GB2420711A

GB2420711A - An autoclave and a latching and locking device therefor

Info

Publication number: GB2420711A
Application number: GB0424962A
Authority: GB
Inventors: Brian John Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-11-11
Filing date: 2004-11-11
Publication date: 2006-06-07
Anticipated expiration: 2024-11-11
Also published as: GB2420711B; GB0424962D0

Abstract

An autoclave is disclosed that comprises a vessel 10 defining a chamber (16, Fig. 3A) and an opening for gaining access to the chamber, said vessel including a surround 18 disposed around said opening. A door 40 is adapted to cooperate with said surround for closing the chamber. A compressible seal 20 is disposed between the door and the surround. A door mounting device is provided for mounting the door adjacent the vessel. The mounting device is adapted to allow the door to rotate about an axis 27, such that upon opening the door can swing from a closed position in which the door abuts the surround through a small arc sufficient to move the door clear of the surround, and to move translationally in a direction parallel to the axis to move the door clear of the opening to allow access to the chamber. Hook-shaped abutment members 60 are adapted to hold the door in a fully closed position. Also claimed is latching and locking device comprising a first latching device 80 mounted on one of the autoclave vessel or the door comprising a reciprocating engaging member 82 which engages a catch 70 which is mounted on the other of said door or vessel. A second high-load locking device comprising a first rotatable coupling member 91 adapted to be mounted on one of the vessel and door and a second coupling member (92, Fig. 10) said first member being rotatable between a disengaged position and an engaged position in which the first member engages the second member when the door is fully closed for holding the door in said fully closed position during operation of the autoclave. The locking device includes an automatic operating mechanism for operating said latching and locking devices according to a predetermined sequence for opening and closing the autoclave.

Description

1 2420711 An Autoclave and a Latching and Locking Device therefor The

present invention relates to an autoclave, particularly an autoclave with a sliding door which requires minimal space in front of the autoclave for opening. The present invention also provide an automatic latching and locking device for an autoclave, including sliding door and other kinds of autoclave.

Sliding door autoclaves are convenient for use in small laboratories and other situations where there is minimal space available in front of the autoclave, for example where there is too little space for a conventional hinged-door autoclave in which the autoclave door swings fully about an axis for opening and closing.

A typical sliding door autoclave comprises a vessel defining a chamber having an opening to allow access to the chamber, a surround disposed round the opening and a door adapted for closing the chamber during operation of the autoclave. The door is mounted with respect to the vessel such that it can slide between such a closed position and an open position in which the door is disposed clear of the opening to allow access to the chamber.

A compressible seal is positioned between the surround and the door to form a substantially air-tight seal when the door is closed.

A problem associated with such sliding door autoclaves is potential damage to the compressible seal during opening. If the door is slid whilst in contact with the seal, then there is likelihood that the seal, which may adhere somewhat to the door when compressed therebetween, may be dragged and thus damaged by the door.

Some prior sliding door autoclaves include complicated systems for displacing the seal from the door prior to opening using air pressure.

An object of the present invention is to provide an improved sliding door autoclave which is suitable for use in locations where there is minimal space available in front of the autoclave for opening the door and which avoids the possibility of damage to the compressible seal between the door and the surround.

A different object of the present invention is to provide an improved locking and matching mechanism for an autoclave, including but not limited to sliding door autoclaves.

A prior latching device is disclosed by the applicant's own prior United Kingdom patent no. 2,325,699.

According to a first aspect of the present invention therefore there is provided an autoclave comprising: a vessel defining a chamber and an opening for gaining access to the chamber, said vessel including a surround disposed round said opening; a door adapted to cooperate with said surround for closing said chamber; a compressible seal disposed between the door and the surround; a door mounting device for mounting the door adjacent to the vessel, said mounting device being adapted to allow the door to rotate about an axis, such that upon opening the door can swing about said axis from a closed position in which the door abuts said surround through a small arc sufficient to move the door clear of the surround, and to move translationally in a direction substantially parallel to said axis to move the door clear of the opening to allow access to the chamber; and door holding means for holding said door in said closed position during operation of the autoclave.

In accordance with the present invention, therefore, upon opening the autoclave door is first moved by rotation clear of the compressible seal and surround, prior to sliding the door to an open position in which the door is disposed clear of the chamber opening.

Upon opening, the door need only be rotated through a small arc in order to remove the door from the compressible seal and surround so as to avoid the possibility of dragging the seal upon subsequent sliding of the door to the open position, and such rotation through a small arc requires only minimal space in front of the autoclave for opening, thereby retaining the advantage associated with sliding door autoclaves if requiring only minimal space in front of the autoclave.

Said door may be capable of rotation through a small arc of less than about 45 from the closed position, preferably less than about 25 . In some embodiments said small arc may be less than 100.

Preferably, said axis is spaced from the surround to facilitate moving the door completely clear of the surround and compressible seal upon rotation through said small arc.

It is undesirable to apply high loads to a hinge between the autoclave door and the vessel, and accordingly, in accordance with the present invention, said door holding means preferably comprise one or more selectively operable high-load fastening devices for holding the door in a fully closed position during operation, such that the seal is compressed between the door and surround for sealing the chamber, the or each fastening device comprising a first coupling member mounted on one of the door and the vessel, a second coupling member mounted on the other of the vessel and the door, and selectively operable operating means for moving one or both of said first and second coupling members to bring them into mutually engagement for fastening them securely together.

In some embodiments, the or at least one of said one or more fastening devices may be positioned adjacent said surround remote from said axis.

In accordance with a particular aspect of the present invention, said door holding means may comprise at least one abutment arranged to abut the door or a part connected thereto in the fully closed position so as to support high outward loads on the door during operation. Said at least one abutment may be disposed adjacent the surround proximate said axis.

Thus, in some embodiments, the door may be held in a fully closed position against high internal loads by said one or more fastening devices which are positioned remote from said axis, and by said one or more abutments that are disposed proximate said axis. In this way, high loads applied to the door mounting device during operation of the autoclave are avoided.

Suitably, said axis may be interposed between said at least one abutment and said surround.

Said door may have an inner face adapted to engage the surround for compressing the compressible seal therebetween, and an outer face adapted to engage said at least one abutment. Said at least one abutment may therefore react against the outer face of the door or a part connected thereto for holding said door in engagement with said surround.

In some embodiments, said door holding means may comprise a plurality of such abutments spaced apart in a direction substantially parallel to said axis. The spacing of the abutments from the axis may increase progressively in the direction of moving the door clear of the opening. In such case, the spacing of said abutments from the axis decreases progressively in the opposite direction which may facilitate movement of the door from an open position to a position aligned with the opening, ready for closing by rotation through said small arc.

Said door may carry a plurality of spacers, each spacer being sized and positioned to engage a respective one of said abutments in the fully closed position with a high tolerance.

Suitably, said door mounting device may be adapted to allow the door to slide in said direction parallel to said axis between a first clear position in which the door can be rotated directly to the closed position and a second open position in which the door is disposed clear of the opening, said door mounting device including means for preventing the door from swinging open from the closed position by more than said small degree in the first clear position. Said preventing means may comprise one or more stops arranged to engage the door or a part connected thereto when the door swings open about the axis.

Thus, upon opening, the door does not impinge substantially upon the space in front of the autoclave.

Advantageously, the door may be permitted to swing through a greater arc in the second open position to facilitate cleaning and/or maintenance.

Preferably, the autoclave according to the present invention further comprises a latching device for releasably latching the door in the fully closed position prior to interengagement of said one or more high-load fastening devices. A suitable latching device disclosed by prior GB-A2325699, the contents of which are incorporated herein by reference.

Accordingly, said latching device may comprise: a first fixed portion that can be fixedly secured to one of the door and the vessel; a second portion that is provided with an engaging member for engaging a catch on the of the door and vessel; and a mechanical linkage for connecting said first and second portions to one another, which mechanical linkage comprises a first toothed member that is eccentrically rotatably mounted on one of said first and second portions, a second toothed wheel that is rotatably mounted substantially concentrically on the other of said first and second portions, and tie means for holding the first toothed member and the second toothed wheel in interengagement; the arrangement being such the rotation of said toothed member and toothed wheel causes translational movement of the second portion relative to the first portion, thereby to move the door relative to the surround between a released position and said fully closed position when the engaging member is engaged with said catch.

According to another aspect of the present invention, at least one of the first and second coupling members of the or each fastening devices is rotatable between an engaged position in which said first and second coupling members are mutually engaged and a disengaged position, said one rotatable member being fitted to the same one of the door and vessel as said latching device, and said autoclave further comprises an opening and closing mechanism for automatically operating said one or more fastening devices and said latching device.

Said opening and closing mechanism may comprise: a first gear engaged with one of said first toothed member and said second toothed wheel for operating the latching device, said first gear having a first toothed arc of sufficient length to move the second portion of said latching device through a complete stroke between said released and fully closed positions and a second non-toothed arc; a second toothed gear that is arranged to engage with said first gear, which second gear is operably connected to said one or more fastening devices for operating the same; and selectively operable bi-directional driving means for driving the first gear; wherein said first gear is arranged to engage the second gear only when the second portion of the latching device is in or proximate the fully closed position, the non-toothed arc of first gear providing lost motion between first and second gears; the arrangement being such that to close the door said driving means are operated to rotate the first gear in a first direction, which rotation causes corresponding rotation of the first toothed member and second toothed wheel of the latching device to move the second portion thereof from the released position to the fully engaged position, the non- toothed arc of the first gear being moved past the second gear such that the latter remains stationary until said second portion is in or proximate the fully closed position, whereupon the first gear engages the second gear and continued movement of the first gear in the first direction causes rotation of the one rotatable member of the or each fastening device from the disengaged position to the engaged position.

In this way, operation of the latching device and the one or more fastening devices is linked such that upon opening or closing the autoclave, the latching device and one or more fastening devices are operated according to a predetermined sequence.

Preferably, the latching device is configured such that in the fully closed position said first toothed member and said second toothed wheel are disposed top-dead-centre (TDC) with respect to the direction of translation of the second portion and continued rotation of the first gear in said first direction causes said first toothed member and second toothed wheel to move over TDC, thereby allowing the second portion to resile slightly from the fully closed position. This has the advantage that when said one or more fastening devices are engaged in the fully closed position, high internal loads applied to the door are not transmitted through the latching device. The latching device is maintained in the closed position over-TDC, preventing the latching device from inadvertently returning to the released position.

Preferably, the opening and closing mechanism according to the present invention is configured such that during movement of the second portion from the released position to the fully closed position, the non-arc portion of said first gear moves past said second gear, and said first gear engages said second gear when the second portion is disposed in said fully closed position, whereupon continued movement of the first gear in the first direction results in movement of the one rotatable member of each fastening device from the disengaged position to engaged position.

Suitably, the autoclave in accordance with the invention may further comprise a linear actuator for driving the door translationally in the direction parallel to the axis.

According to a second aspect of the present invention there is provided a latching and locking device for an autoclave, said device comprising: a first latching device adapted to be mounted on one of an autoclave vessel and door therefor and comprising a reciprocating engaging member adapted to engage a catch member mounted on the other of said door and vessel for moving said door between a released position and a fully closed position; a second high-load locking device comprising a first rotatable coupling member adapted to be mounted on said one of the vessel and door and a second coupling member adapted to be mounted on the other of the door and vessel, said first member being rotatable between a disengaged position and an engaged position in which said first coupling member engages said second coupling member when the door is fully closed for holding the door in said fully closed position during operation of the autoclave; and an automatic operating mechanism for operating said latching and locking devices according to a predetermined sequence for opening and closing the autoclave, which operating mechanism comprises a reversibly drivable input member, a first bi-directional output member for operating said latching device, and a second bi-directional output member for operating said first rotatable coupling member, said first output member being drivably connected to said input member such that operation of the input member in one direction causes corresponding operation of the first output member in the same direction, said second output member being drivably connected to said input member through a lost motion device such that operation of said input member causes no corresponding movement of the second output member until the latching device is in the fully closed position, whereat movement of the input member in the one direction causes corresponding operation of the second output member in the same direction for moving the first rotatable coupling member between said engaged and disengaged positions.

In some embodiments, said first latching device may comprise a rotatable toothed wheel and a mechanical linkage between said engaging member and said toothed wheel for driving the engaging member upon rotation of the tooth wheel.

Said input member may comprise a first gear in engagement with the toothed wheel, said first gear having a toothed arc to move said engaging member through a complete stroke between said and fully closed position.

The second output member may comprise a second gear in engagement with the first gear, said first gear having a non-toothed arc providing lost motion between said first and second gears, when the engaging member is not in or proximate the fully closed position.

Further features, objects and advantages of the present invention will be apparent

from the following description.

Following is a description by way of example only with reference to the accompanying drawings of embodiments of the present invention.

In the drawings: FIGS. 1A to 1D show an autoclave in accordance with the present invention in an operating state, with the autoclave door fully closed. FIG. 1A is a front elevation of the autoclave, FIG. lB is a plan view, and FIGS. 1C and 1D are side elevations of different respective sides of the autoclave.

FIGS. 2A to D show the autoclave of FIGS. 1A to D in an intermediate state with its door in a released position. FIG. 2A is a front elevation of the autoclave, FIG. 2B is a plan view, and FIGS. 2C and 2D are side elevations of different respective sides of the autoclave in the intermediate state.

FIGS. 3A to 3D show the autoclave of FIGS. 1A to D and FIGS. 2A to D in a cleaning state in which the autoclave's door is moved clear of the opening to the autoclave chamber and is swung open to facilitate cleaning. As before, FIG. 3A is a front elevation of the autoclave, FIG. 3B is a plan view and FIGS. 3 and 3D show different respective side elevations of the autoclave in the cleaning state.

FIG. 4 is an enlarged front elevation of part of the autoclave of FIGS. 1A to D, 2A to D and 3A to D with the door in the released position.

FIG. 5 is a plan view corresponding to FIG. 4.

FIGS. 6A and 6B show an opening and closing mechanism for an autoclave in accordance with the present invention, with FIG. 6A showing the opening and closing mechanism in a released position, and FIG. 6B showing a mechanism in a closed position.

FIG. 7 is a front elevation of the opening and closing mechanism of FIGS. 6A and 6B in the released position.

FIG. 8 is an enlarged side view of part of the autoclave of FIGS. 1A to D, FIGS. 2A to D, FIGS. 3A to D and FIGS. 4 and 5, showing one half of each of three high-load fastening devices mounted to the autoclave body and adapted to mate with respective other halves mounted to the autoclave door for holding the autoclave door securely in the fully closed position during operation of the autoclave.

FIG. 9 is a rear elevation corresponding to FIG. 8.

FIG. 10 is a sectional side elevation of the three fastening devices of FIGS. 8 and 9, showing parts mounted to the body of the autoclave and cooperating parts mounted to the autoclave door.

As shown in FIGS. 1A to D, FIGS. 2A to D and FIGS. 3A to D, an autoclave in accordance with one embodiment of the present invention comprises a rectilinear vessel 10 having top and bottom walls 11, 12 respectively, a back wall 13 and side walls 14, 15 respectively. The vessel 10 defines an internal chamber 16 as best shown in FIG. 3A, which chamber is open at the front of the vessel 10. The opening to the chamber 16 is surrounded by a surround 18 which carries a compressible seal 20.

Exteriorly, the body 10 carries a plurality of strengthening hoops 22, each of which encircles the vessel 10 for strengthening the same against high internal pressures during operation of the autoclave.

The vessel 10 is stably supported on a frame 24, such that the vessel 10 may be supported off the floor at a height at least equal to the height of the vessel 10, as best shown in FIGS. 1A and 2A. Said frame 24 includes a laterally extending front lower member 25 which protrudes laterally beyond one side 14 of the autoclave.

The protruding portion of the front lower member 25 carries a first lower swing plate 26 which is pivoted to the front lower member 25 about a substantially vertical axis 27. (See FIG. IC). Said lower swing plate 26 carries an upstanding guide rail 28 constituted by a beam that extends upwardly beyond the top wall 11 of the vessel 10. At its upper end, the guide rail 28 is connected to an upper swing plate 29 which is pivoted about said vertical axis 27 to a bracket member 30 that is welded to two adjacent supporting hoops 22. Said vertically extending guide rail 28 is therefore capable of pivoting about said vertical axis 27.

The guide rail 28, as best seen in FIG. 5, has a substantially rectangular cross- section having opposite front and back surfaces 31, 32 and opposite side surfaces 33, 34.

Said guide rail 28 supports a door 40, which door 40 has an inner face 41 and an outer face 42 as shown in FIG. 5. The outer face 42 carries a plurality of interconnected supporting ribs 44 as best seen in FIG. 4, which supporting ribs 44 serve to strengthen the door for reinforcement against high internal pressures during operation of the autoclave.

Juxtaposed one side 46, said door 42 carries four pairs of opposing rollers which engage with said guide rail 28 to allow translational movement of the door along the rail 28 in a direction substantially parallel to said vertical axis 27. In particular, the front face 42 of the door 40 carries two pairs of rollers 51 in engagement with the opposite sides 33, 34 of the rail 28, one pair being disposed towards the top end 48 of the door 42, and the other pair being disposed towards the bottom 49 of the door 42. The front face 42 of the door 40 also carries two pairs of rollers 52 (only one roller of each pair is shown in FIG. 4) which engage the front and back surfaces 31, 32 of the rail 28. Each pair of rollers 51, 52 is mounted to the front face 42 of the door 40 by means of a respective suitable adjustable bracket (not shown) which allows the position of the rollers 51, 52 relative to the door 40 to be adjusted such that the inner face 41 of the door 40 may engage sealingly with the surround 20 round the opening to the chamber 16.

Said one side 46 of the door 40 comprises a laterally extending portion 50 that protrudes laterally beyond said axis 27 and said one side 14 of the vessel 10 as described in more detail below.

In addition to translational movement along the length of the guide rail 28, the door is capable of rotation about said vertically extending axis 27 by virtue of the upper and lower swing plates 26, 29 pivoted respectively to the front lower member 25 and said bracket 30.

Juxtaposed the one side 46 of the door 40, two adjacent reinforcing hoops 22 carry a plurality of vertically spaced hook-shaped abutment members 60. In the present embodiment, there are three such abutment members 60 which are adapted to hold the door in a fully closed position during operation of the autoclave as described in more detail below. It will be appreciated, however, that fewer or more such abutment members 60 may be employed, depending on the capacity of the autoclave.

As best seen in FIG. 5, each abutment member 60 comprises a base portion 61 that is welded to a plate 62 that extends between said two adjacent supporting hoops 22. The base portion 61 carries a laterally extending hook portion 63 having a forward face 64 and a rear face 65. The forward face 64 is disposed to abut the inner face 41 of the laterally extending portion 50 of the door 40, and the rear face 65 is positioned to abut the outer face 42 of said extension portion 50.

Each of said hook-shaped members 60 may be slightly offset from the others in the front-back direction as shown in FIG. 5 for reasons described in more detail below.

The other side 47 of the door 40 is provided with a laterally extending catch member 70 that is adapted to incorporate with a forwardly extending latching device 80 that is mounted to a plate 81 extending between the two foremost adjacent reinforcing hoops 22 proximate the other side 15 of the vessel 10.

Said other side 47 of the door 40 also carries a plurality of vertically spaced T-bolt assemblies 91 that are adapted to mate with corresponding Tbolt engaging assemblies that are fitted to said foremost reinforcing hoops 22 as shown in FIGS. 8 to 10.

With reference to FIGS. 6A to B and FIG. 7 said latching device 80 forms part of an opening and closing mechanism 90 for the autoclave. The latching device 80 comprises an housing 101 comprising two spaced side walls 102, 103. (See FIG. 7). Said side walls 102, 103 rotatably support a first transverse pin 104 to which is keyed a first pinion 105.

Juxtaposed each face of the pinion 105, the pin 104 further carries two first links 106.

Said links 106 carry between them a second transverse pin 107 which carries a second pinion 108 which meshes permanently with the first pinion 105. Said second pin 107 is rotatable with respect to the first links 106, which links 106 serve to maintain the first and second pinions 105, 108 in meshing engagement.

Said second pin 107 further carries two second links 109 which are rotatable about a third pin 110.

Said third pin 110 is rotatably supported in an elongate pusher bar 112 that is constrained to move within the housing 101 in a front-back direction relative to the vessel and is connected to a hook member 82 that protrudes forwardly of the latching device for engagement with said catch 70.

The hook member 82 is thus moveable between an extended position as shown in FIG. 6A and a retracted position as shown in FIG. 6B. The first links 106 are cut out as shown at 111 to accommodate the third pin 110 when the hook member 82 is extended.

Said first pinion 105 further engages a large partially-toothed wheel 115 comprising a first toothed arc 116 and a second non-toothed arc 117. The large toothed wheel 115 is keyed to a fourth transversely extending pin 118 that is supported rotatably by said side walls 102, 103. Said fourth pin 118 is connected to a lever 120 for operating the opening and closing mechanism as described in more detail below.

Juxtaposed the large toothed wheel 115, the sidewalls 102, 103 carry a further fifth transverse pin 122 which carries a gear 124, said gear 124 being completely toothed.

Said large toothed wheel 115 is arranged such that the first toothed arc 116 remains permanently in engagement with the first pinion 105. When the pusher bar 112 is disposed in the extended position as shown in FIG. 6A, the large toothed wheel 115 presents its non- toothed arc 117 to the gear 124. Rotation of the large toothed wheel 115 clockwise as shown in FIGS. 6A and 6B produces counter-clockwise rotation of the first pinion 105 and clockwise rotation of the second pinion 108. Such clockwise rotation of the second pinion 108 causes the third pin 110 to move rearwards as illustrated in FIGS. 6A, thereby causing the pusher bar 112 and hook member 82 to move towards the retracted position of FIG. 6B.

When the first and third pins 104, 110 are disposed at their maximum separation (in which the door 40 is fully closed as described below) one end 116' of the first toothed arc 116 of the toothed wheel 115 engages the gear 124, whereafter continued rotation clockwise of the large toothed wheel 115 causes counter-clockwise rotation of the gear and also causes continued movement of the second pinion 108 over top-dead-centre as shown in FIG. 6B, such that the pusher member 112 resiles somewhat from the fully retracted position.

Said gear 124 is drivingly coupled by a suitable sub-mechanism (not shown) to a first generally upwardly extending, elongate angle bar 130 as shown in FIGS. 8 to 10 for producing reciprocal movement of said first angle bar 130. Numerous suitable mechanisms for converting rotational movement of the gear 124 to translational movement of the first angle bar 130 are readily available to those skilled in the art and need not be described in more detail herein.

Said first angle bar 130 extends substantially vertically behind the rear face 23 of the foremost reinforcing hoop 22 and has a lower end 131 and an upper end 132. At said lower end 131, the angle bar 130 is pivotally connected to a disk 140 that is fixedly secured coaxially to a rotatable bush member 141 forming part of a lower one of the aforementioned T-boltengaging assemblies 92. Said lower T-bolt engaging assembly 92 is adapted to cooperate with a corresponding respective power one of the T-bolt assemblies 91 mounted to said door 40.

The construction of each of said T-bolt engaging assemblies 92 is substantially the same, comprising a rotatory bush 141 having a front-end 142 that is accommodated within a respective open bore 143 formed in the foremost reinforcing hoop 22 around said vessel 10. Said front end 142 comprises two inwardly extending protrusions at 144 which define an elongate slot, 150 therebetween.

The rotatory bush 141 is externally threaded at 145 for engagement with a corresponding internal thread 146 formed in a cylindrical sleeve 147 that is fixedly secured to said rear surface 23 of the foremost reinforcing hoop 22.

Rotation of the rotary bush 141 in the sleeve 147 thus produces translational movement of the rotatory bush 141 in the front-back direction relative to the vessel 10.

As best shown in FIG. 9, the lower end 131 of the angle bar 130 is pivotably connected to the disk 140 mounted to the rear end of the rotatory bush 141 in such a manner that translational movement of said angle bar 130 produces rotation, and thus translation of the same in a direction substantially orthogonal to the longitudinal direction of the first angle bar 130.

At its upper end 132, the first angle bar 130 is pivotally connected to one end of a rotation bar 148 that is attached to an annular insert 149 which, in turn, is fixedly secured in the rear end of the rotary bush 141 of a second intermediate T-bolt engaging assembly 92. Said rotation bar 148, and its attachment to the upper end 132 of the angle bar 130 are arranged such that reciprocal movement of the angle bar 130 results in rotation of the rotatory bush 141 of the second T-bolt engaging assembly 92 in the same direction as the lower T-bolt engaging assembly 92.

Said rotation bar 92 is further pivotally attached to the lower end 151 of a second elongate angle bar 153, which second angle bar 153 is pivotally attached at its upper end 152 to a circular plate 154 that is mounted to the rotatory bush 141 of a third upper T-bolt engaging assembly 92. As with the first lower and second intermediate T-bolt engaging assemblies 92, the upper end 152 of the second angle bar 153 is mounted to the plate 154 in such a manner as to produce rotation of the rotatory bush 141 of the upper T-bolt engaging assembly 92 upon reciprocal movement of the second angle bar 153.

Said plate 154 may optionally carry an handle assembly 160 for manual operation of the T-bolt engaging assemblies 92. Thus, when fitted, said handle assembly 160 may comprise a knob 161 that is mounted on a stem on a shaft (not shown) which extends radially with respect to the axis of rotation of the rotatory bush 141 of the upper T-bolt engaging assembly 92. Operation of said handle assembly 160 thus causes rotation of the rotatory bush 141 and longitudinal movement of the second angle bar 153 which, in turn, produces rotation of the second intermediate rotatory bush 141 and corresponding translational movement of the first angle bar 130, resulting in simultaneous rotation of the rotatory bush 141 of the first lower T-bolt engaging assembly 92.

The elongate slots 150 formed in the front ends 142 of the rotatory bushes 141 of the T-bolt engaging assemblies 92 all align with one another, and the interconnection of the rotatory bushes 141 ensures that simultaneous rotation thereof.

With reference to FIG. 10, each T-bolt engaging assembly 92 is configured and positioned to mate with a corresponding respective one of the T-bolt assemblies 91 mounted to the door 40.

Each of said T-bolt assemblies 91 comprises a bolt 170 having a solid cylindrical body portion 171 that extends through an open bore 172 formed in the door 40 between its inner and outer faces 41, 42. Body portion 171 is externally threaded at 173 for engagement with an internally threaded bush member 174 that is carried on the bolt 170 on the outward face 42 of the door 40. Said bush member 174 is also externally threaded at for engagement with a thread 176 formed internally of a supporting tubular sleeve 177, which sleeve 177 is welded to the outer face 42 of the door 40.

The internal and external threads of the bush member 174 have different pitches from one another, and the bush member 174 is retained in position by means of a first locking nut 178. A second locking nut 179 is fitted to the rotatory bush 174 on the inner face 41 of the door 40.

The body portion 171 of said bolt member 170 carries a stem portion 181 which protrudes forwardly of the inner face 41 of the door 40 and carries at its extremity a head portion 182, which head portion 182 extends laterally on both sides of the stem portion 181 to form a T-shape therewith. Said T-shape is dimensioned to enter into the slot 150 of the corresponding respective T-bolt engaging assembly 92 that is connected to the vessel 10.

The extent to which the head portion 82 protrudes beyond the inner face 41 of the door 40 can be adjusted by rotating the bolt 170 with respect to the bush member 174. Fine adjustments can be made by rotating the bush member with respect to the threaded sleeve 177. The position of the bolt 171 can then be locked by means of the first and second locking nuts 178, 179.

The head portion 182 of each T-bolt assembly 91 has an inner face 183 that is positioned to engage accurately with an inner face 149 of the inwardly extending protrusion 144 formed at the front end 142 of the rotatory bush 141 of the corresponding respective T-bolt engaging assembly 92.

As best shown in FIG. 6A, said lever 120 is pivotably connected at 121 to a connecting rod 200 that is connected to a first linear actuator 202 for producing reciprocal movement of said connection rod 200, said first linear actuator 202 being fixedly secured to said frame 24 adjacent the said other side 15 of the vessel 10.

Adjacent to the one side 14 of the vessel 10, the frame 24 carries a second linear actuator 210, as best seen in FIGS. 1B, IC, 2B, 2C, 3B, and 3C.

Said second linear actuator 210 is arranged for a reciprocal movement in a substantially vertical direction substantially parallel to said axis 27 and carries a lifting member 212 that he is adapted to engage the bottom 49 of the door 40 for raising and lowering the door 40 along said guide rail 28. Suitably, the lifting member 212 may be fitted with a balltransfer-unit (BTU) for engagement with the door 40.

As shown in FIGS. 1A and 3A, the second linear actuator 210 can be used for raising and lowering the door 40 on the guide rail 28 between an upper position as shown in Figs. 1A to 1D (and also FIGS. 2A to 2D) and a lower position as shown in FIGS. 3A to D. In the lower position, the top 48 of the door 40 is positioned below the bottom wall 12 of the vessel 10 such that the door 40 is disposed clear of the opening to the chamber 60 provided by the vessel. This enables a user easily to gain access to the interior of the chamber 16 for placing or removing objects in or from the chamber 16.

Further, in the lower position, the door 40 is capable of rotation about said axis 27, by virtue of said upper and lower swing plates 26, 29, through an angle of at least 90 from a position in which the door 40 lies closely adjacent to the frame 24, subtending only a small angle with the front of the vessel 10 (as shown in FIG. 5), to a position in which the door extends forwardly of the vessel and frame 24 to facilitate maintenance of the autoclave and cleaning of the inner and outer faces 41, 42 of the door 40. In Figs. 3A to D, the door 40 is shown in an intermediate position. During normal use, when it is desired only to open the autoclave to gain access to the chamber 16, the door 40 may simply be moved to the lower position in the former orientation proximate the frame 24 so that, during such normal operation, the autoclave requires minimal space in front of it.

When it is desired to close the autoclave, the door 40, in its lower position, is first rotated if necessary to the orientation shown in Figs. 2A to D and FIG. 5 in which the door 40 subtends a small angle with the front of the vessel 10, the laterally extending portion 50 of the door 40 being aligned between the forward and rear faces 64, 65 of the hook-shaped abutment members 60. The door 40 is then be raised using the second linear actuator 210 to the upper position as shown in FIGS. 2A to D, FIG. 4 and FIG. 5. As mentioned above, each of hook-shaped members 60 is slightly offset from the others in the front- back direction. More particularly, the rear face 65 of each successive portion 63 as the door 40 is raised from the lower position to the upper position is positioned progressively closer to the surround 18 of the vessel 10. This means that the gap between the rear faces 65 of the hook- shaped abutment members 60 and the outer face 42 of the door 40 is widest for the lowermost abutment member 60 and smallest for the uppermost abutment member 60. This facilitates raising the door 40 to the upper position from the lower position.

As best shown in FIG. 5, the guide rail 28, swing plates 26, 29 and door 40 are configured such that in the position in which the door is raised and lowered as described above, it is ajar relative to the vessel 10. The axis 27 is spaced from the surround 18 such that the inner face 41 of the door 40 is positioned completely clear of the surround 18 and the compressible seal 20 fitted thereto. This allows the door 40 to be moved between the upper and lower positions without interfering with the seal 20.

In the upper position as shown in FIGS. 2A to D, the catch member 70 fitted to said door 40 engages with the hook member 82 carried by the pusher bar 112 of the latching device 80. If necessary, the precise orientation of the door 40 about the axis 27 may be adjusted to ensure that the catch member 70 correctly aligns with the hook member 82. In this position, the door is disposed in a released position, ready for closure.

In order to move the door from said released position to a closed position, said first linear actuator 202 is operated to move the lever 120 downwardly, causing clockwise rotation of the large toothed wheel 115 as represented in FIG. 6A.

As described above, clockwise rotation of the large toothed wheel 115 causes counter-clockwise rotation of the first pinion 105 and clockwise rotation of the second pinion 108. Such clockwise rotation of the second pinion 108 produces translational movement of the third pinion 110 in the rearwards direction relative to the vessel 110, thereby causing the hook member 82 to retract. As the hook member 82 is retracted, it draws the door 40 to a closed position in which its inner face 41 engages the surround 18 formed around the opening to the chamber 16 of the autoclave.

Continued downward movement of lever 120 results in continued retraction of the hook member 82 until the first, second, and third pins, 104, 107, 110 are arranged top- dead-centre in a line substantially parallel to the direction of movement of the pusher bar 112 and hook element 82. In this position, the door 40 is fully closed, with the compressible seal 20 compressed between the inner face 41 of the door and the surround 18, but with effectively metal-to-metal contact between the door 40 and the surround 18.

In the fully-closed position, the inner face 41 of the door 40 contacts the whole of the compressible seal 20 to form an effective high-pressure air-tight seal there between, and the outer face 42 of the door 40 at the one side 46 thereof abuts precisely the inner faces 65 of the abutment members 60. In order to provide an exact, high tolerance fit with said inner faces 65, the outer face 42 of the door 40 may carry ground spacers (not shown), each of which is accurately dimensioned to engage with a corresponding respective one of the abutment members 60. Since the abutment members 60 are offset as described above, it will be appreciated that the thickness of said spacers decreases from the bottom of the door to the top thereof.

The axis of rotation 27 and the door 40 are configured and arranged such that, as mentioned above, in the fully closed position, the inner face 41 of the door accurately contacts the surround adjacent the one side 46 of the door, and also the other side 47 of the door. The abutment of the outer face 42 of the door 40 with the abutment members 60 serves to hold the door in the fully closed position against high internal pressures during the operation of the autoclave, so that such high loads are not applied to the connection between the door 40 and the guide rail 28. The abutment members 60 thus serve the hold the door in the fully closed position against high internal operating pressures at the one side 46 of the door 40. The T-bolt assemblies 91 and corresponding T-bolt engaging assemblies 92 are used as described in more detail below to hold the door against such high internal operating pressures at the other side 47 of the door 40.

Continued downward movement of the lever 120 causes the first, second, and third pins 104, 107, 110, to move over TDC as shown in FIG. 6B. As described above, at the top-dead-centre position, the one end 116' of the toothed arc 116 of the large toothed wheel engages the gear 124, such that continued clockwise movement of the large-toothed wheel produces counter-clockwise movement of the gear 124.

As described above, the gear 124 is connected via a suitable submechanism to cause corresponding reciprocal movement of the first and second angle bars 130, 153.

With the door in the fully closed position, the head portions 182 carried by the bolts of the T-bolt assemblies 91 carried by the door 40 enter into the corresponding respective slots 150 of the T-bolt engaging assemblies 92 carried by the foremost reinforcing hoop 22 round the vessel 10. Linear movement of the first and second angle bars 130, 153, produces rotation of the rotary bushes 141 of the T-bolt engaging assemblies 92, thereby misaligning the slots 150 with the head portions 182, and thereby trapping the head portions 82 within the rotatory bushes 141. At the same time, rotation of said rotary bushes 141 produces rearward translational movement of the same, bringing the inner faces 149 of the inward protruding portions 144 of the bushes 141 into contact with the inner faces 183 of the respective head portions 182. At completion of the downward stroke of the lever 120, the inner faces 183 of the head portions 182 are accurately engaged with the inner faces 149 of the rotatory bushes 141 for holding the other side 147 of the door 40 firmly in the fully closed position against high internal pressures of the autoclave.

Movement of the first, second and thirds pins 104, 106, 110 of the latching device past the top-dead-centre position causes the pusher bar 112 and hook member 82 to resile slightly from the fully closed position, such that the door 40 is held at said other side 47 by the T-bolt assemblies 91 in engagement with the T-bolt engaging assemblies 92, so that loads applied to the door in the fully closed position are not transmitted through the latch device 80.

Further, as shown in FIGS. 6A and 6B, the hook member 82 is advantageously connected to the pusher bar 112 through a joint including a plurality of compressible Belville washers 83, such that any load that is transmitted through the pusher bar 112 and hook member 82 causes compression of said Belville washers to absorb the load.

Once the door 40 is fully supported by the abutment members 60 and T-bolt assemblies in the fully-closed position, the chamber 16 of the autoclave may be pressurized for use.

When it is desired to re-open the autoclave, the procedure described above is reversed. Starting from the position shown in FIG. 6B, the lever 120 is raised by the first linear actuator 202 causing clockwise rotation of the gear 24 which, in turn, causes forward movement of the rotary bushes 141 of the T-bolt engaging assemblies 92 and realignment of the slots 150 with the head portions 182. The first, second and third pins 104, 107, 110 of the latch device 80 are returned to the top-dead-centre position, such that the door is held once more by the latching device acting through the hook member 82 which engages the catch member 70. Any residual pressure within the autoclave may be released by compression of the compressible Belville washers 83 as mentioned above.

A continued upward movement of the lever 120 causes counter-clockwise movement of the large toothed wheel 115, clockwise movement of the first gear 105 and counter-clockwise movement of the second gear 108. Such counter-clockwise movement of the second gear 108 causes the third pin 110 connected to the pusher member 112 to slide forwards, thereby extending the hook member 82, which pushes the door 40 open about said axis 27 to the released position as shown in FIG.5.

In this released position, the door 40 may be lowered using the second linear actuator 210 to the lowered position as shown in FIGS. 3A to D as described above, such that a user may gain unrestricted access to the chamber 16.

By rotating the door 40 upon opening through a small arc relative to the surround 18, before sliding movement of the door to the lower position, the inner face 41 of the door is moved clear of the surround 18 and compressible seal 20. In this way, damage to the compressible seal 20 is avoided.

While the autoclave in accordance with present invention provides for a small degree of rotational movement of the door 40 in the upper position in order to move the door 40 clear of the seal 20 before translational movement of the door 40, the autoclave of the invention has the advantages associated with prior sliding door autoclaves requiring minimal space in front of the autoclave for opening the door.

However, as described above, in the lower position, the door 40 can, if desired, be completely opened by further rotation about the axis 27 in order to facilitate maintenance andlor cleaning.

In the upper position, substantial rotation of the door 40 about the axis 27 is prevented by the abutment members 60. In particular, rotation of the door 40 in the upper position beyond a predetermined small arc about the axis 27 is prevented by engagement of the inner face 41 of the door at the lateral extension portion 50 thereof with the forward faces 64 of the abutment members 60.

Claims

Claims I An autoclave comprising: a vessel defining a chamber and an

opening for gaining access to said chamber, said vessel including a surround disposed round said opening; a door adapted to cooperate with said surround for closing said chamber; a compressible seal disposed between said door and said surround; a door mounting device for mounting the door adjacent the vessel, said mounting device being adapted to allow the door to rotate about an axis, such that upon opening the door can swing about said axis from a closed position in which the door abuts said surround through a small arc sufficient to move the door clear of the surround, and to move translationally in a direction parallel to said axis to move the door clear of the opening to allow access to the chamber; and door holding means for holding said door in said closed position during operation of the autoclave.
2 An autoclave as claimed in claim 1, wherein said axis is spaced from said surround.
3 An autoclave as claimed in claim 1 or claim 2, wherein said door holding means comprise one or more selectively operable high-load fastening devices for holding the door in a fully closed position during operation such that said seal is compressed between the door and surround for sealing the chamber, the or each fastening device comprising a first coupling member mounted on one of the door and the vessel, a second coupling member mounted on the other of the vessel and the door, and selectively operable means for moving one or both of said first and second coupling members to bring them into mutual engagement for fastening them securely together.
4 An autoclave as claimed in claim 3, wherein the or at least one of said one or more fastening devices is positioned adjacent said surround remote from said axis.
An autoclave as claimed in any preceding claim, wherein said door holding means comprise at least one abutment arranged to abut said door or a part connected thereto in the fully closed position so as to support high outward loads on the door during operation.
6 An autoclave as claimed in claim 5, wherein said at least one abutment is disposed adjacent said surround proximate said axis.
7 An autoclave as claimed in claim 6, wherein said axis is interposed between said at least one abutment and said surround.
8 An autoclave as claimed in claim 5, claim 6 or claim 7, wherein said door holding means comprise a plurality of such abutments spaced apart in a direction parallel to said axis.
9 An autoclave as claimed in claim 8, wherein the spacing of said abutments from said axis increases progressively in the direction of moving the door clear of the opening.
An autoclave as claimed in claim 8 or claim 9, wherein said door carries a plurality of spacers, each spacer being sized and positioned to engage a respective one of said abutments in the fully closed position with a high tolerance.
11 An autoclave as claimed in any preceding claim, wherein said door mounting device is adapted to allow the door to slide in said direction parallel to said axis between a first clear position in which the door can be rotated to the closed position and a second open position in which the door is disposed clear of the opening, said door mounting device including means for preventing the door from swinging open from the closed position by more than a small degree in the first clear position.
12 An autoclave as claimed in claim 11, wherein said preventing means comprise one or more stops arranged to engage the door or a part connected thereto when the door swings open about said axis.
13 An autoclave as claimed in claim 11 or claim 12, wherein said door can swing through a greater arc in the second open position to facilitate cleaning.
14 An autoclave as claimed in any of claims 3-10, further comprising a latching device for releasably latching the door in said fully closed position prior to interengagement of said one or more high-load fastening devices.
An autoclave as claimed in claim 14, wherein said latching device comprises: a first fixed portion that can be fixedly secured to one of the door and the vessel; a second portion that is provided with an engaging member for engaging a catch on the other of the door and the vessel; and a mechanical linkage for connecting said first and second portions to one another, which mechanical linkage comprises a first toothed member that is eccentrically rotatably mounted on one of said first and second portions, a second toothed wheel that is rotatably mounted substantially concentrically on the other of said first and second portions, and tie means for holding the first toothed member and second toothed wheel in interengagement; the arrangement being such that rotation of said toothed member and toothed wheel causes translational movement of said second portion relative to said first portion, thereby to move said door relative to said surround between a released position and said fully closed position when said engaging member is engaged with said catch.
16 An autoclave as claimed in claim 15, wherein at least one of the first and second coupling members of the or each fastening device is rotatable between an engaged position in which said first and second coupling members are mutually engaged and a disengaged position, said one rotatable member being fitted to the same one of the door and vessel as said latching device, and said autoclave further comprises an opening and closing mechanism for automatically operating said one or more fastening devices and said latching device, said opening and closing mechanism comprising: a first gear engaged with one of said first toothed member and said second toothed wheel for operating the latching device, said first gear having a first toothed arc of sufficient length to move the second portion of said latching device through a complete stroke between said released and fully closed positions and a second non-toothed arc; a second toothed gear that is arranged to engage with said first gear, which second gear is operably connected to said one or more fastening devices for operating the same; and selectively operable bi-directional driving means for driving said first gear; wherein said first gear is arranged to engage the second gear only when the second portion of the latching device is in or proximate the fully closed position, the non- toothed arc of the first gear providing lost motion between said first and second gears; the arrangement being such that to close the door said driving means are operated to rotate the first gear in a first direction, which rotation causes corresponding rotation of the first toothed member and second toothed wheel of the latching device to move the second portion thereof from the released position to the fully engaged position, the non- toothed arc of the first gear being moved past the second gear such that the latter remains stationary until said second portion is in or proximate the fully closed position, whereupon the first gear engages the second gear and continued movement of said first gear in the first direction causes rotation of the one rotatable member of the or each fastening device from the disengaged position to the engaged position.
17 An autoclave as claimed in claim 16, wherein said latching device is configured such that in the fully closed position said first toothed member and second toothed wheel are disposed top-dead-centre with respect to the direction of translation of the second portion and continued rotation of said first gear in said first direction causes said first toothed member and second toothed wheel to move over TDC, allowing said second portion to resile slightly from the fully closed position.
18 An autoclave as claimed in claim 17, wherein said opening and closing mechanism is configured such that during movement of said second portion from the released position to the fully closed position the non-arc portion of said first gear moves past said second gear, and said first gear engages said second gear when the second portion is disposed in said fully closed position, whereupon continued movement of said first gear in said first direction results in movement of said one rotatable member of the or each fastening device from the disengaged position to the engaged position.
19 An autoclave as claimed in any preceding claim, further comprising a linear actuator for driving the door translationally in said direction parallel to said axis.
A latching and locking device for an autoclave, said device comprising: a first latching device adapted to be mounted on one of an autoclave vessel and door therefor and comprising a reciprocating engaging member adapted to engage a catch member mounted on the other of said door and vessel for moving said door between a released position and a fully closed position; a second high-load locking device comprising a first rotatable coupling member adapted to be mounted on said one of the vessel and door and a second coupling member adapted to be mounted on the other of said door and vessel, said first member being rotatable between a disengaged position and an engaged position in which said first coupling member engages said second coupling member when the door is fully closed for holding the door in said fully closed position during operation of the autoclave; and an automatic operating mechanism for operating said latching and locking devices according to a predetermined sequence for opening and closing the autoclave, which operating mechanism comprises a reversibly drivable input member, a first bi-directional output member for operating said latching device, and a second bi-directional output member for operating said first rotatable coupling member, said first output member being drivably connected to said input member such that operation of said input member in one direction causes corresponding operation of the first output member in the same direction, said second output member being drivably connected to said input member through a lost motion device such that operation of said input member causes no corresponding movement of the second output member until the latching device is in said fully closed position, whereat movement of the input member in one direction causes corresponding operation of the second output member in the same direction for moving the first rotatable coupling member between said engaged and disengaged positions.
21 A latching and locking device as claimed in claim 20, wherein said first latching device comprises a rotatable toothed wheel and a mechanical linkage between said engaging member and said toothed wheel for driving said engaging member upon rotation of said toothed wheel.
22 A latching and locking device as claimed in claim 21, wherein said input member comprises a first gear in engagement with said toothed wheel, said first gear having a toothed arc of sufficient length to move said engaging member through a complete stroke between said released and fully closed positions.
23 A latching and locking device as claimed in claim 22, wherein said second output member comprises a second gear in engagement with said first gear, said first gear having a non-toothed arc providing lost motion between said first and second gears when the engaging member is not in or proximate the fully closed position.
24 An autoclave substantially as hereinbefore described with reference to and as shown in FIGS. 1 to 5 of the accompanying drawings.

An latching and locking device substantially as hereinbefore described with reference to and as shown in FIGS. 6 to 10 of the accompanying drawings LON 1738v1