US 1816017 A
Description (OCR text may contain errors)
y 28, 1931- A. J. LOEPSINGER 1,816,017
Filed Jan. 2, 1929 Inventor (218% J. Loepfiinger a tfo 7 2152 less responsive to .heatchanges. 'In extreme Patented July 28, 1931 TED s r-Ares PATENT "OFFICE Arsenicugiioersrnenn, or rnovrnnncn, nnonn rsLn-nn -iassmivon :roenmmar. "rmsnxrnveursnsn 'COMYAN'Y, or rRovIDENcE, iiironn'rsraivn, econ-rennrrrou or DELAWARE I 1 7 Application filed lfanuary 2,
This invention relates to improvements, .in
links.","More'especiallyit has to do withthermally responsive links which upon rise of temperature to a predetermined degreegglve is way ;and: thereby free whatever has been held thertendency of suchtmaterial to yield grad ually at nnormaltemperatures it has become customary to interlock theseparable parts of thei'link soathatf these parts themselves will carry the major portion. of the load whilethe fusible (material is =-maintaining .this interlocked relation. By thus lessening the amount .of' strain onv the-material the .trouble from .cold flow islargely avoided but the arrangement; is not entirely satisfactory because the fusible. material is usually more or less insulated as it were by the;interlocked parts; and does not respond asquickly to changes: of temperature.
-Moreover' all fusible materialis subject to corrosion. In some cases this eats-awaythe fusible material and permits a premature rupture of the'linkwith possible damaging results if the link has been holding a fire eX-- tinguishing: agent in restraint. 'Far. greater difliculties are encountered, 1 however, in; the cases where the eifectofthecorrosion isuto change the/molecular structure of the fusible metal as for example. where it forms a: sulphideof the metal. :Thisactionis not-apparent-because 1 the 1 external appearance of the material is unchanged, but its effects are exceedingly dangerous because the resulting material has greater holdingpower and is cases thematerial in 'fact' becomes non-fusible. Accordingly, it is not uncommon to find fusible links so corroded as to be entirely inoperative in respect to the functions they are 1 expected to perform. This is obviouslya dangerous possibility and one likely to be 11nnoticed because, as previously stated, the effects of the corrosion can not be seen and the actual condition of the fusible material can s not be determined by visual inspection.
at; relatively high temperatures. Because of LINK 1929. .Serial 1N0. 329,817.
peratures, which will not require supervision or: maintenance, which will respond unfailinglywhen needed, and which has as its yielding' element one which-is capable of bearing the'full forceexerted upon: the link. .It isto the provision of-such. a link that the present invention. is directed.
RA principal objectofth-is invention isto provide a simple? link comprising only separable members which-are engaged by the ties andan element holding saidmembersagainst separation. It is a. feature of the invention that-this element bears all the loadimposed on theilink, is noncorrodible, andbecomes entirely destroyed when heated to. a predeterminedtemperature, thus completely severing allconnection betweenthe ties. As herein illustrated, the thermally responsive element is .aifrangible vessel preferably -made of quartzan'd containing a charge of expansible fluid whichupon being heated to predetermined degree completely destroys. thevessel. The latter may bemade' from tubing with its end portions formed, generally in "spherical shape,:each end beingjoined to the main body: portion of the'vessel by. a neck portion of somewhat smaller dimension. Theiend members of the link engage onlythe spherical ends of the frangible vessel so that the force transmitted by them is entirely carried by the vessel. "Upon the rupture or destruction of thevessel the li'nk ends are instantly and completely set free "with no chance of their becoming entangled or interlocked with one another.
ItIis intended thatthe; patent shall cover by suitable expression in the-appendedclaims whatever features of patentable novelty exist inthe invention disclosed.
In the accompanying drawings,
Figure l is an elevation partly in Section of a thermally responsive link constructed in accordance with the principles of the invention.
, Figure 2 is a. similar view of thesame link viewed as from the leftof Figure 1;
Figures 3 and 4 are similar views showing a modified form of link ends; and
Figure 5 is a view showing the linkend of Figures 3 and 4 as it may be stamped from sheet stock.
Referring particularly to the drawings, the I link of Figures 1 and 2 has end members A formed with a flat portion A1 and a hollow cylindrical portion A2 in alignment with the flat portion. Each end portion has ahole edged with a'grommet B through which ties may be secured to the link. A spherical or ball-shaped end C1 of a frangible vessel 0 is inserted within the hollow ofthe cylindrical portion of each end member, the rim A3 of the cylinder being then turnedor spun inward to fit somewhat loosely about the neck C2 of the vessel. T'husthe separable end members of the link are joined to the vessel. The latter is preferably made of quartz initially formed as a tube and then fused and drawn into a vessel of the shape disclosed, with its ends generally spherical and joined to the body portion C3-by'the contracted neck portions C2. Before being entirely sealed the vessel is charged with a fluid that expands upon being heated. The relation of the expansive force of this fluid to the temperature is such that'the degree at which the vessel will fail to withstand itsinternal pressure can be predetermined with considerable accuracy. Consequently a link employing the frangible vessel as its thermally responsive elementcan be depended upon to withstand without change the eflects of all normal temperature and to-be completely destroyed when exposed to a temperature at which the expansive force of the'fiuid overcomes the strength of the quartz shell. The latter, of course, is noncorrosive and by selecting suitable metal for the link ends the danger from corrosion is substantially eliminated.
The link of Figures 3 and 4 has end members D which can be stamped from sheet stock in the form of a strip with a hole D1 at one end and slot D2 extendingfrom a similar hole D3 at the other end slightly more than half the length of the strip. The hole D3 is larger than the diameter of the ballshaped end C1 of the frangible vessel so that the latter can be inserted therethrough and its neck portion C2 slipped along theslot D2. The strip is then bent around to form a ring D4 with portions D5 off-set therefrom which are 7 clamped together by the grommet B. Thus the ball-end of the vessel is held within the ring of the end member.
Ties (not shown) are attached "to the sepselves in alignment'although there maybe an angular divergance between the planes of the grommets B. The term tie as used in the claims is not to be limited to a flexible band or fastening, but is to be taken as representative of any force-exerting agency capable of being attached to the end members. I claim as my invention: '1. A thermally responsive link comprising,
in combination, separable means adapted to be connected to ties and a frangible vessel holding said separable means from separating and containing an eXpansib-le fluid adapted upon rise of temperature to a predeterrmined degree to destroy said vessel and thereby free said separable means; the said means being connected to the ends of said frangible vessel to permit limited relative movement between them. 1
2. A thermally responsive link comprising, in combination, a frangible vessel containing a chargeof expansible fluid-adapted upon beingheated to a predetermined degree to destroy said vessel; and separable members adapted to be connected to ties and engaging said vessel near its ends with said engagement holding said members from separating until the destruction of the frangible vessel. r
' 3. A thermally responsive link comprising,
in combination, a frangible vessel containing a charge of expansible flllld adapted upon being heated to a predetermined degree to destroy said vessel; and separable members adapted to be connected to ties, eachmember having a ring-shaped portion engaging the surface of said frangiblevessel 1n a manner to permit limited relative movement between them while preventing separation of said members vessel.-
Signed at Providence, Rhode Island, this 28th day of December, 1928.
prior to the destructionof the said freedom for limited relative movement between them,
. 12o ALBERT 4 J. LOEPSING ER.