GB2120813A

GB2120813A - Linear control device

Info

Publication number: GB2120813A
Application number: GB08310502A
Authority: GB
Inventors: Leonard William Norton Jones
Original assignee: James Burn Bindings Ltd
Current assignee: James Burn Bindings Ltd
Priority date: 1982-05-21
Filing date: 1983-04-19
Publication date: 1983-12-07
Also published as: GB8310502D0; EP0095246A1

Description

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GB2 120 813 A

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SPECIFICATION Linear control device

5 The present invention relates to linear control devicessuitableforwire binding machinesforclosing wire binding elements to bind bundles of sheets.

In cerfain operations of such machines relative linear motion is required between components, the 10 stroke beingearefully controlled between several linear positions. Hitherto this action has been provided by coupling several pneumatic cylinders together in tandem and using thefull stroke of each cylinderto move from say Ato B then the next 15 cylinder's full stroke to movefrom BtoCandsoon. This arrangement is somewhat cumbersome and expensive in terms of provision of the several cylinders and corelated control gear.

A linearcontrol device according to the present 20 invention comprises a cylinder, a piston operable within the cylinder, the piston or an attachment thereto being magnetised, at least one magnetically operable switch adjustably mounted along the cylinder, the adjustment of the or each switch mountings 25 being relatively parallel to the direction of movement of the piston, the switches) being operatively connected to control means so that when the piston or magnetic elementthereon reaches a said switch position, the control device stops the flow of fluid 30 moving the piston, whereby the piston is stopped at that switch position.

The control device of the invention enables a single cylinderto be stopped accurately at a predetermined position intermediate the top and bottom ofthe piston 35 stroke so that only a single cylinder need be used.

Preferably the switches are moved on threaded shafts by motors driving the shafts, the motors being controlled to run between adjustable limits.

Embodiments ofthe invention wilf now be de-40 scribed by way of example with reference to the accompanying drawings in which:

Figure 1 shows a closing cylinderfor a binding machine controlled according to a first embodiment and

45 Figure 2 shows a similar but modified arrangement to Figure 1 according to a second embodiment.

In Figure 1a cylinder 28 has a magnetised piston 10 attached to a piston rod 26 which moves through two arms 20,22 of a lever 18 a link 16 to move a closing tool 50 14 upwards and downwards.

Movable upwards and downwards parallel to the piston rod are two reed switches 30,32. The switches are mounted on threaded shafts 34 and 36 respectively, each shaft being driven by a respective motor 38 55 and: 40.

The reed switches each operate when the magnetised piston is adjacent the switch.

The position ofthe reed switches are each controlled via knobs 50 and 51 via known servo control 60 arrangements in an electrical controller 52 so that an indication at particular points ofthe piston stroke is given to the electrical controller 52. As soon as the position indication is received by the controller 52 a solenoid operated spool valve in the pneumatic controller 53 closes the supply of pressure fluid to the cylinder 28 and the piston stops. At the same time a signal is sent to programme control "Biselector" 54 the operation of which is described in ourco-pending British Patent Application No. 8111827 filed 14th April 1981. The Biselector 54 then "knows" the tool 14 has reached a certain position and can then step on to the next stage ofthe programme. A signal is then sent from the Biselector when it reaches its next stage to the controller 52, the shuttle valve is then operated to allow pressure fluid to enterthe cylinder. The piston 10 then moves to the next reed switch positjon and so on to the top of its stroke.

in Figure 2 showing a second embodiment and in which similar components to Figure 1 are similarly numbered the two arms 20 and 22 of Figure 1 are replaced by asingle rocker arm 19connectedtothe closing tool 14'through atumbuckie 17 which allows for adjustment between the piston 10 and the closing tool 14'. The Biselector programme control 54 is replaced by an equivalent pneumatic sequencing programme controller 54'. The motors 40'and 38'are electrically controlled by pairs of switches 50', and 50" and 51r, 51"on a control board so thatthe reed switches 30 and 32 can be moved up or down to visually set positions forthe strokeofthe piston, the visual setting is by observation ofthe position ofthe closing tool 14'.

Thefluid control 53 in both embodiments is a simple shuttle valve movable from a position in which fluid is supplied to the top ofthe piston, to a second position in which no fluid is supplied to the cylinder 28' and to a third position in which fluid is supplied to the bottom ofthe piston. The control of the shuttle valve is by known electro/pneumatic servo arrangements.

It will be appreciated thatthe linear control device of the invention can be used to control any linear or even with suitable linkage part rotary movement involving stopping the piston motion at any position or positions intermediate the top and bottom ofthe piston stroke.

Claims

1. A linear control device comprising a cylinder, a piston operably within the cylinder, the piston or an attachment thereto being magnetised, at least one magnetically operable switch adjustably mounted along the cylinder, the adjustment ofthe or each switch mountings being relatively parallel to the direction of movement ofthe piston, the switch(es) being operatively connected to control means so that when the piston or magnetic elementthereon reaches a said switch position, the control device stops the flow of fluid moving the piston, whereby the piston is stopped at that switch position.

2. A device as claimed in Claim 1 wherein the or each switch is mounted on a threaded shaft which is arranged to be rotated by a motor controlled by the control means.

3. A device as claimed in Claim 1 or 2 wherein two motors are provided each controlling the movements

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The drawing(s) originally filed were informal and the print here reproduced is taken from a later filed formal copy.

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GB2 120 813 A

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of its magnetically operable switch so that the piston can be controlled to move between two positions set by the positions ofthe switches.

4. A device as claimed in Claim 2 wherein the

5 controller is provided with a pair of switches controlling the movement of one motor driven switch in a direction towards one end or the other ofthe stroke of the piston.

5. A wire binding machine having the linear 10 control device of any of Claims 1 to 4 in which the piston is connected operatively to a closing tool.

6. A machine as claimed in Claim 5 wherein between the closing tool and piston an adjustment is providedfor adjusting the position ofthe closing tool

15 relative to the piston.

7. A linear control device substantially as described with reference to the accompanying drawings.

8. A wire binding machine substantially as described with reference to the accompanying drawings.

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New claims or amendmentstoclaimsfiled on 16th August, 1983.

Su perseded clai ms 1.

New or amended claims:—

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1. A linear control device comprising a cylinder, a piston operable within the cylinder, the piston or an attachmentthereto being magnetised, atleastone magnetically operable switch adjustably mounted 30 along the cylinder, the adjustment of the or each switch mountings being relatively parallel to the direction of movement ofthe piston, the adjustment being controlled by a remotely operable control, the switch(es) being operatively connected to control 35 means so that when the piston or magnetic element thereon reaches a said switch position, the control device stops the flow of fluid moving the piston, whereby the piston is stopped at that switch position.

PrintedforHerMajesty'sStationeryOffice byTheTweeddalePress Ltd., Berwick-upon-Tweed, 1983.

Published atthe Patent Office, 25 Southampton Buildings, London WC2A1 AY, from which copies may be obtained.