GAS SAMPLING POINT FOR SMOKE/POLLUTION DETECTION SYSTEMS

Abstract: A sampling point (110) for use in a pollution/smoke detection system for fixture to an apertured panel in a building, this system including a plurality of said sampling points (110) for connection to an aspirated gas reticulation system for drawing gas from said sampling points (110) exposed to a space under surveillance, said sampling point including a portion (19) for securement to a retaining means (10) and a capillary tube (15a) communicating between the sampling point (110) and said aspirated gas reticulation system, the sampling point (110) having an orifice (116) of a predetermined size to communicate between an area to be surveyed and the gas reticulation system, said capillary tube (116) conforming to standard smoke detection requirements as to bore strength flexibility and crush resistance, said sampling point (110) being adapted to be fitted from either the visible or blind side of the apertured panel and including collapsible shroud means (17, 18) capable of passing through said apertured panel and expanding to hide the panel aperture from which it has emerged. A cover (117) releasably fitted to an apertured mounting base (111) and a capillary tube (113) for communicating the mounting base (111) and the gas reticulation system through an aperture, wherein the mounting base (111) and the cover (117) interconnect with a press fit, said cover (117) comprising an aesthetically formed shroud for the sampling point (110), is also disclosed.

Description: GAS SAMPLING POINT FOR SMOKE/POLLUTION DETECTION SYSTEMS The present invention relates to a sampling point for use in pollution and smoke detection systems and specifically very early warning smoke detection apparatus. Sampling points are used to penetrate a wall or ceiling and in operation are coupled to a capillary tube which is in turn connected to a pipe system distributed throughout a building or the like for drawing gas samples from the various sampling points to a pollution detection system. It is important that the sampling points for smoke detectors are strategically positioned to ensure collection of smoke at the earliest possible moment. It is therefore possible or usual for the sample point to be located in conspicuous positions in the room of a building, necessitating good aesthetic appearance of the sampling point. Furthermore it is important that the fitting of such sampling points is a relatively simple operation and yet the device must comply with various standards, for example Australian Standard 1670 which amongst other things calls for penetration of the sampling point for at least 25 mm into the space to be surveyed and the provision of a 50 mm identification ring in the case of use in smoke detection apparatus. It is an objective of the present invention to provide an improved sampling point construction complying with standard requirements has a minimum number of parts, and is simple to manufacture and install. This application is an extended disclosure of that contained in co-pending Application No. PL 2454 filed on the 14th May, 1992 which is hereby incoφorated herein by cross-reference. There is provided according to the present invention a sample point for use in a pollution/smoke detection system for fixture to an apertured panel in a building, this system including a plurality of said sampling points for connection to an aspirated gas reticulation system for drawing gas from said sampling points exposed to a space under surveillance, said sample point including a portion for securement to a retaining means and a capillary tube communicating between the sampling point and said aspirated gas reticulation system, the sampling point having an orifice of predetermined size to communicate between an area to be surveyed and the gas reticulation system, said capillary tube conforming to standard smoke detection requirements as the bore strength flexibility and crush resistance, said sampling point being adapted to be fitted from either the visible or blind side of the apertured panel and including collapsible shroud means capable of passing through said apertured panel and expanding to hide the panel aperture from which it has emerged. In a further aspect of the invention there is provided a sample point adapted to be fixed to an apertured panel or like in a building for use in a pollution/smoke detection system in the building, the system including a plurality of sample points for connection to an aspirated gas reticulation system for drawing gas from said sampling point exposed to a space under surveillance, said sampling point including a retention member for securing a capillary tube to communicate between the sampling point and said reticulation system, the arrangement being such that the capillary tube can be fitted from either the visible or blind side of the apertured panel or the like wherein the sample point includes a collapsible shroud means adapted to pass through said apertured panel or the like for fitment of the sampling point from the blind side of the aperture, said shroud means being expandable upon passing through the aperture to form a cover for the aperture. There is provided according to a further aspect of the present invention a sample point for use in pollution/smoke detection system comprised of a two part construction including an apertured mounting base for fixture to a base surface such as a ceiling for connection to an aspirated gas reticulation system for drawing gas from a plurality of sampling points and a cover loosely fitted to said mounting base and a capillary tube including an aperture for communicating with said apertured mounting base and gas reticulation system, wherein the mounting base and cover interconnect with a press fit, said cover comprising an aesthetically formed shroud for the sample point. Conveniently the shroud is collapsible in one direction only to enable it to support or absorb axial loads applied thereto in the opposing direction. Conveniently the collapsible shroud means includes a part releasably secured to said retaining portion on said sampling point, and hinged radially extending members thereon are adapted to retract when passing through the panel aperture and to expand radially to form said shroud in the manner of an unfolding umbrella. The retaining portion is preferably threaded and is split longitudinally to provide clamping means for rapid and secure fixing of the capillary tube. Said clamping means is engaged by encircling the threaded portion of the sampling point with the shroud member which forces clamping teeth to squeeze into the capillary tube. Below said clamping means the threaded tube is tapered internally to form a tight seal between said nozzle and said capillary tube when assembled avoiding the need for additional parts such as an O-ring to provide the seal. The retaining member and the shroud members preferably include partial thread portions which allow ratcheting of the components over the threaded portion but still provide adequate tightening of the components when screwed together to achieve a secure fitting. The partial thread portion facilitates the ratcheting and quick assembly of components onto the threaded portion of the sampling point avoiding the need to turn the sample point and thereby twist the capillary tube. The invention will be described in greater detail with reference to the accompanying drawings in which Figures 1 and 2 are sectional and elevational views of a retaining member. Figure 3 is an assembly drawing of a sample point including a capillary tube, clamping means, retaining member and a pair of daisy shroud members all in cross-section. Figure 4 is a similar assembly adapted for a thick wall or cavity but not showing the capillary tube. Figures 5 and 6 are a plan and sectional view of the upper daisy shroud members. Figures 7 and 8 are a plan and sectional view of a lower daisy shroud member. Figure 9 is a partial perspective view of the assembly of Figure 3 without thread and retaining member. Figures 10 and 11 are elevational and plan views of the assembly of Figure 9. Figure 12 is an elevation view of the assembly. Figures 13 and 14 are perspective exploded views of the assembly. With reference to Figures 1 and 2, these figures depict a retaining member 10 which can be affixed to a wall or panel through holes 11 fixed to either the visible or blind side of the wall or panel. The retaining member includes a partial thread portion 12 in bore 13 for threaded attachment to a threaded nozzle member which will be described in further detail later. The bore of the retaining member 10 is split at reference 14 to enable flexible movement of the tube member and enable it to ratchet over the thread of the threaded nozzle member which will be described in greater detail later. Figure 3 shows an assembly drawing with the retainer member which may be secured to a visible side of a panel or the like not shown coupled with a capillary tube 15a fitted into the threaded nozzle member 16. The arrangement shown in Figure 3 can be fitted from within a room by affixing the retaining member 10 to a wall or ceiling panel to which can then be fitted the threaded nozzle member 16. The threaded nozzle member 16 is slightly tapered internally to form a tight seal between said nozzle and the capillary tube at the leading edge of the capillary tube. According to the invention a daisy shroud member is made up of the components shown in Figures 5-8 in which upper and lower daisy members 17 and 18 are provided with petals 19 which are hinged by a plastic hinge at 20 to be folded along an axial direction to allow the daisy shroud to be inserted into a wall aperture such as that shown in Figure 4 in a folded umbrella like position and when it emerges from the hole the petals 19 spring out in the manner of an opening umbrella into a radial flare or fan pattern to form a shroud over the hole. Figure 4 shows an alternative version wherein the retaining member 10 is inverted and secured to the blind side of an apertured wall from which the capillary tube and nozzle member 16 may be suspended. According to the invention a daisy shroud member made up of the components shown in Figures 5 to 8 are provided in which the daisy shroud members 17 and 18 have petals 19 which are hinged by a plastic hinge at 20 to be folded along an axial direction to allow the daisy shroud to be inserted into a wall aperture such as that shown in figure 4 in a folded position and when it emerges from the hole the petals 19 spring out into a radial flare to form a shroud of the hole. With reference to Figures 4 and 6 the tubular portion 24 is of such diameter to engage clamps 25 on the nozzle member 16 and thus provide a clamping effect onto the capillary tube when installed. With reference to Figure 4 the positioning of the nozzle member 16 in the wall aperture allows flexibility of centring of the sampling point with respect to the panel and any accidental misalignment in the wall aperture. The two components 17, 18 of the shroud incorporate a pin and matching aperture at 21 , 22 to lock the two components together when fitted together so that the petals overlap one another to form a complete shroud having the diameter shown in Figures 5 and 7. The shroud members 17, 18 are fitted between the capillary tube and the wall or ceiling panel as shown in Figure 4 or alternatively where the retaining member is also secured on the same side of the ceiling or wall, the daisy shroud members are sandwiched between the sampling member 15 and the retaining member 10. In each instance the shroud provides a decorative cover for the aperture as shown in Figure 4 or the retaining member 10 as shown in Figure 3. The hinge of the daisy members is arranged so that the folding of the petals 19 may only be in a single direction to provide mechanical support for the various components when tightened up onto the retaining member. The sampling tube 15 may be formed with ribs 16a or the like to provide a decorative finish to improve the aesthetic appearance of the sampling point. With reference to Figures 1 and 2 of the drawings, the retaining member 10 has a split tubular section 14 having a partial thread 12 on the internal bore of the tubular section which is intended to engage with the nozzle member 16 as shown in Figures 3 and 4. The arrangement is such that the retaining member can be forced over the threaded portion for fast securement and then turned to tighten up on the thread. A similar arrangement is provided with the tubular portion of the daisy shroud member as shown in Figure 6. The retaining member 10 includes apertures for receiving fixing screws not shown for fixing the retaining member to a panel or like structure as shown in Figures 3 and 4. The sampling point includes an orifice 23 for allowing passage of a sample air or gas into the capillary tube mounted within the sample point. With reference to figures 3 and 4 the sampling point includes a radially extending flange 16b which extends beyond the hinge points 20 on the daisy shroud members to facilitate tightening of the sample point to the panel and prevent any over bending of the panels which could possibly affect the final appearance of the installed sample point. With reference to Figures 12 to 14, the sampling point 110 includes a mounting base 1 1 and a cover 117. The mounting base is supported within the ceiling panel and may be fixed by any known means for example by a large nut secured to the tubular part 112a or by securing screws to the ceiling panel. The cover 117 is adapted to be connected to a capillary tube in a reticulation system for carrying gas back from the sampling point to a central monitoring detector. A cover 117 can then be fitted to the mounting base at the same time or subsequently to fitting out of the space and includes a capillary tube gripping portion 113 having flexible fingers 113a which are adapted to engage in a tight fit within the mouth of the mounting base 114. The cover 112 includes a sampling orifice 116 of predetermined size. However the orifice may be increased as required by drilling. The components making up the sampling point device can be injection moulded and have improved aesthetic shapes particularly in its finish. Its installation is facilitated from below the ceiling after initial fitment of the mounting plate and pipe reticulation system above the ceiling. In other words the workman does not need to return to the roof space to finalize the installation of the capillary tubes. It will be appreciated that the sampling point of the invention can be easily fitted from inside or outside a panel depending upon access without any difficulty and wherein the components are quickly and easily secured together in an air tight and secure manner.

Claims: THE CLAIMS DEFINING THE INVFNTION ARE AS FOLLOWS: 1. A sampling point for use in a pollution/smoke detection system for fixture to an apertured panel in a building, this system including a plurality of said sampling points for connection to an aspirated gas reticulation system for drawing gas from said sampling points exposed to a space under surveillance, said sampling point including a portion for securement to a retaining means and a capillary tube communicating between the sampling point and said aspirated gas reticulation system, the sampling point having an orifice of a predetermined size to communicate between an area to be surveyed and the gas reticulation system, said capillary tube conforming to standard smoke detection requirements as to bore strength flexibility and crush resistance, said sampling point being adapted to be fitted from either the visible or blind side of the apertured panel and including collapsible shroud means capable of passing through said apertured panel and expanding to hide the panel aperture from which it has emerged. 2. A sampling point adapted to be fixed to an apertured panel or the like in a building for use in a pollution/smoke detection system in the building, the system including a plurality of sampling points for connection to an aspirated gas reticulation system for drawing gas from said sampling point exposed to a space under surveillance, said sampling point including a retention member for securing a capillary tube to communicate between the sampling point and said reticulation system, the arrangement being such that the capillary tube can be fitted from either the visible or blind side of the apertured panel or the like wherein the sampling point includes collapsible shroud means adapted to pass through said apertured panel or the like for fitment of the sampling point from the blind side of the aperture, said shroud means being expandable upon passing through the aperture to form a cover for the aperture. 3. A sampling point for use in a pollution/smoke detection system comprising a two part construction including an apertured mounting base for fixture to a base surface such as a ceiling for connection to an aspirated gas reticulation system for drawing gas from a plurality of sampling points and a cover releasably fitted to said mounting base and a capillary tube including an aperture for communicating with said aperture mounting base and a gas reticulation system wherein the mounting base and the cover interconnect with a press fit, said cover comprising an aesthetically formed shroud for the sampling point. 4. A sampling point as claimed in claim 1 or claim 2 wherein said collapsible shroud means is collapsible in one direction only to enable it to support or absorb actual loads applied thereto in the opposing direction. 5. A sampling point as claimed in claim 4 wherein the collapsible shroud means includes a part releasably secured to said retaining portion on said sampling point and hinged radially extending members thereon adapted to retract when passing through the panel aperture and to expand radially to form said shroud in the manner of an unfolding umbrella. 6. A sampling point as claimed in claim 1 wherein the retaining portion is threaded and split longitudinally to provide clamping means for rapid and secure fixing of the capillary tube, said clamping means being engaged by encircling the threaded portion of the sampling point with the shroud member which forces the clamping means to squeeze into the capillary tube. 7. A sampling point as claimed in claim 6 wherein the retaining member and the shroud members include partial thread portions which allow ratcheting of the components over the threaded portion but allow adequate tightening of the components when screwed together to provide a secure fitting.

Inventors: COLE MARTIN TERENCE, COLE, MARTIN, TERENCE
Applicants: COLE MARTIN TERENCE, IEI PTY LTD, I.E.I. PTY. LTD.
Application year: 1993
Main classification: G01N21
IPC codes: G01N1, G01N21, G08B17, G08B21