Pavement milling apparatus

Apparatus including a vehicle and rotor means carrying cutter structure is provided, for removing pavement in linear trench configuration or configurations.

BACKGROUND OF THE INVENTION 
This invention relates generally to pavement removal or destruction, and 
more specifically concerns equipment usable to mill pavement such as 
runways, roads etc. 
Pavement such as runways frequently deteriorates as by local cracking and 
spalling to the point that repair is required. Also joints between 
concrete slabs deteriorate so that removal of joint sealer and cutting 
away of local areas is necessary, followed by pouring of concrete or other 
material into the removal zone. In the past, local pavement removal was 
typically carried out using human labor and with jackhammers, picks and 
shovels, so that progress was very slow, and expensive. Accordingly, there 
is need for equipment to rapidly and accurately form trenches in 
deteriorated pavement zones, without damage to adjacent sound pavement, so 
that fresh concrete or other material can be filled into such trenches. 
SUMMARY OF THE INVENTION 
It is a major object of the invention to provide equipment or apparatus 
that will meet the above need, so that rapid repair of pavement can be 
accomplished. For example, equipment in accordance with the invention will 
typically enable milling away of deteriorated concrete and joint sealer 
pavement at the rate of 5000 feet per hour. 
As will appear, the equipment basically comprises: 
(a) a vehicle adapted to be driven over the pavement, 
(b) milling rotor means and drive means therefor, the milling rotor means 
including cutters projecting at the periphery of the rotor means for 
cutting the pavement as the rotor means is driven in rotation, 
(c) structure on the vehicle carrying the milling rotor means for 
adjustable bodily displacement relative to the vehicle and to selected 
positions wherein vehicle weight is exerted downwardly on the milling 
rotor means during cutting of pavement. 
The above structure typically includes first actuator means connected with 
the rotor means, as for example two milling rotors, a via supporting 
links, to displace the rotors downwardly and upwardly relative to the 
vehicle. Thus, the rotors can be displaced downwardly and forwardly for 
vertical cutting of pavement edges, or displaced upwardly for pavement 
wall sawing or grinding. Also, the rotor or rotors and first actuator 
means are typically carried by arbor structure for lateral adjustment, or 
displacement relative to the vehicle; and second actuator means are 
provided to effect such lateral adjustment of the arbor structure, whereby 
accurate lateral positioning of the milling or trenching rotors may be 
accomplished, coincident with longitudinal travel of the vehicle during 
milling. Ballast may be provided on the vehicle to exert downward loading 
on the milling rotor or rotors, and a removable hood or body is applicable 
to the vehicle frame. Finally, an additional scraper or rooter may be 
carried on the vehicle as will be described. 
These and other objects and advantages of the invention, as well as the 
details of an illustrative embodiment, will be more fully understood from 
the following description and drawings, in which:

DETAILED DESCRIPTION 
In the drawings, the equipment 10 for removing pavement 11 is adapted to 
form a trench 12 as seen in FIG. 2, of selected depth d, with sidewardly 
offset or staggered portions d.sub.1 and d.sub.2 (see FIG. 1). The 
equipment is also adapted to produce a trench having two selected 
different depths d' and d", respectively associated with staggered portion 
d.sub.1 and d.sub.2. See FIG. 2a. Each such trench is formed to extend 
longitudinally in the direction of vehicle travel, indicated by arrow 13. 
Also, the trench location may be adjustably shifted laterally, in the 
direction of arrow 14 in FIG. 1, as will appear. 
The equipment 10 includes a vehicle 15 having a frame 16 and wheels 17-20, 
enabling the vehicle to be driven over the pavement during the trench or 
pavement cutting operation. As illustrated the frame includes horizontally 
longitudinally elongated members 21 and 22, and horizontally laterally 
elongated members 23 and 24. A drive for the rear wheels includes internal 
combustion engine 25 mounted near the rear of the vehicle. Rear wheel axle 
housing 26 extends beneath rear frame member 24, and is spring suspended 
at 27 and 28. Two pairs of 19 and 20 rear wheels are employed, and gearing 
in housing 29 is connected between the engine and rear wheel axles. FIGS. 
2 and 6 also show links 91 and 92 pivotally connected between the frame 
and the axle housing 26. See also link 90 in FIG. 7, between 24 and 26. 
In accordance with the invention, milling rotor means is carried by 
structure on the vehicle frame for adjustable bodily displacement relative 
to the vehicle and to selected positions in which vehicle weight is 
exerted downwardly on the rotor means during cutting of pavement. In this 
regard, drive means for the milling rotor means rotates the latter so that 
peripherally projecting cutters engage and cut into the pavement as the 
rotor means is driven in rotation. In the example, primary and secondary 
milling rotors 30 and 31 are independently pivotally suspended by links or 
arms 33 and 34 from frame parts 35 and 36, as by means of transverse 
arbors 37 and 38 acting as pivots. Additional milling rotor assemblies may 
be added for increase of capacity. The arms extend rearwardly and 
downwardly relative to the vehicle, so that as they are swung downwardly, 
in vertical planes, the rotors are displaced relatively downwardly and 
forwardly. Note that the two rotors may be staggered, sidewardly, relative 
to one another, so that two offset trench portions may be simultaneously 
cut, if desired, or alternatively either trench portion may be cut while 
the other remains uncut. Thus, if cracked section of pavement continue for 
one length and then widens along another length, one milling rotor may be 
employed to cut out the cracked section along said one length, and then 
both rotors may be employed to cut away the widened section along its 
other length, all while the vehicle travels forwardly. 
Each rotor includes a series of cutters 40 projecting at the rotor 
periphery for cutting away pavement (as for example concrete) as the rotor 
is rotated. Independent drives for the rotors may typically comprise 
hydraulic or electric motors 41 and 42 best seen in FIG. 6, and carried by 
links 33 and 34 and located in proximity to the rotors. Thus, the motors 
may be directly connected to the rotors, as shown, to rotate them about 
horizontal axes 41a and 42a. As seen in FIGS. 4 and 5, the replaceable 
cutters may comprise steel bodies 40a carrying hardened (carbide) tool 
bits 40b, tips or diamond or abrasive blades etc., to engage the pavement. 
This tooling used singularly or in groups "gang style" can maintain 
whatever width is desired for each rotor assembly. 
The structure on the vehicle carrying the milling rotors include forward 
and rearward, parallel and transverse arbor members or rods 37 and 38, 
defining parallel axes about which the links 33 and 34 are pivotable. As 
is clear from FIG. 4, the arbor member 38 is carried by frame structure 
46-48 to project or extend sidewardly of the frame, and a pair of links 34 
suspends rotor 31 from that arbor. In similar manner, a pair of links 33 
rotatably suspends rotor 30 from the arbor member 37. 
The structure carrying the rotors for adjustable displacement may 
advantageously comprise first actuator means operatively connected with 
the rotors to displace them generally downwardly (and also forwardly due 
to their link suspension as described) relative to the vehicle. That 
actuator means is shown to comprise two actuators 50 and 51 having their 
lower ends respectively operatively correspond with the two rotors, as by 
connection to the links therefor. See for example FIG. 5, wherein linear 
actuator 50 has its lower end pivotally connected at 50a to a link 34 for 
rotor 31. The actuators may for example be hydraulic actuators which are 
extensible and confractible. 
The structure also is shown to include two secondary arbor members 55 and 
56, which extend laterally in parallel relation, and also carried by the 
frame parts 46-48, as seen in FIG. 4. The arbor members 55 and 56 are 
pivotally connected to the upper ends of the actuators 50 and 51. See FIG. 
5 and the pivotal connection 50b, for example. FIGS. 1 and 4 also show 
second actuator means, as for example linear hydraulic actuators 60 and 61 
operatively connected via headers 62 and 63 with the arbors, to 
selectively and independently laterally shift or adjust the rotors and 
their primary actuators, whereby the pavement trench width may be 
controlled, and also the lateral position of the trench relative to the 
vehicle frame position may be controlled. Thus secondary actuator 60 
controls lateral shifting of arbors 37 and 55, and thus of rotor 30 and 
its primary actuator 50, and secondary actuator 61 controls lateral 
shifting of arbors 38 and 56, and thus of rotor 31 and its primary 
actuator 51. First ends 60a and 61a of the actuators 60 and 61 are 
suitably connected to the frame structure 47 (see FIG. 4) and second ends 
60b and 61b of the actuators 60 and 61 are connected to the headers 62 and 
63, as shown. A master control for the actuators and motors 41 and 42 is 
shown at 67, in FIG. 1, with toggle levers to set the actuators in 
selected positions for trench locations, trench width, and trench depth 
(one or two levels, as described), and to control motor torque and speed. 
See also the operator's seat 68, and vehicle steering wheel 69. 
The vehicle front wheels 17 and 18 have axles 17a and 18a which are 
independently suspended relative to and from the frame. Thus the 
transverse axle carriers 70 and 71 are pivoted at 70a and 71a to a plate 
72 rigidly connected to the frame, and springs 73 and 74, and air or 
hydraulic suspension units to pre-load one side or the other, are also 
mounted between the carriers 70 and 71 and extensions of that plate or 
member or yieldably resist upward displacement of the wheels, as is clear 
from FIG. 3. The connections of carriers 70 and 71 seen at 70a and 71a may 
be to torsion bars parallel to the frame members 21 and 22. Steering is 
accomplished via bell crank 75 mounted to pivot about a king pin vertical 
axis and supporting the axle of wheel 17, to turn with the latter. One arm 
75a of the crank is connected via rod 76 to mechanism 77 associated with 
steering wheel 69, whereby rotation of the latter turns wheel 17. A drag 
link 78 connects the other arm 75b of the bell crank with an arm 79 
mounted to pivot about a king pin vertical axis and supporting the axle of 
wheel 18, to turn with the latter, whereby both wheels turn together. 
An additional cutter 80 is carried by the vehicle to cut into pavement in 
spaced relation to the milling rotor, and in response to vehicle 
advancement. Thus, cutter 80 may be carried at the forward end of the 
vehicle to project downwardly in a vertical longitudinal plane between 
wheels 17 and 18. It is shown as suspended via curved spring arm 81, 
carried by a rocker arm 82 pivoted to the frame at 83. An actuator 84 
connected between the frame and arm 82 adjusts the latter about pivot 83, 
to position the cutter 80 or other hydraulic pneumatic pavement breaker 
attachments at selected depth. That cutter may also be employed to clear 
out an already cut trench, or it may be used to first cut away material 
just above the cracked pavement to be milled out by rotors 30 and 31, or 
either of them, or other breaker attachments. 
Ballast weight (water, metal, etc.) may be applied to the vehicle frame 
near the milling rotors to add weight and downward loading to the rotors 
during their operation. See ballast at 95 in FIG. 2. 
FIG. 8 shows a removable vehicle body 93 applied downwardly onto the frame, 
for transportation of the vehicle as under adverse weather conditions. At 
such times, the rotors 30 and 31 would be raised by the actuators 50 and 
51. 
In summary, the pavement milling apparatus provides: 
(a) adjustable horizontal arbor 
(b) infinite speed control 
(c) vertical 90.degree. cutting attachment-core drilling and boring 
(d) 45.degree. wall sawing and grinding 
(e) tooling-single, multiple or gang including: 
(i) carbide cutting heads 
(ii) diamond blades 
(iii) carborundum grinding wheels 
(iv) boring head 
(v) miscellaneous combination of cutters 
(f) mobility 
(i) provides multi-function equipment in one unitized package 
(ii) provides for use of multi-purpose attachments 
Functional additions are provided by attachments to frame 16. These 
attachments are an integral and fundamental consideration in the design of 
this apparatus and therefore are considered to be basic to the integrity 
of the design. These attachments include but are not limited to the 
following: 
(a) debris collection 
(b) sandblasting and blowing and painting 
(c) vacuum and sweeping 
(d) water blasting and high-pressure binder injection 
(e) mortar mixing and distribution 
(f) roping and sealing joints in pavement 
Accordingly, the apparatus is part of a complete system--modular in design.