US3707788A

US3707788A - Locking means for cap-type tooth

Info

Publication number: US3707788A
Application number: US00101859A
Authority: US
Inventors: W Sturgeon
Original assignee: Pengo Corp
Current assignee: Pengo Corp
Priority date: 1970-12-28
Filing date: 1970-12-28
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02

Abstract

Improved retaining means for a tooth having a blade formed at its proximal end with a pocket which receives a shank attached by welding, bolting, etc., to earth excavating equipment. A resilient insert is positioned in the distal end of the pocket. Holes in the pocket walls and shank are initially slightly offset. The resilient insert is deformed by the distal end of the shank when a hard pin is driven through the holes, thereby bringing the holes up to alignment, forcing the tooth rearwardly and causing the margins of the holes in the pocket walls to tightly engage the pin and prevent unintentional dislodgement of the pin. When it is necessary to replace the tooth, the pin may be forcibly driven out of the holes.

Description

United States Patent 1191 Sturgeon 1 1 Jan. 2, 1973 s41 LOCKING MEANS FOR CAP-TYPE 2,936,538 5/1960 Opsahl ..37/142 A TOOTH FOREIGN PATENTS OR APPLICATIONS [75] Inventor: Walter L. Sturgeon, Los Altos,

Cam 490,651 2/1953 Canada ..37 142 R 1 Assign9e= P9929 Corporation, Sunnyvale, Primary Examiner-Edgar s. Burr Calif- Attorney-Julian Caplan [22] F1led. Dec. 28, 1970 ABSTRACT [21] Appl' 101359 Improved retaining means for a tooth having a blade formed at its proximal end with a pocket which [52] US. Cl. ..37/l42 A, 299/92 receives a shank attached by welding, bolting, etc., to [51] Int. Cl. ..E02i 9/28 earth excavating equipment. A resilient i t i i- [58] Field of Search ..37/142; 299/92 tioned in the distal end of the pocket. Holes in the pocket walls and shank are initially slightly offset. The [56] References Cited resilient insert is deformed by the distal end of the shank when a hard pin is driven through the holes, UNITED STATES PATENTS thereby bringing the holes up to alignment, forcing the 2,657,482 11 1953 Launder et al. ..37 142 A tooth teat'watdly and causing the margins of the holes 2,427,651 9 1947 Baer 37/142A in the pocket walls to tightly engage the P and 2,483,032 9/1949 Baer 37/142 A prevent unintentional dislodgement of the pin. When 2,987,838 6/1961 Stratton 37/142 A it is necessary to replace the tooth, the pin may be 3,188,756 6/1965 Baer 37/142 A forcibly driven out of the holes, 2,994,140 8/1961 Laundel' et al. ..37/I42 A 3,091,044 5/1963 Penote et al. ..37/142 R 11 Claims, 14 Drawing Figures holes in the sides of the pocket and in the shank. A

resilient member is located in the bottom of the pocket and is deformed by the distal end of the shank when the tooth is forced into position. The resilient means biases the tooth distally and the shank proximally, thus creating a shear on the retainer pin which prevents unintentional dislodgement of the pin during use. The present invention provides a retaining means which effectively holds a tooth in place on the tooth holder. Despite the vibration and jarring stresses which are imposed upon the tooth during excavation, the pin does not slip out of locking position. The resiliency of the insert insures a secure holding of the pin. in place, preventing its dislodgement until the pin is deliberately driven out of position when it is necessary to change the tooth.

Another feature of the invention is the facility with which the pin may be installed and removed and the tooth replaced when it is necessary to do so.

Still a further feature of the invention is the fact tha no special tools are required to install or remove the tooth.

Still another feature of the invention is the fact that the resilient insert accommodates slight inaccuracies in the dimensions to which the parts are manufactured and accordingly provides tolerance for such inaccuracies.

Teeth of the general type heretofore described havebeen made by welding the pocket on the blade, by forg- When the flex-type pin is lost in the field, no satisfactory means for holding the tooth in place is ordinarily available. The retainer parts of the present invention are more or less standard and readily available; hence loss of the retainer parts is not as critical as in the case of the commonly-used flex pin.

Another advantage of the present invention is the fact that a solid pin of steel or other suitable material actually holds the tooth in place and the resilient insert merely holds the pin against dislodgement. In the aforementioned flex pin the resilient portion is under stress at all times in securing the tooth and holder in, assembled position and hence greater wear is imposed on said resilient portion.

Another feature is that the resilient insert in the pocket of the tooth absorbs some of the shock of the impact of the digging action of the tooth and relieves the tooth and its holder of some of the stress.

A further feature of the invention is reduction in likelihood of premature breakage under severe stress.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

FIG. 1 is a side elevation, partly broken away to reveal internal construction, of one form of the invention showing the parts before final assembly.

FIG. 2 is a view similar to FIG. 1 of the parts assembled.

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2.

FIG. 4A is a sectional view taken substantially along line 4-4 of FIG. 3 showing use of a modified pin.

FIG. 4B is a view similar to FIG. 4A of use of another modified pin.

FIG. 5A is a side elevation of the pin used in FIG. 4A.

FIG. 5B is a side elevation of the pin used in FIG. 48.

FIG. 6 is a view similar to FIG. 2 of a modification.

FIG. 7 is a view similar to FIG. 2 of still another modification.

FIG. 8 is a view similar to FIG. 3 of another modification.

FIG. 9 is a view similar to FIG. 1 of another modification.

FIG. 10 is a perspective view of a metal spring used in the modification of FIG. 9.

FIG. 11 is a view similar to FIG. 2 of a further modification.

FIG. 12 is a sectional view taken substantially along line 12-12 ofFlG.l1.

The various modifications of the present invention find particular application in retaining a tooth 21 on a holder 22. In normal usage the holder is attached by means of welding or bolts or other means (not shown) to the front edge of blade 23 of a bucket of an excavating machine or in a similar installation. The holder 22 is provided with a rearward extended bottom portion 26 which fits under the edge of blade 23 and with a short, upwardly-rearwardly slanted portion 27 which fits on the top edge of the blade. A notch 28 in the back of the holder receives the blade 23. The precise shape of the rearward ends 26, 27 of the holder form no part of the present invention but are of more or less conventional style so that they my be attached to a wide variety of different thicknesses of buckets. The proximal end or shank 29 of the holder is of particular importance in the present invention. The bottom face 31 thereof may be approximately horizontal while the top face 32 slants downwardly-forwardly at an angle of approximately 30. The sides 33 of the distal end of the holder may be substantially vertical and there is a blunt transverse horizontal front edge 34. Shank 29 may be in one fonn of the invention slightly wider (between sides 33) than the proximal end thereof, whereas the distance.

between bottom 31 and top 32 may be slightly less than the corresponding distance of the proximal end. The line 35 where sides 33 join said proximal portion may be rearwardly convex, or straight or angular (see FIG. 6). In cross-section the distal end of the holder is preferably approximately rectangular and uniform as is seen in FIG. 3. It will be understood that the terms horizontal," vertical, rectangular," uniform, and the like are used in a broad sense, and that in actual practice these relationships gave way to considerations such as forging and casting draft, as well as shrinkage.

The tooth 21 shown in FIGS. 1-3 is forged, while the The distal end of the tooth 21 of FIG. 1 comprises a thick, hard, strong, forwardly-downwardly inclined blade 36 having a top surface 37, a bottom surface 38 which tapers forwardly toward top surface 37, substantially vertical side edges 39 and a blunt transverse front cutting edge 41.

The proximal end of tooth 21 has a top surface 42 which is a continuation of the top 37 of the blade, a bottom surface 43 and rear edges 44 which fit,line 35. Formed in the proximal end of the tooth by forging or other means is a pocket 46. The pocket is shaped to accommodate the distal end of the holder and for such purpose has a downwardly-forwardly slanted top wall 47, a substantially horizontal bottom wall 48 and substantially vertical side walls 49. Formed in the bottom of pocket 46 is a recess 51 which is shown in FIG. 1 to be substantially cylindrical.

A transverse hole 52 which may be round, oval or other shape extends through the shank 29 and holes 53 are formed in the sides of the tooth 21. The holes 53 are formed in the sides of the tooth 21. The holes 53 may be the same configuration as hole 52 or they may differ slightly.

A resilient member 56 which is shown in FIG. 1 to be a piece of rubber of round cross-section is installed in the recess 51. Directing attention now to FIG. 1, when tooth 21 is forced on to holder 22 with normal manual pressure, the front edge 34 of shank 29 engages insert 56 and the

holes

52, 53 are slightly out of alignment. Various means may be employed to force the tooth in to position and then, most importantly, to hold the tooth in place. The most convenient means is the use of the steel pin 57 having at least one end 58 chamfered so tat it may be inserted through one hole 53 and driven through hole 52 and the other hole 53. As the tooth is pulled onto the holder 22 by driving the pin 57, the rubber 56 is deformed as is shown in FIG. 2. The deformation of the rubber tends to force tooth 21 forwardly and holder 22 rearwardly. Hence the rear edges of the holes 52 in the tooth pocket 46 engage pin 57 and the front edge of the hole 53 in the holder also engages the pin. The shearing action tends to retain pin 57 in place against unintentional dislodgement. Hence, despite vibration and other stresses imposed, pin 57 is not unintentionally dislodged. When it is necessary to remove the tooth for sharpening, replacement or other reasons, a blunt instrument such as a drift pin may be used to drive the steel pin 57 out of place.

The rubber insert 56 may be installed in various manners. Thus it may be merely laid in the groove 51. As an alternative, the rubber 56 may be vulcanized to the metal or it may be poured into the bottom of the pocket while molten.

In the form of invention shown in FIG. 3, except for the chamfered ends 58, pin 57 is of uniform cross-section. As shown in FIG. A, pin 57b is formed with reduced diameter necks 81 at either end with shoulders 82 spaced the width of shank 29b. As shown in FIG. 4A, the stress on the resilient insert (not shown) forces shank 29b to the right and tooth 21b to the left. The rear margins of holes 53b then engage necks 81 and fit outside shoulders 82, thus locking the pin 57b against unintentional dislodgement.

In the form shown in FIG. 58, pin 57c has pronounced tapers 83 at both ends. The rear margins of holes 53c engage tapers 83 and lock pin 57c against unintentional dislodgement.

In the form of the invention shown in FIG. 6, the tooth 21a is of welded construction. Thus the blade 36a is an integral piece of steel. The pocket forming member 61 comprises a piece of steel which is triangular in side elevation and U-shaped in rear elevation, the

forward end 62 and upper edges 63' of which are welded to the bottom of the blade 36a by welds 64. In cross-section the pocket 46a formed between the bottom of blade 36a and the walls of the pocket forming member 61 is substantially the same as in the forged configuration.

The rubber 56a insert of FIG. 6 is essentially the same as that in FIGS. 1-3. It will be understood that insert 56 may be round, triangular or other shapes.

A preferred means of positioning the pin is in a horizontal position as shown in FIG. 2. On the other hand, it is possible to place the

holes

52d, 53d in a vertical direction or, as shown in FIG. 7, slanted slightly rearwardly-downwardly. This position of pin 57d is more satisfactory where there is a number of teeth located side by side in close proximity and driving pins on or off when there is not much room between the teeth is otherwise difficult. In order to prevent pin 57d from falling out, means in addition to rubber 56d may be employed such as making the head 59 of the pin and the hole 53d in the top of the pocket slightly larger than the hole 52d in the shank.

In the preceding modifications shank 29 has been I substantially rectangular in cross-section. As shown in FIG. 8, shank 29c has downwardly-outwardly top surfaces 71 on either side of the longitudinal center line 73 and upwardly-outwardly bottom surfaces 72. The surfaces 71, 72 are preferably at angles of 7 with the horizontal, a convenient forging and casting draft angle. Sides 33c may be vertical or taper rearwardly. Pocket 460 has its walls complementary to shank 29c.-

As shown in FIGS. 9 and 10, instead of rubber, a crimped, wavy spring 66 of spring steel may be inserted in the bottom of pocket 46f. The distortion of spring 66 functions substantially the same as the distortion of rubber 46 to force tooth 21f forwardly and holder 22f rearwardly and thus retain pin (not shown) in position. It will be noted that hole 53f may be oval, as shown, round or other shapes.

In the preceding modifications, insert 56 has been imbedded in pocket 46 either in recess 57 or otherwise detached from shank 29. Directing attention to FIGS. 11 and 12, front edge 34g of shank 29g is formed with a groove 76 on the top and bottom surfaces 32g, 31g. Recess 513 is deeper than in the preceding modifications. Insert 563 has a bulbous nose 77, which is jammed into recess 51g when tooth 21g is driven into place on shank 22g, and has rearward extensions 78 which fit into grooves 76. Thus insert 51g tends to remain on shank 29g and is more easily inspected prior to assembly of the tooth and shank.

In many respects the structures of FIGS. 4-12 are similar to those of FIGS. 1-3 and corresponding parts are designated by the same reference numerals as in FIGS. 1-3, followed by subscript a in FIG. 6, b in FIGS. 4A and 5A, c in FIGS. 4B and 58, d in FIG. 7, e in FIG. 8,fin FIGS. 9 and 10 and g in FIGS. 11 and 12.

What is claimed is:

1. In combination, a tooth holder having a shank having a transverse forward distal edge, the forward end of said shank being approximately triangular in longitudinal cross-section, a tooth having a blade and means forming a pocket in the rearward end of said tooth, said pocket formed substantially complementary to the forward end of said shank and having opposed walls and a forward end, a resilient insert in'said pocket between said distal edge of said shank and the forward end of said pocket, said distal edge engaging said insert when said tooth is in place with said shank insaid pocket, said shank formed with a round first hole extending transversely through said shank, said opposed walls formed with aligned round second and third holes, said second and third holes being offset forwardly of said first hole prior to deformation of said insert, and a hard pin extending through said first, second and third holes in the assembled position of said tooth and holder to retain the tooth on the holder, said insert being deformed by said shank in said assembled position and biasing said tooth and holder apart, the margins of said secondand third holes engaging said pin under stress of said insert to restrain unintentional, longitudinal movement of said pin.

2. The combination of claim 1 in which said insert prior to assembly of said tooth and holder is loose in the bottom of said pocket.

3. The combination of claim 1 in which said insert is fused in the bottom of said pocket.

4. The combination of claim 1 in which said distal edge is formed with a cavity and said insert is partially within said cavity.

5. The combination of claim 1 in which said tooth is unitary and said pocket is forged in said tooth.

6. The combination of claim 1 in which said means forming said pocket is separate from said blade edges, said means forming said pocket being welded to said blade.

7. The combination of claim 1 in which at least one end of said pin is formed with a taper.

8. The combination of claim 7 in which said margins of said second and third holes engage the taper of said pin, said pin being restrained against movement longitudinally of the axis of said pin by said margins bearing against said taper.

9. The combination of claim 1 in which the ends of said pin are necked, said margins of said second and third holes engaging the necked ends of said pin, said pin being restrained against movement longitudinally of the axis of said pin by said margins bearing against said necked ends.

10. The combination of claim 1 in which said shank is substantially rectangular in transverse cross-section.

11. The combination of claim 1 in which said shank is transverse cross-section has more than four sides.

Claims

1. In combination, a tooth holder having a shank having a transverse forward distal edge, the forward end of said shank being approximately triangular in longitudinal cross-section, a tooth having a blade and means forming a pocket in the rearward end of said tooth, said pocket formed substantially complementary to the forward end of said shank and having opposed walls and a forward end, a resilient insert in said pocket between said distal edge of said shank and the forward end of said pocket, said distal edge engaging said insert when said tooth is in place with said shank in said pocket, said shank formed with a round first hole extending transversely through said shank, said opposed walls formed with aligned round second and third holes, said second and third holes being offset forwardly of said first hole prior to deformation of said insert, and a hard pin extending through said first, second and third holes in the assembled position of said tooth and holder to retain the tooth on the holder, said insert being deformed by said shank in said assembled position and biasing said tooth and holder apart, the margins of said second and third holes engaging said pin under stress of said insert to restrain unintentional, longitudinal movement of said pin.