US 3762780 A
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United States Patent Tomizawa MI Oct. 2, 1973  BUFFER MEANS BETWEEN LINK AND l,765,580 6/l930 Haggurl 305/46 H PLATE IN A CRAWLER TYPE 2,211,897 8/1940 Johnston 305/54 APPARATUS  Inventor: Kazuhiro Tomizawa, 523 Kamagaya,
Kamagaya-cho, Higashikatsushika-gun, Chiba, Japan  Filed: May 25, 1971  Appl. No.: 146,723
 Foreign Application Priority Data July 29, i970 Japan 45/75446  U.S. Cl. 305/46, 305/54  int. Cl 862d 55/28  Field of Search 305/46, 54, 55
 References Cited UNITED STATES PATENTS 1,257,579 2/l9l8 Champlin 305/46 Primary ExaminerRichard J. Johnson At!0rneyDavis, Hoxie, Faithfull & Hapgood  ABSTRACT Resilient buffer means connected between the links and shoe plate in crawler-type apparatus to absorb shock and vibration. Tractive force increasing members are mounted on the shoe plate adjacent the links and in contact therewith for increasing the tractive forces applied to the shoe plate from the links and for retaining the resilient buffer means and links against longitudinal movement relative to the shoe plate.
4 Claims, 4 Drawing Figures BUFFER MEANS BETWEEN LINK AND SHOE PLATE IN A CRAWLER-TYPE APPARATUS The present invention relates to heavy construction machines. More specifically, the present invention relates to buffer means arranged between the links and shoe plate in a crawler-type apparatus, e.g., bulldozers, shoveldozers and the like.
With the increase in construction work it is desirable to reduce the down-time of construction machines and at the same time to increase the quantity of work per unit time by increasing the operatingspeed of construction machines.
Heavy construction machines such as bulldozers, shoveldozers and the like used at present in working the earth employ a crawler traction system requiring low ground contact pressure to supply mobility'to'the machine. In such construction machines, a shoe plate is bolted directly to the rear of two links. In operation,
, and particularly at the higher speeds desired to increase the quantity of work, the shoe plate is subjected to shock and vibration caused by obstacles, e.g., rocks and the like, and the irregular contour of the earth. Such shock accelerates abrasion, breakage and fatigue in the machine components resulting in shortened machine life.
It is the principal object of the present invention to provide construction machines having means capable of increasing work output.
It is a further object of the present invention to allow construction machines to be operated for long periods at high speed.
It is a further object of the present invention to reduce the amount of abrasion, breakage and fatigue occurring in construction machines, thereby prolonging machine life.
It is a further object of the present invention to provide means for increasing the tractive forces applied to the shoe plate from the links.
It is still a further object of the present invention to provide means for reducing the operating noise level of the machine and the vibration and shock during operation to create a more pleasant environment for the operator and to aid in preventing accidents resulting from operator fatigue.
Briefly, buffer pads are provided between each link and the shoe plate of a crawler-type apparatus. Two sets of paired link guides or ribs are arranged on the upper surface of the shoe plate, forming buffer pad receiving channels. A link is positioned between each set of ribs and connected to the shoe plate through a resilient pad, whereby the shock inflicted upon the shoe plate may be absorbed by the elastic deformation of the resilient pad; and abrasion of the link and rotary wheels, and damage to the bearings is prevented by reducing the intensity of the mechanical shock between each link and the lower rotary wheel. Further, a set of ribs is arranged adjacent each link and in contact therewith for increasing the tractive force applied to the shoe plate from the links.
Other objects, aspects and advantages of the present invention, as well as the objects previously mentioned, will be more fully understood when the detailed description is considered in conjunction with the draw ings, as follows:
. FIG. 1 is a perspective view of a conventional link and shoe plate structure for use in a crawler-type apparatus;
FIG. 2 is a perspective view of the assembled buffer means according to the present invention;
FIG. 3' is an exploded perspective view of the apparatus of FIG. 2 with one link omitted for ease of description;
FIG. 4 is a cross-sectional view taken along line IVIV in FIG. 3.
Referring to FIG. 1, a conventional shoe plate 1 is shown'connected directly to a pair of links 2 by means of nuts and bolts 3. In contrast to the conventional apparatus as shown in FIG. 1, the buffer means according to the present invention is shown in FIGS. 2 through 4.
Referring particularly to FIG. 3, a shoe plate 5 is shown having two pairs of rigid, spaced, substantially parallel link guides or ribs 6 and 6a fixedly arranged thereon. Each pair of link guides or ribs 6 and 6a has semi-circular notches 7 and 7a, respectively, symmetrically formed in the front and rear thereof and arranged for axial alignment with bolt apertures 8 and 8a, respectively, formed in the shoe plate 5. Each pair of ribs "6 and 6a defines a resilient-memher-receiving channel for receiving a resilient member or pad 10 and maintaining the longitudinal position of the resilient pad 10 relative to the shoe plate 5. The resilient memberslO each include semi-circular notches 11 and 11a capable of mating with notches 7 and 7a, respectively, forming bushing holes axially aligned with apertures 8 and 8a, respectively.
Further, each resilient member 10 includes a locking protrusion or key 10a adapted to fit within the portion of the channel 5a, formed in the upper surface of the shoe plate 5, that is within each receiving channel formed by the pair of ribs 6 and 6a, to lock. the resilient member 10 against substantial transverse movement. The resilient members or pads 10 may be formed from a high polymer compound such as sythetic rubber, polyurethane and the like.
Links 13 are mechanically coupled to the shoe plate 5 and provide mechanical coupling of the tractive forces thereto. The links 13 include flanges 14 and 15 integrally formed therewith and arranged between the ribs 6 and 6a, in contact therewith. The flanges 14 and 15 include notches 14a and 15a capable of mating with notches 7 and 7a of the ribs 6 and 6a, respectively, forming bushing holes axially aligned with apertures 8 and 8a, respectively.
Although, as shown in FIGS. 2 and 3, the notches7 and 7a formed in the ribs 6 and 6a cause portions of the ribs 6 and 6a circumjacent the notches 7 and 7a to extend outwardly in a semi-circular configuration, it is to be understood that the ribs 6 and 6a may be made wider to eliminate the outward projections- The ribs 6 and 60 may also include reinforcing ridges l7 and 17a connecting the ribs 6 and 6a to the shoe plate 5 for further strengthening the ribs 6 and 6a.
Cut-out sections 18 are formed at the rear edge of the shoe plate 5, generally extending approximately the width of the spaced ribs 6 and 6a, for allowing the toothed periphery of the sprocket (not shown) to pass therethrough during operation of the crawler-type apparatus.
When assembling the apparatus according to the present invention, as shown in FIGS. 2 through 4, the resilient members or pads 10 are fitted within the receiving channels formed by the two sets of paired ribs 6 and 60, respectively, and placed in contact with the ribs 6 and 6a and the upper surface of the shoe plate 5. Notches 11 and 11a are mated with notches 7 and 70, respectively, axially aligned with bolt apertures 8 and 8a, respectively. Links 13 are placed upon the resilient pads with the notches 14a and a mated with notches 7 and 7a, respectively, and thereby forming bushing holes adapted to receive locking bushings 23.
Bolts are inserted through the bolt holes 8 and 9 from the lower surface of the shoe plate 5, as shown in FIG. 3, and locking bushings 23 are positioned circumferentially about the threaded portion of the bolts 20 in the bushing holes, as shown in FIG. '4. Nuts are mated with the bolt threads to provide a compressive force which acts on the peripheral flanges 24 of the locking bushings 23 to hold the resilient members 10 and links 13 in position relative to the shoe plate 5.
The links 13 are held by the compressive action of the bushing flanges 24 on the rib surfaces circumjacent the notches 7 and 7a and on the flange surfaces circumjacent the notches 14a and 15a of the links 13, the resilient pads 10 are thereby compressively held beneath the flanges 14 and 15 of the links 13.
The thickness of the ribs 6 and 6a relative to the flanges l4 and 15 and resilient members 10 is such that the locking bushings 23 compressively retain the resilicnt members 10 with a compressive force below the averageload and within the elastic limit of the resilient members 10 to provide a buffer action. The elasticity and hardness of the resilient members 10 may be advantageously varied in response to machine and ground hardness.
Since the flanges l4 and [5 of the links 13 are pressed downwardly, with a force within the elastic limit of the resilient members 10, toward the shoe plate 5 by flanges 24 of the locking bushings 23, and the locking bushings 23 are connected with the semicircular notches 14a and 15a of the flanges l4 and 15 and the semicircular notches 7 and 7a of the ribs 6 and 6a, the tractive force imparted to the links 13 is transmitted to the shoe plate 5 through the locking bushings 23. Any tractive force acting on the links 13 is thereby transmitted to the shoe plate 5' by the ribs 6 and 6a, providing a tractive force that is more than twice as great as that of the conventional apparatus shown in FIG. 1, where the shoe plate 1 is connected directly to the link 2 through bolts and nuts 3.
When a crawler-type apparatus according to the present invention is operating, any shock inflicted upon the shoe plate 5 is absorbed by the vertical deformation of the resilient pads 10, and the shock between the links 13 and lower rotary wheels (not shownlis substantially reduced. During deformation, the resilient pads 10 may protrude, slightly beyond the transversely extending ribs 6 and 60; however, since the resilient pads 10 are held in position by the locking bushings 23 within semi-circular notches ll and Ila, and the locking protrusions 10a are positioned within the channel 5a, the resilient pads 10 are prevented from working free during operation.
It should be understood by those skilled in the art that various modifications may be made in the specific structure employed in the buffer means according to the present invention without departing from the spirit or scope thereof, as described in the specification and defined in the appended claims.
What is claimed:
1. Buffer apparatus for use with crawler-type apparatus, comprising:
a shoe plate,
a pair of links mechanically coupled to said shoe plate to provide coupling of the tractive forces from the crawler-type apparatus to said shoe plate,
a pair of resilient deformable buffer pads, one of said pair of pads positioned beneath one of said links to absorb shock and vibrations encounted by said shoe plate, said resilient deformable buffer pads extending in the direction in which said shoe plate is moved by the crawler-type apparatus,
two pair of tractive force increasing ribs mounted on said shoe plate and extending in the direction in which said shoe plate is moved by the crawler-type apparatus, each pair of said ribs being arranged to receive one of said resilient pads and one of said links to maintain the longitudinal position of said pads and said links on said shoe plate and increase the tractive force applied to said shoe plate from said pair of links, and
means for compressively coupling said pair of links to said shoe plate through said pair of resilient buffer pads.
2. Buffer apparatus as recited in claim 1, wherein:
said shoe plate includes a channel between said ribs of each pair of ribs,
each of said resilient buffer pads includes a depending protrusion received by said channels for locking said resilient buffer pads against transverse movement on said shoe plate to maintain the relative position between said shoe plate and said resilient buffer pads.
3. Buffer apparatus as recited in claim 1, wherein:
each of said tractive force increasing ribs includes reinforcing means connecting said ribs and said shoe plate.
4. Buffer apparatus for use with crawler-type apparatus, comprising:
a shoe plate,
link means mechanically coupled to said shoe plate to provide coupling of the tractive forces thereto,
resilient deformable buffer means arranged between said link means and said shoe plate to absorb shock and vibrations encounted by said shoe plate,
tractive force increasing members mounted on said shoe plate adjacent said link means and in contact therewith for increasing the tractive force applied to said shoe plate from said link means and for retaining said resilient buffer means and said link means against longitudinal movement relative to said shoe plate, said tractive force increasing members being transversely extending positioning ribs which are coupled to said shoe plate for maintaining the longitudinal position of said resilient buffer means and said link means relative to said shoe plate, said ribs are formed on said shoe plate extending transversely therealong in a spaced, substantially parallel arrangement, defining a plurality of separate buffer receiving channels, each of said ribs having at least one notch arranged therein,
said shoe plate includes apertures arranged therein axially aligned wtih said rib notches,
bushing holes, each of said locking bushings having a peripheral flange positioned circumjacent said bushing holes in contact with said link flange and said adjacent rib, and
means for compressively coupling said link means to said shoe plate through said resilient buffer means, said compressive coupling means including bolt means arranged within said shoe plate apertures and extending axially through said locking bushings for exerting compressive holding forces on said link flanges and said ribs through said peripheral flange.