CA1109935A - Metallized film capacitors - Google Patents
Metallized film capacitorsInfo
- Publication number
- CA1109935A CA1109935A CA360,216A CA360216A CA1109935A CA 1109935 A CA1109935 A CA 1109935A CA 360216 A CA360216 A CA 360216A CA 1109935 A CA1109935 A CA 1109935A
- Authority
- CA
- Canada
- Prior art keywords
- dielectric layer
- metallized
- capacitor
- along
- pleated
- 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
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Abstract
METALLIZED FILM CAPACITORS
Abstract of the Disclosure The present invention provides a product which has all of the many advantages of pleated, wound, electrical capacitors and also has the added advantage that it may be manufactured with commercially available metallized die-lectric materials. A further advantage of the present invention is that the same basic starting materials may be used to manufacture capacitors that have a number of different pleating combinations. Thus, the invention provides for an electrical capacitor segment which comprises a dielectric layer having a center line, a first metallized electrode layer applied to one side of the dielectric layer so that an unmetallized margin ex-tends along each edge of a pair of parallel edges of the di-electric layer, and a second metallized electrode layer applied to the other side of the dielectric layer so that an unmetallized area is located adjacent the second metallized electrode layer.
The dielectric layer is pleated once along the unmetallized areas off of the center line so that one edge of the margin containing edges extends beyond the other of the edges along the same end of the capacitor segment and metallized spray material in contact with the second electrode layer.
Abstract of the Disclosure The present invention provides a product which has all of the many advantages of pleated, wound, electrical capacitors and also has the added advantage that it may be manufactured with commercially available metallized die-lectric materials. A further advantage of the present invention is that the same basic starting materials may be used to manufacture capacitors that have a number of different pleating combinations. Thus, the invention provides for an electrical capacitor segment which comprises a dielectric layer having a center line, a first metallized electrode layer applied to one side of the dielectric layer so that an unmetallized margin ex-tends along each edge of a pair of parallel edges of the di-electric layer, and a second metallized electrode layer applied to the other side of the dielectric layer so that an unmetallized area is located adjacent the second metallized electrode layer.
The dielectric layer is pleated once along the unmetallized areas off of the center line so that one edge of the margin containing edges extends beyond the other of the edges along the same end of the capacitor segment and metallized spray material in contact with the second electrode layer.
Description
3~i ~
METALLIZED FILM CAPACITORS
Back~ound of the Invention This appli.cation is a division of Canadian Serial No. 305,939, filed June 21, 1978.
Electrical capacitors made of thin film dielectric material which is metallized on both sides are used in large quantities in electrieal devices because of their reliability, their desirable elect~
rical characteristic~ and their relatively low cost. IJnited States Patent No. 2, 470" 8~6 issued on l\qay 24" 1949 to W. McMahon illus-trates a capacitor in which a double ~ided metallized c3ielectric layer is folded an odd number of times in a longitudinal direction. ~Ihe folded dielectric material may then be wound along its longitudinal dimension and end termination~ may then be applied to lt b~ spraying of metal against the edges o~.the wound capacitor segment:. ~he type of capacitor de~cribed by McMahon patent is extremely desirable be-cau~e substantially all of the dielectric layer of the capacitor is in the electric field and the capacitor may be made ~vithout the insertion of asl additional dielectric layer in the main boc3y o~ the capacitor, although a short initial unmetallized dielectric strip and a protective l:errninal;ing
METALLIZED FILM CAPACITORS
Back~ound of the Invention This appli.cation is a division of Canadian Serial No. 305,939, filed June 21, 1978.
Electrical capacitors made of thin film dielectric material which is metallized on both sides are used in large quantities in electrieal devices because of their reliability, their desirable elect~
rical characteristic~ and their relatively low cost. IJnited States Patent No. 2, 470" 8~6 issued on l\qay 24" 1949 to W. McMahon illus-trates a capacitor in which a double ~ided metallized c3ielectric layer is folded an odd number of times in a longitudinal direction. ~Ihe folded dielectric material may then be wound along its longitudinal dimension and end termination~ may then be applied to lt b~ spraying of metal against the edges o~.the wound capacitor segment:. ~he type of capacitor de~cribed by McMahon patent is extremely desirable be-cau~e substantially all of the dielectric layer of the capacitor is in the electric field and the capacitor may be made ~vithout the insertion of asl additional dielectric layer in the main boc3y o~ the capacitor, although a short initial unmetallized dielectric strip and a protective l:errninal;ing
2.0 dielectric strip may b~ employed with the capacitor, if de~irec3.
. . .
The type of capacitor construction that is envisiolled by McMahon patent has a number of declded manufacturing and eleclrical advantages.
.~ For example, the prohlem of masking the dielectric layer during elect- :
rode evaporation when the electrode areas are applied to tlle film is sub-25 ~ ~ stantially reduced, In addition, no slitting i5 required as it is during the ~' ;' ~ ~ :
: ' . ' , ' .. . .. . , ,. . ,. , , ,.. . , .: .... ~.. .. .. . .... . .
~ 9~
manufacture of c~nventional wound film c~pacitors. :Furtherrr~ore, the capacitance per unit dielectric area is maximized because of tlle substantially full use of the dielectric layer in the electric field. Shorter winding lengths per unit capacitance are thereby required~ reducing the winding labor~ ~he dielectric lengths can also be calibrated and pre-cut to produce a capacitor of more aceurate values Another advantage of this ~ype of capacitor is that there are no air layers between the metallized electrodes and the pleated film surfaces and his substantially increases the voltage, for example, one hundred volts or more, at which corona di~charge starts, making this capacitor commercially attractive for new applications ~uch as fluorescent lighting circuits. Previously, fifty gauge îilm thickness or more was required of wound film capacits~rs to withstand the corona. With the capacitor of the present invention, thirty-two gauge or less dielectric film thickness may be utilized, making ~und film capa-citors economically feasible for such applications.
~ he McMahon patent suggested that leads could be attached to his capacitor by the well-known Schoop process. ~he applicalion of high velocity metallis spray coatings to~e edges of the capacitor described by Mcl~ahon i~ not commercially practical, however, because l;l~c spray will ,l~enetrate through the dielectric area at a pleat and thereby short one electrode to the other-, If the ternperature and pres~ure of the spray are lowered, penet-ration of the dielectric layers may be reduced but the adhesion of the metallic spray will generally bè very poor. lhe multiple leads suggested in the l~cMahon patent also are not satisfactory since they tend to tear the dielectric .
.
.
.
, , , . . - : :
.
r~aterial and to make the capacitor bllllcy and inductive.
Irl order to solve the above mentioned spray shortin~ problem at a pleated edge, it has been suggested in ~ustralian Patent No~ 159, 958, patented on November 24, 1954 to pro~ide unmetalli~ed dielectric strips behind all of the pleats of a pleated m~tallized capacitor, While this solution may provide a technically feasible method of attaching leads to apleated metallized dielectric layer capacitor, the number of unmetallized strips that are required on the dielectric layer greatly complicates the manu-facturing process for both the dielectric layer itsel~ and the pleated capacitor product. ~For example, in a capacitor having five pleats, there must be, in addition to the two unmetallized margin areas, five unmetallized strips that run along the entire lengtll oi tlle diclectric malerial, with three of these strips being on one side of the dielectric layer and t~vo of these strips being on the opposite side of the dielectric layer. It is apparent that the masking problems and the cost of manu~acturing such a , .
specialized item make the solution of the Australian patent commercially unattractive. This is especially true since the type of metallized dielectric layer that is used in the capacitor of the preserlt invention, ~in which only the margin areas and one unmetalli7ed central strip is required), is readily commercially available. P'urthermore, the employment ol ~n unm~tallized strip behind the single pleated capacitor of the McMahon patent, however, -still would not provide an end termination along the opposite edge of the wound capacitor segment that would allow a metalli~ed spray to be applied to this edge because the ends of the dielectric layer of the McMahon patent at this edge extended beyond both of the metalli~ed electrodes and contact between the metallic spray and the inner e~ectrode area would thereby be prevented, .
~ - 3 -F~
. . .
The type of capacitor construction that is envisiolled by McMahon patent has a number of declded manufacturing and eleclrical advantages.
.~ For example, the prohlem of masking the dielectric layer during elect- :
rode evaporation when the electrode areas are applied to tlle film is sub-25 ~ ~ stantially reduced, In addition, no slitting i5 required as it is during the ~' ;' ~ ~ :
: ' . ' , ' .. . .. . , ,. . ,. , , ,.. . , .: .... ~.. .. .. . .... . .
~ 9~
manufacture of c~nventional wound film c~pacitors. :Furtherrr~ore, the capacitance per unit dielectric area is maximized because of tlle substantially full use of the dielectric layer in the electric field. Shorter winding lengths per unit capacitance are thereby required~ reducing the winding labor~ ~he dielectric lengths can also be calibrated and pre-cut to produce a capacitor of more aceurate values Another advantage of this ~ype of capacitor is that there are no air layers between the metallized electrodes and the pleated film surfaces and his substantially increases the voltage, for example, one hundred volts or more, at which corona di~charge starts, making this capacitor commercially attractive for new applications ~uch as fluorescent lighting circuits. Previously, fifty gauge îilm thickness or more was required of wound film capacits~rs to withstand the corona. With the capacitor of the present invention, thirty-two gauge or less dielectric film thickness may be utilized, making ~und film capa-citors economically feasible for such applications.
~ he McMahon patent suggested that leads could be attached to his capacitor by the well-known Schoop process. ~he applicalion of high velocity metallis spray coatings to~e edges of the capacitor described by Mcl~ahon i~ not commercially practical, however, because l;l~c spray will ,l~enetrate through the dielectric area at a pleat and thereby short one electrode to the other-, If the ternperature and pres~ure of the spray are lowered, penet-ration of the dielectric layers may be reduced but the adhesion of the metallic spray will generally bè very poor. lhe multiple leads suggested in the l~cMahon patent also are not satisfactory since they tend to tear the dielectric .
.
.
.
, , , . . - : :
.
r~aterial and to make the capacitor bllllcy and inductive.
Irl order to solve the above mentioned spray shortin~ problem at a pleated edge, it has been suggested in ~ustralian Patent No~ 159, 958, patented on November 24, 1954 to pro~ide unmetalli~ed dielectric strips behind all of the pleats of a pleated m~tallized capacitor, While this solution may provide a technically feasible method of attaching leads to apleated metallized dielectric layer capacitor, the number of unmetallized strips that are required on the dielectric layer greatly complicates the manu-facturing process for both the dielectric layer itsel~ and the pleated capacitor product. ~For example, in a capacitor having five pleats, there must be, in addition to the two unmetallized margin areas, five unmetallized strips that run along the entire lengtll oi tlle diclectric malerial, with three of these strips being on one side of the dielectric layer and t~vo of these strips being on the opposite side of the dielectric layer. It is apparent that the masking problems and the cost of manu~acturing such a , .
specialized item make the solution of the Australian patent commercially unattractive. This is especially true since the type of metallized dielectric layer that is used in the capacitor of the preserlt invention, ~in which only the margin areas and one unmetalli7ed central strip is required), is readily commercially available. P'urthermore, the employment ol ~n unm~tallized strip behind the single pleated capacitor of the McMahon patent, however, -still would not provide an end termination along the opposite edge of the wound capacitor segment that would allow a metalli~ed spray to be applied to this edge because the ends of the dielectric layer of the McMahon patent at this edge extended beyond both of the metalli~ed electrodes and contact between the metallic spray and the inner e~ectrode area would thereby be prevented, .
~ - 3 -F~
3~
~he leads of the capacitor of the IJnited States Patent No. 3, 854, 075.
i ssued L~ccembcl 10, 1974 to John Philip Vhl, were used as mandrels to willd the pleated capacitOr segment about the center, in a manner similar to that suggested in United States Patent NoO 2, ~87, 649 issued May 19, 1959 to Daniel B. Peck. In the Vhl patent, conductive foil tabs were inserted between the lead.s and the metalli~ed electrode areas to make positive contact with the electrode and to protect the electrode from damage b~ the leads during winding. ~lowever, it has been determined that this construction leads to a higher failure rate than desirable due to opening of the e1ectrode area around the periphery of the metal foil, for reasons which are not completely understood.
l~he configuration of the capacitor of the present invelltion provides a product which has all of the advantages of single pleated, or single pleated and wound, capacitors and also has the added advantage that it may be manufactured with commercially available metallized dielectric material~ A further advantage of the present invention is that the same basic starting material may be used to manufacture capacitors having a numbex of different pleating combinations, which, o~ course, ifi not true for the capacitor of the Au9tralian patent, in which each pleat combin-ation requires a speciallx manufactured die]eclric layer. In ~ddition to the use of the present in-rention to manufacture wound film capacitors, it is also possible to utilize the invention to produce ceramic capacitors in which the capacitor dielectric material is folded while the ceramic material is still in a "greenl' state, in a mamler sirnilar to that dis- -closed in~United States Patent No. 3, 223~ 49~ issued Dccember 14~ -~
1965 to J0 W. Crownover.
''.
~he leads of the capacitor of the IJnited States Patent No. 3, 854, 075.
i ssued L~ccembcl 10, 1974 to John Philip Vhl, were used as mandrels to willd the pleated capacitOr segment about the center, in a manner similar to that suggested in United States Patent NoO 2, ~87, 649 issued May 19, 1959 to Daniel B. Peck. In the Vhl patent, conductive foil tabs were inserted between the lead.s and the metalli~ed electrode areas to make positive contact with the electrode and to protect the electrode from damage b~ the leads during winding. ~lowever, it has been determined that this construction leads to a higher failure rate than desirable due to opening of the e1ectrode area around the periphery of the metal foil, for reasons which are not completely understood.
l~he configuration of the capacitor of the present invelltion provides a product which has all of the advantages of single pleated, or single pleated and wound, capacitors and also has the added advantage that it may be manufactured with commercially available metallized dielectric material~ A further advantage of the present invention is that the same basic starting material may be used to manufacture capacitors having a numbex of different pleating combinations, which, o~ course, ifi not true for the capacitor of the Au9tralian patent, in which each pleat combin-ation requires a speciallx manufactured die]eclric layer. In ~ddition to the use of the present in-rention to manufacture wound film capacitors, it is also possible to utilize the invention to produce ceramic capacitors in which the capacitor dielectric material is folded while the ceramic material is still in a "greenl' state, in a mamler sirnilar to that dis- -closed in~United States Patent No. 3, 223~ 49~ issued Dccember 14~ -~
1965 to J0 W. Crownover.
''.
- 4 ~
g , 3~i Thus broadly, the invention contemplates an electrical capa-citor segment which comprises a dielectric layer havin~ a center line, a first metallized electrode layer appl~ed to one side of the dielectric layer so that an unmetallized ~argin extends along each edge of a pair of parallel edges of the dielectric layer, and a second metallized electrode layer applied to the other side of the dielectric layer so that an unmetallized area is located ad-jacent the seco~d metallized electrode layer. The dielectric layer is pleated once along the unmetallized areas off of the center line 10 so that o~e edge of the margin containing edges extends beyond the other of the edges along the same end o~ the capacitor segment and metallized spray material is in contact with the second electrode lay~or.
In a further embodiment the invention contemplates an electri-cal capacitor segment whi.ch comprises at least one group of pleated layers comprising a dielectric layer, a first metallized electrode layer applied to one side of the dielectric layer so that an un-metall.. zed margin extends along each edge of a pair of parallel ....
edges o~ the dielectric layer, a pair of metallized electrode 20 layers on the other side of the dielectric layer, and at leastone ~nmetallized strip that runs between the metallized layers on the other side of the dielectric layer. The dielectric layer is pleated M nu~ber of times where M = a ~ ~N)b where a is an odd number 3 or greater, and b is an even number 2 or greater, and where N may be zero or any positive integer so that at least one pleat of the pleated dielectric strip extends along one end of the pleated dielectric layer beyond at least one other pleat that extends along the same end as the extending pleat, or pleats, with all of the extending pleats having unmetallized strips behind them 30 along their length. The edges of the metallized dielectric strip which contain the margins extend along the opposite end of the pleated dielectric layer beyond the other ple~ts that extend along the same ~nd as the maryin containi.ng ed~es, where.in the extending pleat or pleats along the one end of the dielectric layer and the margin containing edges along the other end of the dielectric layer . :
are sufficient in length to allow metallized spray material to be sprayed against both of the ends without penetratioll of the spray far enough to contact any of the pleats except the extending pleat or pleats. ~ .
g , 3~i Thus broadly, the invention contemplates an electrical capa-citor segment which comprises a dielectric layer havin~ a center line, a first metallized electrode layer appl~ed to one side of the dielectric layer so that an unmetallized ~argin extends along each edge of a pair of parallel edges of the dielectric layer, and a second metallized electrode layer applied to the other side of the dielectric layer so that an unmetallized area is located ad-jacent the seco~d metallized electrode layer. The dielectric layer is pleated once along the unmetallized areas off of the center line 10 so that o~e edge of the margin containing edges extends beyond the other of the edges along the same end o~ the capacitor segment and metallized spray material is in contact with the second electrode lay~or.
In a further embodiment the invention contemplates an electri-cal capacitor segment whi.ch comprises at least one group of pleated layers comprising a dielectric layer, a first metallized electrode layer applied to one side of the dielectric layer so that an un-metall.. zed margin extends along each edge of a pair of parallel ....
edges o~ the dielectric layer, a pair of metallized electrode 20 layers on the other side of the dielectric layer, and at leastone ~nmetallized strip that runs between the metallized layers on the other side of the dielectric layer. The dielectric layer is pleated M nu~ber of times where M = a ~ ~N)b where a is an odd number 3 or greater, and b is an even number 2 or greater, and where N may be zero or any positive integer so that at least one pleat of the pleated dielectric strip extends along one end of the pleated dielectric layer beyond at least one other pleat that extends along the same end as the extending pleat, or pleats, with all of the extending pleats having unmetallized strips behind them 30 along their length. The edges of the metallized dielectric strip which contain the margins extend along the opposite end of the pleated dielectric layer beyond the other ple~ts that extend along the same ~nd as the maryin containi.ng ed~es, where.in the extending pleat or pleats along the one end of the dielectric layer and the margin containing edges along the other end of the dielectric layer . :
are sufficient in length to allow metallized spray material to be sprayed against both of the ends without penetratioll of the spray far enough to contact any of the pleats except the extending pleat or pleats. ~ .
- 5 ~
:.
3~
Description of the Drawings ~he present invention is illustrat2d by reference to the drawings in which:
Fig. 1 is a perspective view of a portion of a metallized àielectric layer which may be used in the construction of a capacitor in accordance with the present invention;
Fig. 2 is a perspective view of a partially pleated metallized di-electric layer in accordance with Fig. 1 having five pleat lines;
Fig. 3 is a perspective view of a fully pleated dielectric layer in accordance with Fig. 1;
Fig. 4 is a perspective view of the fully pleated dielectric layer of Fig. 3 which, in addition9 shows a winding rnandrel and an unmetallized dielectric insert;
Fig.: 5 is a diagran~matic showing of the winding of a capacitor segment in accordance with the constr~iction of Fig. 4; . .
15 . Fig. 6 is an end vicw of a cap~citor segmellt, bcfore le~d attacllrnent, that is wour~:l in accordance with the showing of Figs.
asld S;
Fig. 7 is an end view of the wound capacitor segment of Fig. 6 . . .
after it has been pressed into an oval shape;
Flg. ~ is ~ slde view of a colllpletcd c;~ cilol~ follo~
a ttachment of axial~ leads;
~:
3~
Fig. 9 is a side view of a completed capacitor following attacll-ment of radial leads;
Fig. 10 i5 a perspective view of an alternate version of a capacitor constructed in ~ccordance with the present invention;
:Fig. 11 is a perspecSive view of an additional alternate embodi ment;
Fig. 12 is a perspective view of a further alternate embodiment;
Fig. 13 is a perspective view of a portion of a metallizecl dielectric Iayer whi~h may be used in the construction of a cap~citor in accordance with the present invention;
Fig. 14 is a perspective view of a single pleated dielectric layer in accordance with Fig. 13; .
:Fig. 15 is a perspec~ive view of the fully pleated dielectric layer , , :
of Fig. 14 which, m addition, shows a winding mandrel and an unmetallizecl ` 15 ~ dielectric insert;
:, ~
Fig. 16 is a diagrarIlmatic showing of the winding of a capacitor ~segrnent in accordance with the construction of :Fi~. 15;
Fig. 17 is a perspective view o~ a portion of a metallized dielectric . .
la~er whlch may be used in:the construction OI a capacitor in accor- :
20 dance with the present invention;
Fi~. 18 is a perspective view of a plcated Illetalli,~.ed ~lic!lcctric Iayer in accordance with Fig. 1;7: having two pleat lines;
::
'' ~ ig. 19 is a diagrammatic showing of the winding of a capacitor segment in accordance with the construction o~ ig. 18; and Fig. 20 is a perspective view of an alternate version of a capacitor constructed in accordance with the present inVelltiOIl.
~echnical Description of the Invention . . .
~ portion of a commercially available metallized dielectric strip which may be unwound from a reel, tl~at is suitable for tlle- mal;ing of a capacitor in accordance with the present invention is shown i~
The metallized dielectric strip is formcd Witll a dielcclric laycl 12 Or a thin film dielectric material, such as polyester, polypropylene, poly-styrene, polycarbonate or other ,suitable material. A thin rneta.llized electrode layer 14 is applied to the uppe.r surface of the dielectric layer ~ .
12 n ~uch a fashion that unmetallized margin areas 16, 1~ e~tend along the longitudinal edges of the strip 10. Two thill n~etallizecl elcctro~e areas 20, 22 are.applied to the lower surface of tlle dielectric laycr 12 so that the metalliæed layer 20 e~{terlds to the left hancl rm~r~;in of the layer as shown in ~ig. 1, while tlle metallized layer 22 extends to the right hand rnargin of the layer. ~ central unrnetailized strip 24 lies between the metallized electrode areas 20, 22.
- .
In the embod~ ent shown in ~ig. 1, the longit-ldillal c3imellsioll of .:
~` 20 the metalJized strip lO is shown ~long the aFrows 26 whi;e ~he narro~
. : - 8 -transverse dimension is shown along the arrows 28. ~he capacitor is pleated along the imaginary line 30 which extends through the length of the unmetallized central strip 24. :rhis version o~ the pr~scnt invention, howeYer, is not limited to one in which folding is along longitudinal lines since a capacitor could be made in accordance with the present invention - by pleating along transverse lines if the appropriate corresponding metallized and unmetallized areas were provided.
' A partially pleated capacitor is shown in Fig. 2 wherein one pleat occuxs along the longitudinal center line 30 and othcr pl~ats occur along the longitudinal pleat lines 32, 3~, 36 and 3~. It i5 to be noted that lines 32, 34, 36 and 38 are spaced so that the center pleat 40 ex-tends beyond the other pleats 42, 44 that run along the right hand long-itudinal edge of the metallized strip 10 of ~ig. 1 so that the inside of the pleat 40 in the area 4G is unmetallized, ~he e~tension of the center pleat 40 beyond the pleats 42, 94 is preferal~ly at lcasl t). 020 inches. In addition, it is noted that the pleats are positioned so that the lOngitudinal ends 48, 50 of the metallizeà strip 10 are aligned with each other but so that they extend beyond the pleats 52, 54 that run along .
the left hand longitudinal edge of the metallized strip. Again, the ex- -tension of the ends ~8, 50 beyond the pleats 52, 54 is pref~ral)ly ~t Ic;lst 0. 020 inchcs. ~he unn~etallized margin 16, therefore, faces upwardly while the unmetallized margirl I~ faces downwar-lly when thc capacit~r :
~ 9- ~
~' 3~ii segment has been fully pleated as shown in ~ig. 3.
After the capacitor has been processed to form the capacitol~ seg-ment shown in Fig. 3, a number of different additional processing steps may be undertaken. For example, the pleated capacitor segment of ~ig. 3 could be used to ~orm a capacitor merely by spraying the right and left hand longitudinal edges of the segment with a metallized spray, such as babbitt or other suitable metal, in accordance with conventional - practice, and then electrical leads could be secured to thern, for e~;ample, by soldering. Alternately, the capacitor segment of Fig. 3 could be cut along a transverse line9 such as the line 43, anù a number of such seg-rnents could be stacked upon each other, with the terminal end 50 of one capacitor segment being adjacent to and aligned with the terminal end 48' of the capacltor segrrrent that is positioned immediatel~r belo~v it, RS SllC)~'Il diagrammatically by the dotted lir~e representative of Fig. 3, and then their ends could be sprayed wlth a metallized spray and leads could therl be secured to the stacked array of such segments. In conjunction with the p resently preferxed embodiment of tlle present invention, however, I;`ig. 3 xepresents two lay~rs o~ a capacitor segment formed by ~villding oE the di-electric strip along the longitudinal dmlellsion of the str~i}) 10, ~s shotvn inFigs. ~ and 5, to form a wound capacitor. Another version Or this capacitor could be ~cllieved, however, by pleating, the capacitor segment of ~ig. 3 a number of times transversely alor~g transverse fold lines such as the line 43, or alternately pleating~several times, and then completing the segrnent by winding the rem~inder OI the length of the dielcctric strip.
,' ~ .
' "
~ , : - .... :
.. . .
3~i ~he winding of the ca~acitor scgl~lent Or Ii`ig. 3 into a ~\'OtlllCl capacitor may be achieved with various winding techniques, including the use of a removable split mandrel such as the mandrel 5G of Figs. 4 and 5.
An unmetallized dielectric strip 58 is desirably initially wound around the mandrel to protect the metallized electrode areas of the metallized strip 10. Near the completion of winding, an aàditional unmetallized dielectric strip 60 is desirably wound into the structure to form all outer protecti~re coating. 'rhe dielectric strip 60 rnay also be heat-sealed to itself to form the pleated capacitor segment 61 which is shown in Fig. 6. rrhe removal of the mandrel 56 from the capacitor segment 61 leaves an opening 62 in the unit. 'Ihe opening 62 may be closed by applying pressure, or pressure and heat, in accordance Witll the type of dlelectric used and conventional rnanufacturing teclmiques, to the capac;tor segment G1 so tl~at it assun~cs ~ .
an oval shape as shown in Fig. 7.
Once the capacitor segment of.the embodiment of :Figs. 4 :
through 7 has been wound, a metallized spray may then be directed against the longitudinal edges o~ the unit in accordance W;t]l conventional processing techniques to intcrconnect tllc elcctrode la5 cr~ aloll~ tllcs edges and to provlde for the connection of electrical leads to the unit.
'~he metallized spray will penetrate into the open area betwecn the ends 48 and 50 on the left hand longitudinal edge of the capacitor segment, as: shown diagrammatlcaLly~ in Fig. 3 to a depth such as that indicated ,' ~ ' :
:~ ' 3~
by the plane G5. ~he plane 65 indicates the maxi~um depth that any high velocity spray particle~ ~vill penetlate and it nl~ tllls le l caled any place between the ends 48 and 50 of the metallized strip 10 and the edges of the pleats 5~ 54. Accordingly the metallized spray material will exterld into the left hand opening of the capacitor between the ends 48 50 far enough to make contact to the t~vo facing metallized electrode areas 20 22, but not so far that it will penetrate through the dielectr;c ma~erial at the pleats 52 54. rhe configuration of the preseilt invention thus provides for reliable lead termination at the left hand longitudinal edge of the capacitor segment of l?ig. 3 witllout tlle necessity of providing unmetallized longitudinal strips along the inside of the pleats 52 54 thereby saving considerable processing expenses in the manufacture of completed capacitors of this type.
;~ .
~ermination to the right hand longitudinal edge of the capacitor L~ segment of Fi~. 3 is similarly provicled by a metallized spray ~h ich ex-tends over the protruding center pleat 40 to a deptil such as that indicated by thc plane 67 which is sufficient to allow the metallized splay to mal~e good contact to the electrode area 14 but which uqll prevent the penetration of the spray mctallic particles througll the dielect-ric at the pleats 42j 44. rhe locationof the plane G7 may l e any~lvhere between the edges of the pleats 42, 44 and the edge of the pleat 40 as long as there is sufficient depth of spray to provide adequate contact ~ ~
termination to the el;ectrode area 14. Again~ a considerable cost s~vin~s ~:
, ' 12 - .
`.
is achieved by the prescnt invention since thc ple~ts ~2, 4a3J like llle pleats SZ, 54, did not have to be provided with their own unmetallized strips. It will be noted in the present invention that only onc unmetallized strip 24 is required in the center of the metallized strip 10, and, thus, the same general pattern.may be used for various pleat configur~tions and a separate individually configurated mctallizcd Stl`i~- iS 110~ l cquil~cd :Eor each pleat pattern.
.
Once the metallic spray has been applied to the edges of the capacitor segment of Fig. 7, either radial or axial leads may be applied lû to i~. For example, axial leads 70, 72 witll conventional spiral "pig-tail"
ends ~not shown) may be soldered, arc-welded or conllected b~r otller IneanS
to the sprayed edge terrnination layers 6~, 68 at the ends of the wound filnn capacitor segment B1, as shown in F.ig. 8. Altcrnately, ra(3ial leads 74, 76 may be soldered, arc-welded or connected by other methods to the sprayed metallized layers 66, 68 if a radial leaded capacitor i~3 desired, as shown in P~ig. 9.
It will be noted from the foregoing dcscription that tllc number of pleats that may be used to form a capaci.tor in ~ccordance with the previously de.scribed embodiment of the present invention is l\I where M = 5 -~ (N)4 and N may be 0 or any positive integer. 'rhe number of pleats M in a capacitor made in accordance with this cmboàiment, , ~ .
therefore, will always be an odd number.
:';
Other alternate versions of the present invention are shown in ;' ~, ~9~
}:~igs. 10-12. In Fig. 10 the pleated capacitor segment is formecl so that the end pleats 42, 44 have unmetalliæed strips 46' behind these pleats ~r,~hile the center pleat 40 does not. 'rhe two end pleats 42, 44 extend be-yond the recessed center pleat 40. I`lliS version is less clesirableJ how-ever, than the version of Fig. 3 becallse it reqllircs all ac~ditiollal striy.
Another alternate embodiment is shown in Fig. 11 wherein only one of the end pleats 42 extenàs beyond the center pleat 40 and the other of the end pleats 44. In this version only one unmetallized strip 46" is re~uired behind the extending end pleat 42, but the cllargillg path i9 longer for this configuration than tllat of Fig. 3.
Still another alternate embodiment is shown in ~ig. 1~ ~hich differs from the version shown in l?ig. 3 in that intermediate dielectric layers 69, 69' are inserted between alternating groups 71, 73 oL pleated layers with the center pleat extended, as in Fig. 3, but with the alternating ,~ 15 groups 71, 73 facing in opposite directions. If the capacitor of E;`ig. 12 is to bc a wound embodirmellt, tlle alternating groups 71, 73 of pleated ].ayers which face in opposite directions may l)e suppliecl from a differerlt pleated segment supply. ~lso, it is apparent that the groups of pleated layers shown in Fi~s. 10 and 11 could be employed ::
to form a capacitor in accordance with the teaching of Fig. 12 by facing ~:~
alternating groups of these layers in opposite dircctions allcl l~y scpar- . .
ating these alterrlating groups with dielectric material.
, ~ ~ ' .
.
.. ~ . , . - .
.. .. .
3~
~ portion of another commercially availablc metallized dielectric strip which may be unwound from a reel, that is suitable for.a mal~ing of a capacitor in accordance with the present invention is shown in Fig. 13.
~his metallized dielectric strip may also be forn1ed witll a dielcctric layer 112 of a thin film dielectric material, such ~s polyesterJ pcl~ rolylellc, polystyrene, polycarbonate or other suitable material. 1~ thin metallized electrode layer 114 is applied to the upper surface of the dielectric layer ~' 112 in such a fashion that unmetallized margin.areas 116, 118 extend along the longitudinal edges of the strip 110. Two thin rnetallized e~ectrode areas 120, 122 are applied to the lower surface o the dielectric layer 112 so that tl-c metallized layer 120 extellds to the l.eft halld m;lrgin of the layer as shown in ~ig. 13, while the metallized layer 122 extends to the right hand margin of the layer. A central unmetallizecl strip :124 lies between the metallized electrode areas 120, 122.
In the embodiment shown in }~ig. 13, the longitudinal dimension of the metallized strip 110 is shown along the arrows 126 ~vll.il~ tl~e narro\v trans~,~erse dimension is shown along the arro~vs 128.. 'rhis is to allo\v the capacitor to be pleated along the imaginary line 130 whicll extends ~ through the length of the unmetallized central strip 124. This versio 2~ of the present invention, however, is also not limited to one in which folding is along longitudinal lines smce a capacitor could be made in accordance :~:
~, wit~h tllis version of the present invention by ~leating along trallsvcl se lillcs , . ~. :
If the appropriate eorrcsponding mctdllizcd and llnn1ct~llizc(1 arcas wcre provid ed .
.
,~-15~
: ' ~i~3~i;
~ capacitor with ~ single pleclt 140 along line 130 is sllowll in Fig. 14 which is sliglltly off of the center linc 131 of the metallizcd strip 110 with tlle inside of the pleat 140 in the area being unmetallized. ~he longitudinal ends 148, 15(3 of the metallized strip 110 are arranged in a staggered patlern so that one end 48 ext~nds beyond the other end 150 along the left hand longitudinal edge of the rnetallized strip because of the off-center pieat of the dielectric layer. ~he e~tension of tllc cnd 1~LS l)eyoncl tl~c end 150 is preférably at least 0. 020 inches, and this extension allows the metallic spray to make contact with at least the upwardly facing electrode area 122 s~own i~ Fig. 14. The unmetallized margin 116 faces upwardly while the .u~met~lli2ed maryin 11~ faces downwardly whe~ the capacitor segment has been pleated as shown in Fig. 14.
~fter the capacitor has been processed to form tlle cll)acitol seg-ment shown in Fig. 14, a number of different additional processing steps i~ may be undertaken. :?or example, the pleated cap~citor segment of Fig. 14 could be used to form a capacitor merely by spraying the right and left hand longitudinal edges of the segment witll a metallized spray~ such as bablitt or otller suital)lc lllclal, i~l accol~d;lllcc \Yitll CC)n-ventional practice, and then electrical leads cou]d l~e securccl lo them, for example, by soldering. ~Alternately, the capacitor segment of :F`ig.
14 could be cut along a transverse line, such as the line 1~3, and a numl~er of such segmellts could be stacked uyon each otl~er, witll llle termil~al end 150 of one capacitor segn~ent being adJacent lo but not extencling as far~as thc terminal end 14~3' of the car)acltor scglllent tllat i~. positioncd immedlately below it, as sho~vn diagrammatically by tlle ~otted line re-.:
- 1 6 ~
. ~ . . : - - ., , ` .
~:~9~3~
presentative of Fig, 14, and then their ends coulcl l)e sprayed with a met-alli~ed spray and leads could thcn be secured to the stacked array vf such segments. In conjunction with the presently preferred embodiment of the present invention, however, ~ig. 1~ reprcscnts two l;~ycrs of a capa(i~o segment formed by winding of the dielectric strip about tlle longitudinal dimension OI the strip 110, as shown in l~igs. 15 and 16, to form a wound capacitor. Another version of this capacitor could be achieved, however, by pleating the capacitor segment of l?ig. 14 a nurmber of times transversely along transverse fold lines, such as the line 143, or alternat.ely, pleating several times and then completing the seg.ment by WiJldi~lg the rcn~ainder of the length of the dielectric strip.
, .
~he winding of the capacitor segment of Fig. 1~ into a wound capacitor may he achieved with various winding techniques, including the .
use of a split mandrel such as the mandrel 156 of Figs. 15 and 16, which 1~ may be removed from the capacitor segment after it llas becn ~ound.
~n unmetaIlized dielectric strip S8 is desirably initiatly wound around the mandrel to protect the ~netallized electrode ~reas of l:he metallized strip 110. ~he winding of the capacitor segment then contillues until it is almost completed, at which time an additional unmetalli~ed dielectric strip 160 is then desirably wound into the structure to form an outer pro-tective coating. ~he dielectric strip 160 may also l~e heat-sealc(l to itself to form a pleated capacitor segment in the manner .sho~vn in ~ig. 5. 'rhe ' -17 - ~.
, .
' ' ~ ' , ' ' , ~ :
removai of lhe mandrel 156 from the wound capacitor segment leaves an open-ing in the Ullit. ~his opening may be closed by applying pressure, or pressure and heat in accordance with the type of dielectric layer used and conventional manufacturing techniques to the capacitor segnlc~lt so tllat it assumes an oval shape as shown in :Fig. 6.
Once the capacitcr segment has been woundJ a metallized spray may then be directed against the longitudirlal edges of the unit in accordance with conventional processing techniclues to interconnect the electrode layers along these edges and to provide for the connection of elcctricLll leads to the unit. rrhe metallized spray will penetrate into the opcn area resulting from the staggering of the ends 148 and 150 0ll thc left hand longitudinal edge of the capacitor segment, so that the inner electrode provided by the metallizecl areas 12OJ 122, is contacted by the sprayed metal particles, but so that the electrode layer 114 is not contacted by such particles, as indicated l~y the imagillary ~lallc 1~5 which represents the maximum depth of penetration of the spray particles. The configuration of the present invention thus provides for reliable lead termination at the left hand longitudinal edge of Lhe capacitor segment of ~ig. I~ in a manner such tllat IllCtallizeCl ellC
terminations may be employed witl~ a sinL~le l leat met:llliz(?(l car)a-citor. I ermination to the right hand longitudinal c~l~e of thc! cal~acitor segment of Ii'ig. 15 is similarly providecl by a ll~etalliæed spray ~ -which extends over the protruding center pleat 140 to a depth wllich_ - la - :
:~ . . . :'' '' is sufficient to allow tlle metallized spray to make good contact to tlle electrode area 114.
Once the metallic spray has l~een ap,olied to thc ed~cs of tl~c capacitor segrnent either radial or axial leads may be applied to it S as previously shown in Figs. 7 and 8, A portion of another commercially available metallized dielectric strip which may be unwound from a reel, that is suitable for a making of a capacitor in accordance with the present invention is sho~vl~ in ~ig. 17, 'Ihis metallized dielectric strip may also be formed ~,vith a dielectric layer 212 of a thin film dielectric material~ such as polyester, polypropylene, polystyrene, polycarbonate or other suitable material. A
thin metallized electrode layér 21~ is applied to the upper surface of the dielectric layer 212 and a thin metallized electrode layer 220 is applied to the lower surface of the dielectric laycr in s~lch a f~shioll ~15 that unmetallized margin areas 216, 218 extend along the opposite long-itudinal edges of the strip Z10 on opposite sides of the strip.
ln the ernbodiment shown in Fig. 17, the longitlldinal dimension of the metallized strip 210 is shown along the arrows 226 ~vhile the narrow transverse dimension is sllo~vn along the arro~vs ~S. rrlle .
capacitor is pleated along two imaginary lines 230, 232 whicl~ cxtend through the length of the strip 210. ~his version of the present invention, however, is also not limited to one in which folding is along t~vo longitudinal - l g - .
.
.~ .
3~
lines since a capacitor could be made in accordance ~;tll this ~ ersiol2 o~
the present invention by pleating along any even number of transverse lines.
.
A pleated capacitor is shown in Fig. 18 wherein one pleat occurs along the longitudinal line 230 and another pleat occurs along the long-itudinal lines 232. It is to be noted tllat pleat lines 230, 232 are spaccd so that the margin area 218 extends beyond the pleat 24~ tllat r~lns along tllc right hand longitudinal edge of the~rnetallized sl:rip 210 of I~ig. 17 uritl~ thc margin area 218 facing dQwnwardly. Ihe extension of the margin area 218 beyond the pleats 242 is preferably at least 0. 020 inches. In addition, it is noted that the margin area 216 is positioned so that it extends beyond the pleat 252 that runs along the left hand longitudinal edge of the rnet~
alli~ed strip and faces upwardly. ~gain, tlle c~;te~sion of lhe l~t;ll`~`in area 216 beyond the pleat 252 is preferably at least 0. 020 inches. :~
fter t~2e capacitor has been processed to form the ca.pacitor seg-ment shown in Fig. 13, a number of different additional processing steps may be undertaken. For example, the pleated capacitor segmerlt of .~ig. 18 could be usecl to for~n ~ capacitor nlelely by s,:~r;lyilln tl~e ri~ht and l:et hand lorlgitudinal edges of the segment witl- a metalli~,cd spray, such as babbitt or other suitable metal, in accordance wi~h conventional practice, and then electrical leads ~:ould be secured to them~ .for ex- .
, : .. .
am~ple, by ~soldering. Altern~atelyO the capacitor segrnent of :Fig. 18 "
` ~: could be cut alo.ng a transverse line, such as the line 243, and a number -- ~0 -~r of SUCII segments could be staclied upon cacll otller, ~ritll thc down-~ardly facing margin 218 of one capacitor segment being adjacent to and aligned with a corresponding upwardly facing margin 21~' of the capacitor segment that is positioned immediately below it, as sho~vn 5 . diagrammatically by the dotted line representative of Fig. 18, and then their ends coùld be sprayed with a metallized spray and leads could then be secured to the stached array of such segments. In conjuIlction with the presently preferred embodiment of the present invention, how-ever, :Fig. 19 represents two layers of a capacitor segment formed by winding of the dielectric strip about the center of the longitudinal dimen-sion of the strip 210, as shown in Fig. 19, to form a wound capacitor seg-ment. Another version of this ca~acitor coukl be achie~red, ho~Y~reI~, by pleating, instead of winding, the capacitor segment of Fig. 18 a number of timeE alon~ transverse fold lines such as the line 243. Alternately, the capacitor segment could be pleated transversely two or more times about transverse lines, such as the line 243, and then the segment could be completed by winding the renlainder o;~ the length of the dielectric strip.
rrhe winding of the capacitor segment of Fig. 18 into a uound ; 20 capacitor may be achieved with various winding techniquesJ including the use of a split mandrel such as the rnandrel 256 of Fig. 19, which is removed from the capacitor segment a~ter it has been wound~ An unmet-allized dielectric strip (not shown) n~ay be wound ~roulld the structure~to - 2 l ~
~ .
.
-form an outer protective coating. ~his dielectric strip may ~e heat- -sealed to itself to form the pleated capacitor segment, as shown in ~ig. 6. ~he removal of the mandrel 56 from the capacitor segment leaves an opening in the unit. Ihe opening may again be elosed by apylying pressure9 or pressure and heat, in accor(lance witll thc l~pc of dielectric layer used and con~,rentional manufacturing techniques to ;~
the capacitor segment so that it assumes an oval shape, as shown in Fig. 7, Once the capacitor segment has been wound, a metal]ized spr~y rnay then be directed against the lon~itudillal edges of thc Ullit il~
accordance with con~rentional processing techniques to interco~ ect the electrode layers along these edges and to provide for the connection ';.:~ . ; , :.of electrical leads to the uni$. The metallized spray will penetrate ;, into the open area between the margin 216 areas on the left hand longituclinal edge of the capacitor segment, as shown diagramm~tically ~in Fig. 18 to a clepth such as that indicated by ~he plane 2(;~, so as ' to make contact with the elcctrode area 220. r~he plane 26~ indicates .
the maximum depth that an~ high velocity spray particles ~vill penetrate and it!may thus be located any place between the end of the margin 216 areas of the metallized s~rip 210 and the edge of the pleat 252.
Accordingly, the m~talllzed spray material ~vi]l cxiell(l inlo tllc left _ :
hand opening of th~e capacitor betweell the margill 21~ areas far cnough to : :
make contact to the facing metalll~ed clectrode on the other side of the dielectric strip, but nc~t so far that it will penetr~te through tile 25~ ~ diel6ctrlc material at tlle picat 252.
, , ~ . . . . ,.~ , , , , . . -"rermination to the right lland longitudillal edge of the capacitor segrnent of Fig. 1~ is similarly provided 'L)y a metallized spra~ wllich extends over the margin 218 area to a depth, swch as that indicated by the plane 268, which is sufficient to allow the metallized spray to rnake good contact to the electrode 214 on the inside of the margin 218 area but ~vllich will prevent the penetration of the spray metallic par-ticles through the dielectric at the pleat 242, 'Ille locatioll of tllc planc 2G8 may be anywhere between the edges of the pleat 242 and the end of the margin area 218 as long as there is sufficient depth of ~ ray to pro-vide adequate contact termination to the electrode area 21~L. 'rhe con-figuration of the present invention thus provides for reliable Icad Ler-mination at the longitudillal ecl~e.~ of the capacitor seg~ cn~ of l~`ig. :lR
without the necessity of providing unmetalli~cd longitudinal slrips alol-g the inside of the pleats 242, 252, thereby saving considcrable processing expenses in the mam~facture of completed capacitors of this type.
Once the metallic spray llas been applied to the cdges of the capacitor segment, either laclial or a};ial leads nla~ c a,~"lic(t to it, again as previously sl10wn in I;'igs. 7 and 8.
Another alternate version of the present invention is sl-own in Fig. 20, wherein two layers oî either a wound or a stacked capacitor segment is shown. 1'his version differs from tllat s~o~n in l~ig. lS in that intermediate dicleclric layers 269, 269' are inserted l~etwecll alterllati : ~ ;
group~s 271, 273 of pleated layers of the capacitor se~nlent ~l icl~ face in opposite directlons. ~If lhe capacltor of Fig. 20 is to be a ~ounù embodi-~25 ment, the alternating groups 271, ~273 of plented l~yers ~YhiCIl face inopposite dLreFtions may~ each be supplied from a different pleatcd seg-ment supply.
23 _ :
~, . , . . .. , . ., ....... . . -I'he previously described eml~oàiments of the present inventiol1 are illustrative, but not exllaustive~ of the various types of configurations that may come within the scope of the present invention. For instance, while winding about the exact center of the dielectric strip is preferred, it is apparent that winding about any number of transversc lines offset from the center, but intermediate the ends of the dielectric strip, arc interlded to be included within the scope of the present inventioll. It is also further apparent that more than two longitudinal pleat lines may be - employed in the version shown in }~ig. 18 wi~hin the scope of the present inventiOn.
, , , '`:
~ ' .. .:
:.
3~
Description of the Drawings ~he present invention is illustrat2d by reference to the drawings in which:
Fig. 1 is a perspective view of a portion of a metallized àielectric layer which may be used in the construction of a capacitor in accordance with the present invention;
Fig. 2 is a perspective view of a partially pleated metallized di-electric layer in accordance with Fig. 1 having five pleat lines;
Fig. 3 is a perspective view of a fully pleated dielectric layer in accordance with Fig. 1;
Fig. 4 is a perspective view of the fully pleated dielectric layer of Fig. 3 which, in addition9 shows a winding rnandrel and an unmetallized dielectric insert;
Fig.: 5 is a diagran~matic showing of the winding of a capacitor segment in accordance with the constr~iction of Fig. 4; . .
15 . Fig. 6 is an end vicw of a cap~citor segmellt, bcfore le~d attacllrnent, that is wour~:l in accordance with the showing of Figs.
asld S;
Fig. 7 is an end view of the wound capacitor segment of Fig. 6 . . .
after it has been pressed into an oval shape;
Flg. ~ is ~ slde view of a colllpletcd c;~ cilol~ follo~
a ttachment of axial~ leads;
~:
3~
Fig. 9 is a side view of a completed capacitor following attacll-ment of radial leads;
Fig. 10 i5 a perspective view of an alternate version of a capacitor constructed in ~ccordance with the present invention;
:Fig. 11 is a perspecSive view of an additional alternate embodi ment;
Fig. 12 is a perspective view of a further alternate embodiment;
Fig. 13 is a perspective view of a portion of a metallizecl dielectric Iayer whi~h may be used in the construction of a cap~citor in accordance with the present invention;
Fig. 14 is a perspective view of a single pleated dielectric layer in accordance with Fig. 13; .
:Fig. 15 is a perspec~ive view of the fully pleated dielectric layer , , :
of Fig. 14 which, m addition, shows a winding mandrel and an unmetallizecl ` 15 ~ dielectric insert;
:, ~
Fig. 16 is a diagrarIlmatic showing of the winding of a capacitor ~segrnent in accordance with the construction of :Fi~. 15;
Fig. 17 is a perspective view o~ a portion of a metallized dielectric . .
la~er whlch may be used in:the construction OI a capacitor in accor- :
20 dance with the present invention;
Fi~. 18 is a perspective view of a plcated Illetalli,~.ed ~lic!lcctric Iayer in accordance with Fig. 1;7: having two pleat lines;
::
'' ~ ig. 19 is a diagrammatic showing of the winding of a capacitor segment in accordance with the construction o~ ig. 18; and Fig. 20 is a perspective view of an alternate version of a capacitor constructed in accordance with the present inVelltiOIl.
~echnical Description of the Invention . . .
~ portion of a commercially available metallized dielectric strip which may be unwound from a reel, tl~at is suitable for tlle- mal;ing of a capacitor in accordance with the present invention is shown i~
The metallized dielectric strip is formcd Witll a dielcclric laycl 12 Or a thin film dielectric material, such as polyester, polypropylene, poly-styrene, polycarbonate or other ,suitable material. A thin rneta.llized electrode layer 14 is applied to the uppe.r surface of the dielectric layer ~ .
12 n ~uch a fashion that unmetallized margin areas 16, 1~ e~tend along the longitudinal edges of the strip 10. Two thill n~etallizecl elcctro~e areas 20, 22 are.applied to the lower surface of tlle dielectric laycr 12 so that the metalliæed layer 20 e~{terlds to the left hancl rm~r~;in of the layer as shown in ~ig. 1, while tlle metallized layer 22 extends to the right hand rnargin of the layer. ~ central unrnetailized strip 24 lies between the metallized electrode areas 20, 22.
- .
In the embod~ ent shown in ~ig. 1, the longit-ldillal c3imellsioll of .:
~` 20 the metalJized strip lO is shown ~long the aFrows 26 whi;e ~he narro~
. : - 8 -transverse dimension is shown along the arrows 28. ~he capacitor is pleated along the imaginary line 30 which extends through the length of the unmetallized central strip 24. :rhis version o~ the pr~scnt invention, howeYer, is not limited to one in which folding is along longitudinal lines since a capacitor could be made in accordance with the present invention - by pleating along transverse lines if the appropriate corresponding metallized and unmetallized areas were provided.
' A partially pleated capacitor is shown in Fig. 2 wherein one pleat occuxs along the longitudinal center line 30 and othcr pl~ats occur along the longitudinal pleat lines 32, 3~, 36 and 3~. It i5 to be noted that lines 32, 34, 36 and 38 are spaced so that the center pleat 40 ex-tends beyond the other pleats 42, 44 that run along the right hand long-itudinal edge of the metallized strip 10 of ~ig. 1 so that the inside of the pleat 40 in the area 4G is unmetallized, ~he e~tension of the center pleat 40 beyond the pleats 42, 94 is preferal~ly at lcasl t). 020 inches. In addition, it is noted that the pleats are positioned so that the lOngitudinal ends 48, 50 of the metallizeà strip 10 are aligned with each other but so that they extend beyond the pleats 52, 54 that run along .
the left hand longitudinal edge of the metallized strip. Again, the ex- -tension of the ends ~8, 50 beyond the pleats 52, 54 is pref~ral)ly ~t Ic;lst 0. 020 inchcs. ~he unn~etallized margin 16, therefore, faces upwardly while the unmetallized margirl I~ faces downwar-lly when thc capacit~r :
~ 9- ~
~' 3~ii segment has been fully pleated as shown in ~ig. 3.
After the capacitor has been processed to form the capacitol~ seg-ment shown in Fig. 3, a number of different additional processing steps may be undertaken. For example, the pleated capacitor segment of ~ig. 3 could be used to ~orm a capacitor merely by spraying the right and left hand longitudinal edges of the segment with a metallized spray, such as babbitt or other suitable metal, in accordance with conventional - practice, and then electrical leads could be secured to thern, for e~;ample, by soldering. Alternately, the capacitor segment of Fig. 3 could be cut along a transverse line9 such as the line 43, anù a number of such seg-rnents could be stacked upon each other, with the terminal end 50 of one capacitor segment being adjacent to and aligned with the terminal end 48' of the capacltor segrrrent that is positioned immediatel~r belo~v it, RS SllC)~'Il diagrammatically by the dotted lir~e representative of Fig. 3, and then their ends could be sprayed wlth a metallized spray and leads could therl be secured to the stacked array of such segments. In conjunction with the p resently preferxed embodiment of tlle present invention, however, I;`ig. 3 xepresents two lay~rs o~ a capacitor segment formed by ~villding oE the di-electric strip along the longitudinal dmlellsion of the str~i}) 10, ~s shotvn inFigs. ~ and 5, to form a wound capacitor. Another version Or this capacitor could be ~cllieved, however, by pleating, the capacitor segment of ~ig. 3 a number of times transversely alor~g transverse fold lines such as the line 43, or alternately pleating~several times, and then completing the segrnent by winding the rem~inder OI the length of the dielcctric strip.
,' ~ .
' "
~ , : - .... :
.. . .
3~i ~he winding of the ca~acitor scgl~lent Or Ii`ig. 3 into a ~\'OtlllCl capacitor may be achieved with various winding techniques, including the use of a removable split mandrel such as the mandrel 5G of Figs. 4 and 5.
An unmetallized dielectric strip 58 is desirably initially wound around the mandrel to protect the metallized electrode areas of the metallized strip 10. Near the completion of winding, an aàditional unmetallized dielectric strip 60 is desirably wound into the structure to form all outer protecti~re coating. 'rhe dielectric strip 60 rnay also be heat-sealed to itself to form the pleated capacitor segment 61 which is shown in Fig. 6. rrhe removal of the mandrel 56 from the capacitor segment 61 leaves an opening 62 in the unit. 'Ihe opening 62 may be closed by applying pressure, or pressure and heat, in accordance Witll the type of dlelectric used and conventional rnanufacturing teclmiques, to the capac;tor segment G1 so tl~at it assun~cs ~ .
an oval shape as shown in Fig. 7.
Once the capacitor segment of.the embodiment of :Figs. 4 :
through 7 has been wound, a metallized spray may then be directed against the longitudinal edges o~ the unit in accordance W;t]l conventional processing techniques to intcrconnect tllc elcctrode la5 cr~ aloll~ tllcs edges and to provlde for the connection of electrical leads to the unit.
'~he metallized spray will penetrate into the open area betwecn the ends 48 and 50 on the left hand longitudinal edge of the capacitor segment, as: shown diagrammatlcaLly~ in Fig. 3 to a depth such as that indicated ,' ~ ' :
:~ ' 3~
by the plane G5. ~he plane 65 indicates the maxi~um depth that any high velocity spray particle~ ~vill penetlate and it nl~ tllls le l caled any place between the ends 48 and 50 of the metallized strip 10 and the edges of the pleats 5~ 54. Accordingly the metallized spray material will exterld into the left hand opening of the capacitor between the ends 48 50 far enough to make contact to the t~vo facing metallized electrode areas 20 22, but not so far that it will penetrate through the dielectr;c ma~erial at the pleats 52 54. rhe configuration of the preseilt invention thus provides for reliable lead termination at the left hand longitudinal edge of the capacitor segment of l?ig. 3 witllout tlle necessity of providing unmetallized longitudinal strips along the inside of the pleats 52 54 thereby saving considerable processing expenses in the manufacture of completed capacitors of this type.
;~ .
~ermination to the right hand longitudinal edge of the capacitor L~ segment of Fi~. 3 is similarly provicled by a metallized spray ~h ich ex-tends over the protruding center pleat 40 to a deptil such as that indicated by thc plane 67 which is sufficient to allow the metallized splay to mal~e good contact to the electrode area 14 but which uqll prevent the penetration of the spray mctallic particles througll the dielect-ric at the pleats 42j 44. rhe locationof the plane G7 may l e any~lvhere between the edges of the pleats 42, 44 and the edge of the pleat 40 as long as there is sufficient depth of spray to provide adequate contact ~ ~
termination to the el;ectrode area 14. Again~ a considerable cost s~vin~s ~:
, ' 12 - .
`.
is achieved by the prescnt invention since thc ple~ts ~2, 4a3J like llle pleats SZ, 54, did not have to be provided with their own unmetallized strips. It will be noted in the present invention that only onc unmetallized strip 24 is required in the center of the metallized strip 10, and, thus, the same general pattern.may be used for various pleat configur~tions and a separate individually configurated mctallizcd Stl`i~- iS 110~ l cquil~cd :Eor each pleat pattern.
.
Once the metallic spray has been applied to the edges of the capacitor segment of Fig. 7, either radial or axial leads may be applied lû to i~. For example, axial leads 70, 72 witll conventional spiral "pig-tail"
ends ~not shown) may be soldered, arc-welded or conllected b~r otller IneanS
to the sprayed edge terrnination layers 6~, 68 at the ends of the wound filnn capacitor segment B1, as shown in F.ig. 8. Altcrnately, ra(3ial leads 74, 76 may be soldered, arc-welded or connected by other methods to the sprayed metallized layers 66, 68 if a radial leaded capacitor i~3 desired, as shown in P~ig. 9.
It will be noted from the foregoing dcscription that tllc number of pleats that may be used to form a capaci.tor in ~ccordance with the previously de.scribed embodiment of the present invention is l\I where M = 5 -~ (N)4 and N may be 0 or any positive integer. 'rhe number of pleats M in a capacitor made in accordance with this cmboàiment, , ~ .
therefore, will always be an odd number.
:';
Other alternate versions of the present invention are shown in ;' ~, ~9~
}:~igs. 10-12. In Fig. 10 the pleated capacitor segment is formecl so that the end pleats 42, 44 have unmetalliæed strips 46' behind these pleats ~r,~hile the center pleat 40 does not. 'rhe two end pleats 42, 44 extend be-yond the recessed center pleat 40. I`lliS version is less clesirableJ how-ever, than the version of Fig. 3 becallse it reqllircs all ac~ditiollal striy.
Another alternate embodiment is shown in Fig. 11 wherein only one of the end pleats 42 extenàs beyond the center pleat 40 and the other of the end pleats 44. In this version only one unmetallized strip 46" is re~uired behind the extending end pleat 42, but the cllargillg path i9 longer for this configuration than tllat of Fig. 3.
Still another alternate embodiment is shown in ~ig. 1~ ~hich differs from the version shown in l?ig. 3 in that intermediate dielectric layers 69, 69' are inserted between alternating groups 71, 73 oL pleated layers with the center pleat extended, as in Fig. 3, but with the alternating ,~ 15 groups 71, 73 facing in opposite directions. If the capacitor of E;`ig. 12 is to bc a wound embodirmellt, tlle alternating groups 71, 73 of pleated ].ayers which face in opposite directions may l)e suppliecl from a differerlt pleated segment supply. ~lso, it is apparent that the groups of pleated layers shown in Fi~s. 10 and 11 could be employed ::
to form a capacitor in accordance with the teaching of Fig. 12 by facing ~:~
alternating groups of these layers in opposite dircctions allcl l~y scpar- . .
ating these alterrlating groups with dielectric material.
, ~ ~ ' .
.
.. ~ . , . - .
.. .. .
3~
~ portion of another commercially availablc metallized dielectric strip which may be unwound from a reel, that is suitable for.a mal~ing of a capacitor in accordance with the present invention is shown in Fig. 13.
~his metallized dielectric strip may also be forn1ed witll a dielcctric layer 112 of a thin film dielectric material, such ~s polyesterJ pcl~ rolylellc, polystyrene, polycarbonate or other suitable material. 1~ thin metallized electrode layer 114 is applied to the upper surface of the dielectric layer ~' 112 in such a fashion that unmetallized margin.areas 116, 118 extend along the longitudinal edges of the strip 110. Two thin rnetallized e~ectrode areas 120, 122 are applied to the lower surface o the dielectric layer 112 so that tl-c metallized layer 120 extellds to the l.eft halld m;lrgin of the layer as shown in ~ig. 13, while the metallized layer 122 extends to the right hand margin of the layer. A central unmetallizecl strip :124 lies between the metallized electrode areas 120, 122.
In the embodiment shown in }~ig. 13, the longitudinal dimension of the metallized strip 110 is shown along the arrows 126 ~vll.il~ tl~e narro\v trans~,~erse dimension is shown along the arro~vs 128.. 'rhis is to allo\v the capacitor to be pleated along the imaginary line 130 whicll extends ~ through the length of the unmetallized central strip 124. This versio 2~ of the present invention, however, is also not limited to one in which folding is along longitudinal lines smce a capacitor could be made in accordance :~:
~, wit~h tllis version of the present invention by ~leating along trallsvcl se lillcs , . ~. :
If the appropriate eorrcsponding mctdllizcd and llnn1ct~llizc(1 arcas wcre provid ed .
.
,~-15~
: ' ~i~3~i;
~ capacitor with ~ single pleclt 140 along line 130 is sllowll in Fig. 14 which is sliglltly off of the center linc 131 of the metallizcd strip 110 with tlle inside of the pleat 140 in the area being unmetallized. ~he longitudinal ends 148, 15(3 of the metallized strip 110 are arranged in a staggered patlern so that one end 48 ext~nds beyond the other end 150 along the left hand longitudinal edge of the rnetallized strip because of the off-center pieat of the dielectric layer. ~he e~tension of tllc cnd 1~LS l)eyoncl tl~c end 150 is preférably at least 0. 020 inches, and this extension allows the metallic spray to make contact with at least the upwardly facing electrode area 122 s~own i~ Fig. 14. The unmetallized margin 116 faces upwardly while the .u~met~lli2ed maryin 11~ faces downwardly whe~ the capacitor segment has been pleated as shown in Fig. 14.
~fter the capacitor has been processed to form tlle cll)acitol seg-ment shown in Fig. 14, a number of different additional processing steps i~ may be undertaken. :?or example, the pleated cap~citor segment of Fig. 14 could be used to form a capacitor merely by spraying the right and left hand longitudinal edges of the segment witll a metallized spray~ such as bablitt or otller suital)lc lllclal, i~l accol~d;lllcc \Yitll CC)n-ventional practice, and then electrical leads cou]d l~e securccl lo them, for example, by soldering. ~Alternately, the capacitor segment of :F`ig.
14 could be cut along a transverse line, such as the line 1~3, and a numl~er of such segmellts could be stacked uyon each otl~er, witll llle termil~al end 150 of one capacitor segn~ent being adJacent lo but not extencling as far~as thc terminal end 14~3' of the car)acltor scglllent tllat i~. positioncd immedlately below it, as sho~vn diagrammatically by tlle ~otted line re-.:
- 1 6 ~
. ~ . . : - - ., , ` .
~:~9~3~
presentative of Fig, 14, and then their ends coulcl l)e sprayed with a met-alli~ed spray and leads could thcn be secured to the stacked array vf such segments. In conjunction with the presently preferred embodiment of the present invention, however, ~ig. 1~ reprcscnts two l;~ycrs of a capa(i~o segment formed by winding of the dielectric strip about tlle longitudinal dimension OI the strip 110, as shown in l~igs. 15 and 16, to form a wound capacitor. Another version of this capacitor could be achieved, however, by pleating the capacitor segment of l?ig. 14 a nurmber of times transversely along transverse fold lines, such as the line 143, or alternat.ely, pleating several times and then completing the seg.ment by WiJldi~lg the rcn~ainder of the length of the dielectric strip.
, .
~he winding of the capacitor segment of Fig. 1~ into a wound capacitor may he achieved with various winding techniques, including the .
use of a split mandrel such as the mandrel 156 of Figs. 15 and 16, which 1~ may be removed from the capacitor segment after it llas becn ~ound.
~n unmetaIlized dielectric strip S8 is desirably initiatly wound around the mandrel to protect the ~netallized electrode ~reas of l:he metallized strip 110. ~he winding of the capacitor segment then contillues until it is almost completed, at which time an additional unmetalli~ed dielectric strip 160 is then desirably wound into the structure to form an outer pro-tective coating. ~he dielectric strip 160 may also l~e heat-sealc(l to itself to form a pleated capacitor segment in the manner .sho~vn in ~ig. 5. 'rhe ' -17 - ~.
, .
' ' ~ ' , ' ' , ~ :
removai of lhe mandrel 156 from the wound capacitor segment leaves an open-ing in the Ullit. ~his opening may be closed by applying pressure, or pressure and heat in accordance with the type of dielectric layer used and conventional manufacturing techniques to the capacitor segnlc~lt so tllat it assumes an oval shape as shown in :Fig. 6.
Once the capacitcr segment has been woundJ a metallized spray may then be directed against the longitudirlal edges of the unit in accordance with conventional processing techniclues to interconnect the electrode layers along these edges and to provide for the connection of elcctricLll leads to the unit. rrhe metallized spray will penetrate into the opcn area resulting from the staggering of the ends 148 and 150 0ll thc left hand longitudinal edge of the capacitor segment, so that the inner electrode provided by the metallizecl areas 12OJ 122, is contacted by the sprayed metal particles, but so that the electrode layer 114 is not contacted by such particles, as indicated l~y the imagillary ~lallc 1~5 which represents the maximum depth of penetration of the spray particles. The configuration of the present invention thus provides for reliable lead termination at the left hand longitudinal edge of Lhe capacitor segment of ~ig. I~ in a manner such tllat IllCtallizeCl ellC
terminations may be employed witl~ a sinL~le l leat met:llliz(?(l car)a-citor. I ermination to the right hand longitudinal c~l~e of thc! cal~acitor segment of Ii'ig. 15 is similarly providecl by a ll~etalliæed spray ~ -which extends over the protruding center pleat 140 to a depth wllich_ - la - :
:~ . . . :'' '' is sufficient to allow tlle metallized spray to make good contact to tlle electrode area 114.
Once the metallic spray has l~een ap,olied to thc ed~cs of tl~c capacitor segrnent either radial or axial leads may be applied to it S as previously shown in Figs. 7 and 8, A portion of another commercially available metallized dielectric strip which may be unwound from a reel, that is suitable for a making of a capacitor in accordance with the present invention is sho~vl~ in ~ig. 17, 'Ihis metallized dielectric strip may also be formed ~,vith a dielectric layer 212 of a thin film dielectric material~ such as polyester, polypropylene, polystyrene, polycarbonate or other suitable material. A
thin metallized electrode layér 21~ is applied to the upper surface of the dielectric layer 212 and a thin metallized electrode layer 220 is applied to the lower surface of the dielectric laycr in s~lch a f~shioll ~15 that unmetallized margin areas 216, 218 extend along the opposite long-itudinal edges of the strip Z10 on opposite sides of the strip.
ln the ernbodiment shown in Fig. 17, the longitlldinal dimension of the metallized strip 210 is shown along the arrows 226 ~vhile the narrow transverse dimension is sllo~vn along the arro~vs ~S. rrlle .
capacitor is pleated along two imaginary lines 230, 232 whicl~ cxtend through the length of the strip 210. ~his version of the present invention, however, is also not limited to one in which folding is along t~vo longitudinal - l g - .
.
.~ .
3~
lines since a capacitor could be made in accordance ~;tll this ~ ersiol2 o~
the present invention by pleating along any even number of transverse lines.
.
A pleated capacitor is shown in Fig. 18 wherein one pleat occurs along the longitudinal line 230 and another pleat occurs along the long-itudinal lines 232. It is to be noted tllat pleat lines 230, 232 are spaccd so that the margin area 218 extends beyond the pleat 24~ tllat r~lns along tllc right hand longitudinal edge of the~rnetallized sl:rip 210 of I~ig. 17 uritl~ thc margin area 218 facing dQwnwardly. Ihe extension of the margin area 218 beyond the pleats 242 is preferably at least 0. 020 inches. In addition, it is noted that the margin area 216 is positioned so that it extends beyond the pleat 252 that runs along the left hand longitudinal edge of the rnet~
alli~ed strip and faces upwardly. ~gain, tlle c~;te~sion of lhe l~t;ll`~`in area 216 beyond the pleat 252 is preferably at least 0. 020 inches. :~
fter t~2e capacitor has been processed to form the ca.pacitor seg-ment shown in Fig. 13, a number of different additional processing steps may be undertaken. For example, the pleated capacitor segmerlt of .~ig. 18 could be usecl to for~n ~ capacitor nlelely by s,:~r;lyilln tl~e ri~ht and l:et hand lorlgitudinal edges of the segment witl- a metalli~,cd spray, such as babbitt or other suitable metal, in accordance wi~h conventional practice, and then electrical leads ~:ould be secured to them~ .for ex- .
, : .. .
am~ple, by ~soldering. Altern~atelyO the capacitor segrnent of :Fig. 18 "
` ~: could be cut alo.ng a transverse line, such as the line 243, and a number -- ~0 -~r of SUCII segments could be staclied upon cacll otller, ~ritll thc down-~ardly facing margin 218 of one capacitor segment being adjacent to and aligned with a corresponding upwardly facing margin 21~' of the capacitor segment that is positioned immediately below it, as sho~vn 5 . diagrammatically by the dotted line representative of Fig. 18, and then their ends coùld be sprayed with a metallized spray and leads could then be secured to the stached array of such segments. In conjuIlction with the presently preferred embodiment of the present invention, how-ever, :Fig. 19 represents two layers of a capacitor segment formed by winding of the dielectric strip about the center of the longitudinal dimen-sion of the strip 210, as shown in Fig. 19, to form a wound capacitor seg-ment. Another version of this ca~acitor coukl be achie~red, ho~Y~reI~, by pleating, instead of winding, the capacitor segment of Fig. 18 a number of timeE alon~ transverse fold lines such as the line 243. Alternately, the capacitor segment could be pleated transversely two or more times about transverse lines, such as the line 243, and then the segment could be completed by winding the renlainder o;~ the length of the dielectric strip.
rrhe winding of the capacitor segment of Fig. 18 into a uound ; 20 capacitor may be achieved with various winding techniquesJ including the use of a split mandrel such as the rnandrel 256 of Fig. 19, which is removed from the capacitor segment a~ter it has been wound~ An unmet-allized dielectric strip (not shown) n~ay be wound ~roulld the structure~to - 2 l ~
~ .
.
-form an outer protective coating. ~his dielectric strip may ~e heat- -sealed to itself to form the pleated capacitor segment, as shown in ~ig. 6. ~he removal of the mandrel 56 from the capacitor segment leaves an opening in the unit. Ihe opening may again be elosed by apylying pressure9 or pressure and heat, in accor(lance witll thc l~pc of dielectric layer used and con~,rentional manufacturing techniques to ;~
the capacitor segment so that it assumes an oval shape, as shown in Fig. 7, Once the capacitor segment has been wound, a metal]ized spr~y rnay then be directed against the lon~itudillal edges of thc Ullit il~
accordance with con~rentional processing techniques to interco~ ect the electrode layers along these edges and to provide for the connection ';.:~ . ; , :.of electrical leads to the uni$. The metallized spray will penetrate ;, into the open area between the margin 216 areas on the left hand longituclinal edge of the capacitor segment, as shown diagramm~tically ~in Fig. 18 to a clepth such as that indicated by ~he plane 2(;~, so as ' to make contact with the elcctrode area 220. r~he plane 26~ indicates .
the maximum depth that an~ high velocity spray particles ~vill penetrate and it!may thus be located any place between the end of the margin 216 areas of the metallized s~rip 210 and the edge of the pleat 252.
Accordingly, the m~talllzed spray material ~vi]l cxiell(l inlo tllc left _ :
hand opening of th~e capacitor betweell the margill 21~ areas far cnough to : :
make contact to the facing metalll~ed clectrode on the other side of the dielectric strip, but nc~t so far that it will penetr~te through tile 25~ ~ diel6ctrlc material at tlle picat 252.
, , ~ . . . . ,.~ , , , , . . -"rermination to the right lland longitudillal edge of the capacitor segrnent of Fig. 1~ is similarly provided 'L)y a metallized spra~ wllich extends over the margin 218 area to a depth, swch as that indicated by the plane 268, which is sufficient to allow the metallized spray to rnake good contact to the electrode 214 on the inside of the margin 218 area but ~vllich will prevent the penetration of the spray metallic par-ticles through the dielectric at the pleat 242, 'Ille locatioll of tllc planc 2G8 may be anywhere between the edges of the pleat 242 and the end of the margin area 218 as long as there is sufficient depth of ~ ray to pro-vide adequate contact termination to the electrode area 21~L. 'rhe con-figuration of the present invention thus provides for reliable Icad Ler-mination at the longitudillal ecl~e.~ of the capacitor seg~ cn~ of l~`ig. :lR
without the necessity of providing unmetalli~cd longitudinal slrips alol-g the inside of the pleats 242, 252, thereby saving considcrable processing expenses in the mam~facture of completed capacitors of this type.
Once the metallic spray llas been applied to the cdges of the capacitor segment, either laclial or a};ial leads nla~ c a,~"lic(t to it, again as previously sl10wn in I;'igs. 7 and 8.
Another alternate version of the present invention is sl-own in Fig. 20, wherein two layers oî either a wound or a stacked capacitor segment is shown. 1'his version differs from tllat s~o~n in l~ig. lS in that intermediate dicleclric layers 269, 269' are inserted l~etwecll alterllati : ~ ;
group~s 271, 273 of pleated layers of the capacitor se~nlent ~l icl~ face in opposite directlons. ~If lhe capacltor of Fig. 20 is to be a ~ounù embodi-~25 ment, the alternating groups 271, ~273 of plented l~yers ~YhiCIl face inopposite dLreFtions may~ each be supplied from a different pleatcd seg-ment supply.
23 _ :
~, . , . . .. , . ., ....... . . -I'he previously described eml~oàiments of the present inventiol1 are illustrative, but not exllaustive~ of the various types of configurations that may come within the scope of the present invention. For instance, while winding about the exact center of the dielectric strip is preferred, it is apparent that winding about any number of transversc lines offset from the center, but intermediate the ends of the dielectric strip, arc interlded to be included within the scope of the present inventioll. It is also further apparent that more than two longitudinal pleat lines may be - employed in the version shown in }~ig. 18 wi~hin the scope of the present inventiOn.
, , , '`:
~ ' .. .:
Claims (14)
- Claim 1. An electrical capacitor segment comprising at least one group of pleated layers comprising a dielectric layer, a first metallized electrode layer applied to one side of said dielectric layer so that an unmetallized margin extends along each edge of a pair of parallel edges of said dielectric layer, a pair of metal-lized electrode layers on the other side of said dielectric layer, and at least one unmetallized strip that runs between said metal-lized layers on the other side of said dielectric layer, said dielectric layer being pleated M number of times where M = a +
(N)b where a is an odd number 3 or greater, and b is an even number 2 or greater, and where N may he zero or any positive integer so that at least one pleat of said pleated dielectric strip extends along one end of said pleated dielectric layer beyond at least one other pleat that extends along the same end as said extending pleat, or pleats, with all of said extending pleats having un-metallized strips behind them along their length, while the edges of said metallized dielectric strip which contain said margins extend along the opposite end of said pleated dielectric layer beyond the other pleats that extend along the same end as said margin containing edges wherein said extending pleat or pleats along said one end of said dielectric layer and said margin con-taining edges along said other end of said dielectric layer are sufficient in length to allow metallized spray material to be sprayed against both of said ends without penetration of said spray far enough to contact any of said pleats except said ex-tending pleat or pleats. - 2. An electrical capacitor segment comprising at least one group of pleated layers comprising a dielectric layer, a first metallized electrode layer applied to one side of said dielectric layer so that an unmetallized margin extends along each edge of a pair of parallel edges of said dielectric layer, a pair of metallized electrode layers on the other side of said dielectric layer, and at least one unmetallized strip that runs between said metallized layers, on the other side of said dielectric layer, said dielectric layer being pleated M number of times where M = 5 + (N)4 and N may be zero or any positive integer so that at least one pleat of said pleated dielectric strip extends along one end of said pleated dielectric layer beyond at least one other pleat that extends along the same end as said extending pleat, or pleats, with all of said extending pleats having unmetallized strips behind them along their length, while the edges of said metallized dielectric strip which contain said margins extend along the opposite end of said pleated dielectric layer beyond the other pleats that extend along the same end as said margin containing edges and metallized spray material sprayed against both of said ends but without penetration of said spray far enough to contact and of said pleats except said extending pleat or pleats.
- 3. An electrical capacitor segment as claimed in Claim 1, wherein said dielectric layer is an elongated layer and said capacitor segment is wound along the elongated dimension of said layer subsequent to said pleating along longitudinal pleat lines and said metallized sprayed material is applied to the ends of said capacitor after said winding has been completed.
- 4. An electrical capacitor segment as claimed in Claim 2, wherein said dielectric layer is an elongated layer and said capacitor segment is wound along the elongated dimension of said layer subsequent to said pleating along longitudinal pleat lines and said metallized sprayed material is applied to the ends of said capacitor after said winding has been completed.
- 5. An electrical capacitor segment as claimed in Claim 1, wherein said dielectric layer is an elongated layer and said capacitor segment is pleated along lines transverse to the elongated dimension of said layer subsequent to said pleating along longitudinal pleat lines and said metallized sprayed material is applied to the ends of said capacitor after said pleating has been completed.
- 6. An electrical capacitor segment as claimed in Claim 2, wherein said dielectric layer is an elongated layer and said capacitor segment is pleated along lines transverse to the elongated dimension of said layer subsequent to said pleating along longitudinal pleat lines and said metallized sprayed material is applied to the ends of said capacitor after said pleating has been completed.
- 7. An electrical capacitor segment as claimed in Claim 3 or Claim 4 wherein a lead is secured to each of said metallized sprayed ends of said capacitor segment.
- 8. An electrical capacitor segment as claimed in Claim 5 or Claim 6, wherein a lead is secured to each of said metallized sprayed ends of said capacitor segment.
- 9. An electrical capacitor comprising a plurality of cap-acitor segments that are stacked upon each other wherein each capacitor segment comprises a dielectric layer, a first metallized electrode layer applied to one side of said dielectric layer so that an unmetallized margin extends along each edge of a pair of parallel edges of said dielectric layer, a pair of metallized electrode layers on the other side of said dielectric layer, at least one unmetallized strip that runs between said metallized layers on the other side of said dielectric layer, said dielectric layer being pleated M number of times where M = a + (N)b where a is an odd number 3 or greater, and b is an even number 2 or greater, and where N may be zero or any positive integer so that at least one pleat of said pleated dielectric strip extends along one end of said pleated dielectric layer beyond at least one other pleat that extends along the same end as said extending pleat, or pleats, with all of said extending pleats having unmetallized strips behind them along their length, while the edges of said metallized dielectric strip which contain said margins extend along the opposite end of said pleated dielectric layer beyond the other pleats that extend along the same end as said margin containing edges wherein said extending pleat or pleats along said one end of said dielectric layer and said margin containing edges along said other end of said dielectric layer are sufficient in length to allow metallized spray material to be sprayed against both of said ends without penetration of said spray far enough to contact any of said pleats except said extending pleat or pleats, wherein said metallized end spray is applied to said ends of said capacitor segments after they have been stacked upon each other.
- 10. An electrical capacitor comprising a plurality of capacitor segments that are stacked upon each other wherein each capacitor segment comprises a dielectric layer, a first metallized electrode layer applied to one side of said di-electric layer so that an unmetallized margin extends along each edge of a pair of parallel edges of said dielectric layer, a pair of metallized electrode layers on the other side of said dielectric layer, at least one unmetallized strip that runs between said metallized layers on the other side of said dielectric layer, said dielectric layer being pleated M number of times where M = 5 + (N)4 and N may be zero or any positive integer so that at least one pleat of said pleated dielectric strip extends along one end of said pleated dielectric layer beyond at least one other pleat that extends along the same end as said extending pleat, or pleats, with all of said extending pleats having unmetallized strips behind them along their length, while the edges of said metallized dielectric strip which contain said margins extend along the opposite end of said pleated dielectric layer beyond the other pleats that extend along the same end as said margin containing edges and metallized spray material sprayed against both of said ends but without penetration of said spray far enough to contact any of said pleats except said extending pleat or pleats.
- 11. An electrical capacitor as claimed in Claim 9, wherein alternating ones of said plurality of capacitor segments face in opposite directions and are separated from their neighboring segments by dielectric material.
- 12. An electrical capacitor as claimed in Claim 10, wherein alternating ones of said plurality of capacitor segments face in opposite directions and are separated from their neighboring segments by dielectric material.
- 13. An electrical capacitor as claimed in Claim 9 or Claim 10, wherein a lead is secured to each of said metallized sprayed ends of said capacitor segment.
- 14. An electrical capacitor as claimed in Claim 11 or Claim 12, wherein a lead is secured to each of said metallized sprayed ends of said capacitor segment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA360,216A CA1109935A (en) | 1977-07-12 | 1980-09-12 | Metallized film capacitors |
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/814,958 US4127891A (en) | 1977-07-12 | 1977-07-12 | Pleated metallized film capacitor with sprayed edge terminations |
| US814,945 | 1977-07-12 | ||
| US05/814,945 US4127890A (en) | 1977-07-12 | 1977-07-12 | Single pleat metallized film capacitor with sprayed edge terminations |
| US814,954 | 1977-07-12 | ||
| US05/814,954 US4128857A (en) | 1977-07-12 | 1977-07-12 | Pleated metallized film capacitor wound about its center |
| US814,958 | 1977-07-12 | ||
| CA305,939A CA1093166A (en) | 1977-07-12 | 1978-06-21 | Metallized film capacitors |
| CA360,216A CA1109935A (en) | 1977-07-12 | 1980-09-12 | Metallized film capacitors |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1109935A true CA1109935A (en) | 1981-09-29 |
Family
ID=27508120
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA360,216A Expired CA1109935A (en) | 1977-07-12 | 1980-09-12 | Metallized film capacitors |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1109935A (en) |
-
1980
- 1980-09-12 CA CA360,216A patent/CA1109935A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4352145A (en) | Multiple element cylindrical metallized film capacitors and method of making the same | |
| US4028595A (en) | Multi-voltage capacitor section | |
| DE3629837A1 (en) | ELECTRIC CAPACITOR FROM A STRENGTHENED WRAP OR STRENGTHED PACK OF METALLIZED PLASTIC LAYERS LAYERED TOGETHER AND METHOD FOR THE PRODUCTION THEREOF | |
| US4146914A (en) | Pleated metallized film capacitor with staggered edges | |
| US4127891A (en) | Pleated metallized film capacitor with sprayed edge terminations | |
| US2887649A (en) | Electrical capacitors | |
| US4378620A (en) | Method of making small sized wound capacitors | |
| CA1109935A (en) | Metallized film capacitors | |
| CA1116706A (en) | Electrical capacitor with a pleated metallized portion and a starting portion wound about the lead wires | |
| US4128857A (en) | Pleated metallized film capacitor wound about its center | |
| US4089037A (en) | Pleated metallized film capacitors | |
| US4638402A (en) | Multi-section capacitor electrically coupled in parallel | |
| US4422127A (en) | Substantially small sized wound capacitor and manufacturing method therefor | |
| US4127890A (en) | Single pleat metallized film capacitor with sprayed edge terminations | |
| ES537874A0 (en) | IMPROVEMENTS IN AN ELECTRIC CONDENSER | |
| CA1093166A (en) | Metallized film capacitors | |
| ATE44842T1 (en) | ELECTRIC CONDENSER FROM A CONSOLIDATED COIL AND METHOD FOR ITS MANUFACTURE. | |
| CA1105578A (en) | Metallized film capacitors | |
| US4570201A (en) | Capacitor | |
| DE2758913C2 (en) | Process for the production of stacked electrical capacitors | |
| EP0202479A1 (en) | Electrical capacitor and process for making it | |
| DE2752767A1 (en) | Laminated capacitor mfr. - by winding master capacitor roll with injected separating foils and cutting roll axially | |
| DE200670T1 (en) | DECOUPLING CAPACITOR AND METHOD FOR THE PRODUCTION THEREOF. | |
| GB2144915A (en) | Multisection wound capacitors and terminations | |
| DE675190C (en) | Electrical wound capacitor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |