EP0081515A1

EP0081515A1 - Mechanism and device for applying a force, in particular the application of a manually-generated force to a workpiece, for example in the separation of co-operating male and female parts

Info

Publication number: EP0081515A1
Application number: EP19820901724
Authority: EP
Inventors: Richard Furneaux Kinnersly
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-06-11
Filing date: 1982-06-11
Publication date: 1983-06-22
Also published as: GB8303804D0; GB2113139A; WO1982004415A1

Abstract

Un mecanisme servant a appliquer une force produite manuellement comprend une pompe a fluide actionnee manuellement (46), de preference sous la forme d'un pistolet de graissage ou d'huilage conventionnel, concu de maniere a delivrer un fluide sous pression, et un dispositif d'actionnement (2) comprenant un piston/cylindre actionne par un fluide (10, 20), Un organe de liaison (18, 47) est utilise pour connecter et deconnecter rapidement la pompe a fluide (46) au dispositif d'actionnement (2). Sur le dispositif d'actionnement (2) est monte un organe applicateur (28) servant a relier de maniere demontable le dispositif d'actionnement a une piece a usiner, ce qui permet de transmettre sous forme de force a la piece a usiner (6, 8) un mouvement relatif entre le piston (20) et le cylindre (10) lorsque celui-ci recoit du fluide sous pression depuis la pompe (46). Il est prevu en outre un dispositif permettant d'appliquer une force importante, pouvant faire partie du mecanisme ci-decrit, et qui comprend un boitier (106) a l'interieur duquel une pluralite de chambres de cylindres (122) sont disposees en serie, un assemblage a piston (132) etant monte de maniere coulissante dans chaque chambre de cylindre. Chaque assemblage a piston (132) autre que l'assemblage a piston extreme (132d) comprend une partie (138) qui, pendant l'utilisation, s'appuie contre un assemblage a piston successif, et il existe des moyens (172, 174, 176; 180, 182, 184) grace auxquels le fluide sous pression applique au dispositif peut etre transfere dans toutes les chambres de cylindres.A mechanism for applying a manually generated force includes a manually operated fluid pump (46), preferably in the form of a conventional grease or oil gun, designed to deliver fluid under pressure, and a device actuator (2) comprising a piston / cylinder actuated by a fluid (10, 20), A connecting member (18, 47) is used to quickly connect and disconnect the fluid pump (46) to the actuator ( 2). On the actuating device (2) is mounted an applicator member (28) used to demountably connect the actuating device to a workpiece, thereby transmitting force to the workpiece (6 , 8) a relative movement between the piston (20) and the cylinder (10) when the latter receives pressurized fluid from the pump (46). There is further provided a device for applying a large force, which may be part of the mechanism described above, and which comprises a housing (106) inside which a plurality of cylinder chambers (122) are arranged in series , a piston assembly (132) being slidably mounted in each cylinder chamber. Each piston assembly (132) other than the extreme piston assembly (132d) includes a portion (138) which, during use, leans against a successive piston assembly, and there are means (172, 174 , 176; 180, 182, 184) by which the pressurized fluid applied to the device can be transferred to all the cylinder chambers.

Description

Title: "Mechanism and device for applying a force, in particular the application of amanually-generated force to a workpiece, for example in the separation of co-operating male and female parts"

This invention is concerned with mechanisms for the manual generation of force, particularly by the use of hand pressure, and for the application of such force to a workpiece. The invention has been devised particularly for the separation of co-operating male and female parts of the kind secured together in a manner such as to resist such separation, for example as by being a press or interference fit, one within the other. Eowever, it will be appreciated that the invention in its ^"broader context has more general applicability, particularly in the application of a large force generated by manual effort in a confined space.

In a large number of circumstances difficulty is encountered in the separation of such male and female parts. A common circumstance -is the requirement to remove a hub from a shaft upon one end portion of which the hub is slidably mounted. The shaft, and a central aperture of the hub through which the shaft extends, may be complementarily splined, or cay be plain cylindrical or of tapered formation of relative sizes to afford an interference fit.

Such latter circumstances are frequently encount¬ ered in vehicles, removal of the hub being required to be undertaken in some servicing operations.

Tools exist to assist the removal of the hub from the shaft. However often such tools are difficult to operate, and/or are of the kind which obtain separation by exerting violent (hammer) action against the parts, or suffer from other disadvantages in construction or opera¬ tion.

OMPI In the use of other mechanisms, such as nut- splitting mechanisms, mechanism for the separation of ball and socket joints, difficulty may be encountered in the ability to generate a sufficient force by hand pressure, particularly when the space available is confined.

According to one aspect of this invention there is provided mechanism for the application of a manually- generated force to a workpiece and comprising:

(a) a manually operated fluid pump adapted to deliver fluid under pressure;

(b) an operating device comprising a fluid-operated piston/cyclinder;

(c) connecting means by which the fluid pump may readily, be connected to and disconnected from the operating device; and

(d) applicator means for releasably connecting the operating device to a workpiece whereby relative movement between the piston and the cylinder of the operating device may be trans¬ mitted as a force to the workpiece.

Preferably the fluid pump is one which is adapted for repeated intermittent operation, whereby fluid under pressure is delivered in small quantities to the operating device.

Conveniently the pump is hydraulic, and is conveniently operated by hand pressure, such as by squeezing pressure of the hand, or by rotating an operating member of the pump. Advantageously used is a proprietory oil or grease gun, the fluid under pressure from which, on operation of the gun, being delivered to the operating device to cause the operating device to exert force.

Preferably therefore ^' the connecting means is capable of connecting the operating device to a conventional oil or grease gun, and is conveniently afforded by a connector means as presently ; ou .-. _~n certain proprietory oil or grease guns.

BAD ORIGINAL Thus preferably the operating device comprises an inlet which is afforded by a nipple of the kind used on greasing points, capable of being connected to such connector means.

The applicator means may be such as will enable force to be applied to the workpiece to cause or to tend to cause relative movement between component parts of the workpiece. Thus the applicator means may be connected to or between a strut and an adjacent component part, whereby force generated by the mechanism may be applied to straighten or deform said strut.

Alternatively the applicator means may be connected to or between a female part and a co-operating male part, where force is to be applied to separate said parts, such as in the removal of a hub from a shaft, or in the removal of a ball from a ball and socket joint.

The force applied by the operating device may be relatively low, and operative over a relatively large distance, as may be required in the separation of co¬ operating male and female parts, or may be relatively high, and operative over a relatively small distance as may be required in the splitting of a nut to be separated from a bolt or other threaded shaft.

Alternatively, the applicator means may be afforded by ancillary mechanism which is operative between the piston and cylinder to convert a linear force as is obtained by operation of the pump to a non-linear force, such as a torque, which may be utilised to remove a nut from a bolt or other threaded shaft.

Preferably the velocity ratio between the input to the pump and the output from the operating device is in excess of 20 : 1 , and preferably in excess of 40 : 1 , whereby a force in excess of 1 ton may be obtained at the operating device on the exertion of a hand pressure of some 55 lbs.

Preferably however the operating devⁱce is canablo of exerting a iorce in excess of cwo tons.

BAD ORIGINAL „_^{l "}7„_. - n -

If desired, a capability may be provided whereby the velocity ratio between the pump and the operating device may be altered, whereby the relationship between the force exerted by the operating device and the distance over which such force is operative in response to a predetermined manual operation of the pump may be selected to suit a particular requirement.

In- the application of this invention to the separa¬ tion of co-operating male and female parts such as in the separation of a hub from a shaft, the invention also provides mechanism for the separation of co-operating male and female parts comprising an operating device comprising a fluid-operated piston/cylinder, and applicator means for supporting one of said male and female parts whereby relative movement between the piston and the cylinder of the operating device may be trans- mitted as a force to the other of said male and female parts, characterised in that the operating device comprises an inlet which is adapted for connection to a conventional oil or grease gun, whereby on operation of the gun fluid under pressure may be delivered to a cylinder of the operating device to cause relative move¬ ment of the piston thereof, and force to be applied between said male and female parts.

Preferably the operating device comprises mechanical means by which relative movement between the piston and the cylinder may be obtained separately from operation of the fluid pump. Thus the relative positions of the piston and the cylinder may be adjusted prior to operation of the fluid pump.

There is also a mere general requirement, particularly in small workshops, for a device which is capable of applying a large force, and which may be powered solely manually, which is relatively inexpensive in its construction, and which is relatively compact. Such ieviees cculd be used ffor example) in wnrkshen pract_.ee ι -_* n as c_^r maintenance and repair.

BAD ORIGINAL ^■. According to this invention there is provided a device for applying force and comprising a housing with which a plurality of cylinder chambers are arranged in series, a piston assembly slidably mounted in each of the cylinder chambers, each piston assembly other than an endmost piston assembly comprising a part adapted in use to bear against a successive piston assembly, and means by which fluid under pressure may be applied to the cylinder chambers.

In this manner the fluid under pressure may be caused to act on each of the piston assemblies to cause them to move, and (other than said endmost piston assembly) to apply a force to the next succeeding piston assembly. Thus a cumulative force will be applied to the endmost piston assembly, from which it may be applied as is desired.

In this manner a large force may be produced from a source of fluid under relatively low pressure, without the need to utilise a piston having a large surface area. Preferably each piston assembly comprises a piston head and a stem extending fixedly from the head. Preferably the head of the piston assemblies (other than a foremost piston assembly) comprises an engagement portion, adapted to be engaged by the stem of a preceding piston assembly, and an operative portion on which fluid under pressure may act.

Preferably the device comprises a single inlet means by which fluid under pressure may be applied to the device, and transfer means by which the fluid applied to the inlet means may be applied from one cylinder chamber to successive cylinder chambers. The transfer means may be afforded by conduits arranged to provide for flow of fluid from one cylinder chamber to the next along paths lying generally on the longitudinal axis of the housing, or along paths spaced outwardly from the longitudinal axis.

Conveniently the housing is elongate, and is provided with a primary cylinder within which sleeve assemblies are located at spaced intervals, said assemblies providing, other than for the foremost piston assembly, a cylinder head against which the fluid under pressure acts.

Such sleeve assemblies may comprise elongate sleeve portions which define the cylinder chambers, and which conveniently afford the or part of the transfer means, the sleeve portions acting against the preceding sleeve assembly other than the sleeve portion of the foremost sleeve assembly which conveniently acts against the housing directly.

Alternatively head portions, against which the piston assemblies act, may be fixedly secured within the primary cylinder.

Means may be provided on each piston head at least to reduce the force applied to the piston assembly when it reaches an endmost point in its path of travel, to reduce the force which would otherwise be applied by the piston assembly to the cylinder head of the next succeed¬ ing assembly.

The device may be adapted for operation with any convenient source of fluid under pressure, particularly hydraulic fluid, but advantageously is adapted for use in conjunction with a conventional grease or oil hand gun, by which fluid under pressure may be applied purely manually. Thus advantageously the device comprises an inlet means to which the nipple of a conventional grease or oil gun may be connected.

Preferably the device for applying force, as set out in the last preceding paragraphs, is utilised as the operating device in the mechanism for the application of a manually-generated force to a workpiece, in accordance with the first aspect of this invention.

There will now be given a detailed description, to be rea _*itn reference to the accompanying drawings, of

B ORIGINAL ¹ various embodiments which have been selected for the purposes of illustrating the invention by way of example. In the accompanying drawings:-

FIGURE 1 is a schematic sectional view of a first embodiment of the invention in carrying out the method of separating co-operating male and female parts, which also an embodiment of the invention;

FIGURE 2 is a scrap view on an enlarged scale, showing the connection of the operating device of the first embodiment to a manually operated hydraulic pump;

FIGURE 3 is a view of an alternative construction of the preferred embodiment;

FIGURE is a scrap view showing the application of the invention to a nut splitter; and

FIGURE 5 is a scrap view showing the application of the invention to a torque wrench;

FIGURE 6 is a longitudinal sectional view of an alternative operating device which may be used in the first embodiment of the invention, and which is in itself illustrative of certain aspects of this invention;

FIGURE 7 is an enlarged view of part of said device; FIGURE 8 is a longitudinal sectional view of a sleeve assembly of the device;

FIGURE 9 is a sectional view of an alternative construction of piston assembly of said device;

FIGURE 10 is an end elevation viewed in the direction of arrow A of Figure 9, of a stem of said piston assembly;

FIGURES 11 and 12 are schematic viewes illustrating alternative forms of pressure relief means of the device; and.

FIGURE 13 is a longitudinal sectional view of a modified form of the operating device illustrated in Figure 6.

The mechanism which is the first embodiment of this invention is adapted for use in the separation of co¬ operating male and female parts, specifically a hub 6 slidably mounted on the end portion of a splined shaft 8, such operation being required to be performed in the replacement of bearings in vehicle maintenance. The mechanism comprises an operating device 2, a conventional hand-held grease gun 46, and means to connect the grease gun to the operating device, said means being afforded by a connector member 47 at the outlet of the gun.

The operating device comprises a body 10 exteriorly threaded as at 10a., and provided with an axial bore, affording a cylinder 12. Extending from an upper end portion of the cylinder 12 is a longitudinal bore 14, said bore 14 opening into a threaded, transverse bore affording an inlet passage 16 of the device. Screwed into one end of the inlet passage 16 is an Inlet nozzle 18, In the form of a conventional grease nipple and screwed into the opposite end of the inlet passage 16 is a bleed screw 1 .

Slidably mounted in the cylinder 12 is a piston 20, which is itself provided with an axial bore 22, which is threaded. A piston member 24 is screw-threaded into the bore 22 with a head 26 projecting a short distance therefrom.

The operating device comprises applicator means afforded by a conventional retraction bracket 28, comprising a collar 29 having a central aperture 30, threaded complementarily to the body 10a., through which the body 10 may be inserted to a desired position relative to the hub 6. In such desired position, the inturned end portions 34 of arms 32 pivotally mounted on the collar 29 may be positioned beneath the hub 6, as is shown in Figure 1.

The operating device of the first embodiment of this invention Is adapted for use in conjunction with a manually operated hydraulic pump in particular an oil or grease gun capable of being operated to deliver lubricat¬ ing fluid at a high pressure, typically of 8,000 p.s.i or more. By connection of the connector member 47 of such a gun to the inlet nozzle 18, and operation of the gun,

. fluid under pressure may be delivered through the inlet nozzle 18, and by way of the inlet passage 16 and bore 14 to the cylinder 12. The piston 20, being slidably mounted in the cylinder 12, is then urged by such fluid pressure in a downward direction (Figure 1 ) to press the head 26 into engagement with the end of the splined shaft 8, exerting a force between the hub 6, by way of the retraction bracket 28 and the flange 32, and the splined shaft 8 to tend to cause separative movement between the hub and shaft..

The velocity ratio between the operating lever 45 of the grease gun and the piston 20 of the operating device is about 10 : 1 and the velocity ratio of the lever 45 on the grease gun is about 4 : 1 , thus giving an overall velocity ratio of approximately 40 : 1. In this manner, a force of about one ton may be applied to the shaft 8 by the head 26 by a hand pressure of about 55 lbs. However, the preferred velocity ratio of the mechanism which is the first embodiment of this invention nay be less, but is preferably in excess of 20 : .^'

When a desired amount of such separative movement has been achieved, fluid may be relieved from the cylinder by loosening the bleed screw 19. However if desired, means may be provided to return such fluid to the gun 46.

To minimise the amount of fluid needed to effect such separative movement, prior to operation of the gun the position of the piston member 24 is conveniently adjusted in a direction axially of the piston 20, such as by the insertion of a tommy bar through an aperture 27 in the head 26, to reduce clearance between the head 25 and the end of the shaft 8 to a minimum.

Figure 2 shows a typical construction of connector member by which the grease gun may be secured to the inlet nozzle 18 of the device.

BAD ORIGINAL ',^• ^- . Thus, said connector member 47 is screwed onto the outlet conduit of the grease gun 46, and may be pressed over the inlet nozzle 18 of the operating device, such action momentarily moving a member 48 of rubber or like elastomeric material against the action of a compression spring 49, such movement allowing a spring collar 50 to be moved away from an internal lip 47a and permitting the inlet nozzle 18 to adopt the position shown in Figure 2. V-Ihen in this position, the collar 50 is urged by the spring 49 into engagement with the lip 47a., in which position it prevents separation of the nozzle 18 from the grease gun 46 by virtue of rectilinear movement there¬ between. Removal of the gun from the inlet nozzle 18 is effected by firstly tilting the gun relative to the inlet nozzle 18, allowing the nozzle to be pulled from lip 47a_.

An advantage of the invention is in the absence of rotational movement between the shaft 8 and the head 16 in engagement therewith, as is present on certain manually-operated mechanisms of the screw-type.

Figure 3 shows an alternative form of the device in which similar numerals, with suffix' have been utilised to identify like parts. Whilst in the first embodiment a retraction bracket Is utilised which has arms which are positioned behind the hub 6, in the construction illus¬ trated In Figure 3, the body is provided with a fixed collar 29' , force being applied to the hub 6 by way of the fixed collar 29', and arms 32' which are secured to the hub 6 by bolts 34' .

It is to be appreciated that whilst the present invention has been described hereinbefore in relation to the application of force, generated manually, in the separation- of interengaging male and female parts, the Invention may be utilised in more general terms in the application of a manually generated force to a workpiece.

Thus as illustrated in Figure 4, the device may be used as a nut splitter, the head 26 being afforded by a

BAD ORDINAL^"* chisel, and the appli-cator means 28 being afforded by a nut locating mechanism.

In the application of the invention to mechanisms such as nut splitters, it is envisaged that a velocity ratio greatly in excess of 40 :1 may be desirable, e.g. 300 : 1 , in order to obtain a large force operative over a small distance.

Figure 5 illustrates the application of the invention in which the head 26 is afforded by a rack, and the applicator means 28 affords a mounting for a pinion 40 engageable by the rack 26. Thus in the operation of the hand g«un relative movement between the rack 26 and pinion 40 is effected, converting the linearly produced force to torque, allowing the invention to be utilised as a torque wrench. In such an application, it may be desirable to incorporate a pressure gauge responsive to pressure in the cylinder 12, which is calibrated in torque. „

Other applications of the invention include strut bending, in which the device is applied between a strut to be deformed and an adjacent body part of the work¬ piece; the removal of a ball from a ball and socket joint; the removal of conical spigots; the removal of steering joints.

It is thus to be appreciated that the invention has wide application, and is particularly advantageous in circumstances where a large force needs to be manually generated, and applied to a workpiece in circumstances where room is limited.

Alternative to the use of the operating device illustrated in Figure 1, for the application of much larger forces an operating device may be used of the kind illustrated in Figures 6, 7 and 8 of the accompanying drawings, which modified device is itself illustrative of certain aspects of this invention, and which may be used to advantage in applications where very high pressures are required to be operative over small distances, particularly where generated by manual effort.

BAD ORIGINAL The device illustrated in Figures 6 to 8 comprises an elongate housing 106 provided with a cylindrical bore 108, the inner end of said bore being closed by a radial face 110 of the housing. The bore provides a primary cylinder of the device, within which there are located successive sleeve assemblies ll6a_, ll6t>, ll6_c. Each sleeve assembly comprises a head portion 118 and a sleeve portion 120 which defines a hollow cylinder chamber 122. The sleeve portion 120a. of the foremost sleeve assembly 116a. abuts against the radial face 110 of the housing 106, and the sleeve portion 120t> of the sleeve assembly ll6b_ abuts against the radial face of the head portion 118a. of the sleeve assembly ll6a_, and the sleeve portion 12θ of the sleeve assembly ll6_c abuts against the radial face of the head portion ll8b_ of the sleeve assembly 116b.

Each head portion 118 is provided with an axial bore 124, one corner of which is chamfered as shown at 126, a bore 129 extending from the chamfered portion to a circumferential groove 128, which is in alignment with one of three radial outlet ports 130. The head portion is additionally provided with Internal and external circumferential grooves within each of which a resilient sealing member is located.

The device also comprises four piston assemblies 132a., 132b_, 132_c and 132d_, each comprising a head portion 136 and a stem 138 extending frc the head. The piston assemblies 132a., 132b_ and 132c; are each mounted for sliding movement within a respective sleeve assembly 116a., Il6b_ and llδ_jo, with the stem 118 thereof extending through the bore 124 of the head portion 118, whilst the piston assembly 132.d is slidable in the endmost part of the cylindrical bore 108, as is shown in Figure 6.

Each piston assembly 136 comprises a central raised portion 140, constituting an engagement portion of the head, and an annular operative portion 144 extending around the engagement portion 140. Each piston head 136

BAD ORIGINAL is additionally provided with a circumferential groove 137, within which a circular sealing member is located.

The device comprises inlet means, provided by a bore 150 into which a conventional greasing nipple 152 is screwed, and from which a passage 154 extends, whereby fluid under pressure may be applied to the primary cylinder.

Provided in a circumferentially outer part of each sleeve portion 120 is a groove 172, which extends by way of a transverse bore 174 to a bore 176 extending through the end face of the head portion 118. Thus fluid under pressure applied by way of the inlet means 150, 152 and 154 will act not only against the piston head of the piston assembly 132, but also by way of groove 172, and bores 174 and 176 to the cylinder chamber within which the next piston assembly is operative.

In the use of the device illustrated in Figures 6, 7 and 8, a conventional grease gun, for example of the kind illustrated in Figure 1 of the drawings, is connected to the nipple 152. On hand operation of the grease gun, grease under pressure is applied to the inner end of the cylinder chamber defined by the sleeve assembly 116a., acting initially against the operative portion 114 of the piston assembly 132a. (the engagement portion 140 thereof being initally in contact with the radial face 110 of the bore) causing the piston assembly 132a. to move axially in the direction of the arrow B (see Figure 1). Subsequent to initial, movement of the piston assembly, such fluid will of course act also on said engagement portion.

The ste 138 of the piston assembly 132_a thus applies a force in the direction of arrow B (Figure 7) against the piston assembly 132_b and hence to the piston assembly 132_c and the piston assembly 132_d.

Fluid under pressure additionally flows through the groove 172 in the sleeve portion 120a. and along the bore 174, passing along the bore 176 to act initially against the operative portion 144, and subsequently against the

BAD ORIGINAL whole of the end face of, the piston head of the piston assembly 132b_. Fluid under pressure likewise flows through the groove 172 in the sleeve portion 120b_, the bores 174 and 176 of the sleeve assembly 120c to act against the piston assembly 132_d.

Thus accumulative force, derived by the action of fluid under pressure on the piston heads of all four piston assemblies, Is transmitted to the stem 138_d of the piston assembly 132_d, from which it may be applied as required.

On downward movement of each of the piston assemblies within their respective cylinder chambers, displaced fluid (which may simply be air) will flow by way of the. chamfered portion 126, bore 129, groove 128 and outlet port 130.

In the embodiment illustrated in Figures 6, 7 and 8, the means by which fluid under pressure is applied to successive cylinder chambers is afforded by the grooves and bores in the sleeve assemblies.

Alterantive to the provision of such a groove 172 and bores 174 and 176 in each sleeve assembly, the piston assemblies 132a., 132t> and 132_c may each be provided with a slot 180 extending diametrically across the domed portion 140 thereof, a through bore 182 extending axially through the piston head 136 and stem 138, and a slot 184 extending diametrically across the ste , as is shown in Figures 9 and 10 whereby fluid delivered under pressure through the inlet means may be applied to said successive piston assemblies.

In the embodiment of the piston assemblies shown in Figures 11 and 12, the piston heads thereof are provided with means to reduce the force applied to the piston assembly when it reaches the endmost postion in its path of travel, to reduce the force applied by the piston assembly to the head, .portion of the next succeeding sleeve assembly. Thus when fluid under pressure is applied to the piston assembly 132£, Figure 11, or the piston assembly 132h_, Figure 12, to cause the piston assembly to move operatively, when the piston head approaches its endmost position in contact with the head portion 118, valve means 84 (which may be a spring-loaded ball valve, as is shown in Figure 11, or a poppet valve as is shown in Figure 12) is moved to its open position to allow at least partial eualisation of pressure on both sides of the piston head.

By the use of the devices illustrated in Figures 6 to 12, a considerable force may be obtained by the use of a compact arrangement. Whilst these devices were devised for use in a mechanism of the kind illustrated in Figures 1 to 5, in which fluid under pressure is generated by manual effort, conveniently by a conventional- oil or grease gun, it is to be appreciated that the devices illustrated in Figures 6 to 12 may be used to advantage in other applications.

In the modified form of the operating device illustrated in -Figure 13, the endmost pi∑jton assembly 132_d is similar in size to the other three piston assemblies, and is also mounted for sliding movement within a sleeve assembly ll6_d similar to the other three sleeve assemblies. All four ports 130 extend to a flow passage 160, which extends to a port 152', conveniently afforded by a conventional grease nipple similar to the inlet 152. The piston assemblies are connected together by a through-bolt 162, and by the application of fluid under pressure to the nipple 152' , and venting through the nipple 152, the device may be used in a pulling operation. This this modified fora may be used in either mode of operation.

OMP

Claims

CLAIMS :

1. Mechanism for the application of a manually- generated force to a workpiece and comprising:

(a) a manually operated fluid pump (45) adapted to deliver fluid under pressure;

(b) an operating device (2) comprising a fluid- operated piston/cyclinder (10,20);

(c) connecting means (47,18) by which the fluid pump may readily be connected to and disconnected from the operating device (2); and

(d) applicator means (28) for releasably connecting the operating device to a workpiece (6,8) whereby relative movement between the piston (20) and the cylinder (10) of the operating device may be transmitted as a force to the. workpiece.

2. Mechanism according to Claim 1 wherein the fluid pump (46) is adapted for repeated ^'intermittent operation.

3. Mechanism according to one of Claims 1 and 2 wherein the fluid pump is provided by a conventional oil or grease gun.

4. Mechanism according to any one of the preceding claims wherein the applicator means (28) is adapted to be connected to a workpiece (6,8) to cause or to tend to cause relative movement between component parts of the workpiece. -

5. Mechanism according to any one of Claims 1, 2 and 3 wherein the applicator means (28) is adapted to be connected to or between a strut and an adjacent component part of a workpiece.

6. Mechanism according to any one of the preceding claims wherein the velocity ratio of the input to the pump and the output from the operating device is in excess of 40 : 1.

7- Mechanism for the separation of co-operating male and female parts (6,8) comprising an operating device (2) comprising a fluid-operated piston/cylinder (10,20), and applicator means (28) for supporting one of said male and female parts whereby relative movement between the piston and the cylinder of the operating device (2) may be transmitted as a force to the other of said male and female parts, characterised in that the operating device comprises an inlet (18) which is adapted for connection to a conventional oil or grease gun (46,47), whereby on operation of the gun fluid under pressure may be delivered to a cylinder (12) of the operating device to ■ cause relative movement of the piston (20) thereof, and force to be applied between said male and female parts.

8. A device for applying force and comprising a housing (106) within which a plurality of cylinder chambers (122) are arranged in series, a piston assembly (116) slidably mounted in each of the cylinder chambers (122), each piston assembly (116) other than an endmost piston assembly comprising a part (138) adapted to bear against a successive piston assembly, and means (172,174,176; 180,182,184) by which fluid under pressure may be applied to the cylinder chambers.

9. A device according to Claim 8 comprising a single inlet means (150,152,154) by which fluid under pressure may be applied to the device, and transfer means (172,174,176; 180,182,184) by which fluid applied to the inlet means may be applied from one cylinder chamber to successive cylinder chambers.

10. A device according to Claim 9 wherein the transfer means is afforded by conduits (172,174,176; 180,182,184) arranged to connect flow of fluid from one cylinder chamber (122) to the next along paths lying generally on the longitudinal axis of the housing, or along paths spaced outwardly from the longitudinal axis.

11. A device according to any one of Claims 8, 9 and 10 wherein the housing (106) is elongate, and is provided with a primary cylinder (108) within which assemblies (116) are located at spaced intervals, said assemblies providing, other than for the foremost piston assembly (132a.) , a cylinder head against which the fluid under pressure acts.

12. A device according to Claim 11 wherein said assemblies (116) each comprise elongate sleeve portions (120) which define the cylinder chambers.

13- A device according to Claim 12 wherein said elongate sleeve portions afford the or part of the transfer means (172,174,176), said sleeve portions acting against the preceding assembly (116) other than the sleeve portion (120) of the foremost assembly (llβ), which acts against the housing (106) directly.

14. A device according to any one of Claims 8 to 13 wherein each- piston assembly comprises means to reduce the force applied to the piston assembly when it reaches an endmost point in its path of travel.

15. A mechanism according to any one of Claims 1 to 7 wherein the operating device is in accordance with any one of Claims 8 to 14.