US1646835A - Automatic cut-out for heating circuits - Google Patents

Description

2:; 1927. l Oct o. PLETscHER, JR

AUTOMATIC CUT-GUT FOR HEATING CIRCUITS original Filed Dec. 4. 1924 Patented Oct. 25, i927.

untreuer-Aras 1,546,835 rar-snr erstes.

. 'orTo PLETSCHER, JR., or Amuse-Innen, :unna snaren,swrznnLANn.

` AUTOMATIC. cnr-OUT rca iinnrrne cis-cuirs.

` Original` application filed `Demeniher 4, 1924, Serial -No.,?i3,820, and in Germany December Divided and` ausfapp11-eati mV flied apra 1, 192e. semi No. 99,173.

.It 'has already frequently been attempted to construct socket devices for heating appa; ratus such as flat-irons, cooking apparatus etc.7 which socket devicesfcontain an'au'tomatic cut-out which cuts oif the current when the heating apparatus reachesa temperature which is too high and is dangerous for itself and its surroundings. These known socket devices with automatic cut-outs'forpprotece tion against overheating all suffer fron'itwo disadvantages, viz, that they necessitate mak ing the socket device of `considerable magnitude and of very different size from that ofthe usual socketdevices and thatthe transmission of heat fromthe heating apparatus to the automatic switch isV very deficient andy very slow inasmuch Sas this transmission only takes place through the electrical conducting wire which naturally is only or" small crosssection. i f i The subject of the presentfinvention is'za socketdevice for heating apparatus with an automatic cut-out f for protection against overheating in which the above-mentioned disadvantages are avoided inasmuch as the size of the socket device is hardly greater than the normal size of a standard socket device and inasmuch as the heat transmission takes place over a metallic cross-section which is not restricted tothe diameter of, the conducting wire. l

= These resultsare obtained by forming the socket which is to Vpass over the contact pin or plug into a cup. at the end Vwhich lies with--V in the socket, on which cup the fusible disc is pressed by means of anvinsulating member which forms a. part of the socket device, whereby the fusible disc retains in electrically and thermally conductive contact a rodA carrying the current to the socket against the influence 0f a .spring which acts on the rod, so that the fusible disc receives heatA over `its whole surface. i v

The drawing shows by way of example two constructional forms of the invention.V

Figs. l and 2 show the first constructional form in axial section in the in and out positions respectively.

Fig. 3 shows the second constructional form in axial section.

A case or housing consists of an enclosing member made in three parts and constructed of insulating material. The middle part of the said case forms a holder 29, to which at the one end the socket connecting member 30 and at the other end a closing cap 3l Vare screwedby means of a meta-l tube 32, which tube 32 is arranged inthe axial hole of the vholder 29. The upper end part of the `tube 32 is adapted to form the terminal 33 for the conductor 34 which passes through theIcap 3l*` and is protected by being constructed in Y the form of a cable. In the hole of the holder 29 a metal ring member 37 is fixed, whichv ring member rests on va*` ledge 36. The ring member 37 is provided with a rod 38 which maintains good connectionfor' the electric current andghas ahead- 39 andl40'respectively at each Vof its two ends. kA helicalspring 4l is arranged around the rod 38 between ,the disc37andfthe head 39, whereby a fusible disc42 fixed at the lower end of the. rod 38 is `pressed by `the head 40V against the lower nally slotted socket 43 `with a eontactplate 44 is inserted in the socket connectingvvmember 3.0, the said slotted socket 43vbeingso dimensioned that when the device is screwed upthe plate 44 presses Iagainst the under surface" of the fusible disc 4,2` and-the hea-d 40 rests in a hollow in the contact plate/44. By tightly screwing the parts 29 and" 30 together a good electrically and thermally conductive connection is obtained, whilstpwhen the'fusible disc is melted, the melted mass is enabled to penetrate into an open spaceand 2) which springs back in the hole in the holder 29 under the influence of the spring 41.` If it be desired to insert a new fusible disc the closing'cap 31 with the tube 32 on the one side and the socket connecting member 30 on the other side are first unscrewed from the holder 29 and the melted mass is removed from the contact plate 44. The rod 38 is then pressed forward, a new fusible disc 42 is placed on the same and the whole device is screwed together again.

Fig. .8 also shows a socket device for flatirons, in which device a holder 47 is screwed Vend `surface/of the holder 29. vA longitudif l fil on to the socket connecting member 46. In

is arranged. The said rod is arranged in a centrally bored metal disc 51 which, for example, may be pressed into a widened portion of the'hole in the holder. An insulation head 52 is screwed on to therod 50.- A helical spring 53 arranged on the rod 50 presses against the head 52 and is adapted to effect the movement of the rod when the fusible material is melted. Vhen'this occurs the head 52 projects out of the holder 47 and thus indicates the destruction of the fusible material. more noticeable the said head 52 may be of a dierent colourfrom the holder 47. The holder is provided with a side armor projectio1r54. A terminal 55 which presses against the disc and is thus in conductive contact with it is provided and an insulating protecting'cover 56k is screwed over the said terminal 55.A

The rod 50 may be arranged on a continuation of the `terminal 55, said continuation projecting into the hole 48. It is also intended that this cut-out may be constructed in a double pole type, in which caseusually only the one -pole would be protected against excesstemperature as the fuse member is not dependent -on or adjusted' to the current strength. f x

Iclaim: I y LSocketdevice for heating or heat developing apparatus with automatic switch for protection against overheating, in combination with a socket, the interior of which is formedinto a cup vat the. opposite end to that which passes over a contact-pin or plug, a fusible disc pressed by meansof an insulating member which formsV part of the socket device V0n said curp, the lower end of the insulating member and the rim of vthe cup being 'b'evelled off in sucha way that aV chamber running circularly round the eX- terior edge of the fusible disc is formed into which the melted matter iows when the fuse blows, a rod carrying the lcurrent to said socket, a spring acting on said rod so as to In. order to render the indication lift the rod from thev cup, a metal ring, on

which ring the spring rests, the` rod being arranged in an electrically conductive manner in said metal ring, the ring Vbeing held in' its position for theproper guiding of the rod by means of a metal tube connected with the wire carrying the; current, said fusible disc retaining the rod in electrically and thermally conductive contact with the socket and receiving heat over its whole under surface.

2. Socket device for heating or heat developing apparatus with automatic switch for'protection against overheating, in combination a housing consisting of anv enclosing member made in three'parts andA constructed of insulating material, the middle part of said housing forming a holder to which at theo-ne end a socket-connectingmember and at the other end aclosing cap are screwed, the latter by `means' of a metal tube, said tube being arranged inthe axial hole of the holder, the upper end part of the tubebeing adapted' to form the terminal for a conductor passing through the cap, a metal ring member provided with a rod which maintains good connection for the electric current and having a head at each of its two ends, a helical spring arranged around the rod between-the metal ring member and the one head of the rod, a fusible disc fixed atthe lower end of the rod and being pressed by the khead of the rod against the lower end surface of the holder, a longitudinally lslotted socket with a contact plate inserted in the socket connecting member, the said slotted socket being so dimensioned that when the device is screwed up the plate of the'longitudinally slotted socket presses against the under surface of the fusible disc and the head rests in a hollow in the contact 'plate of the longitudinally slotted socket, substantially as described.

In testimony whereof I have signed my name to this specification.

OTTO PLETSCHER, JUN.

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