AU628093B2 - Improved windlass - Google Patents

Description

63 APPLICANT: MUIR EN INEHRING PTY. LIMITED NUMBER: PJ 1156/88 FILING DATE: 26/10/88 Form COMMONWEALTH OF AUSTRALIA The Patents- Act, 1052 COMPLETE SPECIFJCATICN FOR AN -[AVENTION ENTITLED: IMPROVED WINDLASS 'the fol lowing statement. is a full description of L1his invention, inciudin.g the best method of performing it known to me/us:, 'C rr This invention relates to an improved windlass and in particular to a windlass which may be used for winding ropes and/o,' chains on boats but is not restricted specifically to such application.

There have previously been proposed man> forms of windlass for use on boats, which will be used as an exemplification and these are normally adapted to move anchor ropes or chains and may on occasions have multiple purposes and can be used for both rope and chains and can also be used in different areas, such as in winding sheets and the like.

These windlasses can be driven in a number of different ways but the windlass to which the invention specifically relates can be considered to be a windlass of a type which can use a ratchet arrangement to permit the windlass to be operated using a forward movement clockwise.

Such windlasses are known and normally have two or more pawls which are adapted to engage ratchet detents, the pawls normally being located about the periphery of a circle and the ratchet being located within a circular member.

The pawls are normally biased outwardly and the detents on the ratchet are such that when the member carrying the ratchet detents is rotated in one direction the pawls can be moved inwardly against their bias to be able to ride over the ratchet. teeth but when the shaft carrying the pawls is rotated the pawls engage behind a face of the ratchet detent so that turning moment is tranmitted to the circular member.

Other windlasses have been known ir, which there is a direct engagement between the driving and driven member, indeed they can be a single member and this provides a positive drive.

-2- Muir/85/Oct89 In me applications it is desirable that a particular windlass or the like can be operated as a ratcheting or ncn-ratcheting windlass and previously in order to provide such an arrangement it has been necessary to provide stop means which can physically prevent the internal rotation of the pawls about their pivots.

Such arrangements have not been satisfactory.

An object of the present invention is to provide a windlass or o'o «the like which can be selectively used as a ratchet or non- 00 ratchet windlass and which is so arranged that it operates effectively in both configurations.

In a first aspect of the invention we provide a windlass having a member adapted to carry pawls the member having a first pawl receiving position at which a pawl can be located and in which o the pawl can be rotatable relative to the member and can coo, operate with a ratchet to permit ratcheting and a second pawl receiving wherein the pawl is fixed relative to the member so that it positively engages a second member to prevent relative rotation, the pawl being locatable in either position.

It is preferred that the same pawls be used in the two configurations and can simply be moved from the first to the second position to provide the required configuration.

In order that the invention may be more readily understood we C:\WP51\SPEC\MUIR.CLS shall describe a particular embodiment of the invention as applied to a windlass but it is to be understood that it is not specifically restricted thereto.

in order that this embodiment can be described we shall refer tot he accompanying drawings in which:- Fig. 1 is a perspective view of the windlass of the invention; C:\WP51\SPEC\MUIR.CLS Fig. 2 is an exploded view of the windlass of Fig. 1; Fig. 3 is a view of the pawl ring of the invention; Fig. 4 is a perspective view of a pawl and pawl spring; Fig. 5 is an enlarged view of the pawl ring showing the pawls in a ratcheting situation; and Fig. 6 is a view similar to Fig. 5 showing the pawls in a locked situation.

0o 0oo In this specification we shall not describe the drive means 11 of the 0 00 o windlass 10 as this well be basically conventional.

0 The windlass to be described can be considered to have a gypsy 12 and an 000 0 0 associated chain peeler 13 and a capstan 14. That is, the arrangement is a windlass which can be used either for chains or lines or sheets.

S This in itself is not critical to the invention.

Referring to Fig. 2 which is an exploded view of the windlass, it can be 0 -0 oo0 considered to have a base member 20, which is associated with the drive 000 00 means and which is made of a corrosion resistant material.

It will be appreciated that the various components of the windlass shall be made of such materials and the specific materials shall not be described herein as they can vary from machine to machine, nor will further comment be made to this.

Extending through an aperture 22 in the base 20 is a main shaft 21 which is driven from the drive means.

-4- Muir/85/0ct89

I

Fitted to the main shaft is a pawl ring 30 which is illustrated more fully in Figs. 3 to 5 and will be described in relation to those fiqures.

At the end of the main shaft 21 there can be a thrust washer 22 or the like and a drive shaft 23 is adapted to overlay the pawl ring 30 which drive shaft has a bottom flared skirt portion 24 which is formed on its inner surface to have ratchet detents or teeth to be contacted and driven by pawls and an upwardly extending portion 25 over which the gypsy 12 and capstan 14 may be located. The assembly is held together with a clutch nut 27 which screws on to the threaded outer end 26 of the drive shaft 6.

Referring to Figs. 3 to 6 the pawl ring 30 which is located over an keyed to o. the drive shaft 21, preferably by a drive pin passing diametrically Stherethrough is provided with four cut-outs in two diametrically opposed pairs and shown as 31 and 32 respectively.

Each cut-out has a cylindrical portion 33 which is coaxial with the pawl ring and a recess 34, 35 the shape of which is different between the two pairs 31 and 32.

o A pair of pawls 40 best illustrated in Fig. 4 have a cylindrical body portion 41 which has a diameter equivalent to the diameter of the cylindrical portion 33 on the pawl ring and an outwardly extending pawl member 42.

The pawl 40 also has a cut-out 44 in which a shaped pawl spring 45 can be located.

These pawls can selectively be located in either the cut-outs 31 or 32 as can be seen from Figs. 5 and 6.

Before location the spring 45 is located in the cut-out 44.

Muir/85/0ct89 ll Referring firstly to Fig. 5 the pawls are shown located in the portion 32.

It will be seen that the shape of these is such that the pawls can move from a position in which they extend outwardly beyond the periphery of the pawl ring, that is the position shown in Fig. 5 to a position where they are within the periphery, as is indicated by the arrows.

The spring 45 acts to cause the pawls to adopt the position illustrated in Fig. It will be seen that when the pawl ring is arranged as illustrated in Fig. 5 on clockwise rotation of the ring the pawls will remain outwardly directed and they can engage with ratchets formed on the inner surface of the belled portion 24 of the drive shaft 23.

Thus when the main shaft 21 is rotated in a clockwise direction t.he pawls engage with the ratchet and a driving connection is achieved.

When rotated in a relatively anti-clockwise direction the pawls can move over the ratchets against the tension of the spring 45 and no drive is obtained.

In the arrangement shown in Fig. 6 where the pawls are in the recesses 31, this movement is not available as the cut-out portion 34 is so configured as to prevent any rotation of the pawl relative to the cut-out.

Thus the pawl cannot move over the ratchet and the pawl ring, and thus the main shaft 21. is in continuous engagement with the drive shaft 23 no matter what direction of rotation.

It will be seen then that the windlass of the present invention can be driven -6- Muir/85/Oct89 I I ~d rotate in the same direction relative to the drive shaft when not being driven but, when oprated in the other configuration the drive shaft 23 and main shaft 24 are effectively continually engaged.

It is, nevertheless, relatively simple to change the configuration. All that is necessary is to remove the clutch nut 27, the capstan 14 and gypsy 12 to enable the removal of the drive shaft 23 and thrust washer 22 at which time the pawls can simply be removed from their location in the pawl ring, located in the other pair of positions and after the dissembly process is reversed the windlass can operate in the other mode.

Whilst we have described herein one particular arrangement of windlass made in accordance with the invention it will be understood that variations can be made in this without departing from the spirit and scope of the o 00 invention.

0 C O .lu i r 8 5 /O t89 -7- M'u ir/85 fOr~t89

Claims (9)

1. A windlass having a member adapted to carry pawls the member having a first pawl receiving position at which a pawl can be located and in which the pawl can be rotatable relative to the member and can co-operate with a ratchet to permit ratcheting and a second pawl receiving position wherein the pawl is fixed relative to the member so that it positively engages a second member to prevent relative rotation, the pawl being locatable in either position.

2. A windlass as claimed in claim 1 wherein the member adapted to carry pawls is a plate attached to the driven main shaft of Lhe windlass.

3. a windlass as claimed in claim 2 wherein there are two pawl receiving positions of each type.

4. A windlass as claimed in either claim 2 or claim 3 wherein each pawl comprises a body and an extending tonglie and wherein each pawl receiving position has a first portion adapted to receive a pawl body and a second portion opening to the exterior of the pawl plate which receives the pawl tongue.

A windlass as claimed in claim 4 wherein the pawl body is cylindrical and the first, portion of the pawl receiving C:\WP51\SPEC\MUIR.CLS 9 position is complementary thereto.

6. A windlass as claimed in claim 4 or 5 wherein the second portion of the pawl receiving position where the pawl is capable of rotation is relieved to permit partial rotation of the pawl about the pawl body and the second portion of the pawl receiving position where the pawl is fixed receives the pawl tongue so that there can be no rotation.

7. A windlass as claimed in any one of claims 2 to 6 wherein each pawl is biased to move the tongue beyond the periphery of the pawl plate, if such movement is possible.

8. A windlass as claimed in any preceding claim wherein the ratchet is formed in the interior of a drive shaft which overlays the pawl plate and to which the operative portion of the windlass is connected.

9. A windlass as claimed in claim 8 wherein the operative portion is a capstan, a chain gypsy, or both. A windlass substantially as hereinbefore described with reference to the accompanying drawings. Dated this 17th October 1991. Muir Engineering Pty. Limited. C:\WP51\SPEC\MUIR.CLS S 7 r /14) f~$ e-'