withthe other road form, are lallowed to float axially.

This construction has not been satisfactory since the one road form alone must guide the apparatus along the forms and resist all of the forces tending to shift the apparatus transversely thereof. Furthermore, -with prior art constructions, the weight of the apparatus is seldom, if ever, evenly divided between the two forms. This causes considerable diiculty in operating kthe apparatus since the uneven loading condition often causes one side of the apparatus to advance down the forms at a greaterv ing'description and from the drawings appended hereto.`

v being removed in the interest of clarity,

Patented Mar. .7, .1961

ice

Figure 1 is a top plan view of apparatus illustrating anv v embodiment of the present invention,

Figure 2 is an enlarged side elevational view of the apparatus shown in Figure 1,

Figure 3 is an enlarged sectional view generally corresponding to the line 3-3 of Figure l,

Figure 4 is a fragmentary, enlarged front elevational view'of the apparatus shown in Figure l, certain parts being broken away to illustrate interior construction,

Figure 5 is a view similar to Figure 4 but with certain parts further broken away and removed to better illusf` trate the interior construction,

Figures 6 and 7 are transverse fragmentary sectional views generally corresponding to respective lines 6-6 and 7-7 of Figure 5,

Fig'ure 8 is a broken perspective view of the main frame of the herein disclosed apparatus, certain parts' normally secured thereto being removed in the interest of clarity, Figure 9 is a broken perspective ,view of one of two frame extensions forming a part of the presently dis" closed apparatus, certain parts normally secured thereto;-

Figures 10 and llfare reduced size, top plan views of the frame of the apparatus, all parts normally carried thereby being removed in the interest of clarity and thel views respectively showing the frame in contracted and expanded relation,

" lIn thel drawings accompanying this specilication` and f Y Figure 12 is a generally diagrammatic view of a' iiuid circuit for-operating the embodiment of the invention shown in Figures 1 through 11,

Figure 13 is a fragmentary sectional view *generally I corresponding to the line 13-13 of Figure 3 but of a modiiied construction, and

Figure 14 is a generally diagrammatic view of a tiuid circuit for operating the embodiment shown in Figure 13;

The present invention is shown applied to a road iinishing machine adapted to span the road forms which deline the edges of the intended road and having a plurality of spaced-apart wheels which engagel respective forms; Such a machine normally carries a screed which "is adapted to be reciprocated'transversely ofthe roadway as the iinishing machine progresses along the forms toV smooth the plastic road materialand form its upper surface to the desired contour, `be it iiat, curved, or other wiseproiiled. It is to be understood, however, that the apparatus herein disclosed is illustrative only and that the invention can also -be Iapplied to other apparatus such as spreading, spraying, floating and joint installing apparatus commonly employed in highway construction.

Referring to Figure 1, it will be noted that the presentembodiment comprises a frame structure 10 rotatably carrying a pair of wheels 11 on each side. The wheels on each side are adapted to be supported lby the usual road forms 12 which normally dene the sides of the intended roadway, the wheels 11 being of the doublev flanged type to reduce the possibility of Ithe apparatus running off the forms and the Aspacing betweenthe flanges being somewhat 'greater than the width of' the upper portion of the forms upon which the wheels ridev (see Figure 5) for a purpose to become clear.A

As best shown in Figures 1,12, 3 and 4, frame structure 10 carries a screed 13 which extends transversely ofthe intended roadway and which, in normal use, rests upon the tops of the forms 12 in the mannerA illustrated. By means later to be disclosed, screed 13r is adapted to be reciprocated transversely of the roadway as the appa# ratus,l moves along .the forms on the wheels 111. .f

While the embodiment herein disclosed employs but a single screed disposed at the front of the machine, it is to be understood that another screed, similar to the one herein shown, may be disposed at the. rear of the machine -if desired.

' Means are provided for elevating the screed 13 when the apparatus is to be transported or when the use of the screed is not required. As seen in Figures 1 through 4, a shaft 14 is supportedV by suitable bearings 15 secured to members 16 which extend transversely of the frame structure in overhanging relation with the screed and which are secured to the top of such structure by` welding or the like. Adjacent each end of shaft 14, a chain 17 is secured, and each chain extends downwardly toward the screed and each terminates in a link 18 which rotatably carries a roller 19 (see Figure 3). Secured in spaced relation to the top of the screed adjacent each chain 17 by means of brackets 20 is a bar, or track, 21 adapted for engagement with roller 19.

When shaft 14 is rotated in a clockwise direction (with reference to the arrangement of parts as shown in Figures 2 and 3) by means of a uid cylinder 22 connected to a lever 23 suitably secured to the shaft 14, each chain 17 will be wrapped about the shaft 14 thus pulling up on the respective links 18 which carry rollers 19. As rollers 19 are elevated, they will engage beneath respective bars 21 and thus raise the screed. Since suicient space is provided between the respective brackets 20 which support each bar 21, the screed may be raised, if desired, without interrupting `its reciprocatory movement. While only two chains 17 are herein disclosed, it will be understood that additional chains may be employed if required.

With particular reference to Figure 3, but as also shown in Figure 5, means are provided for pushing the screed ahead of the apparatus against the resistance of the road material which piles up in front of the screed as the apparatus moves in a forward direction along the forms. In the herein disclosed embodiment, a pair of push rods 24 extend from the outer members 16 to the screed. One end of each push rod 24 is pivotally-secured to the screed by means of respective brackets 2S and the other end of each push rod is pivotally secured to respective members 16 by means of respective brackets 26. It -is to be understood that the pivotal connections of the push rods 24 with the screed and the `members 16 will have suflicient play, or slack, so

, 4 of the apparatus are connected together for unitary rotation by means of a suitable chain 38 operating over sprockets 39 carried by respective wheels.

As most clearly shown in Figures 2, 3 and 4, a shaft 40 extends forward from the drive mechanism 28 and terminates lin a sprocket 41. A sprocket 42 is rotatably carried by the frame structure directly beneath sprocket 41 and a suitable chain 43 connects `the two sprockets together. A stud 44 is secured to, by any suitable means, and projects forwardly from the side of sprocket 42 in off-set relation with the rotational axis of the latter. Stud 44 serves as a crank arm to which one end of a link 45 is rotatably secured. The other end of link 45 is pivotally secured to a stud 46 (see Figure 4) carried by screed 13. It will readily be apparent that as sprocket 42 is rotatedby means of shaft 40, the off-set position of stud 44 will effect reciprocation of link 45 and y consequent reciprocation of screed 13.

l upper surface of the channel members 47a by means that the push rods do not interfere with elevation of the screed iu the manner heretofore disclosed.

As seen in Figures l through 5, frame structure 10` is provided with a platform 27 which supports the drive mechanism 28 of the apparatus. The drive mechanism may take any convenient form; however, the drive mechanism preferred at the present time is a gasoline engine 29 which is operably connected to a suitable gear box 30. Although not shown, suitable clutches may be employed to provide for selective interruption of power transmission lfrom the drive mechanism., Extending from gear box 30 `toward the wheels at respective sides of the apparatus is a drive shaft 31. Each side of the drive shaft 31 is rotatably supported by a bearing 32 secured to respective members 116 and each drive shaft is preferably hollow for a purpose to appear. vPositioned within respective ends of the hollow drive shaft 31 are shaft extensions 33 which are keyed to the shaft for unitary rotation therewith butwhich are slideable axially thereof. Each shaft extension 33 is rotatably carried fby a bearing 34 secured to a portion of the frame structure 10.

l As best shown in Figures l, 2 and 5, a sprocket 35 is carried by each shaftextension 33 and each sprocket of suitable spacers, or pads, for a purpose to become clear.

Secured to the respective inner sides of the channel members 47a, in back to back relation therewith and disposed at one end thereof, are a pair of channel members 47b. Channel members 47b are securely Vwelded to members 47a as indicated and plates 50 are welded in place between the legs of respective members 47b to provide a at smooth surface for a purpose to be disclosed.

The previously mentioned frame extensions 48 and 49 are adapted to be carried by the main frame 47 in telesooping relation to provide for adjustment of the size of the apparatus. As seen in Figure 9, frame extension 48 comprises a pair of spaced channel members 48a secured together as by welding or the like by a pair of spaced cross members 48h disposed at one end. In a manner similar to that employed with members 47b, plates 51 are welded between the legs of channel members 48a for a purpose to be disclosed. v

, Frame extension 49 is similar to frame extension 48 with the exception that while the overall width of extension 49 is such that it slideably fits between members 47a of the main frame, the overall width of extension 48 is such that it slideably ts between the members 47b of the frame extensions, drive shaft length will increase and isA connected by means of. a drive chain 36 to a sprocket l 37 carried by a respective adjacent wheel 1'1. In the present embodiment, the wheels 1-1 on respective sides decrease `automatically as the frame extensions are moved relative to the main frame thus maintaining constant alignment between the associated drive sprockets and chains.

Means are provided for maintaining the relatively movable frame portions in alignment without impeding such movement and, as shown in Figure l, a plurality of rollers are carried by the main frame for engagement with respective frame extensions. Since a similar arrangement 1s employed to guide each of the frame extensions, only the ones employed with extension 48 will be shown and described indetail."

Secured to'the top of main frame 47 by suitablebrackets are a pair off spaced-apart rollers 52 (Figures 1 and 4) which are engageable with ythe upper surface of frame extension 48. Corresponding rollers 52 arecarricd by each of the spaced members which comprise the main frame and each roller 'is engageable with a respective member 48a of the frame extension 48 (see Figure 2). Furthermore, as most clearly seen in Figures 5 and 7, the rollers 52 at the top of the frame are matched by similar rollers 52 positionedfor engagement with the underside of the frame extension.

In addition to rollers 52, spaced'rollers53 are carried by brackets` 54 secured to the main frame, rollers 53 being engageable with respective plates 5I as shown in Figure 6 for the purpose of holding the respective frame extension members closely against the respective inner surfaces of the main frame.

Means are provided. for shifting. the frame extensions and the respective wheels carried thereby transversely of the road'form's V12 so asV to maintain theA Wheels upon the forms despite convergence or divergence of the latter. In the presently disclosed embodiment, positive, power operated means are employed to effect shifting of respective frame extensions relative to the main frame and as seen in Figure l, iluid cylinders 55, 56 are employed for this purpose.

As most clearly shown in Figure 5, cylinder 55 has one end, in this instance its blank end, secured to the under# side of the platform 27 by means of a bracket 57. Piston rod 58 of'cylinder 55 is in turn secured to one of the members 48b of frame extension 48` by means ofa bracket 59. Since cylinder 56 -is mounted in manner similar to cylinder 55 (with the exception, of course, that it is connected to frame extension 49), it is not believed that a detailed description thereof is necessary.

In Figure l2 there is generally diagramrnatically shown a hydraulic circuit for controlling oper-ation of the cylinders 55, 56, The circuit comprises a fluid pump, two

manually operable Huid' control valves 60; 70 having re-k spective actuators 60a, 70a, fluid cylinders 55, 56 and associated connecting conduits. Valves 60, 70 are herein shown to` be identical and, although notrshown, each is preferably spring-biased toinsure its return to the neutral position illustrated when the actuator isV released. It is to 13e-understood that thesevalves will be positioned on the machine withineasy reach ofthe operator who normally rides upon the platforml 27. Valve 60 hasv ports 62, 63, 64, 65 66, 67 and 68 While valve 70 has ports 72, 73, 74, 75,76, 77-and 78.

Ports 62, 64v of valve 60 and port 74 of valve 70 are connected with the pressure ,outlet side of the pump by means of conduits 80 while ports` 72, 73 and 75 of valve 70 are connected with the return inlet of' the pump by' means of conduits 81. A conduit 82 connects -port 68',

with port 78 and condui- ts 83, 84 respectively connect ports 66, 67 with the rod and blank ends of cylinder 55; Conduite 85, 86 respectively connect ports 76, 77 with f the rod andl blank ends oficyli'nder 56.

With valves 60, 70, in the neutral position shown and With the pump (which may be ,driven by thedrive mechanism ofthe apparatus) operating, ilu idwill pass, through conduit 80 tol port -62,"through valve 60 and'out port 68 to valve 70 throughconduit 82 and port 78. The fluid wil-l,

, the respectivev valves 60, 70. This insures that the cylinders kwill remainina fixed position, thus-holding the wheels 11 in 'predetermined spaced-apart relationt'as long as the valves are in neutral.

During operation of the apparatus along the road forms, the operator riding thereon, upon observing that the road forms are converging or diverging, will actuate the valves 60,` 7 0 tov extend or contract the frame extension members to thereupon maintain the road form engaging wheels in engagement with the forms. Normally, both valves will be actuated simultaneously to shift the frame extensions in opposite directions, either toward or away from each other. However, if desired, the valves m-ay be operated to shift cylinders 55, 56 (and consequently the frame extension members) in the same direction to thereby merelyV shift the mainframe of the apparatus toward one or the other road forms without changing the spacing between the wheels. Moreover, if desired, only one valve may be actuated to thereby effect shifting of only one of the frame extensions. In Order to simplify understanding of the uid appara; tus shown in Figure 12, operation thereof when only valveV 60 is actuated will first be described. YAssuming that the operator shifts the actuator 60a of valve 60 from the full line position shown. to dotted line position X, the spool Within the valve will be shifted to close oi the previously described. free ilowing, or by-pass, circuit through ports 62, 68 and to establish communication between ports 64 and 66 and between ports 63 and 67.

vWith. the by-pass circuit interrupted, lfluid will How from the pump through the valve and to the rod end of cylinder 55' through `conduit 80ports 64, 66 and con;y duit 83., Fluid will be displaced from the blank end of cylinder 55 through the valve` and to the inlet of the pump through conduit 84, ports 67, 63 and conduit 81. Accordingly, the piston. rod of cylinder 55 will be retracted. When the operator releases actuator 60a, it will be returned .by any suitable means (not shown) to its full' line position to lockcylinder 55 in position and re-establish the by-pass circuit. C Moving actuator 60a to position Y will 'once againv interrupt the by-pass circuit and establish communication*y between ports 65, 66 and between ports 64, 67. Fluid' will now tlow from the pump through the valve to the blank cndof cylinder 55 through conduit 80, ports 64,' 67, and conduit 84. Fluid will be displaced from the rod end of Vcylinder55 through the valve and to the inlet of the pump through` conduit 83, ports 66, 65,' and con-- duit 81. Accordingly, the piston rod of cylinder 55 wilt be extended', j With the foregoing description of operation of va'lve 60, it is believed that a detailed description of operation of valve 70 is unnecessary since the operation of this valve will'nowbe evident. Note that in the event either valve actuator is shifted from its full line position, the

Figure -14 isl a modified hydraulic circuit design which will automatically shift the road form engaging wheelsV of the apparatus toward or away from each other in response to convergence or divergence of the road" forms without constant attention from the operator. tBriey, this circuit comprises a pair of valves 160, 170which are somewhat similar to valves 60, 70; a fluid pump; a spring-centered, pilot operated valve ;*a manually `operable valve 91 having an actuator 91a which is normally held in the neutral position illustrated by suitable springs (not shown) or Ithe like; uid cylinders 155, 156 which. are similar toV cylinders 55, 56; andr a plurality of conduits which connect the various members of the circuit together. i

Valves 160, are not adapted for manual operation as were valves`60, 70; instead, each. has its actuator en# gageable'with a'respective road form by means of the. following mechanism; .i In.A the modiiied coustruutimtshown in Figure 13, the main body of valve 160 is secured to frame extension 48 by bolts or the like. Also secured to frame extension 48 are a pair of spaced lugs 92 (only one of which is shown) which support a pivot shaft 93. Pivotally carried by shaft 93 between the lugs 92 is a yoke 94 which rotatably carries a feeler wheel 95 engageable with the road form 12 on this side of the machine. Feeler wheel 95 is preferably positioned be- 4tween the wheels 11 on this side of the machine and this wheel is formed with spaced ange portions to insure engagement with the road form. Secured to and extend ing upwardly from yoke 94 is an arm 96 which is pivotally secured to the actuator 160a of valve 160.

, From the construction illustrated in Figure 13, it will be understood that in the event relative movement occurs in a direction transversely of the road forms between the latter and the finishing machine (such relative movement occurring because of transverse shifting of the machine or because of a non-parallel relationship between the road forms) feeler wheel 95 will be tilted in one direction or the other about its pivot shaft 93 thus effecting movement of valve actuator 160a. Although not shown, valve 170 is arranged in a manner similar to valve 160, valve 170, of course,` being carried by frame extension 49 and having its feeler wheel engaged with the opposite road form 12.

It should be pointed out that in the operation of road machines of the general type herein disclosed, considerable power must be applied to the screed to elect transverse shifting thereof. This is particularly true when relatively large amounts of road material pile up in front of the screed. Accordingly, it is not at all unusual for the machine to oscillate transversely of the road forms as it progresses therealong. In view of the fact that such movement frequently occurs, the circuit disclosed in Figure 14 has been designed to effect operation of the cylinders 155, 156 only when the feeler wheels move in opposite directions thus indicating that the forms are in diverging or converging relation. In the event the machine shifts transversely of the forms (for reasons hereinabove disclosed), the feeler wheels will move in the same direction and the cylinders will therefore remain locked in position to maintain the form engaging wheels 11 in xed, spaced-apart relation.

Referring to Figure 14, valves `160, 170 are spool type valves, the respective spools of each being pivotally connected to their respective actuators and being shifted thereby. Valve 160 has ports 161, 162, 163, 164, 165, 166, 167 and 168 while valve 170 has ports 171, 172, 173, 174, 175, 176, 177 and 178. For a purpose to become clear, the spool, of valve 160 is formed with apertures 169 while the spool of valve I170 is formed with apertures 179.

I As previously mentioned, valve 90 is a pilot operated, spring-centered valve having a valve spool adapted to be shifted by pilot pistons 97 and 98 respectively disposed at opposite ends of the valve. Valve 90 has ports 99, 100, 101, 102, 103, 104 and 105 connected to various conduitsy in a manner to be disclosed.

, Manually operable valve 91 has ports A106, 107, 108, 1 08a, 109, 110, 111, 112, 113, 114, 115, 116, 117 and 118 and, as before disclosed, the spool of valve 91 is adapted to be resiliently held in the neutral position shown by suitable springs or the like (not shown).

A conduit 119 connects the pressure outlet of the uid pump with ports 106, 108 and 110 of valve 91 while a conduit 120 is connected to ports 114, 115 of valve 91 and leads to a conduit 121. Conduit 121 has branches whichrespectively connect with ports 172 and 174 of valve-170 and with ports 162 and 164 of valve 160. Conduit 121 further has a branch 122 which connects with port-101 of pilot valve 90.

' .A conduit 123 leads from the inlet of the fluid pump and connects with a conduit 124 having branches connected to ports 171, 173 of valve 170 and to ports 161,

163 of valve 160. Conduit 124 further has branches 125, 126 respectively connected to ports .111, 118 of valve 91. Conduit 124 additionally has a branch -127 connected to port 175 of valve 170 and to port 99 of pilot valve and a branch 128 connected to port 165 of valve 160 and to port 103 of pilot valve 90.

A conduit 129 connects port 100 of pilot valve 90 with the blank end of cylinder 155 and with port 109 of valve 91 while a conduit 130 connects port 105 of the pilot valve with the blank end of cylinder 156 and with port 107 of valve 91. A conduit 131 connects port 102 .of the pilot valve with the rod end of cylinder 156 and with ports 112, 113 of valve 91 while a conduit 132 connects port 104 of the pilot valve with the rod end of cylinder 155 and with ports 116, 117 of valve 91. The chamber in which pilot piston 97 is slideable is connected to ports 166, 168 of valve 160 by means of a conduit 133 which has a branch 134 connected to port 178 of valve 170. The chamber in which pilot piston 98 is slideable is connected to ports 176, 177 of valve 170 by means of a conduit 135 which has a branch 136 connected to port 167 of valve 160.

With all valves in the neutral position illustrated, it will be noted that conduit 130, which is connected to the blank end of cylinder 156, terminates at closed port 107 of valve 91 and closed port 105 of the pilot valve 90 while conduit 131, connected to the rod end of cylinder 156, terminates at closed ports 112, 113 of valve 91 and closed port 102 of the pilot valve. Conduit 129, which is connected to the blank end of cylinder 155, terminates at closed port 109 of valve 91 and closed port of the pilot valve while conduit 132, connected to the rod end of cylinder 155, terminates at closed ports 116, 117 of valve 91 and closed port 104 of the pilot valve. Since fluid can neither enter nor escape from cylinders 155, 156 at this time, the cylinders are locked in position to hold the wheels 11 in fixed, spaced-apart relation.

While the valves are in neutral, fluid will circulate idly through the pump, its llow being traced through conduit 119 to port 108 of valve 91, from port 108 to port and from port 115 to conduits 120 and 121. From conduit 121, a portion of the uid will ow to port 164 of valve 160, through apertures 169 in the valve spool, through port 165 and thence to the inlet of the pump via branch conduit 128, and conduits 124, 123. Also from conduit 121, the remaining portion of the uid will ow to port 174 of valve 170, through apertures 179 in the valve spool, through port 175 and thence to the inlet of the pump via branch conduit 127 and conduits 124, 123. It will be noted that in the event only one of the valves 160, 170 is shifted, fluid will continue t0 idle through the pump through the valve which remains in neutral; accordingly, there will be no build up of pressure to cause shifting of the pilot valve 90 from its central, or neutral, position and, therefore, both cylinders 155, 156 will remain locked in position.

In the event both valve actuators 160:1, 170a move in the same direction (caused by the previously described transverse shifting of the machine) and assuming, for example, that-actuator 160a moves to position Y and that actuator 170a moves to position X, fluid flow through ports 164, 174 of the respective valves will be cut olf. Fluid from the pump outlet will then ilow through ports 162, 167 of valve 160, through conduits 136, to port 177 of valve 170. From port 177, uid will ow through port 173 and to the inlet of the pump via conduits 124, 123. Since this circuit provides a free path for the fluid, once again no pressure will be built up to effect shifting of the pilot valve. It is to be understood that a similar free path will be opened for the fluid in the event valve actuator a moves to position X and valve actuator 170a moves to position Y.

When valve actuators 160a, 170:: move in opposite.

directions (caused by, for example, the road forms 12 actuator will be shifted to the respectivek positions `indicated at X or Y'. Movement of valve actuator'p160aY to position X (as by the fceler wheels 95 being moved away from Veach other by diverging road forms) will close off ports 164 and 166 and establish communication between ports 163 and 167 and between ports 162 and 168, while movement of valve actuator 170a to position X will close off yports 174, 176 and establish communication between ports 173 and 177 and between ports 172 and 178.

Fluid will then ow from conduit 121 through ports 162 and 168 of valve 160 and to pilot valve piston V97 through conduit 133. Fluid will also ilow topilot valve piston 97 through valve 170 through ports 172, 178 and conduit 134. Fluid ahead of pilot piston 98 will be returned to the inlet of the pump through conduit 135, ports 177, 173 of valve 170 and through conduits 124, 123.` Fluid will also be returned to the inlet of the pump through conduit 136 (which connects with conduit 135), ports 167, 163 of valve 160 and through conduits 124, 123. Since tluid from the pump will be admitted to pilot piston 97 and since uid ahead of pilot piston 98 will be returned to the pump, the valve spool of the pilot valve will be shifted to the left.

When the valve spool of the pilot valve is shifted to the left, communication will be established between ports 102, 103 and 104, and between ports 100, 101 and 105. Fluid from the pump will then flow from conduit 121 through branch conduit 122 to port 101 and thence through ports 100, 105. First considering iiuid ow through port 105, uid will pass to the blank end of cylinder 156 through conduit 130 (note that port 107 of valve 91 is closed so that fluid in conduit 130 cannot pass through the valve). Returning now to port 100 of the pilot valve, fluid will ow through this port to the blank end of cylinder 155 through conduit 129 (note that port 109 of valve 91 is closed at this time).

Returning to ports 102, 103 and 104 of the pilot valve and lirst considering port 102, uid from the rod end of cylinder 156 will flow through conduit 131 to ports 102, 103 and thence to the inlet of the pump through branch conduit 128 and conduits 124, 123. Fluid from the rod end of cylinder 155 will flow through conduit 132, ports 104 and 103 and thence to the inlet of the pump through branch conduit 128 and conduits 124, 123.

With the pressure outlet of the pump connected to the blank ends of cylinders 155, 156 and with the rod ends of the cylinders connected to the inlet of the pump, the piston rods of these cylinders will be forced outwardly thus moving the frame extensions 48, 49 and also the wheels 11 away from each other to accommodate the diverging road forms. When the apparatus has been widened sufficiently, feeler wheels 95 will be returned to their neutral position as will valves 160, 170 respectively actuated thereby. Accordingly, pilot valve 90 ,will be returned to its neutral position shown by its springs thus locking cylinders 155, 156 in position as before described.

It will be understood that when valve actuators 160a, 170a are shifted to respective Y positions, as by the feeler wheels 95 being moved toward each other by converging road forms, the pilot valve 90 will be shifted in the opposite direction to that heretofore described thus admitting fluid to the rod ends of both cylinders 155, 156 and allowing uid Yfrom the blank ends of the cylinders to return to the inlet of the pump. This will move the frame extensions 48, 49 and also the wheels 11 toward each other to accommodate the converging road forms 12.

Since the present embodiment of the invention employs separate cylinders (155, 156) for shifting respective sides of the apparatus and since there is a possibility that the cylinders may not be shifted exactly the same amount by reason of, for example, uneven loading of the apparatus, manually. operable valve 91 is provided to permit the operator to extend one of the frame extensions while simultaneously retracting the other extension. Clearly, this will effect movement cf the main frame of the apparatus in `one direction or the other, depending,

upon which direction actuator 91a is shifted, without changing the spacing between the wheels 11.

It was previously pointed out that all fluid ow from the pump outlet to valves 160, 170 passes through valve 91 via conduit 119, ports 108, 115 and through conduit 120 to conduit 121. Accordingly, when valve actuator 91a is shifted in either direction from the neutral position shown, ports 10S, 115 will be closed rand port 114 (connected to conduit 120 by a branch 137) will cornmunicate with port 108:1. Port 108a is connected to the inlet of the pump by a conduit 138; therefore, any pressure which might exist in conduit i120 and the circuits connected therewith, by virtue of the fact that extension or contraction of the machine is taking place at the time valve 91 is manually shifted, will `be bled off to the inlet of the pump and this will allow the pilot valve to returnV to neutral.

During operation of the finishing machine and assuming that the main frame of the machine is closer to one road form 12 than it is to the other, the operator will shift the actuator 91a in the proper direction to center themain frame between the forms. By way of illustration and assuming that the actuator 91a is shifted to the right, ports 10S, 115 will be closed andports 108a, 1l14 will be opened to each other as before mentioned. Ports 109, 113 and ports 110, 112 will be placed in communication with each other as will ports 107, 116 and ports 117, 118.

Fluid will now ilow from the pump outlet through conduit 119 to port 110 ( ports 106 and 108 now being closed) and thence through ports 112, 113 and 109. nFluidl iiow through port 12 will pass to the rod end ofV cylinder 156 through conduit 131 and to the blank end of cylinder 155 through ports 113, 109 and conduit 129. Fluid from the bland end of cylinder 156 will pass through conduit 130, ports 107, 116, through port 117 via a portion of conduit 32, and through port 118 to conduits 126, 124 and 123 to the pump inlet. Fluid from the rod end of cylinder 55 will pass through conduit 132 to ports 117, 118 and through port 118 to conduits 126, l124 and 123 to the pump inlet.

With the rod end of cylinder 156 connected to the pump outlet and the blank end of this cylinder connected to the pump inlet, and with the blank end of cylinder 155 connected to the pump outlet and the rod end of this cylinder connected to the pump inlet, cylinder 156 and the frame extension connected thereto will be retracted and cylinder 155 and its frame extension will be extended. Accordingly, the main frame of the machine will be shifted away from one road form and toward the other without changing the spacing between the form engaging wheels 11. v

When the main frame is properly positioned between the road forms, the operator will release `actuator 91a and the valve will then return to the neutral position shown in the drawing. This will re-establish communication between the outlet of the pump and the valves 160, 170 and therefore control of uid flow to and from cylinders 155, 156 will once again lbe placed under the control of valves 160, 170.

It will readily be apparent that shifting valve actuator 91a to the left instead of to the right will reverse flow of fluid and thus cause shifting of the main frame of the nishing machine in the opposite direction from that electrical components, instead of the hydraulic components disclosed, for controlling iiow of uid to the cylinders.

In |view of the foregoing it will be apparent to those skilled `in the art that we have accomplished at least the principal object of our invention and it will also be apparent to those skilled in the art that the embodiments herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described, hence it will be appreciated that the herein disclosed embodiments are illustrative only, and that our invention is not limited thereto.

We claim:

1. A road finishing machine adapted to travel along a pair of co-extensive tracks which lie along a roadway and are spaced gradually varying distances in their extent, comprising a frame including adjustable portions extendible and retractable in a direction cross-wise of said tracks, said portions carrying track-engaging wheels, motor means for extending and retracting said frame portions, feeler means in engagement with said tracks and 4movable in accordance with variation in track spacing, movement of said feeler means effecting operation of said motor means to adjust said frame portions to correspond to track spacing while said frame is in transit.

2. A road finishing machine adapted to travel along a pair of co-extensive tracks which lie along a roadway and are spaced gradually varying distances in their extent, comprising a main frame adapted for disposition cross-wise of said tracks, a pair of sub-frames carried by said main frame, each extending from a respective side of said main frame and adjustably mounted thereon for extension and retraction relative to said main frame in a direction cross-wise of said tracks, motor means for extending and retracting each of said sub-frames, a movably mounted feeler wheel in engagement with each track, each wheel having double flanges for engagement with opposite sides of its track, said feeler wheels moving away from each other by divergence of said tracks and moving toward each other by convergence of said tracks, and control means actuated by movement of said feeler wheels and operable to'effect operation of said motor means only when said feeler wheels are moved toward or away from each other.

References Cited in the tile of this patent UNITED STATES PATENTS 137,308 McCauley Apr. 1, 1873 179,774 Eaton July 11, 1876 298,736 Dunbar et al. May 20, 1884 664,560 Lahue Dec. 25, 1900 1,180,327 Simpson Apr. 25, 1916 `1,614,029 Holdsworth Jan. 11, 1927 1,662,257 Valerio Mar. 13, 1928 2,346,370 Eustis et al. Apr. 11, 1944 2,556,503 Nelson June 12, 1951 2,650,525 Jones Sept. 1, 1953 2,681,231 Kondracki June 15, 1954 2,767,995 Stout Oct. 23, 1956 FOREIGN PATENTS 733,458 France July 11, 1932 737,575 Germany July 24, 1943 511,621 Great Britain Aug. 22, 1939

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