CA1070740A - Vented plastic enclosure for arcing devices - Google Patents
Vented plastic enclosure for arcing devicesInfo
- Publication number
- CA1070740A CA1070740A CA256,356A CA256356A CA1070740A CA 1070740 A CA1070740 A CA 1070740A CA 256356 A CA256356 A CA 256356A CA 1070740 A CA1070740 A CA 1070740A
- Authority
- CA
- Canada
- Prior art keywords
- housing
- space
- passageway
- parts
- cover
- 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
Links
Landscapes
- Breakers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The cover of a housing has one or more projections which extend into a slot or respective slots in the main body of the housing. Each projection is spaced from the walls defining the slot so as to form a passageway from the interior of the housing to the outside. This passageway is sufficiently long and narrow as to cool burning gases initiated within the housing by an arc, the cooling being sufficient to extinguish the flame before it reaches the exterior of the housing. The passageways completely encircle the interior compartment of the housing so as to provide sufficient passageway area to relieve the internal pressure caused by an explosion within that compartment sufficiently that plastic can be used for the material of the housing.
The cover of a housing has one or more projections which extend into a slot or respective slots in the main body of the housing. Each projection is spaced from the walls defining the slot so as to form a passageway from the interior of the housing to the outside. This passageway is sufficiently long and narrow as to cool burning gases initiated within the housing by an arc, the cooling being sufficient to extinguish the flame before it reaches the exterior of the housing. The passageways completely encircle the interior compartment of the housing so as to provide sufficient passageway area to relieve the internal pressure caused by an explosion within that compartment sufficiently that plastic can be used for the material of the housing.
Description
Appleton ~F-32.01 ECV:ls B~CKGROUND AND SUMMARY OF THE INVE TIO~
Where electrical devices are employed in e~plosive atmospheres precautions must'be taken to avoid igniting those atmospheres by reason of an arc produced by an electrical ' component such as a switch9 a circuit breaker, etc. A con-ventional procedure is to mount such electr:Lcal devices within an enclosure sufficiently rigid to withstand the force of an explosion occurring within the container and thereby preventing the flame occurring within the enclosure from reaching the exterior thereof. Such housings may not be completely fluid tight but may have small passageways which serve as vents permitting the escape of gases while'being sufficiently small to prevent the escape of flame. Since the passageways are small there can be a substantial pressure'build-up in the housing. This necessitates that the housing structure'be quite rigid. Such housings often comprise a metal casting. These are quite expensive to manufacture.
The present invention contemplates the use of a plastic housing which has the advantage of'being substantially less expensive than a metal casting. Furthermore, the plastic is an electrical insulator so that the electrical components within the housing can be mounted directly on the interior portions of the housing, without the necessity of extra parts to serve to insulate the electrical components from the housing walls, as in the case of a metal housing. To compensate for the difference in strength'between metal walls and plastic walls for the housing~ a relatively large venting passageway is provided between the interior of the housing and the ex-terior, the passageway being sufficiently large in area to avoid substantial pressure build up within the housing. At the same time, the passageway is sufficiently long and narrow Appleton ffF-32.01 ECV:ls 1~7074~
as to serve to prevent any flame from wi-thin the housing propa-gating ~o the e~terior of the housing through the passageway.
That is, the plastic walls defining the sides of the passageway will cool the burning gases to the point where they are extin-yuished before reaching the exterior of the housing.
Further objects and advantages will'become apparent from the following description taken in conjunction with the drawings.
DESCRIPTION OF THE DRAWI~GS
Figure 1 is a side elevation of a first embodiment :
of the invention, with portions bro]cen away; ' Figure 2 is an interior view of the cover as seen at line 2-2 of Figure l; .
Figure 3 is a face view of the housing 'body as seen at line 3-3 of Figure l;
Figure 4 is an enlarged view similar to the left side of Figure l;
Figure 5 is a plan view, partially broken away1 of a second embodiment of the invention; and Figure 6 is a side view of the embodiment of Figure 5.
DESCRIPTIO~ OF 5PECIFIC EMBODIMENTS
The following disclosure is offered for public dis- .
semination in return for the grant of a patent. Although it is detailed to ensure adeguacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements.
The embodiment of Figures 1-4 includes a main body, generally 10, and a cover, generally 11. These are'both formed Appleton #F-32.01 ~CV, ls ~Lo'~'7~
of plastic, as for example a glass filled polyester resin.
Normally the body 10 will be fixedly mounted. The cover is secured to the body as by means of screws 12 which extend through the cover and are threaded into the body. The cover and body define a chamber or space 13 which receives an arcing-prone electrical component, such as an electrical switch, a circuit breaker, or the like. The body has a face 14 which is in juxtaposition to a face 15 of the cover. These faces sur-round space 13.
Face 14 has a plurality of ridges 17 which define a plurality of recesses 18. The cover has a plurality of ridges 19 positioned to be received in recesses 18 of the body and a plurality of recesses 20 to receive body ridges 17. As best seen in Figure 4, the plastic walls that define the ridges and recesses are spaced from each other to the end that a passageway 21 extends from the interior space 13 of the housing to the ex-terior thereof. It will be apparent from Figures2 and 3 that this passageway completely surrounds the space 13. Thus while it is relatively small as seen in cross-section (Figure 4)~ its total area is relatively large because of completely surrounding the housing space at the mating faces. To maintain the thickness of the passageway, the dimension T in Figure 4, the body 10 has bosses 22 (or loose spacers) extending outwardly from face 14 a distance corresponding to the desired thickness T. The exterior ridge 19 of the cover abuts boss 22 to supply the desired passage-way thickness. In the disclosed embodiment this thickness is about 0.254 millimeters, but 0.50~ millimeters will provide better venting and will be adequately narrow to provide the re-~uired cooling efect. The axial length of the passageway~ that is its length along its axis as viewed in Figure 4, should ~e atleast 2.54 centimeters. This thickness and length will be suffi-cient so that combustion occurrlng within space 13 will not Appleton ~F-32.01 ECV:ls ~7~7~0 propagate to the exterior of the housing. The walls defining passageway 21 will cool -the flame sufficiently so that it will be extinguished 'before it reaches the exterior of the housing.
Within space 13 is an arc-prone electricaL device such as a circuit 'breaker, generally 25. The details of such structure are well known and will not be described. Suffice it to say, it includes a pair of electrical contacts 26 and 27. Contact 26 is connected to an exterior terminal 28, while contact 27 is connected to a terminal 29. When contacts 26 - ;
and 27 separate during the course of normal operation, an electrical arc will result, which arc will ignite an explosive atmosphere existing in space 13. These contacts could, of course~ 'be the contacts of a switch, etc. The terminals 28 and 29 may be molded into the plastic walls or inserted through suitable openings which are then sealed about the terminals. ~ ~
For the purpose of resetting the circuit breakerg ' there is a handle 31 on the exterior of the cover. ~his handle is attached to the exterior end of a shaft 32. The shaft is rotatably mounted in a bearing 33 in the cover. At the interior end of the shaft is a cam 3~ which, when the shaft is rotated, moves to contact the circuit breaker 25 and reset it to the closed position. If the arc-prone electrical device were a switch, for example~ this shaft could be employed to move the ~ovable switch part.
It should be noted that the circuit 'breaker 25 in-cludes a plurality of metal components which are mounted directly on the body 10. That is, there is no need Eor sepa-rate insulated mountings, etc., to separate the metal components of the circuit breaker from the 'body as is the case when the housing is formed of metal. This results in a cost saving.
The plastic of the housing of the described embodirnent serves ~-, ~~~
- . ~ . .
Appleton ~F-32.01 ECV:ls 1~7~7~L0 as an insulator, not only to electrically separate components of the circuit breaker, but to prevent someone who might contact the exterior of the housing from receiving an electrical charge.
In this embodiment the ridges 17 have a height (as viewed in Figure 1) of 2.362 mm and a wiclth o~ 1.854 mm. The recesses 18 have a depth of 2.362 mm and a width of 2.362 mm.
The ridges 19 have a height (as viewed in ~igure 1) of Z.362 mm and the interior of the ridges have a width of 1.854 mm, while the two exterior ridges have a width of 2.108 mm. The recesses 20 have a height o~ 2.362 mm and a width o~ 2.362 ~m.
In the embodiment of Figures 5 and 6 there is a body, generally 40, and a cover, generally 41. These are held together by screws 42 and de~ine an interior space 43. The face o~ the'body that is in juxtaposition to the cover defines a single recess 45 which completely surrounds the space 43.
The corresponding face o the cover has a single ridge 46 which extends into the recess 45. The recess 45 (as viewed in Figure 6) is 1.27 cm in depth. Thus~ the total axial length of the passageway 47 existing between the space 43 and the exterior of the housing will be in excess o~ 2.54 cm. The height of the ridge 46 (as viewed in Figure 6) is likewise 1.27 cm.
Spacers 48 are employed'between the cover and the body to pro-vide the desired thickness o~ the passageway at the'bottom of the ridge and at the juxtaposed ~aces 'between the cover and the'b~ody. The embodiment of Figures 5 and 6 is for housiny a circuit breaker 25, as previously described.
Appleton #~-32.01 EC~ ls ~(~7(~
S U P P L E M E N T A R Y D I S C I~ O S U R E
DESCRIPTION OF THE DRAWINGS
Figure 7 is a side view? with portions broken away, of another em`bodiment of the invention;
Figure 8 is a face view of the housing 'body of the embodiment of Figure 7;
Figure 9 is a face view of the cover of the embodiment of Figure 7;
Figure 10 is an exploded sectional view of the em'bodi~
ment of Figure 7 as seen at line 10-10 of Figure 8;
Figure lL is an enlarged, partiaL sectional view as seen at line 11-11 of Figure 10 and also including a conductor in sect ion; ~:
Figure 12 is an enlarged, partial sectional view as seen at line 12-12 of Figure 10 and also including a conductor in section; and Figure 13 is an enlarged, partial sectional view as seen at line 13-13 of Figure 10.
DESC_IPTION OF SPECIFIC EMBODIMENT
In the embodiment of Figures 7-13 there is a'body, generally 55, and a coverj generally 56~ which form the housing.
These are held in the assembled condition (to form the housing) ~ ~
'by rivets 57 which pass through openings 58 in the four corners ` ' of the body and cover. On the cover there are bosses 59 through which the openings 58 pass~ These bosses act as spacers and contact the face of body 55 to ensure the required thickness of the exhaust passageway. When the cover is in place on the body~
as illustrated in Figure 7, the two define a space 60 to receive a circuit breaker.
Appleton ~-32.01 ECV:ls ~7~7~
The body has a comparatively h.igh rim 62 encircling space 60. ThiS rim has an outer face 63 which, when the cover is in place, is in juxtaposition to face 64 of the cover. Within rim 62 are a pair of recesses 65 and 66 which define a ridge 67 therebetween. The cover has a mating pair of ridges 68 and 69 which define a recess 70 therebetween.
When the cover is in place on the body the ridges 68 and 69 extend into recesses 65 and 66, respectively, while ridge 67 of the body extends into recess 70 of the cover. In each in- ..
stance the ridge is spaced from the walls defining the recess so that when assembled there is a passageway 73 therebetween. As seen at the top of F.igure 7, this passageway extends from the space 60 within the assembled housing to the exterior of the housing. In this embodiment the passageway has a length of about 2.5 inches (6.35 cm) and a thickness of 0.02 inches (0.508 mm). The passageway is present on all four sides of the housing and takes up substantially all, i.e., at least eighty-five percent, of the periphery of the housing about space 60.
The extent of the passageway is interrupted only to the extent necessary to bring the electrical conductors out o~ the housing, as hereinafter described. Thus the passageway 73 is of maximum cross-sectional area, thereby preventing a pressure build-up within space 60 (as the result o~ an explosion therein). Were such a pressure build-up to occur it could result in a breaking o~ the housing and other undesirable consequences.
At locations on opposite sides of the housing are elect.rodes, generally 74, used to provide the electrical connec-tion from the e~terior to the interior of the housing. Each conductor is in the form of a rod having a main cylindrical portion 75. This represents the minimum size of the conductor and its cross-sectional area is determined by the current carry-ing capacity required. Extending outwardly from the main portion ~`
~ppleton ~F-32.01 ECV:ls 1(~7~
are four annular bosses 76--79. The principal purpose of these bosses is to lock the conductor in place between the cover and the body and thus to prevent the conductor from moving axially, Bosses 77 and 78 fit into recesses 65 and 66 respec-tively. ~s best seen in Figure 12, the portion of the body rim 62 exterior of recess 65 has a slot 82 to receive that part of main portion 75 which exists between bosses 76 and 77. The rim about this slot forms a seat for that portion of the conductor, To fit about the top of that part of the conductor main portion, the cover has a seat 83 (Figures 10 and 13). Within recess 65 the body has a seat ~4 which fits about boss 77 (Figure 11).
The cover also has a seat 85 which fits about the remaining part of boss 77 (Figure 13). Similarly, there are corresponding seats which fit about the central part of the main portion 75 (i.e,, between bosses 77 and 78), about boss 78, and about that part of the conductor main portion that is between bosses 78 and 79.
At each electrode location the body has a shelf 87 and the cover has a shelf 88. These form protective shields and insulators for the e~terior portion of the conductor, These shelves have recesses 89 and 90 to receive a portion of the periphery of boss 76 of the conductor, The outer end of the shelves have flanges 91 and 92 which have slots therein to re-ceive the tee-shaped end of the conductor.
The cover has an opening 95 through which the operating shaft 96 of the circuit breaker may project when the circuit breaker is in the housing (Figure 7). That shaft fits tightly to the cover about the opening so that there is a seal to prevent the escape of burning gases should combustion occur within space 60.
The rim 62 of the body has an opening 98 therethrough and ridges 68 and 69 also have an opening 99 therethrough. When 'S~f"~`i Appleton ~F-32.01 ECV:ls ~7~7~
the housing is assembled these openings are coaxial. However, opening 98 is smaller in diameter than is opening 99. Aftar the unit has been fully assembled, a tool may be inserted through the space provided by coaxial openings 98, 99 Eor the purpose of adjusting the circuit breaker in the course of its calibra-tion. After such adjustment oE the circuit breaker has been completed these openings are sealed closed. This is done by filling them with a hardenable plastic material in mastic form.
Since the openings 98g 99 are of different diameters that plas-tic material is securely locked in place after it hardens.
_g_ : ' ,
Where electrical devices are employed in e~plosive atmospheres precautions must'be taken to avoid igniting those atmospheres by reason of an arc produced by an electrical ' component such as a switch9 a circuit breaker, etc. A con-ventional procedure is to mount such electr:Lcal devices within an enclosure sufficiently rigid to withstand the force of an explosion occurring within the container and thereby preventing the flame occurring within the enclosure from reaching the exterior thereof. Such housings may not be completely fluid tight but may have small passageways which serve as vents permitting the escape of gases while'being sufficiently small to prevent the escape of flame. Since the passageways are small there can be a substantial pressure'build-up in the housing. This necessitates that the housing structure'be quite rigid. Such housings often comprise a metal casting. These are quite expensive to manufacture.
The present invention contemplates the use of a plastic housing which has the advantage of'being substantially less expensive than a metal casting. Furthermore, the plastic is an electrical insulator so that the electrical components within the housing can be mounted directly on the interior portions of the housing, without the necessity of extra parts to serve to insulate the electrical components from the housing walls, as in the case of a metal housing. To compensate for the difference in strength'between metal walls and plastic walls for the housing~ a relatively large venting passageway is provided between the interior of the housing and the ex-terior, the passageway being sufficiently large in area to avoid substantial pressure build up within the housing. At the same time, the passageway is sufficiently long and narrow Appleton ffF-32.01 ECV:ls 1~7074~
as to serve to prevent any flame from wi-thin the housing propa-gating ~o the e~terior of the housing through the passageway.
That is, the plastic walls defining the sides of the passageway will cool the burning gases to the point where they are extin-yuished before reaching the exterior of the housing.
Further objects and advantages will'become apparent from the following description taken in conjunction with the drawings.
DESCRIPTION OF THE DRAWI~GS
Figure 1 is a side elevation of a first embodiment :
of the invention, with portions bro]cen away; ' Figure 2 is an interior view of the cover as seen at line 2-2 of Figure l; .
Figure 3 is a face view of the housing 'body as seen at line 3-3 of Figure l;
Figure 4 is an enlarged view similar to the left side of Figure l;
Figure 5 is a plan view, partially broken away1 of a second embodiment of the invention; and Figure 6 is a side view of the embodiment of Figure 5.
DESCRIPTIO~ OF 5PECIFIC EMBODIMENTS
The following disclosure is offered for public dis- .
semination in return for the grant of a patent. Although it is detailed to ensure adeguacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements.
The embodiment of Figures 1-4 includes a main body, generally 10, and a cover, generally 11. These are'both formed Appleton #F-32.01 ~CV, ls ~Lo'~'7~
of plastic, as for example a glass filled polyester resin.
Normally the body 10 will be fixedly mounted. The cover is secured to the body as by means of screws 12 which extend through the cover and are threaded into the body. The cover and body define a chamber or space 13 which receives an arcing-prone electrical component, such as an electrical switch, a circuit breaker, or the like. The body has a face 14 which is in juxtaposition to a face 15 of the cover. These faces sur-round space 13.
Face 14 has a plurality of ridges 17 which define a plurality of recesses 18. The cover has a plurality of ridges 19 positioned to be received in recesses 18 of the body and a plurality of recesses 20 to receive body ridges 17. As best seen in Figure 4, the plastic walls that define the ridges and recesses are spaced from each other to the end that a passageway 21 extends from the interior space 13 of the housing to the ex-terior thereof. It will be apparent from Figures2 and 3 that this passageway completely surrounds the space 13. Thus while it is relatively small as seen in cross-section (Figure 4)~ its total area is relatively large because of completely surrounding the housing space at the mating faces. To maintain the thickness of the passageway, the dimension T in Figure 4, the body 10 has bosses 22 (or loose spacers) extending outwardly from face 14 a distance corresponding to the desired thickness T. The exterior ridge 19 of the cover abuts boss 22 to supply the desired passage-way thickness. In the disclosed embodiment this thickness is about 0.254 millimeters, but 0.50~ millimeters will provide better venting and will be adequately narrow to provide the re-~uired cooling efect. The axial length of the passageway~ that is its length along its axis as viewed in Figure 4, should ~e atleast 2.54 centimeters. This thickness and length will be suffi-cient so that combustion occurrlng within space 13 will not Appleton ~F-32.01 ECV:ls ~7~7~0 propagate to the exterior of the housing. The walls defining passageway 21 will cool -the flame sufficiently so that it will be extinguished 'before it reaches the exterior of the housing.
Within space 13 is an arc-prone electricaL device such as a circuit 'breaker, generally 25. The details of such structure are well known and will not be described. Suffice it to say, it includes a pair of electrical contacts 26 and 27. Contact 26 is connected to an exterior terminal 28, while contact 27 is connected to a terminal 29. When contacts 26 - ;
and 27 separate during the course of normal operation, an electrical arc will result, which arc will ignite an explosive atmosphere existing in space 13. These contacts could, of course~ 'be the contacts of a switch, etc. The terminals 28 and 29 may be molded into the plastic walls or inserted through suitable openings which are then sealed about the terminals. ~ ~
For the purpose of resetting the circuit breakerg ' there is a handle 31 on the exterior of the cover. ~his handle is attached to the exterior end of a shaft 32. The shaft is rotatably mounted in a bearing 33 in the cover. At the interior end of the shaft is a cam 3~ which, when the shaft is rotated, moves to contact the circuit breaker 25 and reset it to the closed position. If the arc-prone electrical device were a switch, for example~ this shaft could be employed to move the ~ovable switch part.
It should be noted that the circuit 'breaker 25 in-cludes a plurality of metal components which are mounted directly on the body 10. That is, there is no need Eor sepa-rate insulated mountings, etc., to separate the metal components of the circuit breaker from the 'body as is the case when the housing is formed of metal. This results in a cost saving.
The plastic of the housing of the described embodirnent serves ~-, ~~~
- . ~ . .
Appleton ~F-32.01 ECV:ls 1~7~7~L0 as an insulator, not only to electrically separate components of the circuit breaker, but to prevent someone who might contact the exterior of the housing from receiving an electrical charge.
In this embodiment the ridges 17 have a height (as viewed in Figure 1) of 2.362 mm and a wiclth o~ 1.854 mm. The recesses 18 have a depth of 2.362 mm and a width of 2.362 mm.
The ridges 19 have a height (as viewed in ~igure 1) of Z.362 mm and the interior of the ridges have a width of 1.854 mm, while the two exterior ridges have a width of 2.108 mm. The recesses 20 have a height o~ 2.362 mm and a width o~ 2.362 ~m.
In the embodiment of Figures 5 and 6 there is a body, generally 40, and a cover, generally 41. These are held together by screws 42 and de~ine an interior space 43. The face o~ the'body that is in juxtaposition to the cover defines a single recess 45 which completely surrounds the space 43.
The corresponding face o the cover has a single ridge 46 which extends into the recess 45. The recess 45 (as viewed in Figure 6) is 1.27 cm in depth. Thus~ the total axial length of the passageway 47 existing between the space 43 and the exterior of the housing will be in excess o~ 2.54 cm. The height of the ridge 46 (as viewed in Figure 6) is likewise 1.27 cm.
Spacers 48 are employed'between the cover and the body to pro-vide the desired thickness o~ the passageway at the'bottom of the ridge and at the juxtaposed ~aces 'between the cover and the'b~ody. The embodiment of Figures 5 and 6 is for housiny a circuit breaker 25, as previously described.
Appleton #~-32.01 EC~ ls ~(~7(~
S U P P L E M E N T A R Y D I S C I~ O S U R E
DESCRIPTION OF THE DRAWINGS
Figure 7 is a side view? with portions broken away, of another em`bodiment of the invention;
Figure 8 is a face view of the housing 'body of the embodiment of Figure 7;
Figure 9 is a face view of the cover of the embodiment of Figure 7;
Figure 10 is an exploded sectional view of the em'bodi~
ment of Figure 7 as seen at line 10-10 of Figure 8;
Figure lL is an enlarged, partiaL sectional view as seen at line 11-11 of Figure 10 and also including a conductor in sect ion; ~:
Figure 12 is an enlarged, partial sectional view as seen at line 12-12 of Figure 10 and also including a conductor in section; and Figure 13 is an enlarged, partial sectional view as seen at line 13-13 of Figure 10.
DESC_IPTION OF SPECIFIC EMBODIMENT
In the embodiment of Figures 7-13 there is a'body, generally 55, and a coverj generally 56~ which form the housing.
These are held in the assembled condition (to form the housing) ~ ~
'by rivets 57 which pass through openings 58 in the four corners ` ' of the body and cover. On the cover there are bosses 59 through which the openings 58 pass~ These bosses act as spacers and contact the face of body 55 to ensure the required thickness of the exhaust passageway. When the cover is in place on the body~
as illustrated in Figure 7, the two define a space 60 to receive a circuit breaker.
Appleton ~-32.01 ECV:ls ~7~7~
The body has a comparatively h.igh rim 62 encircling space 60. ThiS rim has an outer face 63 which, when the cover is in place, is in juxtaposition to face 64 of the cover. Within rim 62 are a pair of recesses 65 and 66 which define a ridge 67 therebetween. The cover has a mating pair of ridges 68 and 69 which define a recess 70 therebetween.
When the cover is in place on the body the ridges 68 and 69 extend into recesses 65 and 66, respectively, while ridge 67 of the body extends into recess 70 of the cover. In each in- ..
stance the ridge is spaced from the walls defining the recess so that when assembled there is a passageway 73 therebetween. As seen at the top of F.igure 7, this passageway extends from the space 60 within the assembled housing to the exterior of the housing. In this embodiment the passageway has a length of about 2.5 inches (6.35 cm) and a thickness of 0.02 inches (0.508 mm). The passageway is present on all four sides of the housing and takes up substantially all, i.e., at least eighty-five percent, of the periphery of the housing about space 60.
The extent of the passageway is interrupted only to the extent necessary to bring the electrical conductors out o~ the housing, as hereinafter described. Thus the passageway 73 is of maximum cross-sectional area, thereby preventing a pressure build-up within space 60 (as the result o~ an explosion therein). Were such a pressure build-up to occur it could result in a breaking o~ the housing and other undesirable consequences.
At locations on opposite sides of the housing are elect.rodes, generally 74, used to provide the electrical connec-tion from the e~terior to the interior of the housing. Each conductor is in the form of a rod having a main cylindrical portion 75. This represents the minimum size of the conductor and its cross-sectional area is determined by the current carry-ing capacity required. Extending outwardly from the main portion ~`
~ppleton ~F-32.01 ECV:ls 1(~7~
are four annular bosses 76--79. The principal purpose of these bosses is to lock the conductor in place between the cover and the body and thus to prevent the conductor from moving axially, Bosses 77 and 78 fit into recesses 65 and 66 respec-tively. ~s best seen in Figure 12, the portion of the body rim 62 exterior of recess 65 has a slot 82 to receive that part of main portion 75 which exists between bosses 76 and 77. The rim about this slot forms a seat for that portion of the conductor, To fit about the top of that part of the conductor main portion, the cover has a seat 83 (Figures 10 and 13). Within recess 65 the body has a seat ~4 which fits about boss 77 (Figure 11).
The cover also has a seat 85 which fits about the remaining part of boss 77 (Figure 13). Similarly, there are corresponding seats which fit about the central part of the main portion 75 (i.e,, between bosses 77 and 78), about boss 78, and about that part of the conductor main portion that is between bosses 78 and 79.
At each electrode location the body has a shelf 87 and the cover has a shelf 88. These form protective shields and insulators for the e~terior portion of the conductor, These shelves have recesses 89 and 90 to receive a portion of the periphery of boss 76 of the conductor, The outer end of the shelves have flanges 91 and 92 which have slots therein to re-ceive the tee-shaped end of the conductor.
The cover has an opening 95 through which the operating shaft 96 of the circuit breaker may project when the circuit breaker is in the housing (Figure 7). That shaft fits tightly to the cover about the opening so that there is a seal to prevent the escape of burning gases should combustion occur within space 60.
The rim 62 of the body has an opening 98 therethrough and ridges 68 and 69 also have an opening 99 therethrough. When 'S~f"~`i Appleton ~F-32.01 ECV:ls ~7~7~
the housing is assembled these openings are coaxial. However, opening 98 is smaller in diameter than is opening 99. Aftar the unit has been fully assembled, a tool may be inserted through the space provided by coaxial openings 98, 99 Eor the purpose of adjusting the circuit breaker in the course of its calibra-tion. After such adjustment oE the circuit breaker has been completed these openings are sealed closed. This is done by filling them with a hardenable plastic material in mastic form.
Since the openings 98g 99 are of different diameters that plas-tic material is securely locked in place after it hardens.
_g_ : ' ,
Claims (6)
1. A housing for use in an area in which the ambient air may comprise an explosive atmosphere and defining an in-ternal space for holding electrical wiring components between which an arc may occur which arc could ignite said atmosphere within said housing, said housing comprising:
said housing being formed of plastic and including a fixed body part and a cover part affixed to said body part, each of said parts having a portion in immediate juxtaposition to the other part, said portions defining a circuitous passage-way between said space and the outside of the housing, said passageway extending about substantially all the periphery of said parts at said portions and sufficiently wide between said portions to provide a total passageway area to avoid substantial pressure buildup within the housing as a consequence of said atmosphere being ignited within said space, said passageway having an axial length between said space and the outside of the housing of at least 2.54 cm and being sufficiently narrow between said portions to cool any flame propagating from said space toward the exterior of the housing through said passage-way.
said housing being formed of plastic and including a fixed body part and a cover part affixed to said body part, each of said parts having a portion in immediate juxtaposition to the other part, said portions defining a circuitous passage-way between said space and the outside of the housing, said passageway extending about substantially all the periphery of said parts at said portions and sufficiently wide between said portions to provide a total passageway area to avoid substantial pressure buildup within the housing as a consequence of said atmosphere being ignited within said space, said passageway having an axial length between said space and the outside of the housing of at least 2.54 cm and being sufficiently narrow between said portions to cool any flame propagating from said space toward the exterior of the housing through said passage-way.
2. A housing as set forth in claim 1, wherein the body part has a substantial depth in relation to the depth of the cover parts the majority of the depth of said space being defined by the body part, and said body part has a wall surround-ing said space with a recess in said wall and surrounding said space, said cover part including a projection extending into said recess, said passageway being between said projection and the part of said wall defining said recess.
3. A housing as set forth in claim 2, including rotatable shaft means extending through said cover part with an interior end in said space and an exterior end, an operating handle secured to said exterior end, and cam means secured to said interior end, said cam means being positioned for actuat-ing said circuit breaker when said shaft means is rotated.
4. A housing as set forth in claim 1, including spacer means between said parts for maintaining said parts spaced from each other so that said narrowness of said passage-way will not be diminished.
5. A housing as set forth in claim 4, wherein said passageway has an end at said space and an end at the outside of said housing and said spacer means is positioned beyond one of said ends of said passageway so as not to reduce the area of said passageway.
CLAIM BASED UPON SUPPLEMENTARY DISCLOSURE
CLAIM BASED UPON SUPPLEMENTARY DISCLOSURE
6. A housing as set forth in claim 1, wherein said wiring components include two rods, each rod having a main portion of a given cross-sectional size and a plurality of spaced bosses intermediate its ends, integral therewith and defining a gap between adjacent bosses, each boss completely surrounding and extending outwardly from the main portion, said rods extending from said space to the ex-terior of said housing and between said parts at said portions at separate, respective locations at said periphery; and said parts each having seat means at said locations, fitting about the bosses and extending into said gap to a posi-tion in juxtaposition to said main portion at said gap.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US61302175A | 1975-09-12 | 1975-09-12 | |
| US80450177A | 1977-06-08 | 1977-06-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1070740A true CA1070740A (en) | 1980-01-29 |
Family
ID=27086898
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA256,356A Expired CA1070740A (en) | 1975-09-12 | 1976-07-06 | Vented plastic enclosure for arcing devices |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1070740A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4767901A (en) * | 1984-12-21 | 1988-08-30 | Simmons-Rand Corporation | Process for making an enclosure outlet connection device |
| US4771144A (en) * | 1984-12-21 | 1988-09-13 | Simmons-Rand Corporation | Apparatus and process for using a self-aligning bearing |
-
1976
- 1976-07-06 CA CA256,356A patent/CA1070740A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4767901A (en) * | 1984-12-21 | 1988-08-30 | Simmons-Rand Corporation | Process for making an enclosure outlet connection device |
| US4771144A (en) * | 1984-12-21 | 1988-09-13 | Simmons-Rand Corporation | Apparatus and process for using a self-aligning bearing |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |