GB2518874A

GB2518874A - A control arrangement for a gas fire assembly

Info

Publication number: GB2518874A
Application number: GB1317566.6A
Authority: GB
Inventors: Peter Davison
Original assignee: Focal Point Fires PLC
Current assignee: Focal Point Fires PLC
Priority date: 2013-10-03
Filing date: 2013-10-03
Publication date: 2015-04-08
Anticipated expiration: 2033-10-03
Also published as: GB2518874B; GB201317566D0

Abstract

A control arrangement for a gas fire assembly includes a linear supply valve for controlling the supply of gas to a gas burner. The linear slide valve includes an operating rod 19 supported by a valve seat 18 and slideably movable relative thereto to control flow through the valve. A pivotable control lever 7, 13 is coupled to the valve rod 19 to controllably slide the valve rod 19 relative to the valve seat 18. The control lever 7, 13 pivots about a first pivot, with a portion of the valve rod 19 distal from the valve seat 18 connected to the control lever by a second pivot on the control lever. The second pivot is at a position distal from the first pivot such that movement of the control lever about the first pivot moves the valve rod relative to the valve seat.

Description

A Control Arrangement for a Gas Fire Assembly The present invention is concerned with a control arrangement for a gas fire assembly.

s The operator of a gas fire requires some means of controlling and activating the gas valve which supplies gas to the gas burner. Such a control must be easily accessible to a user and should ideally not be positioned in a location which affects the appearance of the fire.

Typically, the gas controls for gas fires are located directly on the firebox where the gas valve and burner are located, and are connected directly to the gas valve. The majority of manual gas fires in at least the United Kingdom include a rotatable control knob rotation of which drives a rod of a rotary control valve in a radial motion. Design constraints surrounding gas fires mean that it is often necessary to locate the operating knob and valve towards the bottom of the gas fire assembly. The gas burner and gas supply are located on the floor of the firebox so the easiest and tidiest place to locate the valve and its associated control knob is underneath the firebox.

It is also known to provide a sliding control element on the side or towards the top of the gas fire assembly which is linked by a series of operating rods and pivoting arms, to a gas valve located at the bottom of the fire. Examples of this are shown in GB 2,462,088, GB 2.350,686, GB 2,323,429, US 2003/0111073 and WO 95/28603.

A problem with the existing low level rotating control manual valve arrangements is that many customers struggle with rotary controls located underneath the firebox. This is particularly true for older people and for left-handed people using rotary controls on the right hand side of fires. Embodiments of the invention also aim to simplify the previous complicated pivot and tension cable arrangements associated with the slider type controls used for controls located higher up on the gas fire assembly. The complicated and multi-part pivoting rod and/or tension cable arrangements are expensive to make and prone to failure, It is also difficult to precisely control the position of the rod within the valve using such arrangements. This difficulty in controlling the position makes it difficult to optimise the flow rate and can therefore adversely affect the flowrate and operation of the fire.

The present invention provides a control arrangement for a gas fire assembly having a gas burner, the arrangement including: a linear slide valve for controlling the supply of gas to the burner, the linear slide valve including an operating valve rod slidingly supported by a valve seat; and a pivotable control lever coupled to the operating rod to controllably slide the valve rod relative to the valve seat, wherein the control lever pivots about a first pivot, a portion of the valve rod distal from the valve seat is connected to the control lever by a second pivot on the control lever at a position distal from the first pivot such that movement of the control lever about the first pivot moves the valve rod relative to the valve seat.

The inventor has appreciated that providing the pivotable control lever coupled to the linear operating valve rod allows one to replace the rotary low-level control with a low-level substantially linear operation. This simplifies the use of operation for people who struggle with rotary controls such as older people and left-handed people.

Preferably the second pivot is on the distal end of the valve rod and at a position on the control lever between its first pivot and its distal end. The inventor has appreciated that such an arrangement makes for a simple and easy to make control mechanism.

Preferably, the second pivot on the control lever is remote from the end of the control lever distal from the first pivot. The inventors have appreciated that such an arrangement can create a mechanical advantage such that a movement of the control lever results in a corresponding smaller movement of the valve rod. This means that the position of the valve rod and hence the flow rate through the valve can be more accurately controlled.

Preferably, a second slideable rod parallel and coupled to the operating valve rod is provided, and arranged for slideable movement together with the operating valve rod. This provides for a high level of reliability in a simple and smooth operation.

Preferably, the distal end of the valve rod and a first end of the second rod are fixed to a fixing element connected to the control rod. This provides a simple and effective way of ensuring that the movement of the two rods matches and they move together simultaneously.

Preferably, the second rod includes at least one notch on its circumference for engagement with a locator. This arrangement allows one to locate the rod at predetermined positions which may correspond to, for example, ignition, maximum gas output and/or minimum gas output.

A preferred embodiment of the invention will now be described by way of non-limiting example with reference to the attached figures, in which: Figure 1 is a perspective view of a gas fire assembly including a control embodying the invention; Figure 2 is a magnified view of detail C of Figure 1; Figure 3 is a cross-sectional view through the gas fire assembly of Figure 1 showing aspects of the current invention; Figure 4 is a front perspective view of the gas burner and control valve arrangement of Figure 1; Figure 5 is a top view corresponding to Figure 4 but also showing the control handle in both the ignition and off positions; Figure 6 is a bottom perspective view showing the control handle in the ignition position; Figure 7 is a bottom perspective view corresponding to that of Figure 6 but showing the control handle in the off position; Figure 8 is a bottom perspective view showing on a single figure the handle in both the ignition and off positions; and Figure 9 is a bottom plan view showing on a single figure the handle in both the ignition and off positions.

Referring to Figures 1, 3 and 4, a flueless gas fire assembly 1 includes a vent 2 in its top surface 3 for waste gases which have been passed over a catalytic converter in the manner described in GB 2,275,331. The gas fire assembly includes a firebox 4 having a gas burnerS, and openable doors 6 for accessing the inside of the firebox. A control handle 7 is located at the front bottom of the gas fire assembly and is shown in Figure 2 in both the ignition (A) and off positions (B).

Referring to Figures 4 and 5, the gas burner 5 is supported on a plate-like burner bracket 9 forming the bottom of the firebox 4. The gas burner 5 is fixed to the plate element by studs. A gas supply is connected to the gas burner via an injector 10. A valve bracket 11 supports the control arrangement which includes a slide control valve 12, control handle bracket 13, igniter 14, valve link 16, control rod 17 and control lever or handle?.

Referring to Figures 6 and 9, a valve seat 18 on the slide control valve 12 has an operating valve rod 19 slideable engaged within it and movable to control the supply of gas through the valve 12. The inlet 21 of the gas valve is configured for connection to a mains gas supply, and the outlet 20 connects to the gas burner 5. Sliding movement of the operating valve rod 19 alters the flow of gas between the inlet and outlet of the valve.

Specifically, the operating valve rod can move between a closed or off position B, in which no gas flows to the outlet, an ignition position A, and maximum and minimum operating positions, in which maimum and minimum operating volumes of gas flow to the gas burner.

In the embodiment shown in the figure and described herein, the off position B is at one extreme of the range of movement of the control handle and the ignition position A is at the other extreme position (see, for example, figures 5 to 9). The nature of the operating valve rod 19 means it can be moved in direction X shown in Figure 5 from its off position to an ignition position in which it operates an ignition system to ignite the burner 5 before being moved back in the direction Y to pass through first the position of minimum flow then progressively increase the flow up to maximum flow and then to the off position with no flow.

The distal end 22 of the operating rod 19 is fixed to a first vertical 23a control plate (forming part of the valve link 16) which is pivotally connected via a bearing 29a to a second horizontal control plate 23b which is pivotally connected via a bearing 29b to the control lever 7. The control lever (see figure 5) comprises a handle portion at its distal end and the valve bracket 11 connected thereto. The control handle and lever arrangement pivots about a control handle pivot 26. Movement of the control handle about the control handle pivot 26 moves the operating rod 19 relative to the seat and thereby controls operation of the valve 12 and the supply of gas to the gas burner 5.

The control handle 7 and L-shaped valve bracket 11 together form a single control rod or lever which pivots about the control handle pivot 26. The position of the bearing 29b at a position on the control rod or lever between its two opposing ends mean that there is a mechanical advantage or scaling effect such that the bearings 29a, 29b and hence the valve rod or spindle 19 moves a smaller distance into or out of the valve seat 18 then the distal end of the control handle is moved. In an accompanying embodiment with a valve rod 19 having a 30 mm range of movement (see figure 9) the distances and angles shown on figure 9 might be: e = 470 L1 = 117mm = 32mm L3 = 106mm L4 = 40mm where e is the range of movement of the control handle between the off and ignition positions, L1 is the distance the control handle moves between the off and operating positions, L2 is the length of the horizontal control plate 29b, L3 is the distance between the distal end of the control handle and the bearing 29b, and L is the distance between the bearing pivot 24b and the control handle pivot 26. Providing an arrangement with an adjustable L (i.e. valve bracket) allows one to increase or decrease the angle of movement e and thereby alter or control the scaling effect. One can have a number of different valve brackets 11 which can be installed to provide different scaling factors to the control of the valve for different fire requirements.

Alternatively one could provide a valve bracket in which the distance between the control lever pivot 26 and the bearing pivot 29b could be adjusted.

The dimensions of the control lever 7 and the mechanism coupling it to the valve rod 19 can be chosen to provide a given or pre-selected scaling factor between movement of the control handle 7 and corresponding movement of the valve rod 19.

A position control rod 17 (see, for example, figure 7) is arranged parallel to the valve operating rod 19. A first end of that position control rod 17 is rigidly connected to the plate-like valve link 16 at a position above where it is connected to the operating valve rod 19. The second end 29 of the position control rod 17 slides through apertures 30 in the valve bracket 11 on which the valve 12 is supported. The position control 17 therefore moves parallel to and together with the operating rod 19 as this is moved by movement of the control handle 7.

The position control rod 17 includes a notch 31 in its circumference which can engage with the locator defined by the edge of the aperture 30 (see Figure 7). The notch is located so that the engagement of the notch 31 with the locator indicates when the position control rod 17 (and hence the operating valve rod 19 it moves with) is at a pre-determined position. In the described and illustrated embodiment there is a single notch which is used to indicate when the operating valve rod 19 is located at the position corresponding to maximum gas flow rate through the valve 12. However, further notches could be provided corresponding to other valve rod positions (e.g. ignition, a recommended minimum operating gas flow rate and perhaps other positions corresponding to intermediate gas flow rates through the valve to the gas burner 5.

Claims

Claims 1. A control arrangement for a gas fire assembly having a gas burner, the arrangement including: a linear slide valve for controlling the supply of gas to the burner, the linear slide valve including an operating valve rod slidingly supported by a valve seat and slideably movable relative thereto to control flow through the valve; and a pivotable control lever coupled to the valve rod to controllably slide the valve rod relative to the valve seat, wherein the control lever pivots about a first pivot, a portion of the valve rod distal from the valve seat is connected to the control lever by a second pivot on the control lever at a position distal from the first pivot such that movement of the control lever about the first pivot moves the valve rod relative to the valve seat.
2. A control arrangement according to claim I wherein the second pivot is on the distal end of the operating valve rod and at a position on the control lever between its first pivot and its distal end.
3. A control arrangement according to any preceding claim wherein the second pivot on the control lever is separated from the end of the control lever distal from the first pivot.
4. A control arrangement according to claim 3 wherein the position of the second pivotis adjustable.
5. A control arrangement according to any preceding claim also including a second slideable rod parallel and coupled to the valve rod and arranged for slideable movement together with the valve rod.
6. A control arrangement according to claim 5 wherein the distal end of the valve rod and a first end of the second rod are connected to the control lever.S
7. A control arrangement according to claim 6 where the valve rod and second rod are fixed to a plate-like element connected to the control lever.
8. A control arrangement according to any of claims 5 to 7 wherein a second end portion of the second rod is slidingly received by an aperture in a support element.
9. A control arrangement according to claim 8 wherein the second rod includes at least one notch on its circumference for engagement with a locator.