Convertible construction machine

A construction machine is disclosed having a main frame that is supported by means of three or four vertically adjustable suspension points from a pair of walking beams located on opposite sides of the main frame. Each walking beam has a vertical steering axis at each of its ends connected to a bogey-mounted self-propelled ground engagement means in the form of a wheel or endless track. In one embodiment one of the walking beams is connected to a side of the main frame by two spaced vertically adjustable suspension means that attach to the beam through pivotal bogey-mounts. One of these adjustable suspension means is pivotally mounted to the frame, while the other is fixed to the frame. The other walking beam is connected to the opposite side of the main frame on a single central vertically adjustable suspension means through a bogey-mount to constitute a three-point suspension on two walking beams for the assembly. In a second embodiment, both walking beams have two spaced vertically adjustable suspension means, one of which on each beam is pivoted on a horizontal axis from the frame to constitute a four-point suspension on two modified walking beams. In each of the embodiments the four ground engagement means at the ends of the walking beams are steerable in pairs, in unison or independently and can be turned or re-oriented about their steering axes so that the direction of travel can be forward or backward (longitudinally) of the frame or toward either side, thus providing flexibility in operation and allowing for side-mounted or straddle-mounted tools. Steering can be in increments, or a full 360.degree. as desired. The frame telescopes in one direction, and the power of the machine used in widening or shortening the frame.

BACKGROUND OF THE INVENTION 
The prior art discloses a number of construction machines having either 
four points of suspension for a flexible frame on four endless tracks, one 
at each corner; or three points of suspension on a pair of endless tracks, 
one on each side of the machine having a rigid frame. Notable among these 
are the machines disclosed in EARLY U.S. Pat. No. 2,844,882; GUNTERT U.S. 
Pat. No. 2,864,452; KNOX U.S. Pat. No. 2,202,009; STEVENS U.S. Pat. No. 
2,128,273 and ALLEN U.S. Pat. No. 2,128,889 along with CURLETT et al U.S. 
Pat. No. 3,230,846; CURLETT U.S. Pat. No. 3,249,026; SWISHER et al U.S. 
Pat No. 3,423,859 and SNOW et al U.S. Pat. No. 3,540,360. The two track 
machines steer by crabbing, a function which causes the machine to steer 
in an uneven wobbly path that has a serious effect on the control of the 
grade, slope and direction of the tool. The machine of MILLER et al U.S. 
Pat. No. 3,606,827 (by the instant inventors) overcomes this and other 
defects by using four tracks, one at each corner, two of which on one side 
carry the rigid frame at a pivot point central of a walking beam. The 
opposite front pair and the opposite rear pair of tracks are tied together 
by linkages so that as to be steerable in pairs, i.e., like the front 
wheels of an automobile. SWISHER et al provide a similar steering 
arrangement operating from a guide line on each side of the machine. The 
SWISHER et al machine has a flexible frame and can be raised to position 
the frame over a truck and the track support members are pivoted upwardly 
off the ground for movement by the truck to a new location. For longer 
hauls, the four track support members are removed and transported on a 
separate truck. 
Road construction machines, such as that disclosed in SWISHER et al U.S. 
Pat. No. 3,423,859 are designed to span the width of one or more lanes of 
a highway for which purpose sizeable flexible frames and/or elongated 
track support beams are required. Understandably some provisions must be 
made for reducing the overall size of the machine for transport from one 
work location to the other, even to the extent of actually disconnecting 
the tracks from the frame. Finite adjustment of slope and grade are best 
provided in machines having a rigid frame. 
SUMMARY OF THE INVENTION 
In accordance with this invention provision is made to preserve the 
advantages of a three-point or four-point suspension in a four-track rigid 
frame machine while at the same time providing flexibility as to the size 
and location of the tool, without the necessity of providing outriggers 
for the tracks or dismantling parts for transport and still further 
providing a machine that can be moved along an axis which extends full 
circle from the frame. Not only can the four tracks be turned 90.degree. 
or more in either direction to make the machine operable along two 
different axes perpendicular to the frame to allow attachment of the tool 
on any of the four sides or in a straddle position, the frame can be moved 
along with all four tracks at any desired angle to the frame and the power 
of one pair of tracks can be used to extend or retract the frame as 
desired along its telescoping positions. 
These multiple functions are made possible by suspending the working tool 
from a frame that telescopes along an axis transverse to the normal 
direction of travel along the grade or lane of a roadway being worked upon 
and supporting the frame from a pair of longitudinally spaced suspension 
points at one side upon a walking beam through a pair of pivotal saddles. 
This walking beam has a track member at each end. The other side of the 
frame is supported by a similar dually suspended second walking beam or by 
a single suspension means upon the midpoint of the second walking beam 
which like-wise has a track member at each end. Each track member is 
rotatably mounted on a vertical steering axis at the end of its respective 
beam. Provision is made for full transport operation of the machine along 
with the raising and lowering functions through the suspension points so 
that the machine can be moved into a straddling position over a tool such 
as a slip form and lowered thereover for attachment of the tool. 
The frame is adapted to be telescoped along an axis perpendicular to the 
walking beams for the compactness required for transport or curb and 
gutter work or to extend the frame so that it can straddle a wide work 
area. Each track is driven by a separate hydraulic drive motor associated 
with and carried by the track.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the machine 10 of this invention is shown in 
diagrammatic form to include the frame 12 comprising the side girder 14 
and the opposite side girder 16 tied together by the pair of tubular 
girders 18 and 20 to form a rigid, flat rectangular structure. Rigidifying 
cross-members such as shown at 22 and 24 form a support for the prime 
mover 26 and the non-skid grill 28 to define a working platform. The 
console 30 is rotatably mounted on the pivot arm 32 which is also pivoted 
from the socket 34 so that the operator can position the console in a 
number of convenient locations to control the machines' operation and also 
observe the work product and the progress of the machine. 
The frame includes an extendible U-shaped frame portion 36 having the outer 
girder 38 that is about the same size and length as the side girder 14 
with a pair of smaller box girders, 40 and 42 (see FIG. 14 momentarily) at 
the ends that extend inside the tubular girders 18 and 20 in a close 
fitting telescoping relationship. The smaller box girders 40 and 42 can be 
as long as or longer than the tubular girders 18 and 20 so that the frame 
12 can be extended to span a working area under the frame that is as wide 
as a single lane of pavement or more. If desired, means can be 
incorporated to lock the frame 12 in selected extended positions or the 
tool that is attached underneath the frame can be affixed to both the 
tubular girders 18 and 20 and the box girders 40 and 42 to fix the 
extended position of the frame. The box girders 18 and 20 can each have 
one or more roller assemblies 44 that have a pair of vertically oriented 
roller members 46 opposed to the openings 48 in the side walls of the 
tubular girders 18 and 20 and engage the sides of the smaller box girders 
40 and 42 to stabilize the U-shaped frame 36 laterally in its extension 
and retraction and provide a friction-less support. Also the box girders 
18 and 20 can have one or more chain roller assemblies 50 that have a pair 
of horizontally oriented roller chain members 52 opposed to suitable 
openings in the top and bottom walls of the tubular girders 18 and 20 and 
like-wise engage the tops and bottoms of the smaller box girders 40 and 42 
to stabilize and provide friction-less support for the extensible U-shaped 
frame 36. The details of the roller assemblies 44 and the chain roller 
assemblies 50 are shown in FIGS. 15, 16, and 17, to be described. 
The frame 12 of the machine 10 and any working tools carried thereby are 
supported in two different manners in accordance with this invention for 
finite control of the grade and slope. 
FIG. 1 illustrates one embodiment wherein the machine 10 is provided with a 
pair of adjustable or extendable support means 60 and 62 on one side, 
connected between the outer girder 38 and the modified walking beam 64 by 
means of the longitudinally spaced saddles or bogey-mounts 66 and 68; and 
the other side of the machine is provided with a single centrally mounted 
adjustable or extendable support means 70 (see also FIG. 5) connected 
between the side girder 16 and the center of the walking beam 72 by means 
of the saddle or bogey-mount 74 through the pivot pin 76. 
Although, as will be described, the mechanical parts of the adjustable 
support means 60 and 62 and 70 are essentially the same, they are 
identified by different numerals for purposes of clarification in 
describing their functions which differ to certain extents and are the 
same in others. 
Referring the FIGS. 1, 3, and 4, the adjustable support means 62 will be 
used to illustrate the parts that are common to the other frame support 
means. These include the open-bottomed guide sleeve or cylinder 80 which 
fits over and slides upon the inner sleeve 82 which is affixed to the top 
plate 84 of the bogey-mount 68 by means of the weldment 86. The guide 
sleeve 80 and the inner sleeve 82 are close fitting cylinders adapted to 
reciprocate in telescoping relationship to provide a linear up and down 
movement. 
The operating ram 88 is contained with the cylinders 80 and 82 with its 
housing supported by means of the top central journal 90 pivotally mounted 
on the clevis pin 92 that extends diametrically across the top of the 
cylinder 80. The lower end of the ram housing extends within the open top 
of the inner sleeve 88 and the piston 94 connects to the piston rod 96 
that extends through the packing gland 98 to and through the top plate 84 
of the bogey-mount 68 where it is affixed by means of the locking flanges 
100 and the lock nut 102. 
The ram 88 can be single or double-acting, since in the former instance the 
weight of the machine can cause the retraction of the ram. The hydraulic 
lines 104 and 106 therefore (FIG. 1) are omitted from FIG. 4 for 
simplicity, one connecting by means of a flexible cable to the housing 88 
above the piston 94 and the other, when used, connecting below the piston. 
The operation of the ram 88 raises and lowers this corner of the frame 12. 
The clevis pin 92 permits a slight play in these parts so that the 
reciprocating sleeves do not bind as they extend and retract, as disclosed 
in U.S. Pat. No. 3,606,827. 
Internally, the extensible support member 60 is the same as the support 
member 62 just described, however, the extensible support member 60 is 
affixed to the girder 38 by means of the bracket or encircling flanges 108 
e.g. it is not pivotally mounted to the frame. This attachment is made 
permanent by welding. 
The adjustable support means 62 is pivotally mounted to the frame 12 on an 
axis that extends horizontally of this side of the frame (FIG. 3). For 
this purpose the pair of support plates 110 is provided that are affixed 
at one end to the opposite sides of the cylinder 80 and extend inwardly 
from the corner of the frame to provide support for the bearing cap 
assembly 112 encircling the pivot pin 114 which is affixed to the 
outermost box beam 38. The pivot pin 114 is of heavy construction and the 
bearing cap assembly 112 can be of the split ring type whereby a slotted 
opening therein allows adjustment of the contact with the pin to prevent 
looseness, as by means of the adjusting bolts 115. The support plates are 
appropriately slotted as at 116 so that assembly and dis-assembly are 
facilitated, and the lock nut 117 provides lateral or axial adjustment of 
this pivotal connection. As the adjustable support means 62 pivots on the 
pin 114 the innermost plate 110 may be in guided relationship against the 
side of the beam 38 or spaced therefrom as shown at 118. 
The extendable support member 60 is vertically aligned with the frame and 
its sleeve 82 attaches to the bogey-mount 66 directly over the pivot pin 
120 which is carried by the end of the walking beam at the steering 
housing 122 defining a vertical steering axis for the second bogey-mount 
124. Similarily, the adjustable support means 62 is mounted over the pivot 
pin 120 of the bogey-mount 68 forming a pivotal attachment to the steering 
housing 122 on the other end of the walking beam 64. Here again the 
housing 122 defines a vertical steering axis for the associated 
bogey-mount 124. Sufficient space at 126 (FIG. 4) is provided between the 
underside of the plates 84 and the pivot housings 122 of these respective 
bogey-mounts 66 and 68 so that the walking beam is free to pivot on the 
pins 120. 
Referring to FIGS. 1 and 5 the extensible support member 70 on the other 
side of the frame 12 is vertically affixed to the girder 16 by means of 
the pair of mounting plates 128 and the encircling flanges 130 in a manner 
similar to the extensible member 60. However, in this instance means are 
provided to maintain the second walking beam 72 in longitudinal alignment 
with the side of the frame 12. This is accomplished by using a pair of ram 
units 60a and 60b, so designated because they are identical to the unit 
60, in side-by-side relationship. Each has an outer guide cylinder 80 and 
an inner sleeve 82 that reciprocates therein due to the action of the rams 
(not shown) which in this instance are operated to extend and retract in 
unison. The inner sleeves 82 are affixed to the top plate of the single 
bogey-mount 74, of larger dimensions and the bogey-mount is pivoted to the 
center of the walking beam 72 by means of the transverse pivot pin 76. The 
two extensible members 60a and 60b constituting the single extensible 
support 70 on the opposite side of the main frame keep the walking beam in 
alignment along the side of the frame 12. The girder 16 has the off-set at 
132 (FIG. 1) and the adjustable support means 70 is recessed therein so 
that this side of the machine is co-planar with the walking beam 72. The 
inner girder 134 ties these parts together. 
Referring back to FIGS. 1, 2 and 5 it is seen that both of the walking 
beams 64 and 72 are positioned parallel to each other and to the sides of 
the main frame, and also that each is about the same length as its 
respective frame side whereby to place the ends of the walking beams under 
and in substantially vertical alignment but spaced below the four corners 
of the frame. The extensible support means 60 and 62 are spaced along the 
one side of the frame member and the extensible support means 70, being 
about the midpoint of the opposite side of the frame is at a midpoint 
between the extensible members 60 and 62 to define a three-point 
suspension between the frame 12 and the walking beams. 
A steering spindle is provided at the ends of each walking beam. Thus, as 
previously described, the walking beam 64 has the steering spindles or 
housings 122 at its ends while the walking beam 72 has the steering 
spindles 122a and 122b at its ends, being identically constructed and 
having the same functions. Each of the tractors 140 has a track frame 142 
carrying an endless track 144 and has a drive motor 146 at one end 
suitably mounted upon the track frame to a drive cog wheel within these 
tractor units. Each tractor is pivotally attached to a bogey-mount 124 by 
means of a pivot pin 150 that attaches through a midpoint of its track 
frame 142. 
The steering spindles 122 each have a cylindrical cap member 152 (see FIGS. 
3, 6, 7, and 8) in which the spindle bases 154 are rotatably mounted, with 
their lower ends affixed to the top plates 156 of the lower bogeys 124 by 
means of the weldments 158. 
In one aspect of the invention each of the steering spindles 122 includes 
means to rotate the lower saddle or bogey 124 and the tractors 140 about 
their vertical axes at least 90.degree. and preferably about 100.degree. 
or more, and, if desired, in a complete circle. This rotation can be under 
finite control and accomplished sequentially, in unison or individually 
with the machine in motion or standing still as desired. 
FIGS. 1, 2, 3, 5, and 6 illustrate one form of steering control and spindle 
mounting that can be used for these purposes wherein in FIG. 1 the 
modified walking beam 64 is shown to include the pair of rams 160 and 162 
extending in opposite directions along the inside of this support member 
and having their housings pivotally attached to the spaced cleats 164 and 
166 that extend from the central portion of the modified walking beam 64. 
Referring to FIG. 3, the tractor 140 at this corner of the frame has been 
turned 90.degree. from its position in FIG. 1 by means of the ram 162 
which now has its operating rod 168 attached to the pivot pin 170 carried 
by the cleat 172 extending from the inside of the top plate 156 of the 
bogey-mount 124. 
This plate 156 also has a second cleat 176 with a bore hole 178 to which 
the rod 168 and pin 170 were attached when the tractor 140 was in the 
position shown in FIG. 1. The pivot pins 170 and 180 at the opposite ends 
of the ram 162 are the quick-release self-locking variety so that the ram 
62 can be easily connected to one or more of the cleats sequentially or 
removed for servicing. The rams 160 and 162 can be of the long stroke type 
whereby the tractors 140 can be turned in an arc of about 30.degree. or 
more, each side of the positions shown in FIG. 1, in a single stroke. A 
third cleat 181 is also shown for further use in turning the tractor 140 
in this manner. 
The hydraulic lines for the ram 160 are illustrated at 182 and 184 and the 
hydraulic lines for the ram 162 are illustrated at 186 and 188. The ram 
160 connects to the bogey-mount 124 by means of a similar cleat 189 (FIG. 
1) and pivot pin, like the pins 170 and 180. Throughout the construction 
as many parts are made interchangeable as possible. 
In either a parallel or tandem position of the tractors on any one walking 
beam, to accomplish a steering function, the rams 160 and 162 are operated 
in unison in opposite directions, that is the ram 160 contracts as the ram 
162 extends so that the tracks 140 remain parallel like the front wheels 
of an automobile (FIG. 1) or remain in tandem (FIG. 3) assuming the other 
tractor is also turned 90.degree.. However, for other purposes these rams 
may be operated independently and in opposite directions, as will be 
described for some steering functions or to position the tractors in a 
tandem relationship along the modified walking beam 64. 
In FIGS. 1, 5 and 6 the manner of attachment of the second pair of 
long-stroke rams 190 and 192 on the other side of the frame 12 is shown. 
The ram 190 connects between the pivot 194 connected to the housing end on 
the underside of the walking beam 72 while its operating rod 196 connects 
to the cleat 198 by means of the quick-release pivot pin 200. Similarly 
the ram 192 connects between the pivot 202 at the housing end and the 
cleat 204 and the pivot pin 206 on the bogey-mount 124 at the other end of 
the beam 72. The hydraulic lines 208 and 210 control the ram 190 and the 
hydraulic lines 212 and 214 control the ram 192. The rams 160 and 162, 190 
and 192 can be identical and are interchangeable, along with their pivot 
pins. These rams may be short stroke rams since multiple connections are 
provided. 
The rams 190 and 192 are also operated independently, oppositely or in 
unison and for the purposes described in connection with the rams 160 and 
162. Thus steering means for turning the four tractors in unison, in pairs 
or individually in the same or opposite directions are disclosed. 
Other forms of steering control can be used in place of the steering rams 
just described. As shown in FIG. 7 the steering housing 122 at the end of 
each walking beam, for example the walking beam 64, can be modified to 
include the conical bearing surfaces 220 at the top and the offset opening 
222 at the bottom which encompasses the base 154 attached to and extending 
from the bogey-mount 124. The base 154 provides a matching conical bearing 
surface 224 to contain two or more tapered roller bearings 226 operating 
on the radial spindles 228 supported from the vertical spindle 230. The 
driven gear 232 is affixed to the top end of the spindle 230 by means of 
the spline 234 and the hold down bolt 236. The drive pinion gear 238 
engages the driven gear 232 and the drive motor, therefore (not shown) 
would be mounted on a non-turning part such as the walking beam 64. A 
suitable safety housing 240 for this arrangement is illustrated in broken 
lines in FIG. 7. 
In order to turn the tractor more than 180.degree. on this vertical 
steering axis the electrical or hydraulic connections from the power 
source of the machine to the motor would be disconnected and repositioned 
to prevent their winding up on the housing 122 or other stationary parts. 
Quick disconnect fittings are used for this purpose. 
In another embodiment shown in FIG. 8 the steering housing 122 at the end 
of the walking beam 64 comprises an open-bottomed cylinder 242 which 
encompasses the base 154 to form a bearing cap arrangement and the spindle 
246 extends through the top center of the cylinder 242 where it is splined 
at 248 to the steering arm 250 and held thereto by means of the nut 252 
attaching to the extension 254. The arm 250 has a suitable boss at its 
extended end having the vertical bore hole 256 to which a steering ram 
such as 160 or 162 attaches. The purpose of the arm 250 is to provide 
leverage for the steering function and also the means by which the arm can 
be quickly detached from the spindle 246 and re-set at a different angle 
therefrom on the spline 248. Upon re-attachment of the ram thereto its 
operation will turn the assembly to the next direction chosen for the 
tractor at that suspension point. These modified steering arrangements of 
FIGS. 7 and 8 can also be used with the walking beam 72. 
In FIG. 9 another steering arrangement is disclosed, in this instance 
illustrated in relation to the modified walking beam 64 although equally 
applicable to the walking beam 72, wherein the pair of bogey-mounts 124 
are tied together by the connecting or radius rod 260 by means of the 
pivot pins 262 and 264 attaching to the respective cleats 266 and 268. The 
length of the rod 260, which can be adjustable, is such that the tractors 
140 are held in parallel relationship. The single ram 162 and its 
operating rod 168 connects between the cleat 166 on the inside of the 
modified walking beam 64 to the pin 170 and associated cleat 172 as 
illustrated in FIG. 3. The number of cleats used on each bogey-mount can 
be varied depending on the steering versatility desired in the machine. 
FIG. 10 illustrates, in relation to the modified walking beam 64, how ram 
162 and its operating rod 168 is connected to the pin 170 carried by the 
cleat 172 which is oriented at about 90.degree. from the cleat 176, and 
the cleat 181 is 90.degree. from the cleat 176. 
FIGS. 11, 12, and 13 illustrate how the ram 162, for purposes of 
illustration, is used to re-orient a tractor 140 from a parallel position, 
FIG. 11, to a tandem position, FIG. 13, in relation to one end of walking 
beam 64. In FIG. 11 the ram is connected to the cleat 172. Retraction of 
the ram moves the parts to the position of FIG. 12. The pin 170 is 
released from the cleat 172 and the ram extended to the position shown in 
FIG. 12 for attachment to the cleat 181. Upon retraction of the ram the 
tractor assumes the tandem position of FIG. 13 at which position the 
piston in the ram is at about the center of its stroke. 
FIG. 13A illustrates the use of four cleats, with the additional cleats 270 
and 272 oriented at 90.degree. from the others. 
This process is repeated for the tractors 140 on the ends of the walking 
beam 72 and the machine, its frame and tractors assume the positions shown 
in FIG. 18. It is apparent that the machine 10 can have its narrowest 
length determined by the box beams 18 and 20. With the tractors 140 
oriented as shown in FIG. 1 the machine can be run upon a trailer and be 
transported to and from work sites. Once the machine has been run off the 
trailer the tractors 140 can be oriented 90.degree. or to the tandem 
positions shown in FIG. 18 and a working tool such as the specially 
designed slip form 280 can be attached by means of its frame support 
members 282 and 284 to spaced bracket mounts 286 on the outer girder 38 
with the frame in its retracted position. The slip form 280 has an open 
rear end 288, from which the extruded concrete curb is deposited upon the 
prepared grade 290, and a shaped top wall 300 to define the properly 
contoured type curbing to be laid. The tubes 302 in the front wall 304 are 
provided for the insertion of reinforcing rods (not shown) by hand as the 
machine progresses in the direction of the arrow 306. The slip form 280 
has the integral vibration hopper 308 in communication with its interior 
just behind the wall 304. 
The cleat 310 provides pivot support for the receiving hopper 312 by means 
of the pin 314 engaging the angle bracket 315 (see FIG. 19). The receiving 
hopper 312 has an integral chute 316 housing the helical conveyor 318 
driven by a motor within the housing 320. The conveyor 318 extends to the 
bottom of the receiving hopper 312 so that ready-mix concrete is picked up 
and moved to the delivery chute 322 which dumps the concrete into the 
vibration hopper 308. In the vibration hopper the concrete is compacted by 
gravity and vibration and fed to the slip form in a manner known in this 
art. The slip form 280 is open at the bottom along its length. The central 
bracket 324 carried by the beam 18 is U-shaped to conform with the contour 
of the chute 316 and can be adjustable to provide the necessary elevated 
support for the conveyor chute. 
The slip form 280 carries the forward grade sensor 326 and the rearward 
grade sensor 328 having their respective sensing arms 330 and 332 in 
contact with the under side of the grade reference line 334 suspended by 
the brackets 336 supported by the spaced stakes 338. The pendulum operated 
slope sensor 340 can be located at any position along the center line of 
the machine extending from the adjustable support means 70, as on the beam 
38, so as to be about halfway between the two grade sensors. Suitable 
adjustable jacks are used to support the sensors 326 and 328 from the tool 
in a manner well known in this art. 
The front steering sensor 342 and the rear steering sensor 344 are located 
on the slip form at or near the ends of this tool with their pendant 
sensors 346 in contact with the inside of the string line 334. With a 
supply of concrete maintained in the hopper 312 from ready mix trucks the 
machine is capable of laying curb and gutter on the grade 290 to 
specifications. When the tool is straddle mounted the sensors can be 
carried on the adjustable bracket 341, shown in FIG. 3, attached to the 
modified walking beam 64. 
In the event the machine is to be used for paving one or more lanes of a 
highway the frame 12 is extended to the position shown in FIG. 19 to 
accommodate the concrete spreading and compacting tool 350 which, as is 
known in the art, includes the screed plate 351 with the side frame 
members 352 and 354 supporting the elongated helical spreader 356 driven 
by the motor 358. The tool 350 is adjustably supported from the frame 12 
by means of the brackets 360 and has the flat finishing plate 362 for 
leveling and smoothing out the concrete which is dumped or roughly spread 
on the prepared grade 290 ahead of the machine, traveling in the direction 
of the arrow 306. A plurality of pneumatic vibrators 364 are provided as 
desired. The tool 350 can be attached on the opposite side 20 of the 
frame, in which event the direction of travel will be opposite to that of 
arrow 306. 
The attachment of either the slip form 280 or the paving tool 350 to the 
machine 10 is facilitated in that with the tool resting on the ground the 
machine can be easily maneuvered alongside and lowered on its adjustable 
supports 60, 62 and 70 for attachment to the connecting support brackets. 
The machine is then raised to its operating position. 
FIG. 14 illustrates one manner by which the frame 12 can be extended or 
retracted, after the machine is run off of its trailer. In this instance 
the tractors 140 on the walking beam 72 have been turned to their tandem 
position and the tractors 140 on the modified walking beam 64 are operated 
in either direction (see arrow 365) in unison to pull the U-shaped frame 
member 36 outwardly or to push the U-shaped frame member 36 inwardly into 
a retracted position. Instead of turning the tractors 140 on the walking 
beam 82 to the tandem position shown in FIG. 14, these tractors can be 
locked or immobilized to provide the necessary braking action for the 
extensive or retraction of the frame 12. Alternately, the tractors 140 on 
the walking beam 64 can perform the locking or braking function and the 
tractors on the walking beam 72 used to supply the power. 
In FIGS. 1, 14, and 19 the U-shaped frame member 36 is shown as telescoping 
inside the box beams 18 and 20. It is apparent that this relationship 
could be reversed or that the adjustable supports 60 and 62 attached to 
the cross-beam 16 on the other side of the frame and the central support 
70 can be attached to the U-shaped frame member 36 on the opposite side of 
the frame. 
Because of the size and weight of the machine, the telescoping action of 
the frame is facilitated by the provision of the roller assemblies 44 to 
include the spaced pair of side rollers 46 on one side of the box beam 18 
(see FIG. 15) supported opposite the openings 48 by means of the identical 
support bracket members 374 that are affixed to the top and bottom of this 
beam. The brackets have suitable cleats 376 which rotatably support the 
rollers on their axles 378. The brackets 374 are double-ended (see FIG. 
17) and have an opposing pair of rollers 46' on the opposite side with a 
similar opening 48' therein allowing the rollers to ride against the 
outer sides of the internal telescoping beams 40 and 42 which are part of 
the U-shaped frame member 36. Any number of such rollers can be used along 
the sides of the frame. 
In addition to the rollers 370 there are provided the roller chain 
assemblies 50 which include the top and bottom roller chains 52 (FIG. 16) 
that are contained within the housings 382, affixed to the box beams 18 
and 20 by means of the brackets 384. The roller chains 52 encompass the 
divider wall 385 provided in each housing which allows the individual 
rollers 386 thereof to be pressed downwardly or upwardly in rolling 
contact against the top and bottom walls 388 of the beams 40 and 42 and 
also allows the entire chain to travel around the guide walls 385. The 
openings 390 are provided in the wall 400 of the tubular girders 18 and 20 
so that rolling contact between the chains and the walls is provided. The 
roller assemblies 50 can be suitably lubricated, as desired. By these 
means both vertical and lateral rolling support for the U-shaped frame 
member within the tubular girders facilitates the telescoping action. 
Actually the beams 40 and 42 are carried within the outer beams 18 and 20 
in longitudinally spaced relationship and the only contact is through the 
rollers 46 and the chains 52. 
Normally it is not necessary to lock the frame in any particular extended 
position since the machine carries the paving tool 350 from both portions 
of the frame by means of the various rigid supports 360 and the screed 362 
is also a rigidifying connecting member which would prevent further 
telescoping once it is attached. However, if desired, the external box 
girders 18 and 20 can be provided with a suitable bore hole 402 to 
accommodate the drop pin 404 which engages any one of a series of spaced 
bore holes 406 in the top wall 388 of the internal girders 40 and 42, as 
shown in FIG. 15. Placement of the lock pin 404 into any one of the bore 
holes 406 as they register with the bore hole 402 will lock the frame in 
that position. 
FIG. 20 illustrates a modification of the general frame and suspension 
assembly wherein the two opposite sides 36 and 16 of the frame 12 which 
can be rigid or telescoping, are supported by the spaced vertical 
adjustable means 60 and 62, with their transverse or lateral pivots 114, 
located at opposite corners of the frame, and with the modified walking 
beams 64 there below supported by the tractors 140. This arrangement is 
useful with the tractors oriented in the positions shown in FIG. 20 and 
the normal directions of travel would be in the directions shown by the 
double arrow 414. The arrangement shown in FIG. 20 can also be further 
modified by reversing one of the modified walking beams 64 along its 
respective side 16 or 36 of the frame 12. This would place the transverse 
or horizontal pivots 114 on the diagonal in relation to the corners of the 
frame. 
Although the embodiment shown in FIG. 20 including the aforesaid 
modification does not share all of the versatility and finite grade or 
slope control of the arrangement of vertical suspension means and walking 
beams shown in FIG. 1, the machine of FIG. 20 can be used for a large 
number of paving and earth working operations. Wherein advantage can be 
taken of the steering versatility along with the ability to negotiate 
grade deviations as opposed to slope control. 
Furthermore the directions of travel for the machine shown in FIG. 20 
whether modified to place the pivots 114 on the diagonal are not to be 
limited to the bi-directional arrow 414 and the machine can travel in 
directions perpendicular thereto as well as at any chosen angular 
direction in relation to the frame 12. 
From the foregoing description it is apparent that the machine of this 
invention is capable of traveling in any of four directions as indicated 
by the arrows 500, 501, 502, and 503 in FIG. 1 in relation to the frame 
and also capable of traveling at any desired angle in relation to the 
frame. A working tool or tools can be carried in any position on the four 
sides or under the frame and thereby be adapted to do work when carried in 
any direction. The most difficult position for the tool as far as control 
is concerned would be on the side of the frame opposite the walking beam 
72 because in this position the tool would be pivoted about its center 
during grade adjustments or when the machine was negotiating deviations in 
the grade. 
Any of the three or four adjustable supports 60, 62 or 70 can be used to 
control the attitude of the machine 10 in relation to grade or slope. With 
the machine traveling in the direction of arrow 500 of FIG. 1, the 
suspension means 60 becomes the front grade control and suspension means 
62 becomes the rear grade control while the suspension means 70 controls 
the slope. If the machine is traveling in the direction of the arrow 502 
the suspension means 62 becomes the front grade control, the suspension 
means 60 becomes the rear grade control, and the suspension means 70 
controls the slope. 
With the machine 10 traveling in the direction of the arrow 501 or the 
reverse direction shown by the arrow 503 the suspension means 60 and 62 
become the front or rear grade control means or either of the suspension 
means 60 or 62 can be used for slope control of the entire machine, when 
operated independently and the suspension means 70 becomes the grade 
control for the front or rear of the machine. It is obvious that with the 
machine traveling in the direction of the arrows 501 or 503 in FIG. 1 that 
the suspension means 70 cannot control slope and becomes either a front or 
rear grade control. 
The unique action of the modified walking beam 64 used in conjunction with 
the walking beam 72 accounts for this, as shown in FIG. 2 where the 
machine is negotiating a deviation 504 in the grade 290. The front or rear 
tractors are higher or lower, as the case may be, with the machine 
traveling in the directions of the arrows 500 or 502. The central pivot 76 
of the central support means 70 on the other side of the frame 12 allows 
that other side to negotiate the deviation 504 without a change in slope. 
The pivots 114 and 120, on the other hand plus the action of the 
bogey-mounts 124 allow the machine to be responsive to the grade sensor 
and average out the deviation. Also, a machine having the suspension 
system of FIG. 20 can correct for such a deviation when traveling in 
either direction, whether or not the deviation extends across the grade in 
front of both pairs of tandem tractors. 
The instant invention also contemplates the use of a homing type of sensor 
and feed back unit, illustrated by the numeral 506 in FIG. 3. The sensor 
506 is mounted in a protective recess 508 in the walking beam 64 just 
ahead of the steering spindle 122 and has its sensor wheel 510 connected 
by means of the drive belt 512 to the pulley 514 that rotates with the 
bogey-mount 124 thereunder. One such sensor 506 would be used at each of 
the steering spindles 122 for the four tractors and a protective housing 
would be provided for these units. 
These sensors 506 are of the homing type having a pre-set angle, zero or 
null point for the sensor wheel 510 at which no signal is sent to the 
servo-hydraulic system controlling the steering rams 160, 162 and 190 and 
192, assuming this type of steering is employed. Alternately, the sensor 
506 can control the drive motors for the pinion gears 230 (FIG. 7) at each 
corner of the machine. When any one track turns, the pulley 514 is rotated 
in relation to the walking beam which moves the belt 512 and turns the 
sensor wheel 510 off the null point. This sends a signal to the 
servo-hydraulic system and operates the steering means of the opposite 
tractor to rotate it the same amount, so that the pairs of front and rear 
tractors steer in unison. 
Other modifications of the machine can be made without departing from the 
invention. A single extensible member instead of the pair of such members 
60a and 60b (FIG. 5) can be used provided means are incorporated to 
maintain the walking beam 72 in parallel aligned relationship with its 
side of the frame. Also, the extensible member 70 can be affixed directly 
to the walking beam 72 through the guide tubes 82 and the transverse pivot 
pin 76 moved up and located between the frame member 16 and the plate 128. 
This places the pivot 176 in the plane of the frame 12 and also in the 
plane of the horizontal pivot 114 for the modified walking beam 64, and 
may be used to gain further finite control of slope and grade. 
The curb and gutter tool 280 shown in FIG. 18 can be replaced by a screed 
adapted to form symmetrical or asymmetrical barrier walls of either linear 
or curved configuration. Such screeds are well known in the art and 
include an adjustable sidewall forming the desired shaped configuration 
and oblique surface portion of the barrier wall so that the respective 
sides of the barrier wall have their corresponding oblique portions at 
predetermined height from the grade or foundation on each side. Also, 
adjustable skirts can be used adjacent both sidewalls to facilitate the 
proper adjustment of the screed lower edges in relation to the grade. The 
adjustable sidewalls are operated manually or automatically from a grade 
reference. 
A suitable hydraulic system for steering grade slope control is illustrated 
in FIG. 21 diagramatically, wherein, the essential parts of the machine 
are shown, namely the pair of beams 64 and 72, with their associated 
tractors and their respective steering rams 160, 162, 190 and 192 along 
with the three suspension points represented by the pair of rams 60 and 62 
on one side of the frame and the single central ram 70 on the other side 
of the frame. Each circuit to a ram includes a check valve and one way 
valve so that the response of the ram is under control. The source of 
hydraulic pressure and return is represented by the lines 400 and 402. 
It is apparent that the slope control 340 at the top of the diagram 
controls the ram 70 through the solenoid valve 404. When the desired slope 
is being maintained as the machine progresses in the direction of the 
arrow 306, the valve 404 is at position 2 and ram 70 remains stationary. 
If the tractors supporting the beam 72 meet a depression and this side of 
the machine lowers, the slope control 340 will cause the valve 404 to move 
to position 1 and oil from line 400 will cause the ram 70 to extend until 
the frame is again level at which time the slope control shifts the valve 
404 back to position 2. If this side of the machine is too high, the slope 
control 340 shifts the valve 404 to position 3 and the oil pressure above 
the piston is returned to sump via line 406. 
At the bottom of the diagram the front grade sensor 326 takes its signal 
from the grade line 334 and controls the solenoid valve 408 controlling 
the front suspension ram 60 at the forward end of the beam 64. The 
shifting of the valve 408 to position 1 raises this corner of the machine, 
the position 2 of the valve 408 represents no height change, while the 
position number 3 represents the position of the valve where a lowering is 
called for by the grade sensor 326. Similarly for the rear corner of this 
side of the machine the grade sensor 322 takes its signal from the same 
grade line 334 and through the solenoid valve 410 causes it to remain 
static in position 2, lower in position 1 and raise in position 3. 
The front steering sensor 342 takes its signal from the grade line 334 and 
through the solenoid valve 412 controls the pair of rams 160 and 190 to 
turn the front tractors left in position 1, maintain the course in 
position 2 and make a right turn in position 3. The rear steering sensor 
344 controls the steering rams 162 and 192 in the same manner through the 
solenoid valve 414 so that the tractors 140 on the rear ends of the beams 
64 and 72 turn left or right in unison. A right turn by the front pair of 
rams will bring the rear steering sensor 344 away from the string line 334 
at the rear of the machine and cause, at first, a slight left turn 
correction by shifting the solenoid valve to position 3, momentarily, to 
maintain the sensor in contact with the string line, then a gradual right 
turn by shifting the solenoid valve 414 to position 1. In this way the 
frame of the machine or the pair of beams 64 and 74 is maintained in a 
chordal position on the inside of a right turn and in a tangential 
position on the outside of a left turn. 
When the front tractor on the beam 64 negotiates a change in the elevation 
of the grade, the change in the attitude of the frame in relation to the 
grade line contacted by the sensing arm 334 in sensed by the grade sensor 
326. This signal shifts the valve 408 to position 1 for extending the ram 
60 and to position 3 for lowering the ram 60. However, as the front 
tractor beneath the ram 60 retracts, for example to allow the machine 
frame to remain at the pre-established slope and grade, the beam 64 must 
also pivot to accommodate the change in the effective distance between the 
bogey-mounts 124 and 68 at the ends of the beam, as shown in FIG. 2. The 
pivot 114 allows the entire rear suspension 62 to pivot slightly in 
relation to the frame so that the rear tractor on this same side remains 
on the grade. The rear suspension 62 (ram 62 of FIG. 21) will therefore 
extend slightly under the control of the grade sensor 322, ie, move to 
position 3, so that this corner of the frame remains on grade. Also, the 
beam 64 will pivot at each of the end pivots 120 while the rear tractor 
remains on the grade due to its saddle mount 124 and pivot 150. 
As the rear tractor on the beam 64 negotiates the change in elevation the 
ram 62 will retract and the suspension 62 will again pivot back to its 
normal vertical position. This pivotal action provided by the pivot 114 
does not disturb the attitude or the front suspension means 60 nor the 
attitude of the single ram 70 on the other side of the machine. 
The solenoid valve system shown in FIG. 21 has proven to be fully operative 
to control the machine. However, a servo system can also be used using 
variable pressure compensated pumps and a proportional feed system or a 
variable flow proportional control system as supplied by 
Minneapolis-Honeywell Corporation. 
Because of the unique action of the beam 64 as shown in FIG. 2, the machine 
of FIG. 20 using one such modified walking beam on opposite sides of the 
main frame has some particular advantages, allowing each of the suspension 
means to be operated individually for some types of tool control and 
individually and in pairs for other types of tool control. 
In laying one or more lanes of pavement, using a straddle mounted tool 350 
of FIG. 19, for example, and a single string line on one side of the 
machine for both grade and steering control, the opposite side of the 
machine can be under the control of a slope sensor. If a slope correction 
is called for the rams on this opposite side can be operated 
simultaneously to make the necessary correction and either or both of the 
rams on the other side can be operated individually or simultaneously to 
control the grade. 
It is to be observed that at the moment the front tractor on the walking 
beam 72 rises up on an obstacle of say 4" height, its bogey-mount will 
raise that end of the beam about one-half that amount or 2". However, 
since the beam 72 is pivoted to the ram 70 at its center, the correction 
called for will be only 1" or half this amount again. By the time the 
front tractor is central of the obstacle and the front of the beam 72 has 
risen the full 4" in height in passing therein the ram 70 will have made 
its full connection of full 2" gradually so that the rate of ram 
operation is reduced as well as the rate of change in elevation of the 
parts. The same action in reverse repeats itself as the rear end of this 
tractor negotiates the obstacle. As the rear tractor negotiates the 
obstacle, the same action and correction takes place as described for the 
front tractor. 
The machine 10 can also be operated with the tractors 140 oriented as shown 
in FIG. 1 with or without the frame 12 in its extended position shown in 
FIG. 14. In this event the hydraulic connections of FIG. 21 would be 
changed so that the rams 60 and 62 are under the control of the slope 
sensor 340 and the ram 70 is under the control of a grade sensor operating 
on a grade reference. In this embodiment, the rams 60 and 62 can be 
operated independently or one of the rams locked and the other used to 
control the slope. The machine could travel in either direction and 
preferably the machine would travel with the ram 70 in front and the rams 
60 and 62 in the rear. 
Since slope is a function of grade but grade is not a function of slope, if 
a grade change is called for by the grade sensors, in order to maintain 
the slope the adjustable support members 60 and 62 must extend or retract 
simultaneously and by the same amount. In those instances where the 
machine is being used with the member 60 controlling slope and the member 
62 controlling grade, then each time the member 62 adjusts the member 60 
must also adjust. By cross-connecting the input lines to the members 60 
and 62 on both their pressure and return lines with a pilot-operated lock 
valve, the slope can be isolated from the grade. If the slope control 
calls for a correction of the member 60, the pilot-operated valves are 
closed and a slope correction is made without influencing the vertical 
position of the member 62. The slope and grade corrections, controlled by 
the adjustable support member 60, 62 and 70 can be isolated one from the 
other by the use of an isolation amplifier system or a dual pilot valve 
system. The cross-connecting pilot lock valve arrangement, the dual pilot 
valve system and the use of an isolation amplifier are described in more 
detail in co-pending application, Ser. No. 615,767 entitled GRADE TRIMMER, 
filed in Sept. 22, 1975 by the instant inventors. 
It is seen from this description that the invention includes as a 
non-limiting feature the provision of a construction machine with a main 
frame that is supported by a first walking beam and its associated pair of 
adjustable support means with a transverse or horizontal pivot on one side 
for one of the support means and a second walking beam with its associated 
centrally mounted single adjustable support means on the other side. 
Another feature of the invention is the provision of a main frame of a 
construction machine with a walking beam and the associated pair of 
adjustable support means and pivot on opposite sides thereof. 
The ground engagement means can be wheels, skids or tractors, ie, tract 
frames carrying an endless track or the like with or without individual 
power drive means therefore, and the suspension of this invention can be 
used on small or large machines. A feature of this aspect of the invention 
is that the ground engagement means are individually steerable about their 
respective vertical steering axes and the steering is co-ordinatable 
whereby the pair of ground engagement means on the ends of one of the 
walking beams and the pair of ground engagement means on the ends of the 
other walking beam are selectively steerable in unison in a direction of 
travel substantially perpendicular to or at an angle to the longitudinal 
axis of said walking beams. Because the steering means are capable of 
turning the ground engagement means more than 90.degree. about the 
vertical steering axis, the steering means are also co-ordinatable so that 
the pairs of ground engagement means on the adjacent or opposite front and 
rear ends of the walking beams, while in tandem relationship along the 
longitudinal axis of the beams, are selectively orientable and steerable 
in pairs in a direction of travel parallel to the walking beams. 
Likewise, each of the ground engagement means includes, in one embodiment, 
a power drive means to propel the ground engagement means in the selected 
direction of travel. The power drive means are individually controlled and 
also co-ordinatalbe whereby in either of the steering positions or paths 
of travel of the machine, the front and rear pairs of the ground 
engagement means are driven at the same or different speeds and the front 
and rear ground engagement means in tandem position along a walking beam 
or in a position wherein their longitudinal axes are perpendicular to a 
walking beam can be driven at the same or different speeds from that of 
the front and rear ground engagement means in the opposite positions in 
relation to the walking beams. As long as the machine is on a prepared 
grade and traveling along a substantially linear path all four ground 
engagement means are normally operated at the same or about the same 
speed. Under these conditions the negotiation of a curve is facilitated by 
speeding up the pair of ground engagement means on the outside of the 
curve or slowing down the pair on the inside of the curve. 
When adverse grade conditions are encountered involving obstacles, 
depressions or mud, it is advantageous to be able to selectively speed up 
or slow down one or more of the ground engagement means so that the 
forward motion of the machine is not lost and the machine does not dig 
itself into the grade. Various types of speed control valves are available 
for this purpose when hydraulically-driven motors are used to propel the 
ground engagement means. Also a variable pressure compensated pump can be 
used to selectively control each drive motor, or pairs of drive motors, 
such as is described in said co-pending application Ser. No. 615,767. 
Since the use of speed control valves and pressure compensated pumps in 
this manner is known in the art, no further description is necessary. 
This versatility in the suspension and steering further provides for the 
use of a telescoping or adjustable frame with or without friction-reducing 
means along the telescoping parts whereby the power of the machine can be 
used in extending and retracting the frame. These features of the 
invention allow the use of a variety of ground working tools, screeds, and 
slipforms to be carried by the main frame in different locations whereby 
the machine and its working tool are best fitted to perform the intended 
work and the slope, grade and steering sensors can be located about the 
frame in the most convenient and accurate positions. 
Other modifications of the machine can be incorporated. Thus, to maintain 
better control of slope, the single input system shown for the control of 
the one-way ram 70 in FIG. 21 is replaced by using valves like 412 and 414 
in place of the valve 404 and the return to sump eliminated. Also, it is 
to be understood that feed back loops are to be included in the system 
shown in FIG. 21 under circumstances where over correction and hunting are 
to be prevented. FIG. 21 discloses but one steering sensor (342 front) for 
the pair of front tractors and one steering sensor (344 rear) for the rear 
tractors. This is for illustration and initiation of the control. 
Actually, each tractor will have its own steering control system and 
steering sensor to either follow a reference or be slaved to a 
corresponding tractor unit for parallel control or tandem control. This is 
accomplished through the use of the sensors 506 (FIG. 3) on each tractor 
140, associated feed back loops connected between said sensors on a front 
and rear pair of tractors, with the sensors 506 of the tandem tractors 
being connected to the respective front and rear steering sensors that are 
taking their signal from the steering reference.