US3452828A

US3452828A - Bulldozer tiltable blade mounting

Info

Publication number: US3452828A
Application number: US585347A
Authority: US
Inventors: Jack M Deli
Original assignee: International Harverster Corp
Current assignee: Dresser Industries Inc
Priority date: 1966-10-10
Filing date: 1966-10-10
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01

Description

y 1,1969 .1. M. DEL. 3,452,828

BULLDOZER TILTABLE BLADE MOUNTING Filed Oct. 10, 1966 .Zfizfenlorf Mack M1. Dell J. M. DELI BULLDOZER TILTABLE BLADE MOUNTING July 1, 1969 Sheet 3 M5 Filed Oct. 10. 1966 l'izflnzog", d'ac/r (#1. Zelz July. 1, 1969 J, DE| 3,452,828

BULLDOZER TILTABLE BLADE MOUNTING Filed Oct. 10, 1966 Sheet 3 of 3 INVENTOR. JA CK M. DELI United States Patent 3,452,828 BULLDOZER TILTABLE BLADE MOUNTING Jack M. Deli, Wheaten, Ill., assignor to International Harvester Company, Chicago, 11]., a corporation of Delaware Filed Oct. 10, 1966, Ser. No. 585,347 Int. Cl. E02f 3/ 76 US. Cl. 172803 10 Claims ABSTRACT OF THE DISCLOSURE Bulldozer blade attachment for bulldozers having proper geometry for tilting the blade without setting up undue stresses in the attachment. The customary diagonal braces, providing lateral stability at each side of the blade between it and a blade connected push arm at that side, are placed with a geometry such that the braceto-blade connection is both medially and rearwardly offset from the push a-rm-to-blade connection on at least one side of the bulldozer. The general tendency of the push arms to elastically bow outwardly during blade tilt is substantially eliminated with this geometry.

This application relates to a tiltable bulldozer blade and a mounting therefor. It more particularly relates to means for so mounting the blade on a bulldozer as to prevent damage from stresses that set up in the mounting means when the blade is moved into tilted position on the bulldozer.

In the drawings:

FIGURE 1 is a top plan view of a tractor bulldozer embodying a preferred form of my invention;

FIGURE 2 is an isometric showing of the bulldozer blade mounting means, as viewed from the right side of the tractor;

FIGURES 3 and 4 are schematic showings consisting of top plan and rear elevational views of the mounting means;

FIGURE 5 is an isometric view similar to FIGURE 2, but showing the mounting means in a changed position and with certain parts removed for simplification;

FIGURE 6 is a showing of a strut, in side elevation;

FIGURE 7 is a view similar to FIGURE 3, but showing a modification; and

FIGURE 8 is a view similar to FIGURE 3, and illustrating schematically the location of axes of swinging.

In a bulldozer tiltable blade mounting having an offset brace connection to the blade so as to embody the improved geometry according to my invention, and having a frame more particularly indicated at 10a in the accompanying drawings, the bending forces normally attendant with tilting of the mounted blade 12 are materially reduced in the mounting frame or substantially eliminated therefrom.

By tilting, in its simplest form, I mean for example the downward angling, about a first point of interconnection 14, of a push arm structure 16 at a first side of the mounting frame 10 relative to the side of the blade structure at that side. In absolute terms, the blade structure actually rises at that side (FIGURE 5) and so does the push arm structure because of the blade articulation 14 thereto, whereas the blade structure at the other side can stay poised at the previous elevation. A diagonal frame brace 18 on the first side, having an articulation 20 connecting it at one end to the adjacent push arm structure 16, provides at its forward end a rearwardly offset second point of connection 24 of the mounting frame to the blade structure at that side. Providing offset to the second point of connection is believed novel, and is actually made at the projecting end of an offset back bracket 26 rigidly secured to the blade structure.

ICC

The first and second points of

connection

14 and 24 thus establish a diagonal axis 28 of relative swinging between the tilting blade and push arm structures, minimizing the bending forces tending to place the brace 18 in unwanted compression and consequently tending to how the push arm structure 16 outwardly. One case where tilting is of particular advantage occurs when power means, such as a tilt cylinder 30 which extends upwardly as a tilt strut between the top of the push arm structure 16 and the blade structure, is provided so that while the vehicle is on the go the blade can be moved into a tilted position relative to the vehicle. In that manner, the vehicle can be readily turned when the blade is working simply by raising the blade at one end, so that the vehicle in ramping itself out of the cut inherently turns as it goes. The rest of the power means is not shown, and includes simply a conventional source of hydraulic high and low pressure on the vehicle, raise-lower-hold tilt valving, and hydraulic hoses 31 and lines having the tilt valving included therein and connected thereby between the high and low pressure source and the tilt cylinder 30.

The push arm structure 16 extends rearwardly from the blade structure 12 and has a trunnion end portion 32 mounted for swinging on an axis 34 upon a trunnion 36 fixed to the side of the vehicle 38'.

Except for the offset of the back bracket 26 and the diagonality of the axis 28, the mounting frame 10a is essentially symmetrical. More particularly, the blade structure 12 has a separate articulation 38 to the other push arm 40, the other push arm being arranged to extend longitudinally rearwardly therefrom and is con nected by a trunnion portion 42 of such other arm to a fixed trunnion 43 on the vehicle. A tilt strut 44 in the mounting frame extends upwardly between the top of the other push arm 40 and the blade structure 12. A diagonal brace 46 which extends from the medial surface of the other push arm 40 to the blade structure, has a brace articulation 48 connecting it to the push arm and pro vides at the front end another point of connection 50 of the mounting frame to the blade structure 12.

Means is provided for raising and lowering the mounting frame and blade structure 12, and includes an appropriate lift frame 52 (FIGURE 1) carried by the vehicle 38 for that purpose.

Illustrative of one raising and lowering means is a pair of identical hoist cylinders 54, the one adjacent the first side of the vehicle being the only one described, in the interests of brevity. A yoke 56 is journaled in one end of the gimbal tube, not shown, carried by the lift frame 52. The yoke 56 supports the cylinder 54 for universal movement and includes a gimbal cap 58 in the connection to the cylinder 54.

Although hoist cables are equally adapted to raise and lower the blade 12, a piston rod 60 extending from the cylinder 54 is illustrated as the power means connected to the blade 12. A universal joint 62 interconnects the rod 60 and the blade to prevent binding.

For purposes of analyzing the geometry of the frame 10 in operation, the frame may be considered a free body. Swinging of the push arm structure 16 caused by extending the cylinder 30 so that it lengthens in its function as a tilt strut, causes the trunnion end 32 to swing about a center 64 in a plane 66 as viewed in FIGURE 3, and to follow an elliptical locus 68 so as to take the position shown by the dotted line 32a in FIGURE 4.

So instead of following the customary locus of points which would appear as the straight line 70 in FIGURE 4, the actual locus 68 according to my improvement, more nearly falls upon the surface of a reference sphere 72 representing all points in space that maintain a constant distance D from the trunnion end 42 of the other push arm. Obviously, if the trunnion end 32 always tries to maintain a constant distance D at all points from the trunnion end 42, then the ends will readily and inherently conform to the fixed spacing D between the

trunnions

36 and 43 fixed to the vehicle.

The blade structure 12 is tilted in the opposite direction by retracting the cylinder 30 to shorten the effective strut length thereof. In that case, the free body position of the trunnion end of the push arm structure 16 takes the dotted line position 321), FIGURE 4, in which again it falls closely adjacent to the surface of the reference sphere 72. So the push arms at the side of the vehicle are subjected to minimum bending forces and hence to minimal outward bowing. As illustrated (FIGURE 3), the axis 28 is coincident with a line 28a intersecting the other push arm 40 such that, as measured from the point of blade articulation 38, the distance to the point of intersection is no less than the distance between the articulation 38 and the point of brace articulation 48 to the other beam 40. The line 28a is actually shown passing adjacent the articulation 48 which connects the diagonal brace 46 and the other push arm 40.

If the hydraulic cylinder 30 is extended so as to increase its length as a tilt strut, at the same time at which the tilt strut 44 on the other push arm 40 is foreshortened so as to decrease its tilt strut length, a greater angle of blade tilt out of a horizontal plane is achieved. The result, in its basic geometry, is illustrated in FIGURE 5, whereas the opposite tilt result is produced if the tilt cylinder 30 is shortened and the tilt strut 44 is lengthened.

If the tilt strut 44 is an hydraulic cylinder, then operating it in opposite direction from the tilt cylinder 30 produces on-the-go tilting to the greater degree mentioned, without the need for the driver to stop the vehicle 38 and make a tilt strut adjustment on the ground.

Making the mounting frame symmetrical as illustrated at 1011 in FIGURE 7, enables the frame to take the position of FIGURE 5 with even further reduction in the bending stresses, the importance of which is apparent. The illustrated embodiment has the simple modification of a back bracket 26a which is like the bracket 26. The back bracket 26a effects a ball connection 24a between the rearwardly projecting end thereof and the diagonal brace 46a which is articulated to the other beam 40.

The two points established by the ball connection 24a of the diagonal brace 18a and the blade articulation 38 (not shown) to the other beam 40 define an axis 74 of relative swinging between the blade structure 12 and the other push arm 40. Such axis 74, when extended, coincides with a line 74a intersecting the push arm structure 16 adjacent the articulation 20 connecting the diagonal brace 18 and the push arm structure 16.

The difference, in sum, is that the FIGURE 5 embodiment has only one swing axis 28 which extends diagonally between the push arms, whereas the FIGURE 7 embodiment has swing axes 28 and 74 both of which extend diagonally between the push arms.

All joints, connections, and articulations illustrated are either ball joints or their equivalent, such as the universal joint 62, FIGURE 1. It is evident that, at some of the points of juncture, a pin joint or other type joint can readily be substituted.

In FIGURE 6, an extensibly and foreshortenably adjustable link 78 is illustrated, to show the

typical balls

80 and 82 in the ball joints thereof. At the point of adjustment, the dimension A can be changed by manipulating the link 78, thereby lengthening or shortening the center-to-center distance between the

balls

80 and 82.

The link 78 is standard for braces such as the

diagonal braces

18 and 46 and for the strut 30 or the strut 44 or both, if hydraulic tilt cylinders are not used as the tilt struts.

Pitching is accomplished by tipping the blade structure 12 about the transverse axis defined by the blade articulations 14 and 38 (FIGURE 3) to the push arms. A frontward pitch so as to tilt the blade forwardly increases the so-called suction angle for ease in handling hard material. A decreased suction angle is employed for soft material.

Decreasing or increasing the suction angle of the blade 12 shown in FIGURE 3 requires lengthening of the diagonal brace 18, but no change in the diagonal brace 46. The reason is that the joint 50 coincides with the pitch axis just described whereas the second point of connection 24 is horizontally rearwardly offset therefrom so as to fall on the diagonal axis 28. Both diagonal braces 18 and 4611 require lengthening in the mounting frame 10!) shown in FIGURE '7, when pitching the blade 12.

Ideally, provided the diagonality of the axis 28, for example, is increased to where it coincides with a line 76 (FIGURE 3) passing through the trunnion end 42 of the other push arm 40, the trunnion end 32 will in relative terms be caused to swing in a locus of points each on the surface of the reference sphere 72 so as to stay at all times precisely equidistant from the trunnion end 42 of the other push arm. As a result in the vehicle 38', all tilt-caused bending stresses can therefore be eliminated from the two push arms associated in the blade mounting structure.

However the ideal, as actually illustrated in FIGURE 8, is sometimes difficult to achieve as a practical matter because an exaggerated offset of the bracket 26b as seen to be required in FIGURE 8 complicates the interconnecting structure and complicates the geometry somewhat for other aspects of blade handling.

The blade structure is a bulldozer blade, a bullgrader blade, or other earth working blade depending upon the material being displaced. It is apparent from the foregoing that the blade, in its various positions of angularity of elevation, tilt, and pitch, is readily positioned by the mounting frames hereof and conforms to the fixed distance D maintained between the

trunnions

36 and 43. In other words, the push arms do not bend unduly despite their noted general tendency at the trunnion ends 32 and 42 to spread apart.

Variations within the spirit and scope of the invention described are equally comprehended by the foregoing description.

What is claimed is:

1. In the mounting for a transversely disposed earth working blade structure which comprises individual push arms, said structure having a separate articulation to each push arm, said push arms arranged to extend longitudinally rearwardly therefrom to trunnion portions of the arms and with one push arm structure disposed at a first side and the other arm at the other side of the mounting, tilt struts extending upwardly between the tops of the push arms and the blade structure, diagonal braces extending from the medial surfaces of the push arms to the blade structure, first adjusting means (30) at at least the first side of the mounting to adjust the length of the tilt strut at that side to effect tilting of the blade structure, means of brace articulation connecting the diagonal braces to the respective push arm structure and other push arm, said blade articulation to the push arm structure constituting a first point of connection of the mounting to the blade structure at the first side and the diagonal brace at that side providing a second point of connection of the mounting to the blade structure at the first side:

the improvement wherein the first and second said points of connection establish an axis of relative swinging between the blade and push arm structure which extends diagonally between the push arms and which, when extended, substantially coincides with a line (28a) intersecting the other push arm at a point such that the distance between the just said point of intersection and the point of blade articulation to said other push arm is no less than approximately the distance between the respective points of blade articulation (38) and brace articulation (48) to said other push arm.

2. The invention of claim 1, characterized by:

means at one side of the mounting to adjust (A) the eflective link length of at least the diagonal brace at that side to accommodate pitching of the blade structure.

3. The invention of claim 1, characterized by:

means (18) at at least the first side of the mounting to adjust (A) the length of the diagonal brace at that side to accommodate pitching of the blade structure.

4. The invention of claim 1, characterized by:

the second point of connection being formed between the rearwardly projecting end of an offset, back bracket (26) on the blade structure and the forward and medially extending end of the adjacent diagonal brace.

5. The invention of claim 1:

the swing axis characterized, when extended, by passing at least closely adjacent the trunnion portion (42) of the other push arm.

6. The invention of claim 1:

a plurality of the points of articulation and connection characterized by ball joints.

7. The invention of claim 1, characterized by:

supported hoist means having means of connection to a support and having means of connection to the mounting for causing lifting and lowering movement;

a plurality of the points of articulation and connection consisting of ball joints and universal joints.

8. The invention of claim 1 including:

a bulldozer having fixed trunnions and swingably carrying said mounting thereon, the blade structure comprising a bulldozer blade which tilts on the mounting, the described improvement effective to reduce stresses set up in the mounting upon such tilting.

9. The invention of claim 1, characterized by:

the first adjusting means comprising an hydraulic cylinder 30 forming the tilt strut at the first side, and further comprising means for extensibly and foreshortenably moving the hydraulic cylinder to change the effective link length of the tilt strut.

10. The invention of claim 4, characterized by:

a back bracket (26a) on the blade structure elfecting a ball connection between the rearwardly projecting end thereof and the diagonal'brace which is articulated to the other beam;

the ball connection of the just said diagonal brace and the blade articulation to the other push arm constituting two points establishing the axis of relative swinging between the blade structure and the other push arm, which axis when extended substantially coinciding with a line (74a) intersecting the push arm structure at a point such that the distance between the just said point of intersection and said first point of connection is no less than approximately the distance between the respective first point of connection (14) and the point (20) where the adjacent diagonal brace has brace articulation to the push arm structure.

References Cited UNITED STATES PATENTS ANTONIO F. GUIDA, Primary Examiner.

35 STEPHEN C. PELLEGRINO, Assistdnt Examiner.