US2924470A

US2924470A - Resilient cushion insert

Info

Publication number: US2924470A
Application number: US634221A
Authority: US
Inventors: Fred L Haushalter
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-01-15
Filing date: 1957-01-15
Publication date: 1960-02-09
Anticipated expiration: 1977-02-09

Description

F. L. HAUSHALTER RESILIENT CUSHION INSERT Feb. '9, 1960 5 Sheets-Sheet 1 Filed Jan. 15, 1957 I v INVENTOR. FRED L.HAU$HALTER BY Mm My ATTORNEYS Feb; 9, 1960 HAUSHALTER 2,924,470

RESILIENT CUSHION INSERT Filed Jan. 15, 1957 3 Sheets-Sheet 2 FIGS.

mu HH| 6 H F3 G.H M.G.I.... g. F.

INVENTOR.

FRED L. HAUSHALTER BY W/MM WyW ATTORNEYS Feb. 9, 1960 F. L. HAUSHALTER 2,924,470

RESVILIENT CUSHION INSERT Filed Jan. 15, 1957 Y 3 Sheets-Sheet 5 IN VENTOR.

FRED L. HAUSHALTER BY WW4) WV ATTO R N EYS RESILIENT CUSHION INSERT Fred L. Haushalter, Pontiac, Mich.

Application January 15, 1957, Serial No. 634,221

3 Claims. (Cl. 287126) The invention relates to a resilient cushion inserts and forms a continuation-in-part of my former application for patent Serial No. 542,354, filed October 24, 1955. In the said application a method is described for introducing into a recess within a rigid member a resilient insert of rubber-like material which in unstressed condition is of a transverse dimension greater than that of the recess in which it is inserted. Thus, when in place it has a tendency to expand, exerting a strong pressure against the walls of the recess so as to be frictionally retained therein and without the necessity of vulcanization or other attachment to said walls. The subject matter of the present case is a structure having such insert, one specific example of which is a track shoe for an endless track type tractor. An essential feature as above stated is that the insert when unstressed is of a greater transverse dimension than that of the recess. There are, however, other advantageous features of this structure as hereinafter set forth.

In the accompanying drawings:

Figure 1 is a cross section on line 1-1 of Figure 4 through a recessed rigid body having a prestressed rubber-like insert therein.

Figure 2 is a cross section illustrating one method of installing the insert within the rigid body and simultaneously pretensioning the same.

Figure 3 is a similar view showing a slightly modified construction.

Figure 4 is an elevation partly in section of a track bar for an endless track type tractor having ,a resilient cushion insert therein.

Figure 5 is a bottom plan view of one of the shoes of a modified type of endless track tractor having a pair of cushion inserts therein.

Figure 6 is a cross section on line 6-6 of Figure 5.

Figure 7 is a section similar to Figure 1 showing a modified construction.

Figure 8 is a cross section somewhat similar to Figure 3 but illustrating another modification.

Figure 9 is a view showing the manner of introducing the insert of Figure 8 in its recess.

Figure 10 is a sectional elevation similar to Figure 4 showing another modification.

While there are many specific constructions in which a resilient insert of my improved construction would be advantageous, I shall describe specifically only its application to a tractor shoe. It has been the practice in the past to vulcanize the rubber-like insert to the walls of the recess which adds a considerable item to the cost of manufacture. Also, shrinkage of the insert by cooling after vulcanization is detrimental. Both of these detrimental features are avoided with my construction, which is as follows:

As shown in Figure '1 the rigid member A is of U-shaped cross section to form a channel-shaped recess within which is placed the elongated resilient insert B. Figure 2 shows the insert B as originally of greater cross-sectional width than the recess within the memited States Patent 0 ice her A. Such insert B is also provided centrally with a longitudinally extending thin slot B which extends in depth from its read edge to within a short distance of its forward edge which as indicated at B is rounded. C is a thin plate-like rigid member within the slot B' extending rearward beyond the same. Thus pressure applied on the outer end of the member C will, as above stated, force the insert edgewise into the recess and at the same time stretch it so as to reduce its width. Figure 3 shows a modified construction in which the insert D has a pair of spaced slots D', D extending therein on opposite sides of the center thereof. The rigid member -E has corresponding spaced thin plate-like rigid portions E and E for engaging said slots. .This will afford a more stable construction than that illustrated in Figure 2 for forcing the insert into the recess. With both constructions the insert will be stretched sufiiciently to reduce its width to that of the recess and after complete insertion the rigid members C and B may be withdrawn, whereupon contraction of the stretched member will close the slots B and D, D

However, the contraction in stretched length required for closing the slots is less than the total stretching during insertion so that the insert is still under stress tending to expand the same transversely. This will insure sufficient frictional cotnact between the insert and the walls of the recess to retain the former without the necessity of vulcanization. As the pressure of the member E is applied to the central portion of the insert and as the side portions thereof are retarded by friction with the walls of the recess, this central portion will be advanced to a greater degree than the side portions. This would result in concaving the outer end of the insert and to avoid such result the central portion is originally extended rearward beyond the side portions. Thus the portion of the insert between the slots D, D projects rearward at D beyond the portions outside of said slots. During insertion of the member D the friction of the spaced portions E and E of the member E on the central portion of the insert which is therebetween will draw this projecting portion D inward so that its rear end will be more nearly in line with the side portions.

Figure 4 is a sectional elevation of one of the transversely extending track bars of an endless track type tractor and of which Figure 1 is a cross section.- It will be noted that the bar A is of inverted U-shape cross section throughout its length but that the vertical depth inthe central portion A of the bar is greater than in the end portions A and A thereof. The insert B also extends the full length of the bar and is fashioned to correspond in depth to the portions A, A and A thereof. It is also provided with one or more longitudinally ex tending slots such as B, Figure 2, or D, D Figure 3 which slots extend in depth from the lower edge of the insert to within a short distance from the upper edge thereof. Rigid members such as C or E engage these slots and form the means for prestretching the insert and engaging the same with the bar as above described. When these rigid members are withdrawn the insert will still be retained by the resilient stresses remaining therein.

The construction illustrated in Figures 5 and 6 is of a track shoe F having spaced projecting lugs F, F and F at one edge thereof and spaced lugs F and F projecting from the opposite edge for engaging the spaces between the aforesaid lugs in the next adjacent shoe and pivotally connected thereto. As heretofore constructed, these shoes are formed with triangular recesses in their underfaces for receiving rubber inserts vulcanized to the metal of the shoe. I have changed the construction by forming channel recesses each with parallel side walls and adjacent respectively with opposite oblique sides of the triangle extending to a common apex. These channels can either beformed in the original casting or, as shown, 7

by spaced bars G and G weldedto thecasting. Cushion inserts H of resilient rubber-like material are inserted edgewise within said channels by the method above described andiby; the; use; of thin rigid members, which are in slots.extending the.full. length of; said members- Thus, the. resilient stresses Within the. insert. tending to. expand it transversely will so. increase; thefriction with. the walls of the. recess; as. to retain the insert; without. the necessity oft vulcanization. Similar: prestretched. inserts. may. be placed in recesses im thetop. of the. shoe, as indicated at I and 11"..

For some-uses it. may. be desirable to provide. the walls oh the recess with one on more inwardly projecting lugs which will be. embedded; in. the. insert and will assist in retaining the. same. Such; a construction. isshown in Figure 7; in; which the member A hasportions: J and J. thereof struck inward from opposite walls. to. form said lugs. The insert Brnay beinstalled'by the method previously'described. during which the; lugs J and J will become embedded in. the. rubber;.

As thus. far described the. rigid member. which is: used for stretching. the. insert to reduce. its width is. later Withdrawn. from. its. slot. which W111i be, closed. by the. resiliency of the insert material. It may, however, be desirable to leave oneor more of. thesev rigid. members permanently within the. resilient insert, such for instance. as, shown. in Figured. Herethespaced thin.rigid mem-bers.E. and E? remain. within. the; insert Di and. also. have. portions E which: project outward. beyond: the. insert. The manner of installingthe insert is illustrated in Figure 9.. wherethe projectingportions.E of the. members E3 and E are first engaged. with. slotsdn a head member E? by which they are impelledto. stretch. the. insert and force it within the recess. If'desireda pingE? may be. used for locking the head E? to the. members; E and E during installation, said pinbeing later removed for detachment of the head. The projecting portionsE Will-.adda to the traction. in soft ground. Also, they. may beusefnh in. amphibious. vehicles for propelling them. through. the water. Where. thev rigid members. are to be. left permanently in the insert itis preferable. that they should be formed of tempered. or hardened. metal.

As shown. in Figure 10. the. projecting portion of the resilient insert: B.is.corrugated=, as. indicated. at El What I claim) as. my invention, is:.

1. A rigid member having a recess thereinv with spaced walls in. fixed. relation to each other, and. an. elongated compressed insert of rubber-like material disposed edge- Wise forwardly within aprojecting edgewise. rearwardly and outwardly of said.recess,.s aid insert originally having a pair of spaced narrow slots intermediate said Walls dividing the rearward end. ofv said insert into. a, central portion and adjacent. side. portions, said slots extending into. saidinsert from the. rearwardedge thereof to. within a short distance of the opposite forward edge of the insert, said central portion defined by said slots extending rear- Wardly from the rearward edge of the side portions, the original width of said insert being greater than the distance between said spaced walls, said side portions being stretched into said recess in the direction of the forward edge thereof while said central portion remains unstretched, whereby, when. stretching force is terminated, the outer surface of said central portion is substantially flush with the outer surfaces of. the adjacent side portions of the insert and theinsert is under compression and in frictional engagement with said walls.

2. The combination set. forth in claim 1 further characterized in that the side walls of the recess are parallel and the slots are parallel to said side walls and to each other.

3. A rigid member having a recess therein with spaced walls in fixed relation to each other, an elongated compressed insert, of. rubber-like, material disposed edgewise forwardly Within.and. projecting edgewise rearwardly and outwardly of said recess, said insert originally having a pair of; spaced narrow slots intermediate said walls dividing the rearward end of said insert into a central portion and adjacent side. portions, said slots extending into said: insert from. the. rearward edge thereof to, Within a; short distance of the. opposite forward edgev of the insert, saidcentral portion. defined; by said. slots extending rearwardly from the rearward: edge of. the side portions, the original width of said insert. being greater than the distance. between said spacedwalls, a pair of rigidzforcing blades. inserted; in said slots, said blades forming the means for stretching said insert into. said.recess, said side portions being-stretched intosaid recessin the direction of the forward edge thereof while said: central portion remains unstretched, whereby, when. stretching force is terminated, the outer surface of said central portion is substantially flush with the. outer surfaces of the adjacent side portions of the insert, and the insert is under compression and inv frictional; engagement with said walls and said blades, said blades thereafter forming part of the assembly.

ReferencesCitedin the file of this patent V UNITED STATES; PATENTS.

831,391 Ubellar Oct. 28, 1905 1,279,386 McEvoy Sept. 17, 1918 2,312,072 Broadwater Feb. 23, 1943 2,645,532 H'ollenkamp July 14, 1953 2,686,697 Baker Aug. 17, 1954 2,753,886 Powers July 10, 1956 FOREIGN PATENTS 339,605 Great Britain Dec. 4, 1930 148,625 Sweden Jan. 25, 1955