Tractor front supported implement attachment frame

A tractor front end frame assembly readily detachable from the tractor body for supporting implements such as a front-end bulldozer blade and supported from the tractor by a front central removable attachment capable of pivotal motion about a substantially horizontal axis perpendicular to the rear axle of the tractor and on each side of the rear axle with optional support of the frame provided at about the midway point on the sides of the tractor. The presence of only a pivotal connection at or near the front of the tractor reduces the possibility of damage producing torque to the vehicle in that area.

BACKGROUND OF THE INVENTION 
The present invention relates to a tractor implement attachment device 
comprised of a frame assembly used to support a variety of front-end 
implements. 
Conventional front-end tractor frame assemblies have been fixedly attached 
to and are not readily detachable therefrom the tractor body at the front 
portion of the tractor and have tended, when in use with a front-end 
implement, to exert strong torque on the front-end of the tractor 
frequently causing damage thereto. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to overcome the aforementioned 
problems by supporting the frame assembly with removable pin connections 
or the like on either side of the tractor at the rear (and optionally at 
about the midway points along the sides of the tractor) and by a single 
central forward slideable pin connection at the front of the tractor. 
The present invention is a supporting frame for an implement such as a 
front-end bulldozer blade for removable attachment to a vehicle such as a 
tractor. The vehicle is provided with a rear axle frame housing a rear 
axle and a pivotal support mounting at the front end of the vehicle. The 
supporting frame comprises, in combination, a longitudinal frame, rear 
axle hanging means for the longitudinal frame, and front pivotal 
connection means attached to the longitudinal frame. The longitudinal 
frame extends more or less from the front of the vehicle to the rear axle, 
lying generally on the underside of the vehicle (or having frame elements 
at the sides of the vehicle). The rear axle hanging means is connected to 
opposed sides of the longitudinal frame, for removably hanging the latter 
on the rear axle frame of the vehicle. The front pivotal connection means 
is connected to the forward portion of the longitudinal frame for 
detachable pivotal mounting thereof on the pivotal support mounting. The 
pivotal connection means may conveniently take the form of a pin and 
mating receptacle, one on the vehicle and the other on the longitudinal 
frame (or element attached to the latter). 
The supporting frame is thus firmly and rigidly attachable to the strong 
part of a tractor, viz. the rear axle frame, whilst the weaker front part 
of the tractor needs only to support the weight of the forward part of the 
supporting frame and attached implement. No torsional stresses are 
transmitted to the tractor nose, since the supporting frame is capable of 
pivotal motion about a substantially horizontal axis substantially 
perpendicular to the rear axle of the vehicle. In most applications, the 
supporting frame when mounted on the vehicle would be generally 
symmetrical about the longitudinal axis of the vehicle. 
In one embodiment, the frame assembly is made up of front and rear side 
sub-frames and rear axle connection assembly with the front side sub-frame 
adapted to receive at its front end a pivotal implement mounting. The 
front side sub-frame is comprised of a pair of generally parallel side 
beam elements each element at its front end having an arm projecting 
upward at an angle with the horizontal suitable for convenient orientation 
relative to the tractor and particularly to the pivotal support mounting. 
A transverse beam connected to the two arms near their upper end has a 
centrally located pin receptacle for slideably engaging a pivot pin 
projecting from the front centre portion of the vehicle and having an axis 
which is parallel to the longitudinal axis of the tractor and 
substantially horizontal. Obviously, the same connection mechanism could 
be achieved by having the pivot pin projecting from the centre of the 
transverse beam element and the pin receptacle located in the front centre 
of the tractor. The front side sub-frame is adapted to receive at its 
front end a pivot frame member comprised of a beam element pivotally 
connected to the front of each side beam element of the front side 
sub-frame and pivotally supported from the upper end of each of the upward 
projecting arms of the front side sub-frame by an interconnecting 
hydraulically-operated piston cylinder unit. The usual implement which the 
frame assembly is intended to support is a bulldozer blade. The free ends 
of the two pivot frame members could also support an attached front-end 
implement such as a front-end loader, plough, snowblower, forklift, hay 
fork, or other similar device. The rear side sub-frame assembly consists 
of two parallel side beam elements joined at the backward end by a rigidly 
attached transverse beam element of a length longer than the spacing of 
the two side beam elements and having at each end equal length portions 
extending beyond the point of attachment to the side beam elements. On 
each extension of the transverse beam element is a mounting bracket 
arrangement used to fasten the rear side sub-frame to the rear axle of the 
vehicle. Each mounting bracket arrangement is movable along the transverse 
beam element extensions so as to accommodate vehicles having different 
widths and is comprised of an upper and lower set of mounting brackets 
vertically arranged so that the upper one clamps to one side of the rear 
axle of the vehicle and has a vertically projecting plate which mates with 
and is received by a vertically projecting clevis projecting up from the 
lower bracket. Both the projecting plate from the upper bracket and the 
projecting clevis from the lower bracket have transverse pin receptacles 
and are fastened together by means of a transverse removable pin mating 
with and received by the said pin receptacles. The lower bracket is 
attached to one of the transverse beam element extensions. Obviously an 
equivalent arrangement would have the clevis projecting down from the 
upper bracket and the plate projecting up from the lower bracket. The 
parallel side beam elements of the rear side sub-frame have a number of 
bolt holes drilled to mate with corresponding bolt holes drilled in the 
rear of the side beam elements of the front side sub-frame. The overall 
length of the frame assembly may be adjusted to fit vehicles of different 
lengths. The frame assembly receives some additional vertical support and 
intermediate tractor frame stability from two interconnecting arms of 
adjustable length which are pinned at one end to the frame assembly and at 
the other end to a bracket on the side of the tractor body approximately 
midway along the tractor.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
In FIG. 1 the side sub-frame assembly is comprised of two parallel 
substantially horizontal side beam elements 1 and 2 joined by transverse 
beam elements 3, 4, and 5. At the front of the side beam elements 1,2 are 
rigidly fastened two upward projecting parallel members 6 and 7 at an 
angle with the horizontal suitable for convenient orientation relative to 
the tractor and to a pivotal support mounting. The upward projecting 
members 6 and 7 are joined at their upper end by a rigidly attached 
transverse beam element 8 having a centrally located pin receptacle 35 
designed to slideably receive a pivot pin 9 rigidly fastened to the 
tractor front end 10 and whose axis is substantially horizontal and 
substantially parallel to the longitudinal axis of the vehicle. 
Alternatively, equivalent front pivotal connection means includes a pin 
receptacle centrally located on the tractor front end 9, and a mating 
pivot pin centrally located on the transverse beam element 8. Obviously, 
any other type of pivotal connection allowing for pivotal motion about the 
longitudinal axis of the tractor and without substantial lateral or 
vertical movement would be within the scope of this invention. The front 
of the front side sub-frame assembly is adapted to receive a pivot frame 
unit comprising two parallel side beam elements 11 and 12 each pivotally 
connected to the front of one of the two side beam elements of the front 
side sub-frame and each supported at its free end from the upper end of 
one of the two upward projecting arms of the front side sub-frame by means 
of an interconnecting hydraulically-operated piston cylinder unit 14 and 
15. The two parallel side beam elements 11 and 12 of the pivot frame are 
welded at their free end to one another by a cross piece 13 which has 
bushings on each end to allow it to be pinned to an implement such as a 
bulldozer blade. The pivot frame would of course be designed to 
accommodate the particular front-end implement for which the frame is 
intended. At the rear of the front side sub-frame at intervals along the 
two horizontal side beam elements in a horizontal axis and perpendicular 
to the longitudinal axis of the frame are a series of bolt holes 19. When 
the two horizontal side beam elements of the rear side sub-frame 16 and 17 
are positioned parallel and in the same horizontal plane as the 
corresponding horizontal beam elements of the front side sub-frame, four 
or more bolt holes in the front side sub-frame mate with corresponding 
holes in the rear side sub-frame in any of several relative positions so 
as to make the frame assembly of adjustable length. 
As seen in both FIGS. 1 and 2, the frame assembly is connected to the 
tractor body in the region of overlap of the side beam elements of the 
front side sub-frame with those of the rear side sub-frame by two 
interconnecting arms 27 and 28 of adjustable length pinned at the lower 
end to the frame assembly and at the upper end to the tractor side support 
mounting bracket 31 by means of quick release pins. The interconnecting 
arms, 27 and 28, however, may be attached to the frame assembly outside 
the region of overlap of the side beam elements in some cases depending on 
the size of the tractor to which it is adapted to fit, or dispensed with 
completely. The rear ends of the two horizontal side beam elements of the 
rear frame are joined to a transverse beam element 18 having ends which 
extend beyond the parallel side beam elements with the two extensions 
being of equal length. Attached onto each of these extensions in an 
adjustable transverse position is an upper mounting bracket 20 which is 
attached to a lower mounting bracket 21 mounted on each side of the rear 
axle of the tractor or other vehicle. 
In FIG. 3 the mounting bracket 20 comprised of two flat rectangular plates 
22 and 23 the top plate 22 having a bolt hole at each of its four corners 
which mates with a corresponding bolt hole on the bottom plate 23 and the 
bottom plate having an integral downward plate 37 with a centrally located 
pin receptacle 38 is mounted on each end of the tractor rear axle 30 such 
that the axis of the pin receptacle is substantially horizontal and 
parallel to the rear axle of the tractor. A corresponding lower mounting 
bracket 21 also comprised of two flat rectangular plates 24 and 25 between 
which is clamped each extension of the transverse beam element 18 and 
having a similar arrangement of bolt holes as the upper mounting bracket 
has an upward projecting clevis 26 integral with the upper plate 24, said 
clevis having a centrally located pin receptacle 29 such that when the 
downward projecting plate 37 of the upper bracket mates with the clevis 26 
of the lower bracket, the pin receptacle of the former plate 38 mates with 
that of the clevis 26. The mating pin receptacles so aligned mate with and 
receive a quick release pin which fastens the upper mounting bracket to 
the lower mounting bracket. 
A tractor adapted to receive the frame assembly herein, shown by way of 
illustration in FIG. 4, has a side support mounting 31 fixed to the 
tractor frame on one side of the tractor, positioned to receive one end of 
the connecting arm 27 and an identical mounting on the other side to 
receive one end of connecting arm 28. 
In operation, when a front-end implement such as a bulldozer blade is 
attached to the pivot frame cross piece 13 and subjected to a force 
through operation, the pivot pin 9 prevents sideways movement of the front 
of the frame with respect to the tractor and also assists in preventing 
downward deflection of the side sub-frame. The interconnecting arms of 
adjustable length 27 and 28 provide substantially vertical support for the 
midway portion of the frame. Both vertical and horizontal support are 
provided by the two rear axle mounting arrangements. The absence of fixed 
connections at or near the front of the tractor prevents it from being 
subjected to damage-producing excessive torque.