Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a temperature-responsive
device, such as a temperature regulator or a thermostat, which
may be used in particular in domestic appliances, comprising
an electrically insulating body, electrical connectors, fixed
and movable contact carriers each carrying a switching contact,
a heat conductive member, a dished bimetallic disc, and means
for transmitting movement of the disc to the movable contact
carrier.
Devices of this type are known in the form of
individual thermostats, most o~ which consist of a pot-shaped
insulating body having switching contacts and electrical
connection means disposed therein, and a generally pot-shaped
closure cap for supporting the bimetallic disc. Furthermore,
a thermoswitch of similar construction has become known which
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~ comprises a rectangular insulator which accommodates the
- switching contacts, which are embedded in a rectangular
depression in the insulator.
` A low price is vital to the marketing of such
devices, so that it is necessary for the manufacture thereof
to be virtually fully automatic. However, the known devices
involve a very complicated method of production, particularly
with regard to insertion of the parts into the pot-shaped
depression, and such production is possible only with
considerable expenditure, i.e. the parts have to be supplied
i~ singly.
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Another disadvantage is that adjustment operations
needed on these devices, particularly adjus~ment of the contact
gap, in most cases cannot be performed completely automatically.
In many domestic appliances it i$ necessary to
incorporate a plurality of temperature responsive devices to
guarantee the safety of the appliance. Thus, for example, it
is usual in coffee machines to provide a temperature responsive
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means in the form of a melting fuse, in addition to a temperature
regulator, which fuse interrupts the supply of current at a
temperature below a critical temperature of the heating means
or the synthetic plastics housing. This involves the dis-
advantages that after it has been triggered, further current
cannot be supplied until the fuse has been replaced, and such
fuses exhibit considerable tolerances with regard to the
temperatures at which they respond, so that with increasing
calcification of the heater the fuse may respond prematurely.
In order to avoid unnecessary fuse changing it has become
known to use instead of the melting fuse a temperature
limiter which, following switch-off and rectification of the
source of the fault, can be switched on again by hand.
An object of this invention is largely to avoid
these disadvantages and to provide an improved temperature
responsive device which can be assembled and adjusted fully
automatically.
According to this invention there is provided a
temperature responsive device comprising an electrically in-
sulating body; a groove in a surface of said insulating bodyand extending in a length direction the total extent of said
insulating body; a recess in a surface of said insulating body
opposite to the surface thereof having said groove therein; a
spring-loaded movable contact carrier and a fixed contact carrier
having a predetermined bending point provided in said groove and
; carrying respective switching contacts for cooperation with one
another; two electrical connectors disposed in said groove and
each extending outwardly of said insulating body from a respect~
; ive end of said groove, each electrical connector being electric-
ally connected to a respective one of said switching contacts via
the respective one o~ said contact carriers; a heat conductive
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member secured to sai~ insulating body; a dished bimetallic disc
responsive to the temperature of said heat conductive member
- disposed in said recess and retained in said recess by said heat
conductive member; and a pin which extends through a bore provided
in said insulating body between said bimetallic disc and said
movable contact carrier for transmitting temperature-responsive
movement of said bimetallic disc to said movable contact carrier
to make or break said switching contacts.
Preferably said recess in said insulating body is
; 10 circular and said heat conductive member includes a circular
projection which is received in said recess.
In accordance with the invention, the insulating
body has a groove which extends the entire length of the body.
This facilitates fully automatic assembly because the parts
can be introduced into the groove, the individual contact parts
and electrical connectors being fed to the installation site in
, a continuous strip and being separated by cutting means just
briefly prior to location in the insulating body. The advantage
of this is that the contact-carrying parts do not have to be
singled out from a total quantity whereby the contacts would
be dirtied by the constant rubbing of the parts against one
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another.
^ The contact carriers and electrical connectors are
during assembly located in the insulating body in such a way
that the movable spring-loaded contact carrier and an electrical
connector are inserted into the groove opening at one end of
the body while the fixed contact carrier with the second
electrical connector are introduced into it at the opposite
end. Provided in the contact carriers and electrical connectors
are bores to accommodate a rivet by means of which in each
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case the contact carrier and the electrical connector are
secured to the insulating body.
The fixed contact carrier has a predetermined
bending point which may for example be formed by a fairly
long aperture at the root of the contact carrier. Automatic
adjustment is effected in that the fixed contact carrier is
so angled upwardly that the movable contact does not touch the
fixed contact at the limit tolerances which are anticipated.
The movahle contact carrier is only moved by a downwardly
directed force and a~ter closure of the contacts, it is
pressed farther in the closure direction by a certain amount.
The circular projection of the heat conductive
member or baseplate serves as a mounting for the dished bi~
metallic disc, and after the insulating body and the baseplace
have been fitted together, the bimetallic disc is ~nclosed in
the circular recess. The pin which extends between the bi-
metallic disc and the movable contact carrier is displaceably
mounted in a circular bore in the insulating body and transmits
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to the movable contact carrier any fluctuation in the height
of convexity of the bimetallic disc due to the effects of
temperature.
,'! Preferably the insulating body and the heat
conductive baseplate are so constructed that different - ~-
dimensions of the bimetallic disc can be accommodated in the
, circular recess, 50 that various baseplates and bimetallic
discs of different diameters can be used in conjunation with a
uniform insulating body.
The invention also extends to a combination of a ~ -
plurality of temperature responsive devices each as recited
above, the heat conductive members of all of the devices
being constituted by a baseplate of heat conductive material
, which is common to all of the devices and the insulating bodies
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of the devices being individual to each of the devices.
Suoh a combination is particularly useful when
it is necessary to equip a domestic appliance with an additional
safety element to supplement a temperature regulator, and
overcomes disadvantages associated with use of two individual
and separate thermostats.
The individual insulating bodies of the combination
can be located either directly beside one another or at a
predetermined distance from one another on the baseplate.
It is advantageous for manufacture of the
combination to be fully automatic, a particularly rational
production being provided for if assembly of the various
insulating bodies, bimetallic discs, transmission pins and so
on, occurs simultaneously on the common baseplate for all of
the devices. Similarly, the necessary adjustment can be
undertaken simultaneously on all of the devices.
Thus, within the time in which only one individual
thermostat can be produced in known manner, a plurality of
devices can be simultaneously assembled to provide the
combination of the invention. A further advantage is the simple
assembly of the combination in the domestic appliance, since
only one fixing is needed for several devices. Furthermore,
the combination ensures even heat transference from the point
of attachment through the common baseplate to the bimetallic
~'J, discs, so that the heat gradient between the individual devices
- remains as low as possible. The advantage of this is that when
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adjusting the switch~off temperatures, tolerances can be more
generously chosen and this in turn lowers the cost of
manufacture. -
The combination may comprise bimetallic discs
having different response temperatures and siwtching contacts
having different functions. Thus it is possible, according
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to the intended purpose, to combine temperature regulators,
temperature monitors and temperature limiters with one another
as desired.
In a preferred embodiment, lugs project from
the baseplate to hold the insulators being bent over to engage
recesses in the region of the corners of the insulating
bodies. In each case two adjacently disposed insulating
bodies can be gripped on each side simultaneously by one lug.
The heat conductive baseplate can comprise tangs
which extend laterally of the insulating body and which, for the
attachment of the temperature responsive device in a domestic ~ -
appliance, can be provided with apertures, slots or the like.
It is possible for the tangs to be disposed on one or on both
sides of the insulating body.
` Alternatively the device can include a threaded
screw disposed in the heat conductive member, enabling the
~ device to be screwed onto a surface which is to be monitored.
;i~ The invention will be further understood from the
following description with reference to the accompanying
diagrammatic drawings, in which:
;- Fig. 1 shows a lateral section through a temperature
- regulator according to an embodiment of the invention;
Fig. 2 shows a plan view of the temperature
regulato~ of Fig. l;
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Fig. 3 is a side view of the temperature regulator
of Fig. l; , ;~
; Fig. 4 is a detail of a baseplate in another embodi-
~`~ ment of the invention;
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Fig. 5 shows a plan view of a combination of devices
according to an embodiment of the invention;
Fig. 6 is a side view of the combination of Fig. 5;
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Fig. 7 shows a plan view of a combination of devices
according to another embodiment of the invention.
In Fig. 1, an electrically insulating body or
insulator 1 has a groove 2 which extends over the total length
of the insulator 1 and in which are located electrical
connectors which extend from the ends of the groove 2, a fixed
contact carrier 5 having a predetermined bending point 5a and a
switching contact 7, and a spring-loaded movable contact
carrier 6 having a switching contact 8. On the surface
opposite the groove 2, the insulator 1 has a circular recess 9
into which projects a circular projection 10 on a heat-
conductive baseplate 11. A dished bimetallic disc 12 is
mounted on the projection 10 within the recess 9, and a ;
transmission pin 14 is displaceably located so as to extend from
the disc 12 through a bore 13 located in the centre of the
insulator 1, to the movable contact carrier 6. The baseplate
11 is provided with lugs 15 which are bent to engage recesses
16 in the insulator 1.
Fig. 2 shows that tangs 17, 1~ which have bores
19, 20 extend laterally o~ the insulator 1 integrally with the
baseplate 11. Fig. 3 clearly shows the groove 2 in the
insulator 1 with the electrical connections 3, 4 disposed
therein, and also shows a threaded screw 21 provided in the - ;
baseplate 11. Either the tangs 17, 18 or the screw 21 may be
used to secure the temperature regulator in useO
Fig. 4 shows an alternative form of tangs 22, 23
which are provided with slots 24, 25. Fig. 4 also shows the
circular projection 10 of the baseplate 11.
Fig. 5 shows a thermostat combination revealing
the location of a device 26, which is not fully shown, along-
side a device 30 on a common baseplate 27. Fig. 5 shows a
preferred embodiment in which the lugs 15 are sufficiently wide
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that, having been bent over to engage the recesses 16, each
lug serves in securing the two adjacently disposed devices
26 and 30 at the corners of the insulators 1, 31, thereof.
This is shown particularly clearly in Fig. 6, which is an
elevation of the combination.
A further embodiment of the combination is shown
in Fig. 7, in which the two devices 26 and 30 are not mounted
directly beside each other on the common baseplate 27 but ~ :
are spaced apart by an arbitrary distance 28. In this case
a bore 29 is provided in the baseplate 27 between the devices
. 26 and 30, by means of which the combination can be mounted in : :
a household appliance.
: It should be mentioned that to simplify the
illustration, each combination shown has only two devices, but ..
naturally more devices may be provided.
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