Connector pin assembly

Abstract

The connector pin assembly releasably retains telescoped excavating support and wear members in their telescoped relationship. The connector pin assembly is removably received in aligned connector openings in the members. A body portion of the assembly blocks removal of the wear member from the support member, and a lock member portion of the assembly is rotatable relative to the body, toward and away from a locking orientation, to releasably lock the body within the connector openings. A resilient sleeve having non-circular interior and exterior surfaces with rounded corners is non-slippably disposed over a rotatable shaft of the lock member in order to slidingly and deformably engage a non-circular shaped interior cavity of the body that rotatably receives shaft and sleeve of the lock member. The sleeve yieldingly resists rotational movement of the lock member away from a locking orientation.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/904,369, filed Mar. 2, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to material displacement apparatus such as excavating equipment and, in illustrated embodiments thereof, more particularly relates to a connector pin assembly for releasably coupling a replaceable excavating tooth point or other wear member to an associated adapter nose structure.

2. Description of the Related Art

An excavator is generally the heavy-duty equipment that uses digging teeth or cutters on buckets and shovels for construction or other applications. Teeth or other such cutting engagements are wear parts to be replaced frequently. A tooth is an elongated body terminating in a sharp edge. An adaptor connects the other end of the tooth to the bucket. A lock pin assembly retains the tooth and adapter in a telescopic relationship. The lock pin assembly has a pin and cam that can be rotated 90 degrees in a lock position or 90 degrees in the opposite direction for an unlock position. The rotation torque is generally provided by a socket wench or similar tool. Related art connector pin assemblies generally have a plastic insert that protrudes through a rectangular hole through the shaft of the pin. When turning the shaft by external torque, the plastic insert will be compressed to pass the narrow area restricted by square sides of an interior section passageway of the pin assembly body.

Without external torque application, the insert aligns itself along diagonally opposing corners of the square hole cavity so that the tooth can be locked up by pin at the lock position or unlocked by the pin at the unlock position. The aforementioned configuration undergoes substantial wear such that the plastic insert usually fails within a few uses thereof.

Thus, a connector pin assembly solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The connector pin assembly releasably retains telescoped excavating support and wear members in their telescoped relationship. The connector pin assembly is removably received in aligned connector openings in the members. A body portion of the assembly blocks removal of the wear member from the support member, and a lock member portion of the assembly is rotatable relative to the body, toward and away from a locking orientation, to releasably lock the body within the connector openings.

A resilient sleeve having a non-circular shaped interior surface, such as a polygon or cam, and a non-circular shaped exterior surface, such as a polygon or cam is non-slippably disposed over a rotatable shaft of the lock member in order to slidingly and deformably engage a polygonal, cam, or other non-circular shaped interior cavity of the body that rotatably receives shaft and sleeve of the lock member. The sleeve yieldingly resists rotational movement of the lock member away from a locking orientation.

These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective, exploded view of the connector pin assembly according to the present invention, with an adapter and excavation tooth.

FIG. 1B is a perspective, partial cutaway view of the connector pin assembly according to the present invention, shown inserted into the adapter and tooth.

FIG. 2A is a section view of the connector pin body of a connector pin assembly according to the present invention with the pin inserted.

FIG. 2B is an exploded, partial cutaway view of the connector pin assembly according to the present invention.

FIG. 2C is a perspective view of the connector pin assembly according to the present invention.

FIG. 3 is a perspective view of the pin member of a connector pin assembly according to the present invention.

FIG. 4A is an end view of a 1st configuration of the sleeve of a connector pin assembly according to the present invention.

FIG. 4B is an end view of a 2nd configuration of the sleeve of a connector pin assembly according to the present invention.

FIG. 4C is an end view of a 3rd configuration of the sleeve of a connector pin assembly according to the present invention.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1A and 1B, the present invention is a connector pin assembly having a body 100 and a pin 300 designed to releasably retain telescoped excavating support and wear members, such as adapter 106 and tooth 102 in their telescoped relationship. The connector pin assembly is removably received in aligned connector openings in the members. The body portion 100 of the assembly blocks removal of the wear member from the support member, and the lock member portion 300 of the assembly is rotatable relative to the body, toward and away from a locking orientation, to releasably lock the body 100 within the connector openings of adapter 106 and tooth 102. As shown in FIG. 1B, retaining lobe 340 is positioned in a locking position under ledge 103 of the tooth body 102. A reverse 90-degree rotation of the lock member 300 unlocks the connector pin assembly so that it can be removed from the aligned connector openings in the members, adapter 106 and tooth 102.

As shown in FIGS. 2A and 4A-4C, a resilient sleeve 200 comprising a non-circular shaped interior surface 202 having rounded corners, such as a polygon with rounded corners 203 or a cam with rounded lobes 205, and a non-circular shaped exterior surface having rounded corners, such as a polygon or a cam with external rounded corners 204, is non-slippably disposed over a rotatable shaft 306 of the lock member 300 in order to slidingly and deformably engage a polygonal, cam, or other non-circular shaped, preferably complementary, interior cavity wall 240b of the body 100 that rotatably receives shaft 306 and sleeve 200 of the lock member 300. The sleeve 200 yieldingly resists rotational movement of the lock member 300 away from a locking orientation. Preferably, the resilient sleeve 200 is made of a polymeric or rubberized compound.

As shown in FIGS. 2A-2C, the connector pin assembly body 100 has a passageway for the lock assembly 300 comprising cavities 240a, 240b, and 240c. Cavity 240a accommodates a shaft portion of the lock assembly 300 that is most proximal to the retaining lobe 340. Cavity 240b is the middle cavity, and has a friction torque producing fit with shaft portion 306 circumscribed by resilient member 200. Cavity 240c is most distal from retaining lobe 340 of the inserted lock assembly 300 and provides a passageway for the end portion 304 of the lock assembly 300. Cavity 240c abruptly ends at wall 241 to constrain the lock assembly in a position such that end portion 304 is aligned below dowel hole 101. Dowel pin 350 fits into dowel hole 101 above end portion 304 in order to constrain longitudinal motion of the lock assembly 300. Additionally, the section of the lock pin shaft most proximal to retaining lobe 340 has a groove 302 in the shaft to accommodate retention of O-ring seal 360. Shaft tip 303 of lock assembly 300 preferably has the same external shape as friction torque producing rotatable shaft 306 in order to facilitate assembly of the sleeve 200 into position over the rotatable shaft 306. As shown in FIG. 3, head portion 308 of lock assembly 300 can be shaped to facilitate a torque tool such as, e.g., a drill with matching driving bit or a hex head socket wrench. As shown in FIG. 3, the head portion 308 has a hex head and a slot down the middle to facilitate usage of the aforementioned torquing tools.

The following equations:

$\begin{array}{cc}N=\frac{T}{4\mathrm{Rf}};& \left(1\right)\\ \mathrm{and}& \\ Q=N\sqrt{1+f^2}& \left(2\right)\end{array}$

are used to evaluate cavity and sleeve design, where:

• N=Normal force on sleeve contact area,
• R=Shaft radius,
• F=Friction coefficient,
• T=Torque,
• Q=Resultant force on contact area of the sleeve.

A static force finite element analysis (FEA) analysis was performed on the contact locking assembly of the present invention. The rounded corners 204 of the sleeve 200 have been demonstrated to encounter the highest static forces when a torque is applied to the locking member 300. A plurality of rounded corners 204 evenly distribute torque stresses throughout the sleeve 200. The torque functionality of sleeve 200 can be achieved in a variety of polygon/cam configurations, such as shown in FIGS. 4A-4C, resulting in the capability of a manufacturer to custom design the torque turning angle according to any desired requirement.

Wear grooves 206, i.e., slots, are disposed lengthwise along external surfaces of the sleeve 200 to facilitate pushing the lock assembly 300 into the cavity of the body 100 during the installation process and reduce wear of the sleeve 200 during operational rotation of the lock pin 300. As shown in FIG. 4A, a substantially rectangular version of sleeve 200 has a plurality of the wear grooves 206 disposed along each of its substantially rectangular sides. It should be noted, however, that rounded corners 204 are free from wear grooves 206. Additionally, the inside surface 202 has rounded corners 203, which are provided to minimize wear down and tearing of the sleeve 200 from the inside surface 202 during rotational operation of circumscribed, preferably complementary shaped, shaft 306.

As shown in FIG. 4B, a cam shaped version of sleeve 200 preferably has a wear groove 206 disposed between any two adjacent lobes 204, so that in the exemplary case where there are 5 lobes, 5 wear grooves 206 are disposed between them. It should be noted, however, that rounded corners 204 are free from wear grooves 206. Additionally, the inside surface 202 has rounded lobes 205, which are provided to minimize wear down and tearing of the sleeve 200 from the inside surface 202 during rotational operation of circumscribed, preferably complementary shaped, shaft 306.

As shown in FIG. 4C, a substantially hexagonal version of sleeve 200 has a plurality of the wear grooves 206 disposed between any two adjacent lobes 204, so that in the exemplary case where there are 6 lobes, a total of 12 wear grooves 206 are disposed between them. It should be noted, however, that rounded corners 204 are free from wear grooves 206. Additionally, the inside surface 202 has rounded corners 203, which are provided to minimize wear down and tearing of the sleeve 200 from the inside surface 202 during rotational operation of circumscribed shaft 306.

Moreover, the connector pin assembly can provide an irregular turning profile by utilizing a cam shape having, for example, a single lobe rotating in a wall cavity having more than one complementary shape, the complementary shapes being displaced from each other over a predetermined angular interval.

It should be understood that the bulging areas defined by thickness of the sleeve 200 describes an area in which torque value can be varied by design. This area is defined as the Torque Band. In this band, theoretically, the torque valued from zero to infinity can be determined by changing the shaft spin diameter in range of the sleeve thickness. Accordingly, geometry (the number of polygonal sides, or the number of cam lobes) of the sleeve 200 determines a profile of the spin torque that must be applied by a user to turn the lock assembly 300. Thus, a spin torque profile that is moderate and gradually generated while turning the lock assembly 300 can be provided so that the normal and contact stresses are substantially distributed in an equal manner over the plurality of rounded corners 204.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. A connector pin assembly, comprising:

a body having a non-circular shaped cavity longitudinally extending through an interior portion of the body;

a lock member having a rotatable shaft, the lock member being received in the cavity and circumscribed by non-circular shaped walls determined by the cavity, the lock member being rotatable relative to the body between locking and unlocking positions; and

a resilient sleeve having a non-circular shaped exterior surface with rounded corners and a non-circular shaped interior surface having rounded corners, the resilient sleeve being non-slippably disposed over the rotatable shaft of the lock member for rotation therewith relative to the body and being circumscribed by the non-circular shaped cavity walls, the resilient sleeve being operative to releasably retain the lock member in either of the locking and unlocking positions and being slidingly engageable with and deformable by the non-circular shaped cavity walls during rotation of the lock member relative to the body in a manner yieldingly resisting rotation of the lock member relative to the body from the locking to the unlocking position.

2. The connector pin assembly according to claim 1, wherein the non-circular shaped walls determined by the cavity define a cam shape.

3. The connector pin assembly according to claim 1, wherein the non-circular shaped walls determined by the cavity define a polygonal shape.

4. The connector pin assembly according to claim 1, wherein the resilient sleeve has a plurality of wear grooves disposed along its length.

5. The connector pin assembly according to claim 1, wherein the lock member further comprises a retaining lobe disposed at the end of the rotatable shaft, the retaining lobe removably engaging a portion of the body to retain the lock pin in a fixed position relative to the body when the retaining lobe is engaged with the body and to allow removal of the lock pin from the body when the retaining lobe is disengaged from the body.

6. The connector pin assembly according to claim 1, wherein the body is an excavation tool wear member adapted for releasable engagement with an excavation tool support member, the wear member and support member being held into engagement with each other by rotation of the lock member into the locking position, the wear member and support member being releasable from each other by rotation of the lock member into the unlocking position.

7. The connector pin assembly according to claim 6, wherein the excavation tool wear member is an excavation tooth.

8. The connector pin assembly according to claim 1, wherein the shape of the cavity walls matches the shape of the resilient sleeve, the circumference of the cavity walls being slightly greater than the circumference of the resilient sleeve to provide a frictional torque-producing fit between the cavity walls and the resilient sleeve.

9. The connector pin assembly according to claim 1, wherein the body has a hole disposed therein adjacent the cavity and the shaft of the lock member has a circumferential channel defined therein, the connector pin assembly further comprising a dowel insertable through the hole and into the circumferential channel in the lock member shaft, the dowel constraining longitudinal movement of the lock member.

10. The connector pin assembly according to claim 1, wherein the lock member further comprises a head formed to facilitate a torque tool.

11. The connector pin assembly according to claim 1, wherein the lock member has a spin torque profile determined by the number of sides or lobes disposed on the lock member.