AU2017100547A4

AU2017100547A4 - Shearing handpiece

Info

Publication number: AU2017100547A4
Application number: AU2017100547A
Authority: AU
Inventors: Tianqiao ZHANG
Original assignee: BEIYUAN AUSTRALIA Pty Ltd
Current assignee: BEIYUAN AUSTRALIA Pty Ltd
Priority date: 2017-05-17
Filing date: 2017-05-17
Publication date: 2017-06-15
Anticipated expiration: 2025-05-17

Abstract

A shearing handpiece including a barrel (7) having a crank spindle (1) supported for rotation within an inner chamber (7a) of said barrel (7), the crank spindle (1) having a front end, a rear end, and a middle portion intermediate said front and rear ends thereof, the front end of the crank spindle being supported by a front bearing (6) located within the inner chamber (7a), a middle bearing (8) located within the inner chamber (7a) for supporting the middle portion of the crank spindle (1), and a sealing cap (10) secured to a rear opening of the inner chamber (7a), the sealing cap (10) having a central opening (9) through which the rear end of the crank spindle (1) passes. ('3

Description

in O O r- o (N r- ο (N δ'

SHEARING HANDPIECE

FIELD OF THE INVENTION

[0001] The present invention is directed to an improved shearing handpiece for shearing machines.

BACKGROUND OF THE INVENTION

[0002] A shearing handpiece is adapted to support and drive shearing cutters used in the shearing of wool. These handpieces include a barrel portion which is gripped by the operator of the handpiece, with the shearing cutters being supported and driven at a front end of the barrel. A hinge arrangement is provided at the rear end of the barrel, this hinge arrangement including an inner joint and an outer joint. The transmission for driving the shearing cutters includes a crank spindle extending through the barrel, the crank spindle being supported for rotation at its front end with a front bearing which abuts a shoulder provided within the barrel. The rear end of the crank spindle is supported on a rear bearing which is itself located within the inner joint of the shearing handpiece. The inner joint is adapted to rotate relative to the barrel and includes an inner sleeve portion beatable within an inner chamber of the barrel, and an outer body portion located outside of the barrel. A tubular bush is provided in the space between the inner chamber of the barrel and the outer cylindrical surface of the inner sleeve portion of the inner joint. This enables the inner joint to rotate relative to the barrel. The rear bearing supporting the rear end of the crank spindle is supported within the outer body portion of the inner joint. Shearing handpiece arrangements of this type are for example shown in Australian Patent No. 721233 in the name of Heiniger AG.

[0003] The above-described arrangement provides two assembly clearances between the inner chamber of the barrel and the tubular bush, and between the tubular bush and the inner sleeve portion of the inner joint respectively. This ο Η Ο (Ν δ' Ο ο ο ο (Ν clearance results in a degree of radial movement of the inner sleeve portion relative to the barrel. This therefore also results in the crank spindle having a floating movement relative to the barrel during turning of the crank spindle. The result of this arrangement is that the transmission of power cannot be smoothly and steadily maintained during operation of the handpiece. Furthermore, the large contact area between the tubular bush and the inner sleeve portion of the inner joint results in relatively high rotational friction during use of the handpiece which can restrict the agility of the movement of the inner joint relative to the barrel.

[0004] Australian Innovation Patent No. 20051000093 describes a shearing handpiece that addresses one or more of the disadvantages associated with the above described prior art shearing handpiece. The construction of the shearing handpiece described in that innovation patent eliminates the need for the tubular bush and inner sleeve portion of the inner joint of the prior art arrangement. This improved construction addresses the disadvantages of the prior art shearing handpiece. Nevertheless, it would be advantageous to make further improvements to the shearing handpiece described in the above mentioned innovation patent that can extend the working life of and improve the reliability of a shearing handpiece.

SUMMARY OF THE INVENTION

[0005] With this in mind, the present invention provides a shearing handpiece including a barrel having a crank spindle supported for rotation within an inner chamber of said barrel, the crank spindle having a front end, a rear end, and a middle portion intermediate said front and rear ends thereof, the front end of the crank spindle being supported by a front bearing located within the inner chamber, a middle bearing located within the inner chamber for supporting the middle portion of the crank spindle, and a sealing cap secured to a rear opening of the inner chamber, the sealing cap having a central opening through which the rear end of the crank spindle passes.

r- ο (N r-

r- O O r- o (N

[0006] The sealing cap may be secured to the rear opening by a retaining clip.

[0007] The sealing cap seals the rear opening thereby acting as a cover to minimise or prevent the ingress of sand or other unwanted material into the inner chamber. This is important for the smooth running of the shearing handpiece and assists in extending the working life of the handpiece.

[0008] At least two rear bearings may be supported at or adjacent the rear end of the crank spindle, and an inner joint housing may be supported by the rear bearings on the spindle. The inner joint housing may therefore be slidably supported on and smoothly rotatable about the rear end of the crank spindle. The use of two or more rear bearings therefore improves the rigidity, stability and working life of the shearing handpiece.

[0009] The shearing handpiece may further include an outer joint assembly including an inner passage, and a drive axle accommodated within the inner passage. At least one slide bearing may be located within the inner passage for rotatably supporting the drive shaft therein. Two slide bearings may be positioned to support the drive shaft adjacent opposing ends of the drive shaft. As no roller bearing is used to support the drive axle, this allows for greater freedom of movement about the rear joint of the handpiece thereby improving the handling of the handpiece and comfort of the user of the handpiece when shearing. The overall reliability of the handpiece is also improved by the removal of the roller bearing, which can fail over time.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] It will be convenient to further describe the invention with respect to the accompanying drawing which illustrates a preferred embodiment of the shearing handpiece according to the present invention. Other embodiments of the invention are possible, and consequently, the particularity of the accompanying

r- ο (N r-

O O r- o (N drawing is not to be understood as superseding the generality of the preceding description of the invention.

[0011] Figure 1 is a side cross-sectional view of a shearing handpiece according to the present invention.

DETAILED DESCRIPTION OF THE DRAWING

[0012] The shearing handpiece according to the present invention includes a barrel 7 which can be gripped by the operator of the shearing handpiece. The barrel 7 is provided with an inner chamber 7a through which passes a crank spindle 1 of the handpiece. The front end of the crank spindle 1 is supported by a front bearing 6 which is accommodated at the front end of the inner chamber 7a and abuts a shoulder 7b provided therein. A middle bearing 8 supports an intermediate portion of the crank spindle 1. This middle bearing 8 is also supported within the inner chamber 7a. The middle bearing 8 can be accurately positioned within the inner chamber 7a by means of a spacer 2 located within the inner chamber 7a between the two inner rings of the front and middle bearings 6, 8. This spacer 2 can be made of material such as nylon, steel or plastic. When the spacer 2 is made of light material such as nylon or plastic, this can help to reduce the overall weight of the shearing handpiece.

[0013] The middle bearing 8 is retained within the inner chamber 7a by means of a sealing cap 10 which is fixed into the end of the barrel 7 to close off the inner chamber 7a. The sealing cap 10 has a central opening 9 extending therethrough through which the crank spindle 1 can pass. The sealing cap 10 is locked in position by a retaining clip 12. The sealing cap 10 seals the inner chamber 7a thereby preventing the ingress of sand and other unwanted material into the inner chamber 7a. This helps to increase the working life of the handpiece.

[0014] A ripple washer 3 is located between the exterior ring of the middle bearing 8 and the sealing cap 10 to apply a compressive force on the middle ο ο (Ν Ο irj Ο Ο r- ο (Ν bearing 8 and thereby allow for the front and middle bearing 6 and 8 together with the spacer 2 located between to be accurately located within the inner chamber 7a of the barrel 7. The crank spindle 1 is therefore supported for rotation without any floating movement of the spindle 1 by the front bearing 6 and the middle bearing 8 respectively. The sealing cap 10 not only ensures the accurate location of the front bearing 6 and middle bearing 8 but can also avoid a problem associated with known shearing handpieces where the thin wall provided at the end of the barrel 7 can be distorted.

[0015] A set of two rear bearings 11 is supported on the rear end of the crank spindle 1. The rear bearings 11 are located within an inner joint housing 4 provided at the end of the barrel 7. The set of two rear bearings 11 supports for rotation the inner joint housing 4 relative to the barrel 7. This arrangement increases the rigidity and stability of the joint area of the handpiece which also assists in extending the working life of the handpiece.

[0016] The handpiece further includes an outer joint assembly 16 including an inner passage 16a and a drive shaft 17. A cog 14 is located at the rear end of the crank spindle 1 to engage a cog 15 provided at a front end of the drive shaft 17. This allows power to be transmitted to the crank spindle 1 to operate a shearing cutter assembly 13 provided at the front end of the barrel 7. A pair of slide bearings 18 are located in the outer joint assembly 16 to support the drive shaft 17 at adjacent ends thereof within the inner passage 16a.

[0017] The shearing handpiece according to the present invention provides an improved arrangement that can extend the working life of the shearing handpiece.

[0018] Modifications and variations as would be deemed obvious to the person skilled in the art are included within the ambit of the present invention as claimed in the appended claims.

Claims

CLAIMS:

1. A shearing handpiece including: a barrel having a crank spindle supported for rotation within an inner chamber of said barrel, the crank spindle having a front end, a rear end, and a middle portion intermediate said front and rear ends thereof, the front end of the crank spindle being supported by a front bearing located within the inner chamber, a middle bearing located within the inner chamber for supporting the middle portion of the crank spindle, and a sealing cap secured to a rear opening of the inner chamber, the sealing cap having a central opening through which the rear end of the crank spindle passes.
2. A shearing handpiece according to claim 1, wherein the sealing cap is secured to the rear opening of the inner chamber by a retaining clip.
3. A shearing handpiece according to claims 1 or 2, wherein the handpiece includes an inner joint housing, and wherein at least two rear bearings are supported at or adjacent the rear end of the crank spindle for supporting the inner joint housing thereon.
4. A shearing handpiece according to any one of the preceding claims, wherein the handpiece includes an outer joint assembly including an inner passage, a drive shaft accommodated within the inner passage, and a slide bearing located within the inner passage for rotatably supporting the drive shaft.
5. A shearing handpiece according to claim 4, wherein two slide bearings are positioned to support the drive shaft adjacent opposing ends of the drive shaft.