Patent Description:
Various annular elements such as bearings, gears and pulleys are used on various axles. To remove an annular element from an axle, pullers are used. A conventional puller includes two claws pivotally connected to a collar. An abutting element such as threaded rod or a hydraulic device is inserted in the collar. In use, the claws are engaged with the annular element. Then, the abutting element is operated to abut an end thereof against an end of the axle. The operation of the abutting element is continued to move the collar and the claws away from the axle. Thus, the annular element is detached from the axle. However, the claws are not interconnected so that each of the claws is engaged with or disengaged from a portion of the annular element independent of the other claw. Attention has to be paid to the engagement of each of the claws with the corresponding portion of the annular element because the former might be disengaged from the latter accidentally. Such accidental disengagement is hazardous for a user of the puller.

Referring to <FIG>, another conventional puller includes three claws <NUM> pivotally connected to the collar <NUM> formed with a screw hole for receiving an abutting element <NUM>. Each of the claws <NUM> includes a slot <NUM>. A synchronizer <NUM> is formed with lugs <NUM> movably inserted in the slots <NUM>. A spring <NUM> is compressed between the synchronizer <NUM> and the collar <NUM>. In use, the synchronizer <NUM> is moved toward the collar <NUM>. The synchronizer <NUM> opens the claws <NUM> as the lugs <NUM> move along the slots <NUM>. The claws <NUM> are located around an annular element to be detached from an axle. An end of the abutting element <NUM> is abutted against an end of the axle. The synchronizer <NUM> is released so that the spring <NUM> moves the synchronizer <NUM> away from the collar <NUM>. The synchronizer <NUM> closes the claws <NUM> as the lugs <NUM> move along the slots <NUM>. Thus, the claws <NUM> are engaged with the annular element. The abutting element <NUM> is rotated relative to the collar <NUM> to move the collar <NUM> and the claws <NUM> away from the axle, thereby detaching the annular element from the axle. The insertion of the lugs <NUM> of the synchronizer <NUM> in the slots <NUM> of the claws <NUM> synchronizes the pivoting of the claws <NUM>. However, the insertion of the lugs <NUM> of the synchronizer <NUM> in the slots <NUM> of the claws <NUM> limits the pivoting of the claws <NUM> to a small angle so that the puller is not suitable for detaching an annular element that too small or too large from an axle. In addition, it is difficult to replace the claws <NUM> with longer or shorter claws because the lugs <NUM> of the synchronizer <NUM> are inserted in the slots <NUM> of the claws <NUM>. Hence, a user has to purchase and keep several pullers of various sizes, and this is expensive and inconvenient.

Another conventional puller includes a collar, claws pivotally connected to the collar, and an adjusting assembly for adjusting the angle of the pivoting of the claws relative to the collar. Each of the claws includes a protrusion at an upper end and a barb at a lower end. The adjusting assembly includes adjusters connected to a ring. Each of the adjusters includes two abutting portions. Each of the adjusters is located between a corresponding one of the claws and the collar. The adjusters are movable downwards relative to the collar so that the first abutting portions of the adjusters push the protrusions of the claws to enlarge the angle of the pivoting of the claws. The adjusters are movable upwards relative to the collar so that the second abutting portions of the adjusters push the protrusions of the claws to reduce the angle of the pivoting of the claws. However, each of the adjusters is located between a corresponding one of the claws and the collar, thereby limiting the range of the pivoting of the claws. The adjusters might be disengaged from the claws. To avoid such disengagement, the sizes of the elements must be increased, and this renders the puller bulky and heavy, and the operation of the puller is difficult. Each of the adjusters is connected to the ring independent of the other adjusters. Hence, it is difficult to locate the adjusters at a same level relative to the collar. Hence, the angles of the pivoting of the claws relative to the collar are different so that the barbs of the claws are located at different levels. Thus, it is difficult to effectively engage the barbs of the claws with an annular element to be detached from an axle. Such disengagement might endanger a user.

<CIT> discloses a valve nut removal and replacement system according to the preamble of claim <NUM>, including a plurality of associated tools and methods used for above ground access to, replacement of, and maintenance of worn, misshaped, abused or otherwise faulty valve nuts located at a subsurface location. Further pullers are described in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.

It is the primary objective of the present invention to provide a simple, effective, safe and convenient puller.

To achieve the foregoing objective a puller having the features of claim <NUM> is disclosed. Advantageous embodiments are subject matter of the dependent claims. The puller includes a collar, claws, a synchronizer and an abutting element. The collar includes slots and pivotal connectors located corresponding to the slots. The claws are pivotally connected to the pivotal connectors. Each of the claws includes a protuberance movable in and along a corresponding one of the slots. The synchronizer includes a receiving portion for receiving the protuberances. The synchronizer is movable in the collar between an opening position and a closing position. In the opening position, the synchronizer opens the claws by the protuberances. In the closing position, the synchronizer closes the claws by the protuberances. The abutting element is extensible from the collar.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

The present invention will be described via detailed illustration of three embodiments versus the prior art referring to the drawings wherein:.

Referring to <FIG> and <FIG>, a puller includes a collar <NUM>, two claws <NUM>, a synchronizer <NUM> and an abutting element <NUM> in accordance with a first embodiment of the present invention. The claws <NUM> are pivotally connected to the collar <NUM>. The synchronizer <NUM> is used to synchronize the pivoting of the claws <NUM> to claw an annular element <NUM> to be detached from an axle <NUM> (<FIG>). The abutting element <NUM> is inserted in and connected to the collar <NUM>. The abutting element <NUM> is extensible from the collar <NUM> to detach the annular element <NUM> from the axle <NUM> (<FIG>).

Referring to <FIG> and <FIG>, the collar <NUM> includes a space <NUM>, a screw hole <NUM> in communication with the space <NUM>, two opposite slots <NUM> in communication with the space <NUM>, and two pivotal connectors <NUM> located corresponding to the slots <NUM>. The combination of the space <NUM> with the screw hole <NUM> axially extends throughout the collar <NUM>. The abutting element <NUM> is inserted in the space <NUM>. The claws <NUM> are connected to the pivotal connectors <NUM> in a manner to be described. Each of the pivotal connectors <NUM> includes two lugs <NUM> each of which includes an aperture <NUM>. Each of the slots <NUM> is located between the lugs <NUM> of a corresponding one of the pivotal connectors <NUM>. Each of the slots <NUM> includes a closing limit <NUM> and an opening limit <NUM>. The limits <NUM> and <NUM> of each of the slots <NUM> are used to limit the range of the pivoting of a corresponding one of the claws <NUM>.

The puller further includes two discs <NUM> and <NUM>. The disc <NUM> includes several screw holes <NUM>. The disc <NUM> includes orifices <NUM> corresponding to the screw holes <NUM>.

Each of the claws <NUM> includes a barb <NUM> at a lower end, a protuberance <NUM> at an upper end, and a pivotally connective portion <NUM> in the vicinity of the barb <NUM>. The barb <NUM> of each of the claws <NUM> is used for engagement with a portion of the annular element <NUM> (<FIG> and <FIG>). The pivotally connective portion <NUM> of each of the claws <NUM> is formed with an aperture <NUM>.

In assembly, the protuberance <NUM> of each of the claws <NUM> is movably inserted in a corresponding one of the slots <NUM> so that the upper end of each of the claws <NUM> is located between the lugs <NUM> of a corresponding one of the pivotal connectors <NUM>. A pivot <NUM> is fitted in the apertures <NUM> of the lugs <NUM> of each of the pivotal connectors <NUM> and the aperture <NUM> of a corresponding one of the claws <NUM>. Thus, the pivotally connective portion <NUM> of each of the claws <NUM> is pivotally connected to a corresponding one of the pivotal connectors <NUM> of the collar <NUM>. Each of the pivots <NUM> can be a pin, a rivet or a combination of a threaded bolt with a nut.

As mentioned above, the protuberances <NUM> of the claws <NUM> are movably inserted in the slots <NUM> of the collar <NUM>. Thus, the protuberances <NUM> are moved in and along the slots <NUM> as the claws <NUM> are pivoted relative to the collar <NUM>. Each of the protuberances <NUM> includes a closing limit <NUM> on an upper face and an opening limit <NUM> on a lower face. The closing limits <NUM> of the protuberances <NUM> are in contact with the closing limits <NUM> of the slots <NUM> to limit the closing of the claws <NUM>. The closing limits <NUM> of the protuberances <NUM> are in contact with the opening limit <NUM> of the slots <NUM> to limit the opening of the claws <NUM>. The limits <NUM> and <NUM> of each of the slots <NUM> extend away from each other as they extend to an internal face of the collar <NUM> from an external face of the collar to enlarge the angle of the pivoting of a corresponding one of the claws <NUM>.

The synchronizer <NUM> is preferably a collar formed with an internal flange <NUM> at an upper end and a receiving portion <NUM> at a lower end. The receiving portion <NUM> of the synchronizer <NUM> includes several bores <NUM>. The bores <NUM> can be made in an external face of the synchronizer <NUM> only or throughout the synchronizer <NUM> in a radial direction.

In assembly, the synchronizer <NUM> is movably inserted in the space <NUM> of the collar <NUM>. A spring <NUM> is compressed between the synchronizer <NUM> and the collar <NUM> so that the spring <NUM> tends move the synchronizer <NUM> away from the collar <NUM>. The spring <NUM> includes an end in contact with the internal flange <NUM> of the synchronizer <NUM> and an internal flange of the collar <NUM> formed around the space <NUM>. The spring <NUM> is hidden in the synchronizer <NUM> in consideration of aesthetics of the puller and safety of a user.

The protuberance <NUM> of each of the claws <NUM> is inserted in a corresponding one of the bores <NUM> of the synchronizer <NUM>. Thus, the synchronizer <NUM> is moved relative to the collar <NUM> to synchronously pivot the claws <NUM> relative to the collar <NUM>. To keep the protuberances <NUM> in the corresponding one of the bores <NUM>, the protuberances <NUM> are made with an adequate length and strength.

The disc <NUM> is attached to the collar <NUM> so that they are not movable relative to each other. To this end, the disc <NUM> is formed with a cavity (not numbered) in which an upper end of the collar <NUM> is fitted.

The disc <NUM> is attached to the synchronizer <NUM> so that they are not movable relative to each other. To this end, the disc <NUM> is formed with a cavity (not numbered) in which the upper end of the synchronizer <NUM> is fitted.

A screw <NUM> is inserted in each of the screw holes <NUM> of the disc <NUM> through a corresponding one of the orifices <NUM> of the disc <NUM>. Thus, the discs <NUM> and <NUM> are movably connected to each other.

The screw holes <NUM> can be replaced with orifices like the orifices <NUM> in an alternative embodiment. A nut (not shown) is used with each of the screws <NUM> in such an alternative embodiment.

The abutting element <NUM> is preferably a hydraulic or pneumatic device including a cylinder <NUM> such as one made by SKF company, a piston rod <NUM> movably inserted in the cylinder <NUM>, and a lever <NUM> operable to increase hydraulic or pneumatic pressure in the cylinder <NUM> to extend the piston rod <NUM> from the cylinder <NUM>. The cylinder <NUM> is formed with a threaded section <NUM> inserted in the screw hole <NUM>, thereby connecting the cylinder <NUM> to the collar <NUM> while allowing changing the elevation of the cylinder <NUM> relative to the collar <NUM>. The lever <NUM> can be replaced with a manual pump, an electric pump or a pneumatic pump. Preferably, an end element <NUM> made of a harder material than the piston rod <NUM> is used. The end element <NUM> is attached to the piston rod <NUM>. The end element <NUM> is formed with an insert <NUM> at an end and a tip <NUM> at an opposite end. The insert <NUM> of the end element <NUM> is inserted in a cavity of the piston rod <NUM>. The tip <NUM> of the end element <NUM> is used for abutment against an end of the axle <NUM>. However, the end element <NUM> can be made in one piece with the piston rod <NUM> in another embodiment.

Referring to <FIG>, the spring <NUM> keeps the synchronizer <NUM> in an upper position relative to the collar <NUM>. The synchronizer <NUM> retains the protuberances <NUM> of the claws <NUM> in an upper position relative to the collar <NUM> so that the claws <NUM> are pivoted toward the abutting element <NUM> about the pivots <NUM>, i.e., closed. The closing limit <NUM> of the protuberance <NUM> of each of the claws <NUM> is in contact with the closing limit181 of each of the slots <NUM> of the collar <NUM> so that the angle between each of the claws <NUM> and the abutting element <NUM> is at a smallest value. Moreover, the protuberances <NUM> keeps a lower section of the synchronizer <NUM> in the collar <NUM>, thereby keeping the spring <NUM> in position.

Referring to <FIG>, to detach the annular element <NUM> from the axle <NUM>, the user presses the disc <NUM> toward the disc <NUM>, thereby moving the synchronizer <NUM> toward the collar <NUM>. Thus, the protuberances <NUM> of the claws <NUM> are moved toward the opening limits <NUM> of the slots <NUM> of the collar <NUM>, thereby pivoting the claws <NUM> away from the abutting element <NUM>, i.e., opened. The spring <NUM> is compressed as the synchronizer <NUM> is moved toward the collar <NUM>.

Referring to <FIG>, the claws <NUM> are located around the annular element <NUM>. Then, the discs <NUM> and <NUM> are released to allow the spring <NUM> to move the synchronizer <NUM> away from the collar <NUM>. Thus, the protuberances <NUM> of the claws <NUM> are moved toward the closing limits <NUM> of the slots <NUM> of the collar <NUM>. Hence, the claws <NUM> are pivoted toward the abutting element <NUM>, i.e., closed, to engage the barbs <NUM> of the claws <NUM> with lower portions of the annular element <NUM>. Now, the tip <NUM> of the end element <NUM>, which is attached to the piston rod <NUM>, is located above an upper end of the axle <NUM>.

Referring to <FIG>, the lever <NUM> is operated to extend the piston rod <NUM> from the cylinder <NUM> and hence lower the piston rod <NUM> relative to the collar <NUM>, thereby moving the end element <NUM>, which is attached to the piston rod <NUM>, toward the axle <NUM> so that the tip <NUM> of the end element <NUM>, which is attached to the piston rod <NUM>, is abutted against the upper end of the axle <NUM>. The extension of the piston rod <NUM> from the cylinder <NUM> is continued to move the collar <NUM> and the claws <NUM> away from the axle <NUM>. The claws <NUM> move the annular element <NUM> upwards relative to the axle <NUM> because the barbs <NUM> of the claws <NUM> are engaged with the lower portions of the annular element <NUM>. Eventually, the annular element <NUM> is detached from the axle <NUM>.

In another embodiment, the screw hole <NUM> of the collar <NUM> is replaced with an aperture, and the internal flange <NUM> of the synchronizer <NUM> is formed with a screw hole for receiving the abutting element <NUM>. Thus, the rotation of the abutting element <NUM> relative to the synchronizer <NUM> in a sense of direction causes upward movement of the synchronizer <NUM> and the claws <NUM> relative to the abutting element <NUM>.

Referring to <FIG>, each of the claws <NUM> can be replaced with a claw 20A of another size. The claw 20A is otherwise identical to the claws <NUM>. To this end, each of the pivots <NUM> is detached from a corresponding one of the pivotal connectors <NUM> and the pivotally connective portions <NUM> of a corresponding one of the claws <NUM> to allow a corresponding one of the claws <NUM> to be detached from a corresponding one of the pivotal connectors <NUM> of the collar <NUM>. Then, the claws 20A are connected to the pivotal connectors <NUM> of the collar <NUM> by the pivots <NUM>.

During the replacement of the claws <NUM> with the claws 20A, the screws <NUM> avoid detachment of the discs <NUM> and <NUM> from each other. The disc <NUM> presses the upper end of the synchronizer <NUM> to keep the lower end of the synchronizer <NUM> in the collar <NUM>, thereby keeping the spring <NUM> in position (<FIG>). Moreover, each of the slots <NUM> is kept in communication with a corresponding one of the bores <NUM> to facilitate the insertion of the protuberance <NUM> of a corresponding one of the claws 20A (or the claws <NUM>) into each of the slots <NUM> via a corresponding one of the bores <NUM>.

Referring to <FIG>, the abutting element <NUM> is used with two extensive elements <NUM> for example when the abutting element <NUM> is not long enough to detach the annular element <NUM> from the axle <NUM>. Each of the extensive elements <NUM> includes an insert <NUM> at an upper end and a cavity <NUM> in each end. The insert <NUM> of an upper one of the extensive elements <NUM> is inserted in the cavity of the piston rod <NUM>. The cavity <NUM> of the upper extensive element <NUM> receives the insert <NUM> of a lower one of the extensive elements <NUM>. The insert of the end element <NUM> is inserted in the cavity <NUM> of the lower extensive element <NUM>. The tip <NUM> of the end element <NUM> is used to abut against the upper end of the axle <NUM> in operation.

Preferably, the insert <NUM> of each of the extensive elements <NUM> is formed with an annular groove (not numbered) for receiving an elastic ring (not shown) or a bore (not shown) for receiving a spring-biased ball (not shown). The elastic ring or spring-biased ball is used to keep the insert <NUM> in the corresponding cavity.

Similarly, the insert <NUM> of the end element <NUM> is formed with an annular groove (not numbered) for receiving an elastic ring (not shown) or a bore (not shown) for receiving a spring-biased ball (not shown) to keep the insert <NUM> of the end element <NUM> in the cavity <NUM> of the lower extensive element <NUM>.

Referring to <FIG>, shown is a puller according to a second embodiment of the present invention. The second embodiment is identical to the first embodiment except for including three claws <NUM> connected to three pivotal connectors <NUM> of the claws <NUM>.

Referring to <FIG>, shown is a puller according to a third embodiment of the present invention. The third embodiment is identical to the first embodiment except for two things. Firstly, the abutting element <NUM> includes a threaded rod <NUM> inserted in the screw hole <NUM> and a lever <NUM> connected to the lever <NUM>. Secondly, the end element <NUM> is made in one piece with the threaded rod <NUM>, i.e., the tip <NUM> is formed at an end of the threaded rod <NUM>. The lever <NUM> is operable to rotate and hence translate the threaded rod <NUM> relative to the collar <NUM>.

As described above, the synchronizer <NUM>, which is movable relative to the collar <NUM>, is used to synchronize the pivoting of the claws <NUM>, which are pivotally connected to the collar <NUM>, toward or away from the annular element <NUM>. Hence, the puller is simple in structure.

Furthermore, between the claws <NUM>, there is only the abutting element <NUM> used to abut against the upper end of the axle <NUM>. Hence, there is nothing to interfere with the pivoting of the claws <NUM> or replacement of any of the claws <NUM> with another claw.

Moreover, the protuberance <NUM> of the claws <NUM> are inserted in the slots <NUM> of the collar <NUM> and some of the bores <NUM> of the synchronizer <NUM>, thereby keeping the lower section of the synchronizer <NUM> in the collar <NUM> in operation. During the replacement of any of the claws <NUM> with another claw, the screws <NUM> keep the discs <NUM> and <NUM> to each other to keep the lower section of the synchronizer <NUM> in the collar <NUM>, without having to use any other element. This also simplifies the structure of the puller. The easy replacement of any of the claws <NUM> with a claw 20A of another size saves the user from purchasing and keeping pullers of various sizes which would otherwise be expensive and inconvenient.

In addition, the diverging gap between the limits <NUM> and <NUM> of each of the slots <NUM> allows a large range of the pivoting of a corresponding one of the claws <NUM>. However, the limits <NUM> and <NUM> of the slots <NUM> keep the pivoting of the claws <NUM> to a reasonably large range.

Claim 1:
A puller comprising:
a collar (<NUM>) comprising slots (<NUM>) and pivotal connectors (<NUM>) located corresponding to the slots (<NUM>);_
claws (<NUM>) pivotally connected to the pivotal connectors (<NUM>), wherein each of the claws (<NUM>) comprises a protuberance (<NUM>) movable in and along a corresponding one of the slots (<NUM>);_
a synchronizer (<NUM>) comprising a receiving portion (<NUM>) for receiving the protuberances (<NUM>), wherein the synchronizer (<NUM>) is movable in the collar (<NUM>) between an opening position and a closing position, wherein the synchronizer (<NUM>) opens the claws (<NUM>) by the protuberances (<NUM>) in the opening position, wherein the synchronizer (<NUM>) closes the claws by the protuberances (<NUM>) in the closing position; and
an abutting element (<NUM>) extensible from the collar
characterized by
further comprising a first disc (<NUM>) connected to the collar (<NUM>) and a second disc (<NUM>) connected to the synchronizer (<NUM>), wherein the first and second discs (<NUM>,<NUM>) are pushed toward each other to move the collar (<NUM>) toward the synchronizer (<NUM>) and further comprising at least one screw (<NUM>) for interconnecting the first and second discs (<NUM>,<NUM>).