EP0618790A1

EP0618790A1 - A bath for use by a physically handicapped person

Info

Publication number: EP0618790A1
Application number: EP92924832A
Authority: EP
Inventors: Raymond Metcalf; John Frederick Hills
Original assignee: HAMPSHIRE MEDICAL DEVELOPMENTS Ltd
Current assignee: HAMPSHIRE MEDICAL DEVELOPMENTS Ltd
Priority date: 1991-12-13
Filing date: 1992-12-14
Publication date: 1994-10-12
Also published as: GB2278273A; GB2278273B; GB9411727D0; WO1993011729A1

Abstract

Système de bain (1) conçu pour une personne handicapée physique et comprenant une baignoire (2) pourvue d'un bord phériphérique (3) et d'un dispositif (4) servant à aider la personne à rentrer dans la baignoire (2) et à en sortir. Le dispositif (4) comprend une colonne télescopique (5) comportant une partie extérieure fixe (6) située au-dessous du bord (3) et une partie intérieure (7) mobile par rapport à la partie extérieure (6) à l'intérieur d'une ouverture (8) située dans le bord (3). De plus, le dispositif (4) comprend un élément de siège (15) accouplé de façon démontable à la partie intérieure mobile (7) de la colonne télescopique (5) et constitué par un siège (16), ainsi que par un montant de support de siège (17), dont l'une extrémité s'accouple de façon démontable à la partie intérieure mobile (7). L'ensemble est conçu de façon à pouvoir rentrer la partie intérieure mobile (7), lorsque celle-ci est désaccouplée de l'élément de siège (15), jusqu'à une position repliée située sensiblement au niveau du bord (3), où on peut ensuite fermer l'ouverture (8) au moyen d'un couvercle (20), de façon à recouvrir ladite partie intérieure (7) rentrée. L'invention décrit également un dispositif d'intensification de pression hydraulique (110) servant à faire fonctionner un organe de commande hydraulique (101), tel que la colonne télescopique (5) du dispositif de bain (1), ainsi qu'une prise pneumatique (200) qu'on peut utiliser dans un système de commande pneumatique (210) conçu pour faire fonctionner un dispositif de levage (4) comprenant un ensemble de siège mobile (15).Bathing system (1) designed for a physically handicapped person and comprising a bathtub (2) provided with a peripheral edge (3) and a device (4) serving to help the person to enter the bathtub (2) and to get out of it. The device (4) comprises a telescopic column (5) comprising a fixed outer part (6) located below the edge (3) and an inner part (7) movable with respect to the outer part (6) inside an opening (8) located in the edge (3). Furthermore, the device (4) comprises a seat element (15) coupled in a removable manner to the movable inner part (7) of the telescopic column (5) and constituted by a seat (16), as well as by an upright of seat support (17), one end of which is detachably coupled to the movable inner part (7). The assembly is designed so as to be able to retract the movable inner part (7), when the latter is uncoupled from the seat element (15), to a folded position located substantially at the level of the edge (3), where the opening (8) can then be closed by means of a cover (20), so as to cover said interior part (7) which has been retracted. The invention also describes a hydraulic pressure intensification device (110) for operating a hydraulic control member (101), such as the telescopic column (5) of the bathing device (1), as well as an outlet pneumatic (200) that can be used in a pneumatic control system (210) adapted to operate a lifting device (4) comprising a movable seat assembly (15).

Description

A BATH FOR USE BY A PHYSICALLY HANDICAPPED PERSON

This invention relates to a bath for use by a physically handicapped (or physically impaired) person, to a hydraulic actuator which may be used with such a bath, and to a hydraulic pressure intensifier for operating such an actuator. This invenrion also relates to a pneumatic plug and socket connector particularly, but not exclusively, to a connector suitable for use in a pneumatic control system adapted to operate a bath hoist comprising a movable seat unit associated with a bath to enable a physically handicapped (or physically impaired) person to be lowered and raised within the bath tub.

As used herein, the term "hydraulic" includes water as well as oil.

According to a first aspect of the present invention, there is provided a bath for use by a physically handicapped person which comprises a bath tub, and apparatus for assisting the person into and out of the bath tub, the apparatus comprising a telescopic column having a stationary part, plus a seat unit demountably connectable to the movable inner part of the telescopic column.

The bath tub is preferably provided with a peripheral rim with the stationary part of the telescopic column being disposed beneath the rim, and said other part movable within an aperture formed in the rim, said apparatus being arranged so that with the seat unit disconnected from the movable part, said movable part can be retracted to substantially the level of the rim.

The bath is preferably provided with a cap receivable by the aperture formed in the bath tub rim, so as to cover the retracted part of the telescopic column.

The telescopic column is preferably disposed laterally of the longitudinal axis of the bath tub.

The seat unit preferably comprises a seat support arm, one end of which is demountably connectable to the movable part of the telescopic column. One side portion of the bath tub is preferably of lesser height than the opposite side portion thereof.

The telescopic column is preferably directly operable by hydraulic fluid, which may be pressurised by an electrically-powered pump or by water-powered means. Operation of the telescopic column may be controlled by a pneumatic control system.

According to a second aspect of the present invention, there is provided a hydraulic pressure intensifier for operating a hydraulic actuator which comprises a relatively large area piston movable within a first cylinder, a relatively small area piston movable within a second cylinder, the first and second cylinders being in substantially co-axial alignment, one behind the other, a piston rod interconnecting the two pistons, inlet and outlet means for admitting hydraulic fluid to the first cylinder and for allowing hydraulic fluid to escape therefrom, and inlet and outlet means for admitting hydraulic fluid to the second cylinder and for allowing hydraulic fluid to escape therefrom.

The invention also provides the combination of the intensifier of the second aspect of this invention and a hydraulic actuator having hydraulic fluid inlet and outlet means connectable, respectively, to the hydraulic fluid outlet and inlet means of the second cylinder.

The hydraulic pressure intensifier of the second aspect of the present invention has particular application to baths for use by physically handicapped persons wherein hydraulic actuators in the form of telescopic columns are used to lift and lower a seat within a bath tub. Thus, the telescopic column of the bath according to the first aspect of the present invention may be a hydraulic actuator operated by a hydraulic pressure intensifier in accordance with the second aspect of the present invent ± . i.

According to a third aspect of the present invention there is provided a removable manual actuator for a pneumatically-controlled bath hoist.

Thus, in accordance with the third aspect of the present invention, a bath may be provided with a hoist drive means but the hoist itself and the pneumatic manual actuator can be made removable, so that when removed the bath has a substantially normal appearance. The bath employed in this aspect of the invention may thus be a bath in accordance with the first aspect of this invention in which operation of the telescopic column is controlled pneumatically.

There is a need in hotels and like accommodation for baths to be readily converted from a normal mode into a mode in which a bath hoist is provided. The provision of a removable pneumatic plug and socket connector facilitates the conversion of the bath from one mode to the other.

According to a fourth aspect of the invention, a pneumatic plug and socket connector comprises a plug in the form of a single probe portion adapted to be received within a bore of the socket, the probe portion being provided with at least two axially spaced-apart radial ports which are independently connected internally of the plug to a respective at least two supply passages at the outer end of the probe for connection to re™oecti pneumatic lines, the plug and socket connector being provided with at least three annular spaced-apart sealing means which are arranged such that when the plug and socket are fully inter- engaged, each of the radial ports is positioned axially between a respective pair of the annular sealing means, the socket being provided with respective passages communicating respectively with the chambers defined between the respective pairs of annular sealing means. Although one or more of the annular sealing means could be provided in the socket, it is more convenient for the annular sealing means to be carried by the probe, conveniently located in external annular recesses in the probe. The outer end of the probe is preferably arranged to connect with a pneumatic conduit in which a plurality of pneumatic lines are contained within an outer sheath.

The connection between the outer end of the probe and the pneumatic lines is preferably housed within a handgrip portion of the plug.

The probe and the socket bore are preferably of complementary plain cylindrical shape. Then, in use, the pneumatic pressure present in one of the annular chambers defined axially between adjacent annular sealing means will act with equal force in opposite axial directions on the plug. That is, there will be no net axial force acting to eject the plug from the socket. However, if desired, additional means may be provided to provide a mechanical lock retaining the plug and socket inter-engaged, such as a bolt and spring detent captive to the socket and co-operating with an annular groove in the probe. Whilst the plug and socket connector is suitable for use in bathrooms, where any electrical equipment needs to be very carefully guarded against the ingress of water, and is particularly suited for use in operating a bath hoist, the connector could be used with other devices, and at relatively high pressures and flows. The invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:

Figure 1 is an exploded side view in perspective of a bath in accordance with the first aspect of the present invention;

Figures 2 and 3 are fragmentary side views which illustrate details of the bath shown in Figure 1; Figure 4 is an end view of another bath in accordance with the invention;

Figures 5 is a semi-diagrammatic illustration which shows how the telescopic column may be operated; Figure 6 is a partially cut away side view of the bath shown in Figure 4 illustrating the hydraulic operating means;

Figure 7 is another semi-diagrammatic illustration showing an alternative arrangement for operating the telescopic column;

Figure 8 is a semi-diagrammatic drawing, which is a side view, in section, of a hydraulic pressure intensifier and associated hydraulic actuator in accordance with the second aspect of the present invention;

Figure 9 is a schematic longitudinal cross-section of a plug of a plug and socket connector of he fourth aspect of the present invention, connected to a pneumatic conduit containing two independent pneumatic lines; and

Figure 10 is a schematic longitudinal cross- section of a socket adapted to receive the probe of the plug of.Figure 9. . . .

With reference to Figures 1, 2 and 3, a bath 1 for use by a physically handicapped or physically impaired person comprises a bath tub 2 provided with a peripheral rim 3 and apparatus 4 for assisting the person into and out of the bath tub 2. The apparatus 4 comprises a vertically-disposed telescopic column 5 having a stationary outer or cylinder part 6 disposed a little beneath the rim 4 and an inner or ram part 7 movable relative to the outer part 6, within an aperture 8 formed in the rim 3.

In addition, the apparatus 4 comprises a seat unit 15 demountably connectable to the movable inner part 7 of the telescopic column 5, and formed by a seat 16 and a seat support arm 17, one end of which is demountably connectable to the movable inner part 7.

With particular reference to Figure 3, the arrangement is such that, with the seat unit 15 disconnected from the movable inner part 7, the inner part can be retracted to an unobtrusive position, substantially at the level of the rim 3.

A used herein, the words "substantially at the level of the rim" include a position slightly (say 20.00mm to 80.00mm) below said level.

When the inner part 7 of the telescopic column 5 is in the unobtrusive position shown in Figure 3, the aperture 8 can be closed by a cap 20, so as to cover the retracted inner part 7.

The seat support arm 17 extends, in a cantilever¬ like manner, from a base 21, into apertures 22 formed in the sides of the back rest of the seat 16. The upper end of the inner part 7 is formed with a central recess 23 of circular cross-section which locates, with small side clearance, a central, co-operating, spigot 24 projecting downwardly from the base 21. The load imposed on the seat 16 by the weight of a person carried thereby is transferred to the inner part 7 by way of the arm 17, and the spigot 24 of the base 21. The length of the spigot 24 is such that the weight load imposed cannot result in the spigot being tipped out of the recess 23. The arrangement also allows the base 21 and thus the arm 17, to swivel about the inner part 7.

The seat 16 and arm 17 are readily removed from the inner part 7.--All that needs to be done is to lift the arm, with its rronnected base 21, from the inner part 7.

With reference once again to Figure 3, the cap 20 is formed with central, downward extending, spigot 25 whereby the cap 20 is held in place by location of the spigot by the recess 23. Alternatively, or in addition, the cap 20 and/or aperture 8 may be formed so that the cap is held in place more securely. For example, the cap may be made to engage with the aperture 8 by way of a bayonet connection. As shown in Figure 1, the bath tub 2 has one side portion of lesser height than the opposite side portion thereof. This is to assist entry to and exit from the bath tub.

Figure 1 also shows a mixer bath tap 30, hanc* grips 31, adjustable tub supports 32, a waste outlet 33, an overflow duct 34, and a load reaction base 35 for the column 5. Also evident is that the telescopic column 5 is .-.sposed laterally of the central longitudinal axis 36 of the bath tub 2. The arrangement enables the seat 16 to be raised from a lowered, (in bath tub) position, to an elevated position, and then to swivel the seat to a position in which it extends over the rim 3. Also, to swivel the seat 16 in the opposite direction and then lower it into the bath tub 2.

Figure 4 illustrates an alternative seat support arm comprising a vertical shaft 60 to which a horizontal seat support shaft 61 is mounted at a point somewhat below the top end 62 of the vertical shaft 60. Support shaft 61 extends into an aperture formed in the side of the back rest of the seat 16. A handle 63 is provided for swivelling the seat 16 about the vertical shaft 60 to allow a user to mount the seat 16 outside the bath tub 2. The vertical shaft 60 has a base 65 having a spigot (not shown) which is received by the upper end of the inner part 7 of the telescopic column 5. the seat 16 and seat support arm 60, 61 are readily removed from the inner part 7 of the telescopic column 5 by lifting the arm 60, 61 and associated base 65 from the inner part 7. The inner part 7 can then be retracted to its unobtrusive position and the aperture in the bath tub rim closed by a closure member (not shown).

With reference to Figure 5, the telescopic column 5 is directly operable by hydraulic fluid by way of combined flow and return ducts 40, 41, connected to a pump 42 driven by an electric motor 43. The pump and motor together form a hydraulic power unit 44, which is controlled manually by a remote switch 45, electrical power being provided by a cable 46. The inner part 7 of the telescopic column 5 is powered in both up and down directions, and does not rely on the weight of a person carried by the seat 16, or action by another, such as a nurse, pressing downwardly on the seat, in order to retract the inner part. Thus accidental trapping of fingers by retraction of the inner part 7 is avoided as far as possible.

Figure 6 illustrates how the hydraulic operating mechanism shown diagrammatically in Figure 5 can be arranged in the bath shown in Figure 4. Thus, an electro-hydraulic power pack comprising the pump 42, and power unit 44 are mounted on a removable steel chassis (now shown). A valve block 70 (not shown in figure 5) is provided from which the flow and return ducts 40, 41 extend to the telescopic column 5. The power pack also has an oil reservoir 71 (not shown in Figure 5). The power pack is electrically powered by suitable circuitry (not shown). This electrical circuitry may be pneumatically controlled by a pneumatic control means (not shown) operated by a removable manual actuator (not shown). The pneumatic control means may include a pressure sensitive switch housed in the bath and adapted to operate the power pack. The manual actuator may be connected to the pressure sensitive switch by pneumatic lines via a plug and socket which permit the manual actuator and associated pneumatic lines to be removed when the bath is not in use. The socket is shown in the bath illustrated in Figure 6 and is identified by the numeral 210. The present invention enables both a handicapped and a non-handicapped person to use the same bath. Assuming the handicapped person to use the bath 1 first, the seat unit 15 is then removed, the inner part 7 of the telescopic column 5 retracted, and the cap 20 placed in position. With the seat unit 15 stowed out of sight, there is nothing to indicate that earlier the dual purpose bath 2 had functioned in another mode.

The telescopic column 15 may be replaced by one which has a movable outer part and a stationary inner part.

The invention has particular application to hotels and like accommodation where the bath can readily be converted from one mode to another.

Figure 7 illustrates a modification wherein the hydraulic fluid is pressurised indirectly by water- powered means comprising a water-pressure intensifier 50. Water at mains supply pressure enters and leaves the intensifier 50 by way of flow and return pipes 51, 52 respectively. The intensifier 50 operates so that a relatively low water mains pressure is used to apply a relatively large force to the hydraulic fluid. A suitable intensifier is illustrated in Figure 8. In Figure 8, a hydraulic actuator 101 in the form of a telescopic column is used to lift and lower the seat within the bath tub (not shown), enabling a physically handicapped person to use the tub.

The actuator 101 comprises an outer stationary part 102 and an inner movable part 103.

The actuator 101 is operable by a hydraulic pressure intensifier 110 comprising a relatively large area piston 111 movable within a first cylinder 112, and a relatively small area piston 113 movable within a second cylinder 114. The first and second cylinders 112, 114 are in substantially co-axial alignment, one behind the other, in tandem relationship, with a common longitudinal axis 115. A piston rod 116 interconnects the two pistons 111, 113. A piston rod seal 117 prevents direct flow of fluid between the cylinders 112, 114.

Inle /outlet ducts 120, 121 comprise reversible inlet and outlet means which allow hydraulic fluid to be admitted to the first cylinder 112 and hydraulic fluid to escape therefrom.

Similarly, inlet/outlet ducts 122, 123 comprise reversible inlet and outlet means which allow hydraulic fluid to be admitted to the second cylinder 114 and hydraulic fluid to escape therefrom.

The ends of the ducts 120, 121 remote from the cylinder 112 are connected to a two-way control valve 125 operable by a lever 126. The valve 125 has a water inlet 127 connected to the mains supply and a water outlet 128 discharging the waste. The valve 125 is operable so that the inlet 127 can be connected either to the duct 120, as shown, or to the duct 121. Simultaneously, the duct 121 can be connected either to the outlet 128, as shown, or to the inlet 127.

The cylinder 114 and ducts 122, 123 connected thereto, plus the interior 130 of the actuator outer part 102, are filled with hydraulic oil. The inner part 103 of the actuator 101 is of stepped section, the smaller diameter portion thereof being sealed to the outer part 102 by a seal 131.

In operation, to lift the inner part 103 of the actuator 101, the valve 126 is positioned as shown, so that water at a relatively low pressure is admitted to the first cylinder 112 so that it acts on the piston 111, displacing it to the right, as indicated by arrow 135. At the same time, water is displaced from the back of the piston 111, and flows to waste, by way of the drain 128.

Displacement of the piston 111 causes corresponding displacement of the piston 113 whereby hydraulic oil, at higher pressure than that of the water acting on piston 111, (because of the difference in piston areas), is caused by piston 113 to enter the hydraulic interior 130 and move the inner part 103 of the actuator upwardly. Any oil trapped in the space 130 returns to the cylinder 114 by way of duct 122.

To lower the inner part 103 of the hydraulic actuator 103, the lever 126 of the control valve 125 is moved to the right whereby the fluids move through the ducts 120, 121 and 122, 123 in directions opposite to those previously followed.

The actuator 101 could be replaced by one having an inner stationary part and an outer movable part.

A plug and socket connector in accordance with the fourth aspect of the present invention, which is suitable for use in a pneumatic control system for operating a bath hoist (such as that illustrated in Figures 1 and 4) is shown in Figures 9 and 10.

With reference to Figure 9, a pneumatic plug 200 of a plug and socket connector comprises a single probe portion 201 and a handgrip portion 202. The probe portion 201 is provided with two axially spaced-apart radial ports 203 which are independently connected internally of the plug 200 to respective supply passages 204 which terminate in nipples 205 at the outer end of the probe 201 for connection to respective pneumatic lines 206. The handgrip portion 202 includes a recess 207 in which the outer end of the probe portion 201 is mounted. At the junction of the probe portion 201 and the handgrip portion 202 the parts may be threaded to facilitate secure connection. With reference to Figure 10, a socket element 210 of the plug and socket connector is shown. The socket 210 has a bore 211 adapted to receive the probe portion 201 of the plug 200. The probe 201 and the socket bore 211 are of complementary plain cylindrical shape.

With reference to both Figures 9 and 10, the probe portion 201 of the plug 200 is provided with three annular spaced-apart sealing means 215 which are arranged such that when the plug 200 and socket 210 are fully inter-engaged, each of the radial ports 203 is positioned axially between a respective pair of the annular sealing means 215. The socket 210 is provided with respective passages 216 communicating respectively with the chambers defined between the respective pairs of annular sealing means 215. The passages 216 terminate in connecting nipples 217.

The outer end of the probe 201 is arranged to connect with a pneumatic conduit 220 in which the pneumatic lines 206 are contained within an outer sheath 221. The connection between the outer end of the probe 201 and the pneumatic lines 206 is housed within the recess 207 of the handgrip portion 202 of the plug 200.

The illustrated socket 210 is suitable for mounting on a bath, for example on a side panel of the bath. The connecting nipples 217 of the socket 210 can be connected to a pressure-sensitive switch or control mechanism associated with a hoist actuator, which may be concealed in a housing associated with the bath tub or remote therefrom. The plug 200 may be connected to a removable hand control (not shown) comprising a push button/bellows/valve unit adapted to be mounted on or adjacent to the bath tub when a detachable hoist is mounted in position. It will be appreciated that the plug 200 could be lengthened to accommodate more than two air passages for controlling more than two supply lines.

Claims

C AIMS

1. A bath for use by a physically handicapped person, comprising a bath tub, and apparatus for assisting the person into and out of the bath tub, the apparatus comprising a telescopic column having a stationary part, and another part movable relative to the stationary part plus a seat unit demountably connectable to the movable part of the telescopic column.

2. A bath as claimed in claim 1, wherein the bath tub is provided with a peripheral rim with the stationary part of the telescopic column being disposed beneath the rim, and said other part movable within an aperture formed in the rim, said apparatus being arranged so that with the seat unit disconnected from the movable part, said movable part can be retracted to substantially the level of the rim.

3. A bath as claimed in claim 2, provided with a cap for closing off the aperture formed in the bath tub rim, so as to cover the retracted movable part of the telescopic column.

4. A bath as claimed in claim 1, 2 or claim 3, wherein the telescopic column is disposed laterally of the longitudinal axis of the bath tub.

5. A bath as claimed in claim 4, wherein the seat unit comprises a seat support arm, one end of which is demountably connectable to the movable part of the telescopic column.

6. A bath as claimed in any one of claims 1 to 4, wherein the telescopic column is directly operable by hydraulic fluid.

7. A bath as claimed in claim 6, wherein the hydraulic fluid is pressurised by water-powered means.

8. A bath as claimed in claim 6 or 7, wherein the telescopic column is a hydraulic actuator operated by a hydraulic pressure intensifier which comprises a relatively large area piston movable within a first cylinder, a relatively small area piston movable within a second cylinder, the first and second cylinders being in substantially co-axial alignment, one behind the other, a piston rod interconnecting the two pistons, inlet and outlet means for admitting hydraulic fluid to the first cylinder and for allowing hydraulic fluid to escape therefrom, and inlet and outlet means for admitting hydraulic fluid to the second cylinder and for allowing hydraulic fluid to escape therefrom.

9. A bath as claimed in claim 6, wherein the hydraulic fluid is pressurised by an electrically- powered pump.

10. A bath as claimed in any one of claims 1 to 9, wherein one side portion of the bath tub is of lesser height than the opposite side portion thereof.

11. A bath as claimed in any one of claims 1 to 10, wherein the telescopic column is operated by a pneumatic control system, said pneumatic control system having a removable manual actuator.

12. A hydraulic pressure intensifier for operating a hydraulic actuator, comprising a relatively large area piston movable within a first cylinder, a relatively small area piston movable within a second cylinder, the first and second cylinders being in substantially co-axial alignment, one behind the other, a piston rod interconnecting the two pistons, inlet and outlet means for admitting hydraulic fluid to the first cylinder and for allowing hydraulic fluid to escape therefrom, and inlet and outlet means for admitting hydraulic fluid to the second cylinder and for allowing hydraulic fluid to escape therefrom.

13. A bath, substantially as hereinbefore described, with reference to Figures 1 to 7 of the accompanying drawings.

14. A hydraulic pressure intensifier for operating a hydraulic actuator, substantially as hereinbefore described, with reference to Figure 8 of the accompanying drawings.

15. A bath provided with a pneumatically- controlled bath hoist and a manual actuator for the bath hoist, said manual actuator being removable from the bath.

16. A bath according to claim 15, wherein the bath hoist is also removable.

17. A pneumatic plug and socket connector comprising a plug in the form of a single probe portion adapted to be received within a bore of the socket, the probe portion being provided with at least two axially spaced-apart radial ports which are independently connected internally of the plug to a respective at least two supply passages at the outer end of the probe for connection to respective pneumatic lines, the plug and socket connector being provided with at least three annular spaced-apart sealing means which are arranged such that when the plug and socket ar fully inter- engaged, each of the radial ports is positioned axially between a respective pair of the annular sealing means, the socket being provided with respective passages communicating respectively with the chambers defined between the respective pairs of annular sealing means.

18. A pneumatic plug and socket connector according to claim 17, wherein the annular sealing means are carried by the probe, located in external annular recesses in the probe.

19. A pneumatic plug and socket connector according to claim 17 or 18, wherein the outer end of the probe is arranged to connect with a pneumatic conduit in which a plurality of pneumatic lines are contained within an outer sheath.

20. A pneumatic plug and socket connector according to claim 17, 18, or 19, wherein the connection between the outer end of the probe and the pneumatic lines is housed within a handgrip portion of the plug.

21. A pneumatic plug and socket connector according to any one of claims 17 to 20, wherein the probe and the socket bore are of complementary plain cylindrical shape.

22. A pneumatic plug and socket connector according to any one of claims 17 to 21, wherein additional means is provided to provide a mechanical lock retaining the plug and socket inter-engaged.

23. A pneumatic plug and socket connector according to claim 22, wherein the additional means comprises a bolt and spring detent captive to the socket and co-operating with an annular groove in the probe.

24. A pneumatic plug and socket connector substantially as hereinbefore described, with reference to Figures 9 and 10 of the accompanying drawings.