Metal working – Means to assemble or disassemble – Puller or pusher means – contained force multiplying operator
Reexamination Certificate
2000-06-19
2001-07-31
Hail, III, Joseph J. (Department: 3723)
Metal working
Means to assemble or disassemble
Puller or pusher means, contained force multiplying operator
C029S261000
Reexamination Certificate
active
06266860
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a puller for removing a pulley assembly from a crankshaft and, in particular, to a pulley remover for removing a double pulley-type assembly that is common on small lawn and garden tractors. Such tractors use small internal combustion motors which are vertically mounted in the tractor with the motor output or crankshaft extending vertically downward toward the ground. The double or multiple pulley assembly is firmly mounted on the crankshaft. Typically, in such small lawn and garden tractors, the double pulley assembly includes a smaller diameter pulley for receiving the transmission belt mounted above a larger diameter pulley for receiving the mower belt.
If the small lawn and garden tractor motor requires removal from the tractor for service, the double or multiple pulley assembly first has to be removed from the crankshaft. The pulley assembly is often force-fit on the crankshaft and without a puller, such as the present invention, the pulley assembly, because of its flimsy structure, is very often destroyed during removal from the crankshaft, thereby requiring a new pulley assembly to be supplied when reassembling the tractor, resulting in additional cost.
Various pullers have been disclosed in the past, such as, U.S. Pat. No. 4,235,004, dated Nov. 25, 1980, issued to William G. Floyd, which discloses a puller adapted for removing pulleys from the shafts of engines, such as lawnmower engines, small tractor engines, etc. The Floyd patent discloses a puller including a generally box-like member of heavy steel plates with one wall open. A jack screw is threaded through one sidewall for engagement with the end of a crankshaft to which the pulley assembly is mounted. A U-shaped spacer tool having an enlarged portion and a reduced shoulder portion is placed between the central or hub portion of the pulley on the side of the frame opposite that through which the jack screw passes. The reduced shoulder portion of the U-shaped spacer is effective to transmit the thrust from the jackscrew to the central or hub portion of the pulley. The pulley assemblies are removed from under the tractor. Problems may rise though with the Floyd design in that the box-like member may be very difficult to get into position on the double or multiple pulley combination because of the lack of sufficient working space under the tractor. Also, the box design does not allow adjustment for different sizes of pulley combinations and the U-shaped spacer would be difficult to position above the upper most pulley for the same reasons.
Other pullers are known in the art such as in U.S. Pat. No. 3,174,218, dated Mar. 23, 1965, issued to Thomas
0
. McConaha, there is disclosed a bearing removal and installation device specifically adapted for removing a bearing from an axle. Although such a device would work for bearings, it would not work for the double or multiple pulley assemblies used on small tractors because of their flimsy nature.
In U.S. Pat. No. 3,059,327, dated Oct. 23, 1962, issued to Allen Burrows, is disclosed a pulley removing device for removing pulleys from a generator. The pulley removing device utilizes a pair of flanges that engage the groove in the pulley. Such a pulley removing device requires a strong pulley structure that will not have the walls of the pulley collapse in the area of the grooves when the device is used.
SUMMARY OF THE INVENTION
The present invention provides a puller useful in the removal of a pulley assembly from a crankshaft. Such a pulley assembly typically includes at least one pulley affixed to a hollow tubular member. The hollow tubular member is fixedly mounted on the crankshaft. The one pulley typically has a central aperture passing through it and is positioned proximate one end of the crankshaft. Usually, the crankshaft has a crankshaft aperture at the one end. The puller includes a pair of oppositely disposed thrust plate members. Each of the thrust plate members have thrust plate joining bolt apertures passing therethrough. The joining bolt apertures of one of the thrust plate members is in alignment with the joining bolt apertures of the other thrust plate member when they are in operative relationship. Thrust plate joining bolt members pass through the aligned joining bolt apertures. The joining bolt members preferably each have a threaded portion in one end thereof. Joining bolt nut members are provided in threaded engagement with the threaded portion of the joining bolt members. Each of the thrust plate members have a hollow tubular member engagement portion in the periphery thereof. The thrust plate members further include a semi-circular pulley hub push members affixed to the plate members at the tubular member engagement portion. Preferably the pulley hub push members are of predetermined length and are coaxially aligned with the hollow tubular member when in operative arrangement with the pulley assembly.
A pulley butt plate member has a jackscrew aperture passing through it in coaxial alignment with the crankshaft. A threaded jack screw receiving member is provided in coaxial alignment with a jack screw aperture. Also included is a threaded jackscrew assembly sized to operatively engage the receiving member. The pulley butt plate member has connecting bolt apertures passing therethrough. The thrust plate members have threaded portions at the periphery at the connecting bolt apertures. The connecting bolt apertures of the pulley butt plate member and the thrust plate members are oppositely disposed and are in alignment when in operative relationship. Also included are connecting bolt members each passing through the oppositely disposed connecting bolt apertures and in engagement with the threaded portions of the thrust plate member.
Utilizing the puller of the present invention, when the puller is operatively positioned on the pulley assembly, the jackscrew assembly may be progressively tightened so as to exert a push on the crankshaft resulting in the pulley hub push members of the thrust plate members exerting a force against the hub of the one pulley, thereby causing the pulley assembly to separate from the crankshaft for easy removal without damage to the pulley assembly.
Preferably, the pulley hub push members have a length greater than one half the width of the grooved rim of the one pulley. Preferably the jackscrew assembly includes a threaded jackscrew having a central conical extension portion nearest the crankshaft when in operative position. In the case where the crankshaft aperture is threaded, the jackscrew may further preferably comprise an extension member sized to fit through the central pulley aperture and engage the threaded portion of the crankshaft proximate the crankshaft aperture. Preferably, the extension member at one end thereof has a central recess therein shaped to mate with the conical extension portion of the jackscrew. Preferably, the extension member at the other end is threaded, whereby the extension member may screw into the threaded portion of the crankshaft.
REFERENCES:
patent: 1227457 (1917-05-01), Langan
patent: 1870711 (1932-08-01), Cooney
patent: 2860407 (1958-11-01), Grunder
patent: 3059327 (1962-10-01), Burrows
patent: 3174218 (1965-03-01), McConaha
patent: 3599311 (1971-08-01), Ellis
patent: 4235004 (1980-11-01), Floyd
patent: 4451977 (1984-06-01), Matthews
patent: 4502197 (1985-03-01), Harder
patent: 4672731 (1987-06-01), Taylor
patent: 4908925 (1990-03-01), Johnson
patent: 5058256 (1991-10-01), Taylor
patent: 1060277 (1952-07-01), None
Hail III Joseph J.
Lombard Ronald S.
Shanley Daniel
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