GB2345537A

GB2345537A - Ventilator for a prison cell window

Info

Publication number: GB2345537A
Application number: GB0000479A
Authority: GB
Inventors: Peter Brown
Original assignee: Crittall Windows Ltd
Current assignee: Crittall Windows Ltd
Priority date: 1999-01-08
Filing date: 2000-01-10
Publication date: 2000-07-12
Anticipated expiration: 2020-01-10
Also published as: GB0000479D0; GB2345537B; GB9900443D0

Abstract

A prison cell window (11, Fig 1) has ventilator (10) along a vertical edge. The ventilator has a housing (16) with a valve member (24) operated by rotation of a control knob (28) at one end of an axially slidable spindle (29). The valve member (24) is a pivotable flap which opens and closes an air passage between perforations (17, Fig 1) and air gap (18). The valve member may also be a slidable flap (124, Fig 4) sliding on four roll pins (150, Fig 4). The passage in the housing (16) may also contain an insect mesh or grille (25) or spacer elements (118, Fig 4).

Description

Ventilator The present invention relates to a ventilator and more particular to a ventilator for use in secure environments such as a prison cell. In such environments, where opening windows are not a practical option, a ventilator needs to operate as efficiently as possible since it is replacing, rather then supplementing, an opening window.

Existing ventilators comprise stainless steel louvre mechanisms or slide vents. The slide member of a slide vent is usually arranged to move horizontally, since, if arranged vertically, it tends to be moved by gravity into its lower position, even when the upper position is desired. Also the actuating member is externally accessible and this can lay the ventilator open to vandalism. Moreover the actuating member can act as a suspension point (i. e. the ventilator is not ligature-proof) and this has disadvantages in a prison cell.

The present invention seeks to provide a ventilator which overcomes or reduces one or more of the above disadvantages.

According to a first aspect of the present invention there is provided a ventilator comprising a housing with means defining an air passage within the housing from an inlet to an outlet, valve means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the control means comprises a spindle operatively connected at one end to a control knob and at its other end to the valve member, and wherein rotation of the control knob causes axial movement of the spindle to selectively open and close the valve member.

In one embodiment, rotation of the control knob occurs through a limited angular range only, e. g. a quarter turn.

In another embodiment the control knob may be rotated continuously in either direction.

The control knob may be circular and is preferably substantially flush with the adjacent housing surface.

In a preferred embodiment the valve member is a slidable flap. Alternatively a pivotable flap may be provided.

According to a second aspect of the present invention there is provided a ventilator comprising a housing with means defining an air passage within the housing from an inlet to an outlet valve means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the valve means comprises a slidably mounted flap member.

The flap member preferably slides on or in at least one guide element. In a preferred embodiment the flap member has four holes through which pass four respective fixed pins or rods as guide elements.

According to a third aspect of the present invention there is provided a ventilator comprising a housing with means defining an air passage within the housing from an inlet to an outlet, value means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the valve means comprises a pivotally mounted flap member.

The control means preferably comprises a spindle, one end of which is in operative connection with a control member, rotation of which produces axial movement of the spindle, and the other end of which is in operative connection with the flap member, wherein said axial movement causes pivoting of the flap.

The pivot axis of the flap preferably extends vertically.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which: Fig. 1 is a view of the interior face of a ventilator in accordance with the present invention located along the vertical edge of a non-opening window; Fig. 2 is an exterior view of the ventilator of Fig. 1 ; Fig. 3 is an enlarged top plan view showing a cross-section of a ventilator in accordance with a first embodiment at a central region thereof; Fig. 4 is a top plan view showing a cross-section of a ventilator in accordance with a second embodiment at a central region thereof; and Fig. 5 is an interrupted view in the plane A-A of the entire height of the ventilator of Fig. 4.

Referring to the drawings, a ventilator 10 is arranged vertically along the edge of a non-opening secure window 11, e. g. of a prison cell. Ventilator 10 and window 11 are firmly held within a strong common frame 12.

In a first embodiment, Fig. 3, the ventilator has an extruded aluminium housing 16 of two parts 22,23 forming the exterior part of the vent, the parts being separated by an air gap 18 for ventilation. A stainless steel insect mesh 25 is provided between the housing parts. Secured to the housing 16 is a steel security cover 21 perforated at spaced locations 17 along its length. Cover 21 is fixed to housing 16 by means of screws 37 which, after installation of the ventilator, are concealed behind strong vertical bar elements 14 of frame 12.

The interiors of housing 16 and cover 21 are in communication via an opening which extends over substantially the entire height of the ventilator and which is arranged to be selectively covered or opened by a ventilating flap 24 which likewise extends over substantially the entire height of the ventilator. Thus flap 24 serves as the valve member of the ventilator. The flap 24 is attached to housing part 23 by means of a continuous integral hinge 33 and at its opposite edge has a stepped portion 53 with a compressible air seal 27 which engages the housing part 22.

To control movement of the flap 24 there is provided a centrally-arranged operating mechanism 60 having its own housing 32. Housing 32 is provided in two parts, both secured to cover 21 by screws 34 and nuts 35. The operating mechanism 60 comprises a spindle 29 with a cam surface (not shown) which co-operates with a cam surface (not shown) within a spindle guide member 30 fixed to housing 32. The spindle 29 and member 30 are also provided with co-operating stop members (not shown) which limit the rotation of the spindle to a quarter turn, during which the spindle moves axially.

The interior end of spindle 29 has attached thereto a control knob 28 of a hard material such as brass or self-lubricating nylon which is non-toxic. The interior surface 58 of the knob protrudes only slightly from cover 21 and has two recesses 56 for engagement by the finger and thumb of a user.

Its circumference 57 is slightly stepped to prevent the insertion of a tool in any unauthorised attempt to remove or damage the knob.

The other end of spindle 29 is attached by a screw 39 to the flap 24. Accordingly, when knob 28 is rotated through a quarter-turn from the position shown, spindle 29 operates to move flap 24 from its fully closed to its fully open position (not shown). Of course, intermediate positions are also possible.

End caps (not shown) are provided for the ventilator housing.

The above-described ventilator has numerous advantages. In particular there is no tendency for flap 24 to move out of its set position. This is mainly because its pivot is arranged vertically, so that gravity has no effect, but also due to its positive control mechanism which holds the flap at the precise angle at which it has been set. In addition there are no points of attack which could make the ventilator liable to be vandalised, and it is also ligature-proof.

Because it can be arranged vertically, the ventilator provides improved circulation. The uninterrupted inlet of air gap 18 also assists circulation. Moreover the meandering inlet passage minimises water penetration and the ingress of sound is also reduced. An additional advantage of the ventilator is that it can be retro-fitted to existing openings, with the width of cover 21 corresponding to the space between the two existing bar elements 14.

Various modifications may be made to the above described ventilators. For example, the operating mechanism 60 can be arranged at the top or bottom if desired. Other arrangements may be provided for pivoting the flap, for example a threaded spindle drive, and rotation may not be limited to only a quarter-turn. The face 58 of knob 28 can be precisely flush with the adjacent surface of cover 21.

Instead of, or in addition to, insect screen 25, an air filter may be installed in the air passage.

The ventilator may be installed horizontally if required.

It is envisaged that the operating mechanism 60 could also be used to control a sliding flap, e. g. by means of a ratchet drive. Because the flap would be held in an adjusted position, similar advantages would be provided.

A second embodiment, Fig. 4, also comprises a slidable valve flap rather than one that pivots. Here, the ventilator 101 has an aluminium housing 116 with two extruded parts 117,119 and two pressed parts 122,123 forming the exterior part of the vent. The parts 122,123 have their free ends attached by a spacer element 118 to maintain an air gap for ventilation. A stainless steel insect mesh 125 is provided between the extruded housing parts 117,119. Secured to the housing 116 is a steel security cover 121 similar to the cover of the embodiment of Figure 3.

The interiors of housing 116 and cover 121 are in communication via an opening which extends over substantially the entire height of the ventilator and which is arranged to be selectively covered or opened by a ventilating flap 124 which likewise extends over substantially the entire height of the ventilator. Flap 124 has a cover plate 144 attached thereto by means of two rivets 145.

Flap 124 is arranged to undergo outward translational movement between the illustrated closed position and a fully open position indicated in broken lines in Fig. 4. In the closed position, draughts are prevented by compressible air seals 127 engaging housing parts 117 and 119.

To control movement of the flap 124 there is provided a centrally-arranged operating mechanism 160 having a housing part or bracket 132 secured to cover 121 by screws 134 and nuts 135. The operating mechanism 160 comprises a spindle 129 with a cam surface (not shown) which co-operates with a cam surface (not shown) within a spindle guide member 130 fixed to housing parts 117,119. As spindle 129 is rotated it also moves axially thus producing axial movement of the flap 124. In this embodiment there are no stop members to limit rotation, so the spindle may be rotated without restriction in either direction, with the flap moving between closed and fully open positions during each rotation. It will be appreciated that by an appropriate partial rotation of the spindle, flap 124 may be moved or any desired intermediate position to allow continuous control of the airflow through the ventilator 101.

The interior end of spindle 129 has attached thereto a control knob 128 of a hard material such as brass or selflubricating nylon which is non-toxic. The interior surface 158 of the knob has a central bar 159 which protrudes only slightly from cover 121.

The other end of spindle 129 is attached by a screw 139 to the flap 124.

To avoid tilting of the flap 124 during the movement perpendicular to its place, it is arranged to slide on four fixed roll pins 150 which extend through the housing. The roll pins 150 are arranged to pass through corresponding holes in the flap which allows an even sliding movement.

The embodiment of Fig. 4 has similar advantages as the embodiment of Fig. 3. It is particularly convenient to connect the mesh 124 between channels 155 which are formed during the extension of parts 117 and 119. This gives more design freedom for the housing parts 122,123 which can be pressings, (which are less expensive to manufacture) and/or made of steel, (which is a stronger material). The omission of stop members for limiting the rotation of the spindle increases the resistance of the ventilator to damage. Also, since mesh element 125 is relatively large, it is less likely to clog up.

Similar modifications may be made to the embodiment of Fig. 4 as to the embodiment of Fig. 3. In addition, if desired, parts 122,123 may be made of aluminium, which may be extruded. The flap 124 may have external guide means adjacent to the edge thereof. The features of the embodiments may be interchanged as desired.

With the use of spacer elements 118, additional external openings may be provided to increase the ventilation. In such cases, an additional housing part together with a spacer element 118 is inserted between housing parts 122 and 123 (or parts 22 and 23).

Claims

Claims 1. A ventilator comprising a housing with means defining an air passage within the housing from an inlet to an outlet, valve means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the control means comprises a spindle operatively connected at one end to a control knob and at its other end to the valve member, and wherein rotation of the control knob causes axial movement of the spindle to selectively open and close the valve member.
2. A ventilator according to claim 1, wherein the valve means comprises a sliding flap.
3. A ventilator according to claim 2, wherein the flap slides in at least one guide element.
4. A ventilator according to claim 1, wherein the valve means is a pivotable flap.
5. A ventilator according to any preceding claim, wherein the control knob is substantially flush with the surrounding surface of the ventilator housing.
6. A ventilator comprising a housing with means defining an air passage within the housing form an inlet to an outlet, valve means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the valve means comprises a slidably mounted flap member.
7. A ventilator according to claim 6 wherein the flap member slides on or in at least one guide element.
8. A ventilator according to claim 7 wherein the flap member slides no a plurality of fixed pins or rods which pass through respective holes in the flap member.
9. A ventilator comprising a housing with means defining an air passage within the housing form an inlet to an outlet, valve means for selectively opening and closing said passageway, and control means accessible from outside the housing to selectively move the valve means, wherein the valve means comprises a pivotally mounted flap member.
10. A ventilator according to any of claims 6 to 9 wherein the control means comprises a spindle, one end of which is in operative connection with a control member, rotation of which produces axial movement of the spindle, and the other end of which is in operative connection with the flap member, wherein said axial movement causes opening or closing of the flap member.
11. A ventilator according to any preceding claim, wherein rotation of the spindle is limited.
12. A ventilation according to any of claims 1 to 10 wherein rotation of the spindle is limitless.
13. A ventilator according to any preceding claim, comprising a mesh element across said air passage.
14. A ventilator according to claim 13, wherein said mesh element extends generally perpendicular to the valve means.
15. A ventilator according to claim 13, wherein said mesh element extends generally parallel to the valve means.
16. A ventilator according to claim 15, wherein the ventilator housing comprises parts produced by extrusion and parts produced by pressing and wherein the mesh element is mounted in channels which are produced during extrusion of the extruded parts.
17. A ventilator according to any preceding claim wherein the air passage is at least partially defined by a spacer element located between different parts of the ventilator housing.
18. A ventilator substantially as herein described with reference to Figs. 1,2 and 3 or to Figs. 1,2,4 and 5 of the accompanying drawings.
19. A prison cell window having a ventilator according to any preceding claim mounted along a vertical edge thereof.