US1613479A - Fusible link or strut - Google Patents

Description

I Jan.

C. F. PECKHAM FUSIBLE LINK 0R STRUT Patented Jan. 4, 1927.

Uhll'lED STATES PATENT @FFECE.

FUSIBLE LINK OR STRUT.

Application filed December 13, 1924. Serial No. 755,788.

My invention relates to fusible links, struts or similar connections employed with automatic fire-extinguishing systems for holding the valves of sprinkler-heads closed or for retaining fire doors, shutters or the like normally open, and consists in improvements in the construction and method of operation of the same.

One object of the invention 1s to provide a device of the type specified in which the separable parts of the link or strut may be more securely bonded or held together by the fusible material, while being adapted for quicker release when exposed to a predetermined degree of heat.

Another object of the invention is to provide a link or strut in which the separable members interengage or interlock 111 such manner as to take the stress of the parts which they hold, without placing undue straln on the fusible material which bonds them together. 4

Another object of the invention is to provide a device of the type specified 1n which the separable parts of the links have a tendency to spring apart upon the fusing of their bond so that their release will be substantially instantaneous and posit ve without any chance of sticking or dragging.

Another object of the invention 1s to provide a link or strut of simple constructlon adapted for economical manufacture and capable of being produced in large quantitles with greater uniformity to insure the required degree of accuracy 1n its control of the devices which it operates.

Further objects of the improvement are set forth in the following specification wh ch describes a preferred embodiment of the 111- vention as illustrated by the accompanying drawings. In the drawings Fig. 1 is a perspective view illustrating my improved fusible l1nk or strut applied to use on a sprinkler-head to connect the arms or levers which holdthe valve closed;

Fig. 2 is an enlarged plan View of the fus1- ble link or strut showing it in its preferred form: n

Fig. 3 is a greatly magnified plan view showing portions of the overly ng strips of wire-netting or screen-cloth which form the two parts of the link with their strands interengaging to substantially lock the parts against longitudinal movement;

Fig. 4; is a lateral cross-sectional view taken on line 4-4 of Fig. 8, and also showing the manner in which the strands of the two strips of screen-cloth interlock;

F 5 is a similar magnified longitudinal sectional view taken on the line 55 of Fig. 3, and further illustrative of the inter'engagement of the strands of the two strips of screen-cloth; and

Fig. 6 is a plan view of a modified form of the improved fusible link or strut.

Referring first to Figs. 1 and 2 of the drawings, a preferred form of my improved link or strut comprises two sections or strips 2 and 3 of reticulated material, such as wirenetting or screen-cloth, laid one over the other and bonded together with solder or an equivalent fusible metal which is flowed through the interstices of the mesh.

To prevent the strands of the screencloth from pulling apart or ravelling at the ends of the strips 2 and 3 I may employ suitable binding-strips 4 of thin sheet-metal folded over the edges thereof and crimped thereagainst, or fastened permanently thereto with hard solder or by brazing. Each strip or section 2 and 3 of the link has a hole or eye 5 punched through the netting near its end, and preferably the eyes are formed partly in the binder-strips f after the latter are applied to the netting so that they serve as a reinforcement for the holes. As illustrated in Fig. 2, the holes or eyes 5 in the two strips 2 and 8 register where the ends of one strip overlies the punched port1on of the other strip, it being noted that one strip preferably .does not extend the full length of the other strip but is short of the edge of the binder-strip 4;. It will be understood that the holes or eyes 5 provide means for engaging the link or strut with the hooked ends of the valve-levers 1 of the sprinkler-head H, see Fig. 1, or in other instances they may receive the hooks at the ends of the wire cords or chains employed for holding lire-doors or shutters. In either case the levers or other parts to be held to gether will engage against the reinforcing binderstrips at at the ends of the two members 2 and 3 so that there will be no tendency to pull apart the strands of the netting or screen-cloth.

Referring now to Figs. 3, 4 and 5, the two strips or sections 2 and 3 of the link are superimposed in such manner that the projecting bends or knuckles of the lateral strands of wire on the face of one strip will.

interlock with or engage. against the corre- 5 also illustrates the interengagement or interlocking of the lateral strands at 70, 7c,

. the purpose of this arrangement being to restrain the two strips from sliding longitudinally with respect to each other.

After the strips 2 and 3 have been laid one over the other with their strands of wire interposed and interlocked in the main ner as above described, the solder s or other fusible metal or alloy is flowed over them to bond the strips together. Usually the solder s is applied to the strips or members 2 and 3 across their full width and throughout the greater portion of their length, but leaving a narrow space between the solder and the edges of the binder-strips 4. The solder flows freely through the mesh of the strips and efi'ects a continuous and substantial bond between the two members or parts of the link so that the joint is practically proof against accidental rupture or disintegration.

In Fig. 6 I have illustrated another embodiment of the invention in which the hinding-strips at the ends of the members 2 and 3 are dispensed with and eyelets 6 inserted through the screen-cloth to provide means for connecting the link to the parts which it holds. Various other modifications may be made in the method of constructing and reinforcing the parts of the link without departing from the spirit or scope of the in vention. The method of operation of the device is as follows:

After the two parts of the link have been placed one over the other and bonded together in the manner as above explained the whole forms a relatively light-weight, yet strong and sturdy connecting device which may be used for various purposes as well known to those versed in the art. W'hen employed as a link or strut for sprinklerheads, as shown in Fig. 1, the ends of the valve-levers 1 are hooked through the holes 5 at the ends of the link to hold the ;.valve closed, and the link will sustain a very considerable stress without danger of rupturing the soldered bond and pulling the two sections apart. The interlocking engagement between the lateral strands or crosswires of the two strips of netting tends to resist longitudinal displacement. between the parts while they are held together by the solder and the solder itself forms a-very secure and substantial bond since it penetrates through the interstices of the mesh of both strips. lVhen however, the link is subjected. to an abnormal degree of heat the head, or in other uses to release theconnections of the fire-door or shutter.

\Vith the present improved link or strut the rupture of the bond and the separation of the parts is accelerated and rendered practically instantaneous due to a peculiar coaction of the novel form of interlocking means hereinheforc described. Immediately the solder begins to soften under the effect of the heat there will be tendency for the two parts of the link to spring apart due to a cam-action between the interlocked crosswires of the netting. That is to say, the tensile strain tending to pull the link-members lengthwise will have the effect of camming the interengaged cross-wires one on another to cause them to ride up over each other to force the two members apart to more quickly break the soldered bond. In other words, the rupture of the bond is rendered more prompt, without any tendency for the parts of the link to cling and drag on each other. My invention therefore provides a more eflicient and dependable device for the purpose intended which is more quickly re sponsive to break the connection when the heat reaches a prescribed degree.

The improved link or strut is adapted for economical manufacture and may be produced in quantity with a high degree of uniformity as regards the breaking factor, whereby it is rendered more accurate and dependable in its control. At the same time the peculiar construction of the link provides for a secure bond between the parts without danger of accidental rupture either in use or under rough handling.

Without limiting myself to the precise de tails of construction and arrangement of the device as herein shown and described, I claim:

1. A fusible link or strut comprising reticulated metal strips held in overlying relation by a bond of fusible material such as solder.

2. A fusible link or strut comprising reticulated metal stri s held in overlying relation by a bond of fusible material and provided' with means for connecting it with the. parts to be held.

3. A fusible link or strut comprising reticulated metal strips held in overlying relation by a bond of fusible material and provided with eyes at either end adapted to engage the connections of the parts to be held.

t. A fusible link or strut comprising strips of wire screen-cloth held in overlying relation by a bond of fusible material and provided With reinforcing elements permanently secured to their ends to prevent the Wires of the screen-cloth from pulling apart.

5. A fusible link or strut comprising strips of Wire screen-cloth held in overlying relation by a bond of fusible material and having reinforcing strips of sheet-metal folded over their edges and permanently secured thereto to prevent the strands of the screen-cloth from pulling apart.

6. A fusible link or strut comprising reticulated metal strips disposed in overlying relation with the mesh of one strip interlock ing with that of the other strip and bonded together by fusible material such as solder.

7 A fusible link or strut comprising overa lying strips of Wire screen-cloth disposed with the laterally extending strands of one strip interengaging With the corresponding strands of the other strip and held together by a bond of fusible material such as solder. 8. In a device of the type specified, the combination of superimposed strips of wire screen-cloth arranged With the bends of the Wire strands on one strip projecting into the interstices of the other strip to interlock the Wires to resist longitudinal displacement of one strip on the other, and fusible material flowed through the mesh of the strips to bond them together.

In testimony whereof I aflix my signature.

CHARLES F. PEOKHAM.

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