CA1268804A - Three stage pressure switch - Google Patents
Three stage pressure switchInfo
- Publication number
- CA1268804A CA1268804A CA000490959A CA490959A CA1268804A CA 1268804 A CA1268804 A CA 1268804A CA 000490959 A CA000490959 A CA 000490959A CA 490959 A CA490959 A CA 490959A CA 1268804 A CA1268804 A CA 1268804A
- Authority
- CA
- Canada
- Prior art keywords
- pressure
- membrane
- pressure switch
- switch
- disc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Abstract
ABSTRACT
A pressure switch device for use in an air-conditioning system, specifically a three stage device capable of switching, for example, a combined low/high pressure switch, and an on/off switch for activating compressor and condenser elements of the system, respectively. The device includes an operating chamber, a yieldable plastic membrane having roll membrane faces for transmitting system pressure level changes to pistons, a leaf spring disc and levers activating pairs of switching contacts. Upon application of three different operating pressures, each of the pistons transmitting a different pressure level, the levers and lever joints having tension springs, operate to bias the switching contacts to open and closed positions, thereby activating or deactivating the system elements.
A pressure switch device for use in an air-conditioning system, specifically a three stage device capable of switching, for example, a combined low/high pressure switch, and an on/off switch for activating compressor and condenser elements of the system, respectively. The device includes an operating chamber, a yieldable plastic membrane having roll membrane faces for transmitting system pressure level changes to pistons, a leaf spring disc and levers activating pairs of switching contacts. Upon application of three different operating pressures, each of the pistons transmitting a different pressure level, the levers and lever joints having tension springs, operate to bias the switching contacts to open and closed positions, thereby activating or deactivating the system elements.
Description
~L26~
s r,~s G~
PRESSURE SWITCH
The invention relates to a pressure switch comprisîng two pairs of switching contacts and a pressure chamber, which can be connected to a source of operating pressure, and is terminated towards said pairs of switching contacts by a plastic membrane, which acts via pistons and a leaf spring disc on said pairs of switching contacts. A
preferred field of use is the installation of said pressure switch in a vehicle air-conditioning system.
The invention is based on the object of creating a simply constructed and functionally safe three stage pressure switch with one operating pressure chamber, which is - especially suitable as combined safety-low-pressure-switch and safety-high-pressure-switch for the compressor clutch, and as switch for switching on and off a condensor ventilator for a vehicle air-conditioning system.
This object is solved with a pressure switch of the above described type in that according to the invention ~z~0~
a) three roll membrane faces are provided in said plastic membrane in a plane, which are in connection with three vertically guided pistons, b) said leaf spring disc has three disc segments, two of which form together with two levers lever joints, c) said disc segments are biased in such a manner that upon three different operating pressures, under the effect of one each of said three pistons and the according roll membrane face they are moved vertical-ly, and d) between securement points on two of said disc segments and a securement point on said third disc segment or a fixed point, respectively, one tension spring each is provided, said lever joints being respectively arranged in the ~egion between said securement point of said two disc segments and said securement point of said third disc segment or said fixed point, respectively.
With a three stage pressure switch constructed in such a manner, it is possible via the first pair of switching --~ contacts at a first pressure level to switch on a load, Z5 via the second pair of switching contacts at a second pressure level to switch on a further load, and via the first pair of switching contacts at a third pressure level to switch off the first load again, whereby if the operat-ing pressure sinks below the three pressure levels, the switching processes are performed in reversed sequence.
Preferably, the first load can be the compressor clutch and the second load a condenser ventilator of a vehicle air-conditioning system, the operating pressure chamber ~2~
being connected to the pressurized refrigerant of the air conditlon.ing system.
Expedlently, the pistons are guidecl vertica:!ly in a pressure plate comprising bot-tom stop means.
The plastic membrane is advantageously adhered to cl p]ate resting on said pressure plate.
Furthermore, -the disc segmel~ts are expedielltly pressed ag..linC;t;
the pressure plate by spiral pressure springs biasecl by means of ad~ustment screws, which permits a s:imple acljustmerlt: of t;he bias and thus of the three pressure levels.
Advalltaqeously, -the pressure switch is constructecl in suc`n a manner that the pistons are guided radially by means of recesses in the clisc segments of the leaf spri.ng clisc.
Moreover, expediently adjustable stop means are provided, which limit the patils of said levers and clefine the switcll:ing points of said pairs of switching contacts.
On the levers, insulating bodies are expediently provided, which press upon resilient cont.act tongues of the pair of switching contacts to open sa.id switching contacts.
The membrane may be formed by applying pressure to the pressure chamber or control body, respectively.
~n the followin~ the inventi.on is described in detail with respect to an embodiment anc1 with reJ.erence to the drawi.ngs.
In the drawin~s show 5 Fiy. 1 a three stage pressure swi.tcll :in a perspectlve e~ploded view, ~LZ~8804 Fig. 2 the pressure switch according to Fig. 1 in cross-section, Fig. 3 a schematic representation of the two switches contained in the three staqe pressure switch, and Fig. 4 a diagram of the switching on and switching off of the three stage pxessure switch versus the operating pressure.
The pressure switch shown in the drawings comprises a screw connection 1, which is connected for example to the Frigen circulation of a vehicle air-conditioning system.
The screw connection 1, a plate 2 connected therewith, and a plastic membrane 3 form a pressure ~hamber A, to which operating pressure P is conducted to actuate the pressure switch. The plastic membrane 3 preferably consists of a polyimide film and includes roll membrane 2Q faces R, ~' and R" formed at three positions in a common plane~ T~he roll membrane faces R, R' and R" are on the - side facing away from the pressure chamber A, in connect-ion with three pistons 4,-4' and 4", which in term act on the three disc segments B, B' and B" of a leaf spring disc 5. The membrane 3 may be formed by applying pressure to the pressure chamber A or control body, respectively.
The pistons 4, 4' and 4" are vertically guided in a pressure plate 6 with bottom stop means S, S' and S". By means of recesses 7, 7' and 7" in the disc segments B, B ' and B" of the leaf spring disc 5, the pistons 4, 4', 4"
are radially guided. The plastic membrane 3 is advantage-ously adhered to the plate 2 resting on ~he pressure plate 6. Con-trary to the stretched plastic film membranes known until now, the ~LZ6~
forming of the three roll membrane faces R, R', R" in the plast.ic membrane pe.rmits a loncJer opera-ti.ng path of the pistons 4, 4', 4" when transmitting the operating pressure in the pressure charnber A to the disc segments B, B ', B" ~
The disc seyments B, B', B" of the leaf spring disc 5 are pressed ag~inst the pressure plate 6 either by means oc their own tension, or, as shown in the clrawings, by coil pressure spring.s 9 biased via adjustment scre~ls 8. The acl~ stmellt screws 8 are scret/ed into corresponcling nutmembers 10 which include a col:lar, and permi.t a change o.r acljustm~nt of the hias. The coil pressure springs 9 are seated on the collar of the nutmembers 10. In order to overcome the pressure exerted by the coil pressure springs 9, according operating pressures P in the pressure chamber A are necessary. The spring bias :is selected such that ~ith increasing pressure P in the pressure chamber A, firstly the piston 4, then the pi.ston ~' ancl finally -the piston 4" is moved against the according stop means S, S' or S", respectively, in the pressure plate 6.
Underneath the clisc segments B ancl B', t~o levers 11, 11' are provided, ~hich together with the disc segments B, B', form lever joints X, X'. The paths of the levers 11, 11' aYe limitecl by ad-)ustable stop means D1, D2 or Dl', D2', respectively.
Between a securement point Y on the :Lever 11 ancl a secllreme point Z on the clisc segmen-t B", a tension spring 1~ is mounted, and between a securement point Y' orl the lever 11' and a fixed poin-t on the pressure plate 6, a tension spring 12' is moun-ted. The securement points are select.ecl suc'h thclt the lever joint X is situatecl bet~leen securemen-t ~., ~`t~ ~
~26~8~
point Y and securement point Z, and the lever joint X' is situated between the securement point Y' and the fix point on the pressure plate 6.
Below the lever 11 or 11', respectively, a pair of switch-ing contacts 13, 14, or 13 ', 14', respectively,is arranged.
Furthermore, on the underside of the lever 11, 11', insulating bodies 15, 15', are secured, which are in engagement with resilient contact tongues of the movable switching contacts 14, 14', and lead to the fact that upon a movement of the lever 11,.11' in downward direction the movable switching contacts 14, 14' are moved away from the stationary switching contacts 13, 13 ', to open said pairs of switching contacts 13, 14, or 13 ', 14', respectively.
The adjustable stop means D1, D2 and D1', D2' define the ` switching points of the pairs of switching contacts 13, 14 and 1 3 ', 14', respectively.
The positions of the lever joint X and the securement point Z as well as of the lever joint X' and the fixed point on the pressure plate 6 are selected such that in the pressureless state of the pressure chamber A, the levers 11, 11' are drawn by the tension springs 12, 12' to the stop means D1, D1'. Accordingly the insulating bodies 15, 15', press against the resilient contact tongues provided with the switching contacts 14, 14', and thus open the electric connection to the switching contacts 13, 13'.
Upon an increase of the operating pressure P in the pressure chamber A to a first pressure level I (Fig. 4), on account of the lowest bias of the disc segment B first~
ly the piston 4 as the first moves towards the stop means S. Accordingly, the lever joint ~ passes the connecting line between the securement points Y and Z and the lever 11 snaps against the stop means D2. The switching contact 14 now has the possibility to rest against the switching 126~
contact 13, so that the pair of switching contacts 13, 14, corresponding with the switch 100 in Fig. 3, for example switches on the compressor clutch KK of a vehicle air-conditioning system.
s A further increase of the operating pressure P in the pressure chamber A to a pressure level II tFig. 4) correspondingly leads to the fact that the piston 4' moves towards the stop means S'. The lever joint X' thus passes the connecting line between the securement point Y' and the fix point on the pressure plate 6 and the lever 11' snaps against the stop means D2'. The switch-ing contact 14' now has the possibility to rest aga:inst the switching contact 13', whereby the pair of switching contacts 13', 14', corresponding with the switch 200 in Fig. 3, is closed, and thus for example a condenser ventilator KL of a vehicle air-conditioning system is switched on.
A further increase of the operating pressure P in the pressure chamber A to a pressure level III (Fig. 4) leads to the movement o-E the piston 4" against the stop means S". Thus the securement point Z moves on the disc sesment - B" in such a manner that it results in a relative passing of the connecting line between the securement points Y
and Z in reversed direction. This results in the fact that the lever 11 snaps back against the stop means D1 and thus opens the pair of switching contacts 13, 14, corresponding with switch 100 in Fig. 3.
If the operating pressure P in the pressure chamber A now sinks to a value be~ow the pressure level I, for e~ample to zero, all the described switching stages, or movements, - 8 _ ~2688~
respectively, are performed in reversed sequence, and the pressure switch is ready for a new switching and movement cycle.
With the described pressure switch, it is possible to replace the pressure controlled switches used until now for a vehicle air-conditioning system,. namely safety-low-pressure-switch and safety-high-pressure-switch for the compressor clutch as well as switch fox switching on and off a condenser ventilator, by one single three stage pressure switch arrangement.
s r,~s G~
PRESSURE SWITCH
The invention relates to a pressure switch comprisîng two pairs of switching contacts and a pressure chamber, which can be connected to a source of operating pressure, and is terminated towards said pairs of switching contacts by a plastic membrane, which acts via pistons and a leaf spring disc on said pairs of switching contacts. A
preferred field of use is the installation of said pressure switch in a vehicle air-conditioning system.
The invention is based on the object of creating a simply constructed and functionally safe three stage pressure switch with one operating pressure chamber, which is - especially suitable as combined safety-low-pressure-switch and safety-high-pressure-switch for the compressor clutch, and as switch for switching on and off a condensor ventilator for a vehicle air-conditioning system.
This object is solved with a pressure switch of the above described type in that according to the invention ~z~0~
a) three roll membrane faces are provided in said plastic membrane in a plane, which are in connection with three vertically guided pistons, b) said leaf spring disc has three disc segments, two of which form together with two levers lever joints, c) said disc segments are biased in such a manner that upon three different operating pressures, under the effect of one each of said three pistons and the according roll membrane face they are moved vertical-ly, and d) between securement points on two of said disc segments and a securement point on said third disc segment or a fixed point, respectively, one tension spring each is provided, said lever joints being respectively arranged in the ~egion between said securement point of said two disc segments and said securement point of said third disc segment or said fixed point, respectively.
With a three stage pressure switch constructed in such a manner, it is possible via the first pair of switching --~ contacts at a first pressure level to switch on a load, Z5 via the second pair of switching contacts at a second pressure level to switch on a further load, and via the first pair of switching contacts at a third pressure level to switch off the first load again, whereby if the operat-ing pressure sinks below the three pressure levels, the switching processes are performed in reversed sequence.
Preferably, the first load can be the compressor clutch and the second load a condenser ventilator of a vehicle air-conditioning system, the operating pressure chamber ~2~
being connected to the pressurized refrigerant of the air conditlon.ing system.
Expedlently, the pistons are guidecl vertica:!ly in a pressure plate comprising bot-tom stop means.
The plastic membrane is advantageously adhered to cl p]ate resting on said pressure plate.
Furthermore, -the disc segmel~ts are expedielltly pressed ag..linC;t;
the pressure plate by spiral pressure springs biasecl by means of ad~ustment screws, which permits a s:imple acljustmerlt: of t;he bias and thus of the three pressure levels.
Advalltaqeously, -the pressure switch is constructecl in suc`n a manner that the pistons are guided radially by means of recesses in the clisc segments of the leaf spri.ng clisc.
Moreover, expediently adjustable stop means are provided, which limit the patils of said levers and clefine the switcll:ing points of said pairs of switching contacts.
On the levers, insulating bodies are expediently provided, which press upon resilient cont.act tongues of the pair of switching contacts to open sa.id switching contacts.
The membrane may be formed by applying pressure to the pressure chamber or control body, respectively.
~n the followin~ the inventi.on is described in detail with respect to an embodiment anc1 with reJ.erence to the drawi.ngs.
In the drawin~s show 5 Fiy. 1 a three stage pressure swi.tcll :in a perspectlve e~ploded view, ~LZ~8804 Fig. 2 the pressure switch according to Fig. 1 in cross-section, Fig. 3 a schematic representation of the two switches contained in the three staqe pressure switch, and Fig. 4 a diagram of the switching on and switching off of the three stage pxessure switch versus the operating pressure.
The pressure switch shown in the drawings comprises a screw connection 1, which is connected for example to the Frigen circulation of a vehicle air-conditioning system.
The screw connection 1, a plate 2 connected therewith, and a plastic membrane 3 form a pressure ~hamber A, to which operating pressure P is conducted to actuate the pressure switch. The plastic membrane 3 preferably consists of a polyimide film and includes roll membrane 2Q faces R, ~' and R" formed at three positions in a common plane~ T~he roll membrane faces R, R' and R" are on the - side facing away from the pressure chamber A, in connect-ion with three pistons 4,-4' and 4", which in term act on the three disc segments B, B' and B" of a leaf spring disc 5. The membrane 3 may be formed by applying pressure to the pressure chamber A or control body, respectively.
The pistons 4, 4' and 4" are vertically guided in a pressure plate 6 with bottom stop means S, S' and S". By means of recesses 7, 7' and 7" in the disc segments B, B ' and B" of the leaf spring disc 5, the pistons 4, 4', 4"
are radially guided. The plastic membrane 3 is advantage-ously adhered to the plate 2 resting on ~he pressure plate 6. Con-trary to the stretched plastic film membranes known until now, the ~LZ6~
forming of the three roll membrane faces R, R', R" in the plast.ic membrane pe.rmits a loncJer opera-ti.ng path of the pistons 4, 4', 4" when transmitting the operating pressure in the pressure charnber A to the disc segments B, B ', B" ~
The disc seyments B, B', B" of the leaf spring disc 5 are pressed ag~inst the pressure plate 6 either by means oc their own tension, or, as shown in the clrawings, by coil pressure spring.s 9 biased via adjustment scre~ls 8. The acl~ stmellt screws 8 are scret/ed into corresponcling nutmembers 10 which include a col:lar, and permi.t a change o.r acljustm~nt of the hias. The coil pressure springs 9 are seated on the collar of the nutmembers 10. In order to overcome the pressure exerted by the coil pressure springs 9, according operating pressures P in the pressure chamber A are necessary. The spring bias :is selected such that ~ith increasing pressure P in the pressure chamber A, firstly the piston 4, then the pi.ston ~' ancl finally -the piston 4" is moved against the according stop means S, S' or S", respectively, in the pressure plate 6.
Underneath the clisc segments B ancl B', t~o levers 11, 11' are provided, ~hich together with the disc segments B, B', form lever joints X, X'. The paths of the levers 11, 11' aYe limitecl by ad-)ustable stop means D1, D2 or Dl', D2', respectively.
Between a securement point Y on the :Lever 11 ancl a secllreme point Z on the clisc segmen-t B", a tension spring 1~ is mounted, and between a securement point Y' orl the lever 11' and a fixed poin-t on the pressure plate 6, a tension spring 12' is moun-ted. The securement points are select.ecl suc'h thclt the lever joint X is situatecl bet~leen securemen-t ~., ~`t~ ~
~26~8~
point Y and securement point Z, and the lever joint X' is situated between the securement point Y' and the fix point on the pressure plate 6.
Below the lever 11 or 11', respectively, a pair of switch-ing contacts 13, 14, or 13 ', 14', respectively,is arranged.
Furthermore, on the underside of the lever 11, 11', insulating bodies 15, 15', are secured, which are in engagement with resilient contact tongues of the movable switching contacts 14, 14', and lead to the fact that upon a movement of the lever 11,.11' in downward direction the movable switching contacts 14, 14' are moved away from the stationary switching contacts 13, 13 ', to open said pairs of switching contacts 13, 14, or 13 ', 14', respectively.
The adjustable stop means D1, D2 and D1', D2' define the ` switching points of the pairs of switching contacts 13, 14 and 1 3 ', 14', respectively.
The positions of the lever joint X and the securement point Z as well as of the lever joint X' and the fixed point on the pressure plate 6 are selected such that in the pressureless state of the pressure chamber A, the levers 11, 11' are drawn by the tension springs 12, 12' to the stop means D1, D1'. Accordingly the insulating bodies 15, 15', press against the resilient contact tongues provided with the switching contacts 14, 14', and thus open the electric connection to the switching contacts 13, 13'.
Upon an increase of the operating pressure P in the pressure chamber A to a first pressure level I (Fig. 4), on account of the lowest bias of the disc segment B first~
ly the piston 4 as the first moves towards the stop means S. Accordingly, the lever joint ~ passes the connecting line between the securement points Y and Z and the lever 11 snaps against the stop means D2. The switching contact 14 now has the possibility to rest against the switching 126~
contact 13, so that the pair of switching contacts 13, 14, corresponding with the switch 100 in Fig. 3, for example switches on the compressor clutch KK of a vehicle air-conditioning system.
s A further increase of the operating pressure P in the pressure chamber A to a pressure level II tFig. 4) correspondingly leads to the fact that the piston 4' moves towards the stop means S'. The lever joint X' thus passes the connecting line between the securement point Y' and the fix point on the pressure plate 6 and the lever 11' snaps against the stop means D2'. The switch-ing contact 14' now has the possibility to rest aga:inst the switching contact 13', whereby the pair of switching contacts 13', 14', corresponding with the switch 200 in Fig. 3, is closed, and thus for example a condenser ventilator KL of a vehicle air-conditioning system is switched on.
A further increase of the operating pressure P in the pressure chamber A to a pressure level III (Fig. 4) leads to the movement o-E the piston 4" against the stop means S". Thus the securement point Z moves on the disc sesment - B" in such a manner that it results in a relative passing of the connecting line between the securement points Y
and Z in reversed direction. This results in the fact that the lever 11 snaps back against the stop means D1 and thus opens the pair of switching contacts 13, 14, corresponding with switch 100 in Fig. 3.
If the operating pressure P in the pressure chamber A now sinks to a value be~ow the pressure level I, for e~ample to zero, all the described switching stages, or movements, - 8 _ ~2688~
respectively, are performed in reversed sequence, and the pressure switch is ready for a new switching and movement cycle.
With the described pressure switch, it is possible to replace the pressure controlled switches used until now for a vehicle air-conditioning system,. namely safety-low-pressure-switch and safety-high-pressure-switch for the compressor clutch as well as switch fox switching on and off a condenser ventilator, by one single three stage pressure switch arrangement.
Claims (21)
1. A pressure switch comprising:
(a) a housing unit having at least one operating chamber in communication with a pressure source;
(b) said chamber including a plastic membrane supported by a support plate and deformable in response to a predetermined pressure applied to said operating chamber;
(c) said membrane including roll membrane faces formed by deformation of the membrane by said predetermined pressure;
(d) actuating means located on a side of said membrane opposing said faces for transmitting pressure changes;
(e) a switch assembly biased by said actuating means in response to at least two differing pressures;
(f) said assembly having a leaf spring disc in contact with said actuating means and connected to at least two pressure springs and a lever apparatus movably activating associated switch contacts; and (g) an adjustment means in communication with said pressure springs for varying the amount of pressure capable of activating said assembly.
(a) a housing unit having at least one operating chamber in communication with a pressure source;
(b) said chamber including a plastic membrane supported by a support plate and deformable in response to a predetermined pressure applied to said operating chamber;
(c) said membrane including roll membrane faces formed by deformation of the membrane by said predetermined pressure;
(d) actuating means located on a side of said membrane opposing said faces for transmitting pressure changes;
(e) a switch assembly biased by said actuating means in response to at least two differing pressures;
(f) said assembly having a leaf spring disc in contact with said actuating means and connected to at least two pressure springs and a lever apparatus movably activating associated switch contacts; and (g) an adjustment means in communication with said pressure springs for varying the amount of pressure capable of activating said assembly.
2. A pressure switch as claimed in claim 1, wherein said actuating means comprises at least two pistons being vertically guided within a pressure plate having bottom stop means for limiting piston movement.
3. A pressure switch as claimed in claim 1, wherein said leaf spring disc includes at least two segments being biased toward said pressure plate by said pressure springs and away from said membrane by said pistons.
4. A pressure switch as claimed in claim 3, wherein said switch assembly lever apparatus includes levers, each of said levers having a post associated with a tongue of said switch contact, and being connected to said disc segments by at least two tension springs positioned between securement points on said segments and a fixed point on said pressure plate.
5. A pressure switch comprising:
(a) a housing unit having first and second operating chambers;
(b) said first chamber connected to a source of operating pressure and defined in part by a plastic membrane having at least first and second annular roll membrane faces yieldably deformed by application of pressure in said chamber;
(c) said second chamber including first and second pistons each engaging said membrane within a respective roll membrane face, each piston movable in response to operating pressure acting upon said plastic membrane, and a leaf spring disc having first and second segments in contact with said pistons;
(d) a switch-back asssembly including switching contacts associated with lever joints defined by levers and segments of said leaf spring disc, tension springs engaged with said disc segments, and a fixed point on one of said disc segments; and (e) said assembly being biased by said first piston upon application of one operating pressure and by said second piston upon application of another operating pressure.
(a) a housing unit having first and second operating chambers;
(b) said first chamber connected to a source of operating pressure and defined in part by a plastic membrane having at least first and second annular roll membrane faces yieldably deformed by application of pressure in said chamber;
(c) said second chamber including first and second pistons each engaging said membrane within a respective roll membrane face, each piston movable in response to operating pressure acting upon said plastic membrane, and a leaf spring disc having first and second segments in contact with said pistons;
(d) a switch-back asssembly including switching contacts associated with lever joints defined by levers and segments of said leaf spring disc, tension springs engaged with said disc segments, and a fixed point on one of said disc segments; and (e) said assembly being biased by said first piston upon application of one operating pressure and by said second piston upon application of another operating pressure.
6. A pressure switch as claimed in claim 5, wherein said pistons are supported in said second chamber by a pressure plate having bottom stop means for limiting piston movement.
7. A pressure switch as claimed in claim 6, wherein said plastic membrane is adhered to a plate supported by said pressure plate.
8. A pressure switch as claimed in claim 6, wherein said disc segments are biased toward said pressure plate by pressure springs having adjustment means for varying the spring bias.
9. A pressure switch as claimed in claim 5, wherein said pistons are radially guided by recesses in said leaf spring segments,
10. A pressure switch as claimed in claim 5, wherein adjustable stops are provided for controlling movement of said levers.
11. A pressure switch according to claim 5, wherein insulating bodies are provided on said levers movably contacting resilient tongues of said contacts.
12. A pressure switch comprising:
(a) a housing providing an internal chamber portion in communication with a pressure source;
(b) at least first and second pressure actuated control means supported in said housing;
(c) a support plate fixed in said housing between said chamber portion and said control means, said support plate defining at least first and second guideways each extending through said support plate;
(d) said control means including respective operating plungers extending through said support plate via said guideways;
(e) a thin flexible membrane supported by said housing and defining a wall of said chamber, said membrane supported by said plate and engaging said plungers for transmitting pressure forces from said chamber individually to said plungers, said membrane including first and second yielded annular roll sections disposed respectively about said first and second plungers, said roll sections moving when the plungers are actuated to prevent resilient deformation of said membrane; and (f) said plungers biased toward said membrane to resiliently resist pressure responsive motion.
(a) a housing providing an internal chamber portion in communication with a pressure source;
(b) at least first and second pressure actuated control means supported in said housing;
(c) a support plate fixed in said housing between said chamber portion and said control means, said support plate defining at least first and second guideways each extending through said support plate;
(d) said control means including respective operating plungers extending through said support plate via said guideways;
(e) a thin flexible membrane supported by said housing and defining a wall of said chamber, said membrane supported by said plate and engaging said plungers for transmitting pressure forces from said chamber individually to said plungers, said membrane including first and second yielded annular roll sections disposed respectively about said first and second plungers, said roll sections moving when the plungers are actuated to prevent resilient deformation of said membrane; and (f) said plungers biased toward said membrane to resiliently resist pressure responsive motion.
13. A pressure switch as claimed in claim 12, wherein said support plate defines annular roll section supporting recesses about said respective guideways.
14. A pressure switch as claimed in claim 13, wherein said roll sections are yieldably formed in situ upon application of a predetermined over-pressure to said chamber with said supporting recesses shaping said roll sections.
15. A pressure switch comprising two pairs of switching contacts and a pressure chamber, which can be connected to a source of operating pressure, and is terminated towards said pairs of switching contacts by a plastic membrane, which acts via pistons and a leaf spring disc on said pairs of switching contacts, further comprising three roll membrane faces provided in said plastic membrane in a common plane, which are in connection with three vertically guided pistons, said leaf spring disc having three disc segments, two of which form together with two levers lever joints, said segments being biased in such a manner that upon three different operating pressures, under the effect of one each of said three pistons and the according roll membrane face they are moved vertically, and one tension spring each being provided between securement points on two of said disc segments and a securement point on said third disc segments or a fixed point, respectively, said lever joints being respectively arranged in the region between said securement point of said two disc segments and said securement point of said third disc segment or said fixed point respectively.
16. A pressure switch according to claim 15, wherein said pistons are guided vertically in a pressure plate comprising bottom stop means.
17. A pressure switch according to claim 16, wherein said plastic membrane is adhered to a plate resting on said pressure plate.
18. A pressure switch according to claim 17, wherein disc segments are pressed against said pressure plate by spiral pressure springs biased by means of adjustment screws.
19. A pressure switch according to claim 15, wherein said pistons are guided radially by means of recesses in said disc segments of said leaf spring disc.
20. A pressure switch according to claim 15, wherein adjustable stop means are provided which limit the paths of said levers.
21. A pressure switch according to claim 15, wherein on said levers insulating bodies are provided, which press upon resilient contact tongues of said pair of switching contacts to open said switching contacts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000490959A CA1268804A (en) | 1985-09-17 | 1985-09-17 | Three stage pressure switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000490959A CA1268804A (en) | 1985-09-17 | 1985-09-17 | Three stage pressure switch |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1268804A true CA1268804A (en) | 1990-05-08 |
Family
ID=4131414
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000490959A Expired - Lifetime CA1268804A (en) | 1985-09-17 | 1985-09-17 | Three stage pressure switch |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1268804A (en) |
-
1985
- 1985-09-17 CA CA000490959A patent/CA1268804A/en not_active Expired - Lifetime
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121205 |