Wheel substitutes for land vehicles – Tracks or treads – Having master link
Reexamination Certificate
2000-10-23
2002-07-02
Stormer, Russell D. (Department: 3617)
Wheel substitutes for land vehicles
Tracks or treads
Having master link
C305S201000
Reexamination Certificate
active
06412887
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a chain link. More particularly this invention concerns two-piece master chain link used on a conveyor or track chain.
BACKGROUND OF THE INVENTION
A standard master link for a track chain or the like is formed of a pair of link members that extend between a sleeve at one end and a pin at the other, the sleeve and the pin being centered on parallel axes spaced apart in a standard pull or tension direction. Each link member is in turn formed by a pair of link parts each having an outer end centered on one of the respective axes and an inner end coupled to the inner end of the other link part. One side of each link is normally bolted to a grouser plate and the opposite side of each link rides on the drive and idler wheels over which the chain passes for conveying material or advancing a vehicle using the chain as traction element. At each axis there is a pin passing through a sleeve and having ends projecting past the sleeve ends. The outer ends of two of the link members of one link are fixed on the pin ends and the outer ends of the two link members of an adjacent link are fixed therebetween on the sleeve so that the two links can pivot relative to each other, with rotation of the pin and sleeve relative to each other.
The master link is intended to be opened for removal or repair of the chain. To this end the link parts are coupled together between the two axes, normally by interengaging teeth. In U.S. Pat. No. 3,659,112 of Stedman such a system is described where the two link parts are joined together generally at a plane extending perpendicular to the outer-end axes. The interengaging teeth extend and interengage parallel to these axes and the two link parts are secured together by one or more bolts extending parallel to the axes, with the shank of each bolt threaded into one of the link parts and the head of each bolt bearing on the other link part. The teeth are triangular so that tension in the link cams the parts apart and subjects the bolts to considerable shear forces.
In commonly owned U.S. Pat. No. 4,361,364 of Brunn the teeth are hook-shaped and arcuate, centered on one of the axes. Thus the link parts can be hooked together with most of the force transmission being between the faces of the interengaged teeth. In this system the grouser-plate screws keep the two link parts parallel to each other and are not subject to significant shear forces from tension in the chain. Both these systems have the disadvantage that assembly of the master link is fairly difficult, especially at it is normally done in a tracked vehicle in the upper stretch where there is little room to work above the chain.
In the systems of U.S. Pat. No. 3,427,079 of Skromme, U.S. Pat. No. 4,105,260 of Blunier, U.S. Pat. No. 4,365,848 of Grilli, and U.S. Pat. No. 4,457,565 of Bissi two link parts meet at a plane extending generally diagonally of the pull direction so that rather than right and left link parts one has upper and lower link parts. The interengaging teeth extend across this connection plane and the two link parts are held together by bolts extending perpendicular to the tension direction. In all these systems, which have the advantage of easy assembly, the teeth serve principally to position the link parts relative together while the assembly bolts provide the force to hold them together. Once again, these bolts are subject to considerable shear. If they fail the link will open.
Another problem with all these systems is that the link parts are expensive to manufacture. They are normally produced by casting and forging, then they must be carefully machined to produce the interfit that is necessary for good force transmission.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide an improved master link for a conveyor or track chain.
Another object is the provision of such an improved master link for a conveyor or track chain which overcomes the above-given disadvantages, that is which is of simple and inexpensive manufacture, which will have a long service life, and which is easy to install and remove.
A further object is to provide an easy-to-assemble master link where the assembly bolts are not subject to any substantial shear.
SUMMARY OF THE INVENTION
A chain master link has first and second link parts having outer ends centered on respective substantially parallel first and second axes and coupled-together inner ends. Each inner end is formed with at least one tooth extending transversely across a plane including the two axes and having an inner face turned toward the respective axis and forming with the plane an angle of at least 90° open away from the respective axis. The teeth are engaged together with the inner faces bearing on each other so that tension pulling the parts apart along the plane pulls the teeth into engagement with each other.
Thus a force pulling the outer ends of the link parts part will pull the teeth into tighter engagement with each other. Instead of this force camming the teeth apart, it actually forces them into more solid engagement with each other.
According to the invention each part is formed with a pocket receiving the tooth of the other part and having an outer face forming with the plane an angle open away from the respective axis and greater than the respective inner-face angle. Thus the two parts can be fitted together simply by pivoting their inner ends toward each other about the respective outer-end axes. Thus the inner and outer faces of each part actually converge toward each other. If the two parts are pushed slightly together, it is very easy to unhook them from each other, so that disassembly is as easy as assembly. There is no need to clamp the two parts temporarily while an assembly bolt is fitted and tightened.
In order that the chain incorporating the master link according to the invention can move around guide or drive wheels, a certain hinge angle is necessary. This angle represents the maximum deflection of the plane of one link to the adjacent link, of course about the axis where they are joined. In accordance with the invention the angle of the tooth inner face is a function of this hinge angle as well as of the coefficient of friction between the engaging tooth faces.
In accordance with the invention one of the link parts is formed with a throughgoing hole extending substantially perpendicular to the plane and the other link part is formed with a threaded hole aligned with the throughgoing hole. A bolt bears on the one link part, extends through the throughgoing hole thereof, and is threaded into the threaded hole of the other link part. This bolt fits with play in the throughgoing hole of the one link part.
REFERENCES:
patent: 3053579 (1962-09-01), Trudeau
patent: 3427079 (1969-02-01), Skromme
patent: 3659112 (1972-04-01), Stedman
patent: 4105260 (1978-08-01), Blunier
patent: 4351573 (1982-09-01), Bedis et al.
patent: 4361364 (1982-11-01), Brunn
patent: 4365848 (1982-12-01), Grilli
patent: 4457565 (1984-07-01), Bissi
patent: 4636014 (1987-01-01), Dennison et al.
Böttger Friedrich
Ketting Michael
Dubno Herbert
Intertractor GmbH
Stormer Russell D.
Wilford Andrew
LandOfFree
Two-piece master chain link does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Two-piece master chain link, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-piece master chain link will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2821773