US1564115A

US1564115A - Safety device fob hot-wateb systems

Info

Publication number: US1564115A
Authority: US
Publication date: 1925-12-01
Anticipated expiration: 1942-12-01

Description

Dec. 1; 1925.

G. A. ROBERTSHAW SAFETY DEVICE FOR HOT WATER SYSTEMS Filed June 2'7, 1923 2 Sheets-Sheet 1 G. A. ROBERTSHAW SAFETY DEVICE FOR HOT WATER SYSTEMS Dec.- 1 I 1925. 1,564,115

Filed June 27, 192,3 2 Sheets-Sheet 2 Patented Dec. 1, 1925.

UNITED STATES.

A 1,564,115 PATENT OFFICE.

,, GEORGE A. ROBERTSHAW, 0F GREENBURG, PENNSYLVANIA.

SAFETY DEVICE FOR HOT-WATER SYSTEMS.

Application filed June 27, 1923. Serial No. 648,001f

- a thermostatically operated valve for controlling the supply of gas to the burner in a hot water system. In such a system the circulating pipe and heating coils fill up most rapidly due to corrosion and deposits because these are the parts which are subjected to the highest temperatures. It is possible to create a dangerous pressure in thecirculating pipe and coils if the circulation is retarded. Therefore, it is desirable to provide means controlled by the temperature of the circulating pipe for cutting off the supply of gas when that temperature exceeds the limit of safety. A thermostat inserted in the circulating pipe is subject to corrosion or insulating deposits and other disadvantages. By the present invention there is provided a safety device of simple construction and embodying avalve to be placed in the gas supply line and a fuse for controlling the valve and adapted to be positioned upon the exterior of the circulatlng P In the accompanying drawing, there 1s shown, for purposes of illustration only, one embodiment of-the present invention, it being understood that the drawings do not define the limits of the invention, as changes may be made in the construction and operation therein disclosed without departing from the s irit of the invention or scope of my broa or claims.

In the drawings:

Figure 1 is a side elevation of a hot water system having a safety device in accordance with my invention associated therewith;

Figure 2 is a view partly in section and partly in elevation of the safety device and assoclated parts of the hot water system;

Fi re 3 is a sectional viewtaken on the line II- III of Figure 2; and

Figure 4. is a perspective view of the fusl ble link.

In Figure 1 there is shown a hot water system of usual construction, comprising a boiler A and a gas heater B. Gas is supplied to the burner 2 of the heater through the u'su'alpipe 3. This pipe may have a thermostat 4 therein for controlling the supply of gas to the burner 2 within normal temperature ranges, or this thermostat may be omitted. The circulating pipe is indi.

cated by the reference numeral 5.

The safety device of the present invention may comprise a suitable T-shaped valve casing 6 tapped into the gas supply pipe 3 and having a valve seat 7 with which cooperates a valve 8. The leg 9 of the T-shaped casing 6 is screw threaded for cooperation with the screw threaded reduced portion 10 of a head 11 which is screwed into said leg until the shoulder 12 between said reduced portion 10 and the head engages the end of said leg thereby forming a gas tight closure. The stem 13 of the valve 8 extends through an opening 14 in the head 11. The reduced portion 10 is provided with a recess 15 and surrounding the stem 13 and arranged in said7recess is a packing gland 16 and a washer 1 Surrounding the stem 13 and interposed between the washer 17 and the valve 8 is a coil spring 18. Revolubly mounted upon a reduced portion of the head'll and extending towards the circulating pipe 5 are a pair of legs 19 having curved feet 20in engagement with said pipe 5. Thelegs 19 constitute means for maintaining the

pipes

3 and 5 roperly spaced apart against the reaction 0 the 0011 spring 18 in case the gas supply pipe 3 is not firmly supported, and as these logs are revolubly mounted, the valve casing 6 may be placed in a vertical, horizontal or inclined position. The stem 13 is provided with one or moreopenings 21 extending transversely therethrough. Engaged in one of theopenings 21 is one end of an S shaped hook 22.. The valve 8 is normally maintained away from its seat 7 by means of a fusible link surrounding the pipe 5 and engagin the other end of the hook 22. This fusible link is shown in detail in Figure- 4 and may comprise sim 1y a pair of wires 23 each of which is douhled upon itself to form a loop 24, the free ends of the two doubled wires 23 being joined by a spot of 110 fusible solder 25. The solder to be employed will be one melting at a temperature below that considered dangerous. Preferably, it will consist of an alloy of lead, tin and bismuth or cadmium. In hot water heaters a melting temperature of 200 to 25Q F. 1s generally considered low enough to prevent a dangerously high pressure in the system.

In case the gas supply pipe 3 is firmly supported, it will not be necessary to provide the legs 19 on the head 11. Moreover, when the device is used on heaters which do not have a circulating pipe, the fusible link may be attached to the outside of the boiler or to the hot water outlet pipe near the boiler.

The advantages of the present invention are many. The fusing solder is open to the atmosphere and is not subject to corrosion or insulating deposits. The fusible link may be.replaced without shutting off the water or otherwise disturbing the system. There is no special tapping required in order to associate the safety device with the system. The fusible link may be located on the circulating pipe, in which dangerous temperatures and. pressures are most likely to. develop. The spring-closing valve with internal self-adjusting packing gland is not accessible from the exterior so that it cannot be tampered with. The S-hook for engagement with the loops. 24 of the fusible link permits the valve 8 to be turned 180. The fusible link is inexpensive to manufacture and the same link may be utilized over and over again by simply reuniting the free ends thereof with the spot of fusible solder. The

entire device is of extremely simple construcother system.

WVhile I have illustrated my invention as applied to a hot water system, it will. be understood that its use is not necessarily limited to such systems.

I claim:

1. In a hot water circulating system, the combination with a gas-supply pipe and a hot-water circulating pipe, of a safety device comprising a valve tapped into the gas-supply pipe, means tending to move said valve into engagement with its seat, and means for normally maintaining said valve away from its seat, comprising a fusible link looped. around said hot-water circulating pipe and connected to said valve, substantially as described. y

2. In a hot water system, the combination with a gas-supply pipe and hot-water circulating pipe, of a safety device comprising a valve tapped into the gas-supply pipe, means tending to move said valve into engagement with its seat, means for normally maintaining said valve away from its seat, comprising afusible link looped around said hot-water circulating pipe and connected to said valve, and spacing means engaging the valvecasing and said hot water circulating pipe, substantially as described;

In testimony whereof I have hereunto set my hand.

GEORGE A. ROBERTSHAW.