US3605902A

US3605902A - Reinforced fusible element

Info

Publication number: US3605902A
Application number: US806123A
Authority: US
Inventors: Wayne E Ault
Original assignee: ATO Inc
Current assignee: Scott Technologies Inc
Priority date: 1969-03-11
Filing date: 1969-03-11
Publication date: 1971-09-20
Anticipated expiration: 1988-09-20

Abstract

A REINFORCED FUSIBLE ELEMENT USEFUL IN FIRE EXTINGUISHING SPRINKLERS, FUSIBLE LINKS ON FIRE DOORS AND THE LIKE IS DISCLOSED WHEREIN THE FUSIBLE MATERIAL USUALLY SOLDER OF A LEAD ALLOY OR THE LIKE IS PROVIDED WITH REINFORCING MEANS FOR STABILIZING ITS SIZE AND SHAPE BY ACTING TO PREVENT COLD FLOW OF THE ALLOY AS A RESULT OF COMPRESSIVE OR TENSION FORCES THEREAGAINST. SPECIFICALLY A FUSIBLE ELEMENT MAY BE PROVIDED WITH REINFORCING FIBERS OF SUITABLE MATERIALS INCLUDING NATURAL FIBERS, SYNTHETIC FIBERS AND METAL FIBERS OR FINE STRANDS MAY BE MIXED INTO THE ALLOY SO AS TO BE DISPOSED CONTINUOUSLY THERETHROUGH AND STILL ANOTHER VERSION ENCLOSES A SECTION OF FUSIBLE MATERIAL IN A WOVEN JACKET ENGAGING THE SURFACE OF THE FUSIBLE MATERIAL THAT WOULD ORDINARILY EXPAND WHEN THE SAME IS SUBJECTED TO COMPRESSIVE FORCES, ETC.

Description

Sept. 20, 1971 w. E. AULT 3,605,902

REINFORCED FUsIBLE ELEMENT Filed March 11, 1969 swam/lac Wayne E. Au/i- United States Patent Ofice Patented Sept. 20, 1971 3,605,902 REINFORCED FUSIBLE ELEMENT Wayne E. Ault, Aurora, Ohio, assignor to A-T-O Inc., Cleveland, Ohio Filed Mar. 11, 1969, Ser. No. 806,123 Int. Cl. A62c 37/30 U.S. Cl. 169-42 1 Claim ABSTRACT OF THE DISCLOSURE A reinforced fusible element useful in fire extinguishing sprinklers, fusible links on fire doors and the like is disclosed wherein the fusible material usually solder of a lead alloy or the like is provided with reinforcing means for stabilizing its size and shape by acting to prevent cold flow of the alloy as a result of compressive or tension forces thereagainst. Specifically a fusible element may be provided with reinforcing fibers of suitable materials including natural fibers, synthetic fibers and metal fibers or fine strands may be mixed into the alloy so as to be disposed continuously therethrough and still another version encloses a section of fusible material in a woven jacket engaging the surface area of the fusible material that would ordinarily expand when the same is subjected to compressive forces, etc.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to fusible elements of the type normally employed to hold other devices in predetermined relation pending attainment of a predetermined temperature upon which the other devices are to be released by fusing, that is softening of the fusible element.

(2) Description of the prior art Prior fusible elements have generally consisted of appropriately shaped units of a desirable fusible alloy, the fusing or softening temperature of which may be readily predetermined. Such elements are generally in compression in a device using the same such as a fire extinguishing sprinkler head wherein the levers holding a cap on a discharge orifice are in turn held in desired position by the physical presence of the fusible element and so arranged that alteration in shape of the fusible element permits the levers to move to a position opening the cap on the discharge orifice.

The present invention insures the retention of the desired physical shape of the fusible element and precludes accidental operation due to cold flow of the fusible element or other alterations in its shape due to causes other than those responsive to temperature at a desired degree.

SUMMARY OF THE INVENTION A fusible element comprises a pellet like portion of a metallic alloy such as for example an alloy which will fuse at 165 F. and consists of 30.51% lead, 24.45% tin, 41.22% bismuth and 3.82% cadmium.

Those skilled in the art will recognize that the percentages of the materials will vary depending upon the temperature at which the fusible element is to become operable.

The ability of fusible alloys such as the above example to withstand compression without cold flow of the alloy is limited and the present invention provides means for insuring against such cold flow and thereby maintaining the physical shape of the fusible alloy as desired until the fusing temperature is reached. This is made possible by the addition of fibers of bondable material throughout the fusible element and/or the jacketing of the fusible element in a woven flexible non-stretchable sleeve.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a fire extinguishing sprinkler showing a fusible element holding the mechanical levers thereof in fixed orifice closing position.

FIG. 2 is a greatly enlarged side elevation of a fusible element having a girdle thereabout.

FIG. 3 is an end view of the fusible element and girdle of FIG. 2.

FIG. 4 is a cross section on a greatly enlarged scale of a fusible element incorporating suitable fibers disposed throughout and bonded to the alloy of the fusible element.

FIG. 5 is a perspective view on a greatly enlarged scale showing a fusible element having a loosely woven flexible but non-stretchable jacket thereabout.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 of the drawing a typical environmental use of a fusible element may be seen to comprise a fire extinguishing sprinkler which device includes a frame 10 a threaded base 11 defining a passageway normally closed by a cap 12. A deflector 13 is ai'fixed to the frame 10 in oppositely disposed relation to the cap 12 as will be understood by those skilled in the art. A compression pin 14 positioned centrally through the upper portion 15 of the frame 10 engages a plurality of

levers

16, 17 and 18 respectively with the levers 18 being held in spaced apart relation by a fusible element 19.

The exterior configuration of the oppositely disposed spaced apart levers 18 is such that they cannot move through an opening 20 in the lever 16 until the fusible element 19 fuses so as to change shape and permit the lovers 18 to move toward one another sufiiciently that their configurations will clear the opening 20 whereupon the

levers

16, 17 and 18 fall free and permit the cap 12 to open the discharge orifice in the sprinkler.

In the prior art constructions the fusible element 19 is simply formed of a metal alloy that would fuse at a desired predetermined temperature. For example, these are conventionally 212, 286 and 360 F. In practical experience it has been found that when compression is constantly maintained on a fusible element it tends to alter its shape by reason of cold flow of material and sometimes to the point where accidental operation of the device controlled thereby results.

In order to utilize an inexpensive easily assmbled mechanical lever arrangement in a fire extinguishing sprinkler such as that shown in FIG. 1 of the drawings, it is necessary to place the fusible element under some degree of compression. By utilizing the invention disclosed herein the modified fusible element becomes capable of withstanding the compressive forces applied thereto without altering the shape and yet is fully responsive in operation to a fusing temperature.

In FIG. 2 of the drawings a fusible element 21 of solid cylindrical shape is shown in side elevation with a band like girdle 22 positioned about the middle portion thereof. The fusible element 21 is formed of a fusible alloy such as that hereinbefore described and the band like girdle 22 is formed of a harder metal such as brass which is sufiiciently hard so as to Withstand any tendency of the fusible element 21 to enlarge radially.

In FIG. 3 of the drawings an end view of the fusible element 21 may be seen and it will be observed that the band like girdle 22 is annular and extends completely thereabout.

In FIG. 4 of the drawings a fusible element 23 is illustrated which is a solid cylindrical shape of fusible alloy such as hereinbefore described and incorporating a plurality of random length loose fibers 24 distributed throughout. The fibers may be natural fibers, synthetic resin fibers, metallic fibers such as fine metal wire or metal shavings such as steel wool and the like and bondable to the fusible alloy so as to become an integral part thereof. The reinforcing action of the many fibers within the body of the fusible element 22 reinforces the same and prevents its growth longitudinally or radially except at fusing temperatures of the alloy.

In FIG. 5 of the drawings a perspective view of a fusible element 25 may be seen and it is enclosed on its outer circular surface with a loosely woven jacket 26 of diagonally positioned woven fibers 27 so as to form a flexible but non-stretchable jacket thereabout. A prefered em bodiment of the form of the invention illustrated in FIG. 5 would comprise a loosely woven wire braid such as for example that used in hydraulic hose constructions and bondable to the surface of the fusible element so as to prevent relative movement therebetween while being capable of collapse upon fusing of said element.

It will thus be seen that a fusible element has been disclosed in several forms which is reinforced to prevent changes in its physical shape at temperatures less than the fusing temperature of the alloy of which the fusible element is formed, The fibers of FIG. 4 and the flexible, collapsible woven jacket of FIG. 5 prevent undesirable change of shape of the fusible element and thereby meet the principal object of the invention.

Although but three embodiments of the present invention have been illustrated and described it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.

I claim:

1. A fusible element comprising a shaped section of a fusible alloy having means restraining cold flow of said alloy at temperatures less than the fusing temperature of said alloy, said means consisting of a non-stretchable loosely woven jacket enclosing said fusible element capable of collapsing upon fusing of said fusible element.

References Cited UNITED STATES PATENTS 1,362,236 12/1920 Delaney 169-38 2,004,833 6/1935 Rowley 16938 2,502,754 4/1950 Rowley 169-38 3,053,713 9/1962 Juras 161-170 3,336,984 8/ 1967 Macartney 16938 3,282,658 11/1966 Wainer 29-1835 3,303,006 2/ 1967 Morley 29-183.5X

M. HENSON WOOD, JR., Primary Examiner M. Y. MAR, Assistant Examiner US. Cl. X.R.