AU745273B2

AU745273B2 - Clutching turn unit

Info

Publication number: AU745273B2
Application number: AU14265/99A
Authority: AU
Inventors: David Lumby
Original assignee: KABA BOYD Pty Ltd
Current assignee: Kaba Australia Pty Ltd
Priority date: 1998-05-15
Filing date: 1999-01-29
Publication date: 2002-03-14
Anticipated expiration: 2019-01-29
Also published as: AU1426599A

Description

S F Ref: 451687

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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Name and Address of Applicant: Byd Lock Company y. Lmited 137 Bonds Road Riverwood New South Wales 2210

AUSTRALIA

F SEC I-l 113 u )VT 0

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Actual Inventor(s): Address for Service: David Lumby Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Invention Title: ASSOCIATED PROVISIONAL [311 Application No(s) PP3535 Clutching Turn Unit APPLICATION DETAILS [33] Country

AU

[32] Application Date 15 May 1998 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815 1 Clutching Turn Unit Technical Field The present invention relates to locks and more particularly, to turn units for locks.

Background of the Invention It is not uncommon for doors to be provided with a mortice lock which is key operated from one side and "turn unit" operated on the other side. Typically, such arrangements are used in low security accommodation in corrective service installations. A key operated cylinder unit fitted on the outside would allow prison wardens access to the room if required. However, an occupant of the room to which the door provides access, may hold the "turn unit" and prevent rotation of the key and therefore maintain the door closed. Denying the warden access to the room is a substantial disadvantage of these previously available "turn units".

S"Object of the Invention It is the object of the present invention to overcome or substantially ameliorate the above disadvantage.

Summary of the Invention "i There is disclosed herein a turn unit for installation on a door to operate a lock, said turn unit having: a body providing opposite ends between which a passage extends; a turn shaft mounted within said passage and having opposite first and second end portions, the first end portion being provided to operate the lock; a turn handle mounted on the second end portion so that a torque can be applied to the shaft by the handle to cause operation of the lock; and clutch means connecting the handle and shaft to limit the magnitude of the torque that can be applied to the shaft by said handle by permitting movement of the handle about said shaft when a predetermined torque is exceeded.

In one aspect of the invention, the above-mentioned clutch means includes a recess formed in the second end portion, a cavity formed in the handle, which cavity is alignable with the recess, a clutch member mounted in the cavity and engageable in the recess so that torque can be applied to the shaft by the handle, and resilient means urging the clutch member into engagement in the recess. When a predetermined torque has been exceeded, the clutch member retreats into the cavity and permits relative movement between the shaft and handle.

[N:\LIBTT]01457:LAM I In a further aspect of the invention, the turn unit is provided with means to limit angular movement between the handle and body.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Fig. 1 is a schematic part sectioned side elevation of a turn unit; Fig. 2 is a schematic end elevation of the turn unit of Fig. 1; Fig. 3 is a schematic further end view of the turn unit of Fig. 1; Fig. 4 is a schematic part sectioned side elevation of a modification of the turn unit of Figure 1; **Fig. 5 is a schematic end elevation of the turn unit of Figure 4; and Fig. 6 is a schematic further end view of the turn unit of Figure 4.

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15 Detailed Description of the Preferred Embodiment 0oo ~In Figures 1 to 3 the accompanying drawings there is schematically depicted a turn unit 10 to be mounted in a door to operate a mortice lock. The turn unit includes a body 11 having opposite ends 12 and 13. Extending between the ends 12 and 13 is a passage 14 within which there is rotatably supported a shaft 15. The shaft 15 has a longitudinal axis 16.

The shaft 15 has a first end portion 17 provided with a cam member 18, which cam member pivots about the longitudinal axis 16 to operate the mortice lock. The cam member is fixed to the end face 19 of the shaft 15 by means of threaded fasteners The shaft 15 has a second end portion 21 upon which there is mounted a turn S" 25 handle 22. The end portion 21 is provided with a recess 23 which is normally aligned with a cavity 24 formed in the handle 22. Located in the cavity 24 is a spring 25 and clutch member 26. The clutch member 26 is urged into engagement in the recess 23 by means of the spring The recess 23, cavity 24, spring 25 and clutch member 26 provide a clutch assembly 27 which limits the magnitude of the torque that can be applied to the shaft by the handle 22. More particularly, if a predetermined torque is exceeded, the clutch member 26 retreats into the cavity 25 and permits relative movement between the shaft and handle 22. More particularly, the relative movement would be pivoting or rotational movement about the axis 16.

The clutch 27 is rendered operative to transmit torque between the handle 22 and shaft 15, when the clutch member 26 is again located in the recess 23.

The turn unit 10 is intended to be used in cooperation with a cylinder lock on the other side of the door. Should an attempt be made to retain the door closed, i.e. by N:\LIBTIO1457:LAM holding the handle 22, operation of the handle 22 can be overridden by operation of the cylinder lock. When sufficient torque is applied to the shaft 15 by the cylinder lock the clutch member 26 retreats into the cavity 24 and therefore, permits movement of the shaft 15 and operation of the mortice lock.

In Figures 4 to 6, there is schematically depicted a modification of the turn unit In this embodiment, the body 11 is provided with a passage 27 which receives a pin 28. The pin 28 has an extremity 29 received within an arcuate slot 30 formed in the handle 22. Accordingly, the handle 22 is limited to pivoting through an acute angle relative to the body 11 about the axis 16.

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Claims

1. A turn unit for installation on a door to operate a lock, said turn unit having: a body providing opposite ends between which a passage extends; a turn shaft mounted within said passage and having opposite first and second end portions, the first end portion being provided to operate the lock; a turn handle mounted on the second end portion so that a torque can be applied to the shaft by the handle to cause operation of the lock; and clutch means connecting the handle and shaft to limit the magnitude of the torque that can be applied to the shaft by said handle by permitting movement of the handle about said shaft when a predetermined torque is exceeded.

2. The turn unit of claim 1, wherein said clutch means includes a recess formed in the second end portion, a cavity formed in the handle, which cavity is alignable with the recess, a clutch member mounted in the cavity and engageable in the 15 recess so that torque can be applied to the shaft by the handle, and resilient means urging the clutch member into engagement in the recess, said clutch member retreating into the cavity to permit relative movement between the shaft and handle upon the predetermined torque being exceeded.

3. The turn unit of claim 1 or 2 further including means to limit movement of the handle relative to said body. ooo

4. The turn unit of claim 3, wherein the means to limit relative movement between the handle and body includes a cooperating recess and projection, with the recess being arcuate so as to extend about said shaft.

5. The turn unit of claim 4, wherein said projection is a pin, with said O 25 pin being mounted in said body and projecting toward said handle, with said slot being formed in said handle and receiving an extremity of the pin.

6. A turn unit substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

7. A turn unit substantially as hereinbefore described with reference to Figures 4 to 6 of the accompanying drawings. DATED this Twenty-ninth Day of January 1999 Boyd Lock Company Pty. Limited Patent Attorneys for the Applicant SPRUSON FERGUSON [N:\LIBTTJO1457:LAM