GB2221519A

GB2221519A - Gas furnace switch

Info

Publication number: GB2221519A
Application number: GB8818395A
Authority: GB
Inventors: Lung-Hsiung Lee
Original assignee: SHINREX KITCHEN UTENSILS CO LT
Current assignee: SHINREX KITCHEN UTENSILS CO LT
Priority date: 1988-08-02
Filing date: 1988-08-02
Publication date: 1990-02-07
Also published as: GB8818395D0

Abstract

A gas furnace switch includes a switch base plate (1) with an ignition trigger member (11), and a spring-biased rotating shaft (2) extending through the baseplate (1) and having an ignition finger (211) and a restriction finger (212). Normally, the restriction finger (212) is confined within an area between the blunt inner edges of two limiting elements (41 and 42) which have tapered outer edges so that the rotary knob cannot be rotated. When the rotary knob and hence the rotating shaft (2) are in a depressed position, a gas on-off valve is opened and the ignition finger (211) abuts against the baseplate (1) allowing the ignition finger (211) to be rotated to activate the ignition trigger member (11) so as to achieve the ignition. The release of the thrust to the rotary knob allows the restriction finger (212) to be biased by the spring action so as to rest on a housing (3) outside of the area. At this time, the restriction finger (212) may be rotated clockwise or counterclockwise outside of the area to adjust the magnitude of the fire until it enters the area where the rotary knob cannot be rotated. <IMAGE>

Description

PUSH-TYPE GAS FURNACE SWITCH WITH A ROTARY KNOB This invention relates to a gas furnace switch, particularly to a push-type gas furnace switch with a rotary knob, The improvement of this invention is directed to a conventional non push-type gas furnace switch shown in Fig. 1. The conventional switch includes a switch baseplate 91 on which an ignition trigger member 92 and an obstructing projection 93 are provided. A rotating shaft 94 extends through the baseplate 91. A ring 95 is sleeved rigidly on the rotating shaft 94 by a retaining ring. When the rotating shaft 94 is turned in the direction indicated by the arrow, the projecting arm of the ring 95 pushes the ignition trigger member 92 so as to achieve ignition. Then, the arm of the ring 95 may be rotated within a range of 180 or 360 degrees to adjust the gas feeding quantity, thereby controlling the magnitude of the fire.

Recently, house owners tend to use push-type gas furnace switch. However, the rotary knob of a conventional push-type switch can only rotate within a range of 90 or 180 degrees for the purpose of adjusting the gas feeding quantity. Accordingly, the non pushtype switch of Fig. 1 should be modified into a pushtype switch.

It is therefore the main object of this invention to provide a push-type gas furnace switch with a rotary knob.

According to this invention, a gas furnace switch includes a switch baseplate with an ignition trigger member mounted on the outward surface thereof and operatively connected to an ignition system, a springbiased rotating shaft extending through the baseplate to incorporate with a gas cock and biased to move axially outwardly, a gas on-off valve installed on the rotating shaft and opened when the rotating shaft is pushed so as to move axially inwardly, and a rotary knob mounted on the outer end of the rotating shaft and spaced apart from the baseplate at a predetermined distance.

This invention is characterized by an ignition finger extending radially outwardly-from the rotating shaft between the baseplate and the rotary knob; a restriction finger also extending radially outwardly from the rotating shaft in general alignment with, and spaced apart from, the ignition finger circumferentially around the rotating shaft; two spaced-apart limiting elements, disposed between the baseplate and the rotary knob, each of the limiting elements having a tapered outer edge and a blunt inner edge; and two resilient elements respectively biasing the limiting elements away from the baseplate so that the restriction finger is confined within an area between the blunt inner edges of the limiting elements.

Thereby, the rotary knob can be pushed inward to abut the ignition finger against the outward surface of the baseplate so that the restriction finger is no longer confined between the limiting elements, thereby enabling the ignition finger to rotate and activate the ignition trigger member. When the rotating shaft is no longer in a depressed position so that the restriction finger is biased to move away from the base plate outside of the area, the restriction finger can rotate either clockwise or counterclockwise until it enters the area where the gas on-off valve is closed.

Other features and advantages of this invention will become apparent in the following detailed description of a preferred embodiment of this invention with reference to the accompanying drawings in which; Fig. 1 is a schematic view of a non push-type gas furnace switch; Fig. 2 is an exploded view of a push-type gas furnace switch according to this invention; Fig. 3 is a partially sectional front view showing the interior structure of the switch according to this invention; Fig. 4 is a sectional view taken along the line IV-IV in Fig. 3; and Fig. 5 is a sectional view taken along the line V-V in Fig. 3.

Referring to Figs. 2-5, a push-type gas furnace switch of this invention is shown. The switch includes a switch baseplate 1 on which an ignition trigger member 11, two cylindrical tongues 12 and an obstructing projection 13 are provided. Only one of the tongues 12 is shown. The obstructing projection 13 is positioned near the ignition trigger member 11. A spring-biased rotating shaft 2 extends through the base plate 1 and connected to a gas cock at the inner end thereof. A ring 21 is sleeved on the rotating shaft 2 and locked on the same by a C-shaped retaining ring 22 so that the ring 21 cannot slide on the rotating shaft 2. The flat outer wall of the rotating shaft 2 engages with the flat inner wall of the ring 21 so that the ring 21 cannot rotate relative to the rotating shaft 2.

An ignition finger 211 and a restriction finger 212 project radially outwardly from the periphery of the ring 21 in a spaced-apart relationship. The rotating shaft 2 extends through both a housing 3 and a large compression spring 51 into a rotary knob. A pivot pin 32 extends through the hole 31 of the housing 3 and the pivot holes 414, 424 of two limiting elements 41, 42 so that the limiting elements 41 and 42 are mounted pivotally on the housing aside by side. The right limiting element 41 has a blunt inner edge portion, and a tapered outer edge portion which is defined by two inclined surfaces 411, 412. Similarly, the left limiting element 42 has a blunt inner edge portion, and a tapered outer edge portion which is defined by two inclined surfaces 421, 422.Each of the limiting elements 41, 42 also has a cylindrical cavity 413, 423 in which the outer end of a small compression spring is received. The inner ends of the small compression springs are respectively sleeved on the cylindrical tongues 12 which project from the base plate 1. The housing 3 is screwed to the baseplate 1 by four locking bolts. Only one of the locking bolts is shown. A positioning pin 23 extends through the circular hole 24 of the inner end portion of the rotating shaft 2 and the hole of an gas on-off valve 62 which is connected between the rotating shaft 2 as well as a gas cock, as shown in Fig. 4. Referring to Fig. 5, the positioning pin 23 can move in a slide slot 61 so as to control the gas on-off valve 62. Because the gas cock and the gas on-off valve 62 do not form part of this invention, a more detailed description thereof will be omitted.

Referring particularly to Fig. 3, the restriction finger 212 is normally positioned within an area between the blunt inner edges of the limiting elements 41 and 42 so that the rotating shaft 2. and hence the rotary .knob cannot be rotated. When the rotary knob and the rotating shaft 2 are pushed inward to open the gas on-off valve 62, the ignition finger 211 abuts against the outward surface of the baseplate 1. Because the restriction finger 212 moves inwardly out of the area to be positioned between the baseplate 1 and the limiting elements 4)., 42, the rotary knob can be turned counterclockwise so as to rotate the ignition finger 211 to activate the ignition trigger member 11, thereby achieving the ignition.At this time, the rotary knob cannot be turned clockwise due to the fact that it would be hindered by the obstructing projection 13. The release of the thrust to the rotary knob allows the restriction finger 212 to be biased by the spring action to move outward toward the housing 3.

The restriction finger 212 will rest on the housing 3 outside of the area which is positioned between the limiting elements 41 and 42. At this time, the restriction finger 212 may be rotated freely outside of the area to adjust the magnitude of the fire. When it is desired to close the gas on-off valve 62, the restriction finger 212 can be rotated into the area, at whick point the rotary knob cannot be rotated any further.

With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.

Claims

CLAIMS:

1. A switch for gas furnace including a switch baseplate with an ignition trigger member mounted on an outward surface thereof, a spring-biased rotating shaft extending through said baseplate to incorporate with a gas cock and biased to move axially outwardly, a gas on-off valve installed on said rotating shaft and opened when said rotating shaft is pushed to move axially inwardly, and a rotary knob mounted on an outer end of said rotating shaft and spaced apart from said baseplate at a predetermined distance, characterized by:: an ignition finger extending radially outwardly from said rotating shaft between said baseplate and said rotary knob; a restriction finger also extending radially outwardly from said rotating shaft in general alignment with, and spaced apart from, said ignition finger circumferentially around said rotating shaft; two spaced-apart limiting elements, disposed between said baseplate and said rotary knob, each of said limiting elements having a tapered outer edge and a blunt inner edge; and two resilient elements respectively biasing said limiting elements away from said baseplate so that said restriction finger is confined within an area between said blunt inner edges of said limiting elements; whereby, said rotary knob can be pushed inward to abut said ignition finger against said outward surface of said baseplate so that said restriction finger is no longer confined between said limiting elements, thereby enabling said ignition finger to rotate and activate said ignition trigger member; when said rotating shaft is no longer in a depressed position biasing said restriction finger to move away from said base plate outside of said area, said restriction finger can rotate either clockwise or counterclockwise until it enters said area where said gas on-off valve is closed.

2. A switch as claimed in Claim 1, wherein a housing is sleeved slidably on said rotating shaft between said baseplate and said rotary knob and connected securely to said baseplate so that said limiting elements are mounted pivotally on said housing.

3. A switch as claimed in Claim 1, wherein a ring is sleeved rigidly on said rotating shaft between said baseplate and said rotary knob, said ignition finger and said restriction finger projecting radially outwardly from periphery of said ring.

4. A switch as claimed in Claim 1, wherein each of said limiting elements has a cavity formed therein, said resilient elements being respectively received in said cavities of said limiting elements at one end thereof and fixed on said baseplate at the other end thereof.

5. A switch as claimed in Claim 4, wherein said baseplate includes two tongues on which said resilient elements are sleeved respectively.

6. A switch substantially as described hereinbefore with reference to figures 2-5 of the accompanying drawings.