US2817349A - Safety device for fire valves - Google Patents

Description

Dec. 24, 1957 D. AfsEAvER' SAFETY DEVICE FOR F IRE VALVES INVENTOR Donald A. Seas/er Filed May 19, 1955 TORN EY 2,817,349 Patented Dec. 24, 1957 filice SAFETY DEVICE FOR FIRE VALVES Donald A. Seaver, Cheshire, Manufacturing Company, tion of onnecticut Application May 19,1955, Serial'No. 509,536 5 Ciaims. (Cl. 137-75) Cnn., assiguor to Scovill Waterbury, Coma, acorpora- This invention relates to safety devices, one form of which may be incorporated in fire valves such as used for connecting oil lines leading to oil burners and the like.

In previously known fire valves there has been provided a fusible element made of Woods metal or the like, which holds the valve open against pressure of a spring. When subjected to excessive heat the fusible element melts and allows the spring automatically to close the valve. Such valves, however, have not been able to meet certain underwriters specifications because when the valves are subjected to. temperatures much below the fusion point, for example 125 Fahrenheit, over a considerable period of time and while under compression, the fusible element will break down by crumbling and buckling.

To overcome the above fault it is the purpose of this invention to incase the fusible element within a confining chamber that will serve to hold the fusible element in its original shape until such time that the valve is subjected to fire or temperatures in excess of the fusion point of such element, whereupon the fusible material will fuse or melt and escape from its confining chamber and allow the valve to shut-off.

The full nature of this invention along with other objects and various advantages thereof will be more apparent from a consideration of the following description when read in connection with the accompanying drawing, in which,

Fig. l is a vertical sectional view of my safety device as applied to a fire valve provided with an improved handle construction embodying my invention.

Fig. 2 is a sectional view taken along the line 22 of Fig. 1.

Fig. 3 is an exploded view in section of the several parts that make up the handle.

Fig. 4 is a sectional view of the handle appear in the process of being assembled.

Fig. 5 is a vertical sectional view of my safety device as applied to a safety plug such as used on boilers or gas tanks embodying my invention.

Fig. 6 is a similar view to Fig. 5 showing the plug as it appears in 21 released state.

Referring to the drawing, the numeral 10 designates a valve body having a valve seat 11 and a lateral extension 12 to which a cap 13 is threadedly attached. The body 10 is formed with a valve chamber 14 within which operates a plunger or head 15 having a sealing disc 16 at. one end which is adapted to engage the valve seat 11 for closing the valve. The head 15 is connected to a stem 17 that extends upwardly through an opening 18 in the cap 13. That portion of the stem 17 that extends through the cap 13 is provided with a flattened surface 17a and the opening 18 is of complementary shape so as to prevent relative turning between the stem 17 and the valve body 10. The stem 17 is normally urged downwardly by a coiled spring 19 surrounding the stem 17 within the chamber 14 and compressed between the stem head 15 and the end cap 13.

My improved safety device in this particular construcparts as they tion is applied to the handle H which may be used for operating on safety valve. The handle H, as best illus-- trated in Figs. 1 and 3, consists of an outer annular handle grip 20 having a reduced extension. 21 terminating in an inwardly formed flange 22. Positioned coaxially within the handle grip 20 is a bushing 23 having a tapped hole 24 for threaded engagement with the threaded portion 17b of the stem 17. The upper end of the bushing 23 is formed with a radial outwardly extending flange 25.

The adjacent walls of the handle grip 20 and the bushing,

23 along with their respective flanges 22 and 25 define an annular chamber 26 which is loaded with an. annular ring or sleeve of fusible material 27 such as. Woods alloy.

As shown in Fig. 1 the handle H is held in spaced relation to the cap 13 by a spacer ring 28 fitted snugly about the. handle grip extension 21. It is to be noted that by reason of the spring 19 a constant axial downward force is exerted on the valve stem 17 and imparted to the bushing 23. To prevent the full axial force on the stem and bushing being imparted to the fusible. ring 27, the lower end of the bushing 23 is formed with a slightly reduced section 29 to provide a relatively narrow shoulder 30. A split wire ring 31 embraces the reduced section 29 and is wedged between the shoulder 30 and the upper surface of the handle grip flange 22. This ring thus serves as a releasable locking means to prevent relative telescopic movement between the inner and outer parts.

The dimensions of the fusible sleeve 27 before it is.

assembled are such that said sleeve is adapted to have a free slip fit into the interior of the handle grip 20,, and the bushing 23 in turn has a free slip fit into the interior of the fusible sleeve 27. The axial dimension of the sleeve 27 in its initial state is several thousandths greater than the distance between the adjacent faces of the flanges 22. and 25 of the. handle H. Also to provide a suitable exit for the fusible ring 27 when in a fused state, there should be several thousandths of an inch for free slidable clearance between the periphery of the flange 25 and the adjacent surface of the handle grip 20 and there should be a greater clearance between the periphery of. the flange 22 and the adjacent wall of the bushing reduced section 29.

Fig. 4 shows the manner in which the parts of the handle H may be assembled. The bushing 23 is inverted and placed with its flange 25 resting on a suitable anvil as a support. The fusible sleeve 27 is next fitted over the larger diameter of the bushing 23 to a position of rest on the flange 25. The split ring 31 is then slipped over the bushing reduced section 29 up to the fusible ling 27. The handle grip 24) is inverted and dropped over the outside of the fusible ring 27 with its flange 22 resting upon the split ring 31. With the parts of the handle thus assembled they may be placed in a suitable press and axially compressed until the flanges 22 and 25 are brought. into a common plane with the adjacent ends of the bushing 23 and handle grip 20 respectively. This operation will cause the fusible sleeve 27 to. be compressed and distorted to bear tightly against the walls of the chamber 26 and. at the same time drifted and compacted about the split ring 31. The distorting and compacting, of the fusible sleeve 27 within the. chamber 26 is sufficient to bind the bushing 23 to the handle grip 20 as a unit so that the handle can function to operate any device to which it may be attached without danger of slippage.

It is to be noted from Fig. 1 that the axial downward force exerted on the stem 17 by the spring 19 will be supported principally by the spring ring 31 incased in the fusible material and engaged between the bushing shoulder 30 and the handle grip flange 22 rather than impart the entire expansive force of the spring 19 upon the fusible material.

In case the handle is subjected to an excessive heat or force at which the parts of the handle are supposed to release, the fusible sleeve 27 will fuse and force the material outwardly through the clearance allowed between the peripheries of the flanges 22 and 25 and the adjacent walls of the bushing reduced section 29 and handle grip 20. Upon fusion of the ring 27 the split ring 31 consequently will be free to expand and slip over the bushing shoulder 30 and permit axial movement of the bushing 23 relative to the handle grip 20 thus allowing the spring 19 to close the valve.

Figs. and 6 show another application of my invention wherein the fusible ring may be applied to a blowout plug such as might be used in pressure gas tanks, boilers, and the like. In this form of the invention the plug consists of a hollow body member 32 having a threaded portion 33 and a hexagonal head 34 terminating in an inward flange 35. The hexagonal head 34 is provided to accommodate a wrench for removing or assembling the blow-out plug to a device.

Positioned within the body 32 is an insert bushing 36 having a radial flange 37 at one end that has a loose sliding fit within the hollow of the body 32. The interior wall of the body 32 and the exterior wall of the insert bushing 36 along with their respective flanges 35 and 37 define a chamber within which the collar of fusible material 38 may be jammed or compressed in the manner as explained in the first described embodiment of the invention. The insert bushing 36 opposite the flange 35 has a slightly reduced portion 39 providing a shoulder 40. Considerable clearance is provided between the flange 35 and the adjacent surface of the bushing reduced portion 39. A split ring 41 is gripped between the shoulder 40 and the body flange 35 and functions in the same manner as the split ring 31 as described in the first form of the invention. The insert bushing 36 is provided with an axial bore 42 extending part way of its length and which bore is intercepted by a cross bore 43.

In the operation of this blow-out plug when it is subjected to excessive heat the insert bushing 36 will be urged upwardly causing the fused material to be squeezed out past the split ring 41 through the annular space provided between the normal clearance allowed between the bushing flange 37 and the interior wall of the body member 32. This fusing of the material 38 will cause the bushing 36 to rise within the body 32 to a position where the cross bore 43 will clear the head end of the body 32 and release the excessive pressure of the device to which the blow-out plug may be attached.

As a result of my invention the fusible element in a safety device of the character described is tightly confined so that it will not permit the device to be released until such element actually fuses. This is an important improvement over a device where the fusible element is not confined and thus may break down when under compression at temperatures substantially below the fusing temperature.

Two forms of the invention are presented herein for the purpose of exemplification, but it will be appreciated that the invention is susceptible of changes and other structurally modified forms coming equally within the scope of the appended claims.

I claim:

1. A safety device for use in fire valves and the like comprising two telescopically interfitted members having a chamber therebetween, said members having flanges substantially closing the opposite ends of said chamber, a tubular ring of fusible material compressed within said chamber, and locking means disposed within said chamber for holding said members in fixed relationship and normally supported in locking position by said fusible material under normal conditions of operation and pressure, said locking means being releasable upon fusing of the ring.

2. A safety device for use in fire valves and the like comprising two telescopically interfitted inner and outer members having a chamber therebetween, said inner member having an outwardly extending flange substantially closing one end of said chamber, the outer member having an inwardly extending flange substantially closing the other end of said chamber, one of said members having an annular shoulder adjacent the flange of the other of said members, a split ring embraced between said shoulder and said adjacent flange to hold said members against relative telescopic movement, and a cylindrical ring of fusible material disposed within said chamber and surrounding said split ring to hold it in locking position.

3. A safety device for use in fire valves and the like comprising two telescopically interfitted inner and outer members having a chamber therebetween, said inner member having an outwardly extending flange substantially closing one end of said chamber, the outer member having an inwardly extending flange substantially closing the other end of said chamber, one of said members having an annular shoulder adjacent the flange of the other of said members, a split ring embraced between said shoulder and said adjacent flange to hold said members against relative telescopic movement, and a mass of fusible material compressed within said chamber and about said split ring to hold it in locking position.

4. A safety device for use in fire valves and the like comprising two telescopically interfitted inner and outer members having a chamber therebetween, said inner member having an outwardly extending flange substantially closing one end of said chamber, the outer member having an inwardly extending flange substantially closing the other end of said chamber, said inner member having a reduced section adjacent the flange of said outer member to provide a shoulder, a split ring wedged between said shoulder and said adjacent flange, and a mass of fusible material compressed within said chamber and about said split ring to hold it in locking position.

5. An operating handle for use on a shut-off valve having a projecting valve stem normally urged inwardly under spring tension, said handle comprising inner and outer telescopically interfitted members, said inner member having threaded engagement with said stem, said members being spaced from each other and each having an end flange extended toward the other to define a substantially closed chamber therebetween, a mass of fusible material filling said chamber and bearing tightly against said inner and outer members to bind said members together so as to operate upon said stem as a unit, and means supporting said outer member in spaced relation to said valve.

References Cited in the file of this patent UNITED STATES PATENTS 1,243,690 Blauvelt Oct. 17, 1917 1,332,283 Bancroft Mar. 2, 1920 1,892,674 Lovekin June 10, 1930 1,919,508 Griffith July 25, 1933 2,301,014 Burklin Aug. 29, 1941

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