US891743A - Fire and temperature alarm or indicator. - Google Patents

Description

No. 891,743. PATENTED JUNE 23, 1908.

G; L. SMITH;

FIRE AND TEMPERATURE ALARM 0R INDICATOR. APPLICATION FILED MAR.19, 1908.

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G. L. SMITH.

FIRE AND TEMPERATURE ALARM 0R INDICATOR. AYPLIOATION FILED MAR.19, 1908.

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No. 891,743. PATENTED JUNE 23, 1908.

GEORGE LAWRENCE SMITH, OF ABERDEEN SGOTLAND.

FIRE AND TEMPERATURE ALARM OR INDICATOR.

Specification of Letters Patent.

Patented June 28, 1908.

Application filed March 19, 1908. Serial No.'422,147.

T 0 all whom/it may concern:

Be it known that I, GEORGE LAWRENCE SMITH, a subject of the King of Great'Britain, residing at Aberdeen, Scotland, have invented certain new and useful Improvements -in Fire and Temperature Alarms or Indicators, and of which the following is a specification.

In the specification of my United States Patent No. 850681 dated 16th April 1907, I have described a fire and temperature alarm orindicator apparatus, operating by pneumatic expansion, and in which a metal tube of small diameter containing airat atmospheric pressure is employed extending through a distance around a place where a sudden rise of temperature is to be indicated, the said tube communicating with a closed expansible chamber at one end, a movement produced in the latter chamber by air expansion due to the sudden rise of temperature being adapted to make or break an electric circuit for the purpose of sounding an alarm the opposite end of the tube of this apparatus is closed, and an air vent is provided by which the air may pass to or from the tube to the atmosphere nary variations of temperature, but upon a sudden rise of temperature, the chamber is expanded and operates an alarm.

Now the present invention refers to improvements upon the invention described in my prior patent specification aforesaid, the object being to so construct the apparatus that not only shall an alarm be given upon a upon ordisudden and unusual rise of temperature, but

in addition to this, the object of the present invention is to provide that another signal shall "be given should the small diameter metal tube, extending around the place to be protected, become fractured or broken by accident or otherwise, so that there is a free escape of air therefrom other than by the leak or throttled passage provided. To effect this object, the tube extending around the premises to be protected, is closed at one end and at the other communicates, as in the before-mentioned apparatus, with an exansible chamber,- and there is an air vent or eak communicating with the passage of the tube which permits air to pass slowly to and from said tube. The said air vent communicates with a chamber containing air or gas at a pressure difleringfrom that of the atmosphere", and consequently normally the pressure in the pressure chamber is equal to to escape by the art. nicates, by the passage 10, with the tub 11 the pressure in the tube by reason of the communicating vent. By reason of this arrangement, upon a sudden and'unusual rise of. temperature in the place to be protected, the air expands in the metal tube too rapidly said air vent, and conse 'uently the expansible tube-chamber is expan ed, an electric circuit thereby completed, and a fire alarm given, whereas should the metal protecting tube be damagedsay fracturedthe .pressure air would escape, the expansible tube-chamber would contract, another electric circuit would be completed, and another signal'given indicating that the apparatus was not in working order, that is, what I term a trouble call would be given. I

In the accompanying drawings a simple example of construction is shown at Figure 1 invertical section, and by the description hereafter iven relating to this figure, the Working of the a paratus will be readily understood, while Fig. 2 shows, also in vertical section, a preferred form of construction of the apparatus, Fig. 3 being a detail view of a valve employed in the construction at Fig. 2.

Referrm to Fig. 1 of the drawings, I prochamber or reservoir 2 communicating by two assages 3, 4 respectively with two chambers 5, 6. The side walls of the chambers 5, 6 are composed of three flexible diaphragms, 'i. e. a central dia hragm 7 and two outer diaphragms 8, 9, t e peripheries of these dia hragms being secured to the body part 1 of the apparatus in any suitable or convenient manner, the drawing being sufficient to render the construction of the ap aratus sufficiently clear for persons skille in One of these chambers 6 comg uwhich passes around a room or other place to be protected, and the said chamber 6 also communicates, by a passage 12 with what is termed a leak in my previous patent s ecification; the leak consists of a screw 13 aving a valve-likehead fitted with a porous washer l4, and the valve-like head covers the passage 12 and also covers the passage 15 communicatin with the chamber 5. Thus instead of the oak from the tube 11 communicating direct with the atmos here, it communicates, in this case, with the chamber 5 which normally contains air (or gas) pressure equal to the air (or gas) pressure in the chamber 6 and in the tube.

eyond this, the-chamber 5 can be caused to vide a bory part 1 containing a pressure e interior of phragm 9 .voir 2 to any "pressure cham communicatewith the tube-chamber 6 by means of the passage 4, which is fitted with a valve 16 by which the said passage 4 can be permanently "closed when desired. 17 is an air inlet valve of any ordinary or well known construction through which air can be pumped by an suitable force pump into the pressure cham er.

The central flexible diaphragm 7 is connected with one pole of the battery 17*, and hasa central contact 18' on each-of its sides, one in the tube-chamber .6 and the other in the chamber 5. The outer diaphragm 8 has a contact 19 electrically connected with the fire or alarm circuit, while the outer diaof the tube-chamber 6 has a contact 20 connected with the trouble cirwit; and beyond this, there are adjustment screws 21 carried by stationary bridges'23 which limit .the outward movement of the diaphragms 8 and 9 and which can be brought to act upon the external faces of the outer diaphragms to adjust the contacts which the carry as regards distances from the central diaphragm.

The air is pumped i to the, ressure reserdeslred pressure above atmospheric pressure, and at the same time is admitted by the valvef16 and the by-pass 4 into the tube-chamber 6-, so that the pressure in the tube-chamber 6 and in the pressure.

chamber 5 are equalized, and then the bypass passage 4 is hermetically closed. When this is done, the central diaphragm 7 will reand the outerheld distended main in its normal position, diaphragms 8, 9, will be against their adjustment screws and with their contact'points away-from the central diaphragm, whereas if no pressure existed in chambers, the outer diaphragmcontact points would close onto the central. dia-' phra m.

en an ordinary or. radual rise of temerature occurs in the ace through which the tube 11 passes an so pressure is increased inthe tube, the air will raduallyass through the leak (which pre erably is orouswasher) and into the er, and so the pressure in the pressure chamber and in the tube-chamber would still remain equal and no ca will be made When the ressure, however, is suddenly. increased in t e tube by a fire for not pass through the and consequently tted with a leak sufliciently rapidly, the central diaphragm will contact with the contact pin 19 carried'by the dia hragm closing the pressure chamber, and a Ere callwould be made.

In case of any damage to the apparatus, such for instance as some accident causing a leakage b fracture of the tube, the pressure in the tu e chamber would fall rapidly, be-

cause the be forced over into leak by which the tube commumcatesf with the pressure chamber would notsupply pass away through the leak and escapeat the su posedfault in the tubing 1 1, and then-the 'ot ierouter diaphragm 8 would close down into contact with the central diaphragm and bring the fire circuit also into operation. .shown at Figs. 2 and 3, thepressure chamber 24 is formed by an air-ti ht closed box .which contains an expansible case 25 substantially equivalent to the tube-chamber previously described; this expansible case 25 communicates, by a passage 26, with the tube 11 passing around the room or other place, but otherwise the said expansible case 25 is closed. The passage 26 is also provided'with a leak, governed by a screw 27, located within the pressure chamber. Within thesaid chamber 24 is mounted an adjustable bar 28 of insulating material carrying electrical contacts 29 and 30, and the expansible case 25 carries a contact 31 located between the conpipe 11 passes to a control ing valve located in any suitable position, as for instance fixed to the pressure chamber as shown." In the casing or frame of this valve there is a fpassage 32 from the tube 11 to theyalve ace, and there'is also a passage 33 to the valve face communicating with-a pipe to a reservoir 40 containing pressure air or gas.

The valve illustrated by way of exam le consists of a revoluble disk 35 operated bya handle 36 connected with disk, and the face of the disk 35 hearing on the valve face .is shown at Fig. 3; it is formed with a,;groove 37,'and the positions of the'passages 32 and 33 are indicated by dotted lines, while the dotted lines 38 indlcate a groove formed in the face "of the valve case.

'When the ha die 36 and disk 35 are in the cannot pass by way of the passage'33, nor can air escape from the pressure-chamber 24, through the valve by way of the communicating passage 39. When the handle'36 is rocked-1n the direction of the'arrow, Fig. 3, pressure air will be permitted to pass by the to t e passage 32 and to the tube .11, and simultaneou sly by the groove air pressure 1n the tube 11 and in the charm The banfrom the pressure chamber 5 would gradually tacts 29 and 30. The op osite end of the 34 leadingthe spindle of the positionshown in the drawings, pressure air ber 24 will be equal, and no movement of the. j,

In the preferred form of construction-g pas age 33 and the groove 37 of the disk 35 38 (Fig.- 3) in the case, to the pressure chamber24, so that the",

dle 3.6 is then again brought to the normal position shown in the drawings, closing the passages 32 and 33.

Should a sudden rise of tem erature occur, the expansion of air in the tu e 11 will then act in the interior of the expansible case 25, and the contact 31 will be brought against the contact 29, and by theelectric connections, for instance such as indicated, the fire alarm will be given. On the other hand, should damage happen tie pressure air escape, the expansible chamber 25 would contract and the electrical contact 31 be brought against the contact 30,

and a trouble call be given through the electrical connections indicated. be a gradual riseof temperature, the slow expansion of air in the tube 11 would pass by the leak screw 27 to the pressure chamber 24 and equalize the pressure,

When the handle 33 and the disk are turned in the opposite direction to the arrow (Fig. 3) pressure is then admitted by the pas sage 33 to the passage 32 only, and thereby to the tube 11, and thus a test alarm can be given in order to definitely ascertain that the apparatus is in perfect working order.

What I claim as my invention and desire to secure by patent is 1. In fire and temperature alarms; the combination with a small diameter metal tube closed at one end, an ex ansible chamber with the interior of whic the open end of said tube communicates, said tube having a vent for ermitting air to pass slowly to and from said tube and expansible chamber; of a pressure chamber with the interior of which said air vent communicates, the movable diaphragm of said-expansible chamber being also located insaid pressure chamber, means for sup lying air at pressure to said pressure cham er, to said tube and to the mterior of said expansible chamber, an electric battery, two electric alarm devices, and electric contacts and connections calculated to complete one electric circuit and sound one alarm device u on the ex ansion of the expansible chamher by su den rise of temperature expanding the air in said tube, and

to sound the other alarm device upon pressure air escaping from said tube and the interior of said ex ansible chamber to the outer atmosphere, su stantially as set forth.

2. In fire and temperature alarms; the combination with a small diameter metal tube closed at one end, an ex ansible chamber with the interior of whic the open end of said tube communicates, said tube having a vent for permitting air to pass slowly to and from said tube and expansible chamber; of an air-tight ressure chamber within which said expansi le chamber and said vent are located, means for supplying airpressure to said pressure chamber and to the interior of said expansible chamber' and said tube,

to the tube 11 and,

Should there said air pressure being normally equalized through said vent, two insulate stationary electric contacts located at a distance apart in said pressure chamber, an electric contact mounted on the movable diaphragm of said expansible chamber and extendin between said two stationary contacts, two e ectrically olperated alarm devices, an electric battery, e ectric connections calculated to operate one of said alarm devices when the expansible chamber is expanded by sudden rise of temperature acting upon the tube causing the electric contact carried by said expansible chamber to contact with one of the stationary contacts, and electric connections to cause the other alarm device to operate when the contact carried by the exp'ansible chamber contacts with the other stationary contact, substantially as set forth.

3. In fire and temperature alarms; the combination with a small diameter metal tube closed at one end, an expansible chamber with the interior of whichthe open end of said tube communicates, said tube having a vent for permitting air to pass slowly to and from said tube and expansible chamber; of an airtight pressure chamber within which said vent and expansible chamber are located, means for su plying air at pressure to said pressure cham er and to the interior of said expansible chamber and said tube said air pressure being normall equalized through said vent, two insulate stationary electric contacts located at a distance apart, a bar of insulating material fixed to the walls of said pressure chamber to carry said stationary contacts, an electric contact mounted upon the movable diaphragm of said expansible chamber and extending between said two stationary contacts, twd electrically operated alarm devices, an electric battery, an electric conductor connecting one pole of said battery to one pole of each of said alarm devices, an electric conductor from the other pole of one of said alarm devices to one of said stationary contacts, and an electric conductor from the other pole of the second alarm device to the other stationary contact, and an electric conductor from the other ole of said battery to the contact carried by the movable diaphragm of said ex ansible chamber in order that when said 0 amber is expanded by the action of heat on said tube, its contact shall make connection with one of said stationary contacts and sound a fire alarm by one of said alarm devices, while when said tube is fractured and said expansible chamber contracts, the contact of the latter shall make connec- 'tion with the other stationary contact and sound the other alarm device, substantially as set forth. o I

4. In fire and temperature alarms; the combination with a small diameter metal tube closed at one end, an expanslible chama vent for permitting air to pass slowly) located, a reservoir forcontaining air at a tube connecting said reservoir pressure,

means for conwith said pressure chamber,

trolling the supply of said pressure air from said reservoir to said pressure chamber, two

insulated stationary electric contacts located at a distance apart in said pressure chamber, an electric contact mounted on the movable diaphragm of said expansible chamber and extending between said two stationary contacts, two electrically operated alarm devices, an electric battery, electric connections calculated to operate one of said alarm devices'when the expansible chamber is expanded by sudden riseof temperature contact carried-by said expansible chamber to contact with one of the stationary contacts, andjelectric connections to causethe other alarm device to operate when the contact carried by the expansible chamber contacts with the other stationary contact, substantially as set forth.

5. In fire and temperature alarms; the combination with a metal tube of small diameter having a corres ondingly small bore containing air and close at one end, a closed exp'ansiblephamber with which the other open end of said tube communicates, said tube having a vent for acting upon the, tube causing the electric,

slowly to and from the ore of the tube upon a gradual and ordinary variation of temperature, and means for re ulating said vent; of an air-ti ht pressure 0 amber within which the sai expansible chamber and said vent are located, means for supplying air pressure to said pressure chamber and to the interior of said expansible chamber and said tube said air pressure being normally equalized through said vent, two insulated stationary electric contacts located at a distance apart in said pressure chamber, an electric contact mounted on the movable diaphragm of said expansible chamber and extending between said two stationary contacts, two electrically operated alarm devices, an electric battery, electric connections calculated to operate one of said alarm devices when the expansible chamber is expanded by sudden rise of tem erature acting upon the tube causing the e ectric contact carried by the expansible chamber to contact with one of the stationary contacts, and electric connections to cause the other? alarm device to operate when the contact carried by the expansible chamber contacts with the other stationary contact, substantially as set forth.

Inwitness whereof I have hereunto set ermitting air to pass my hand in the'presence of two witnesses GEORGE LAWRENCE SMITH. Witnesses:

WM. SHERMAN- CARsoN,

ARTHUR J. SMITH.

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