US3880609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for manufacturing cylindrical resistors by thick-film silk-screening
Assignee: Individual
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Filing: 1973-12-14
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Granted: 1975-04-29
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Expires: 1993-12-14
Abstract
Abstract A ''''silk-screen'''' is provided with a patterned pervious portion the dimension of which, in the direction of screen movement, is substantially less than the circumference of the cylindrical substrate. The screen is then moved beneath a squeegee through a distance which is greater than the indicated dimension of the pattern but less than the substrate circumference, the result being that a thick film of resistive material is metered onto the substrate without any overlapping or smearing. The squeegee, at the end of the screen-printing stroke, is located at an impervious portion of the screen, so that even unspindled smalldiameter ceramic substrates are disengaged from the screen with no sticking or smearing. Such cylindrical substrates are solid in order to be economical, and to permit zero moisture intrusion. It is a feature of the invention that such economical solid substrates can be used, and are driven solely by screen friction so that loading, unloading and other problems are minimized. The method and apparatus further employ an air jet in a certain manner to separate certain types of resistors from the screen. This greatly extends the capability of the method and apparatus. The screen pattern is preferably a serpentine noninductive one which includes end regions so located as to be the last pattern regions to pass beneath the squeegee. These end regions may therfore extend clear to the ends of the cylindrical substrate, which is important for maximized termination effectiveness. The apparatus makes use of limit switches, an air cylinder, a certain type of stabilized squeegee, and friction-minimizing components to effect very smooth and substantially vertical liftoff of the squeegee from a precisely-determined region of the screen, the result being that a high degree of repeatability is achieved. The apparatus further employs a certain type of cylinder carriage, and preset stop devices, to make it extremely easy to load and unload the machine and to make it simple to change to different sizes of cylindrical substrates. The apparatus employs a compound lever system for the squeegee support arm and the flood-bar support arm, which system operates smoothly and simply to achieve the precise desired movements of the flood bar and squeegee.
Inventors
- 👤 Richard E Caddock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:28
CPC Classifications
H; H01; H01C; H01C7/00; H01C17/00; H01C17/06; H01C17/065; H01C7/22; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
170 words
A method of manufacturing silk-screened film-type cylindrical resistors, which comprises: a. providing an elongated cylindrical substrate, b. providing a silk screen incorporating a pervious area which corresponds to the resistive film pattern which it is desired to provide adherently on the exterior cylindrical surface of said substrate, c. causing one dimension of said pervious area to be substantially less than the circumference of said surface, d. moving said silk screen and said substrate relative to each other, in a direction parallel to said one dimension, and simultaneously effecting rolling contact between said silk screen and said surface, e. continuing said moving step for a distance at least equal to said one dimension, until all of said pervious area has engaged said surface, f. disengaging said substrate from said silk screen without effecting any overlapping of the film pattern on said surface, and g. providing termination means at the ends of said cylinder and in electrical contact with opposite end portions of the region which was screened with said film pattern.
Claim 2
Independent Claim
170 words
A method of manufacturing silk-screened film-type cylindrical resistors, which comprises: a. providing an elongated cylindrical substrate, b. providing a silk screen incorporating a pervious area which corresponds to the resistive film pattern which it is desired to provide adherently on the exterior cylindrical surface of said substrate, c. causing one dimension of said pervious area to be substantially less than the circumference of said surface, d. moving said silk screen and said substrate relative to each other, in a direction parallel to said one dimension, and simultaneously effecting rolling contact between said silk screen and said surface, e. continuing said moving step for a distance at least equal to said one dimension, until all of said pervious area has engaged said surface, f. disengaging said substrate from said silk screen without effecting any overlapping of the film pattern on said surface, and g. providing termination means at the ends of said cylinder and in electrical contact with opposite end portions of the region which was screened with said film pattern.
Claim 3
Dependent Claim
36 words
The invention as claimed in claim 1, in which said method further comprises causing said substrate to be formed of a heat-resistant ceramic, and causing said pervious area to be in the shape of a line.
Claim 4
Dependent Claim
49 words
The invention as claimed in claim 1, in which said method further comprises causing said one dimension of said pervious area to be less than the circumference of said surface by a distance which exceeds the width of the working edge of the squeegee associated with said silk screen.
Claim 5
Dependent Claim
27 words
The invention as claimed in claim 1, in which said method further comprises causing said substrate to be a solid ceramic extrusion having a smooth exterior surface.
Claim 6
Independent Claim
265 words
A method of manufacturing a cylindrical resistor, which comprises: a. providing an elongated ceramic cylinder, b. providing a silk screen having an impervious portion and also having a pervious printing area which is a line serpentine in shape, c. providing a squeegee for said silk screen, d. causing one dimension of said printing area to be less than the circumference of the exterior cylindrical surface of said cylinder by an amount which is greater than the width of the working edge of said squeegee, e. flooding said printing area with a film-forming resistive material, f. moving said printing area toward said cylinder and in a direction parallel to said one dimension while maintaining said screen in stRaight-line contact with said surface, and simultaneously effecting rotation of said cylinder about its own axis at a speed corresponding to the speed of movement of said screen, whereby rolling contact is effected between said surface and said screen, g. maintaining said working edge of said squeegee in contact with the side portion of said screen opposite the straight-line region of contact between said screen and said surface, whereby said resistive material in the shape of said serpentine area is screened onto said cylindrical surface, h. stopping said movement of said screen after all of said serpentine shape has been screened onto said surface, and before any overlapping occurs, i. removing the coated cylinder from contact with said screen without first reversing substantially the direction of screen movement, and j. providing termination means at opposite ends of said cylinder and in electrical contact with the coating of resistive material.
Claim 7
Independent Claim
265 words
A method of manufacturing a cylindrical resistor, which comprises: a. providing an elongated ceramic cylinder, b. providing a silk screen having an impervious portion and also having a pervious printing area which is a line serpentine in shape, c. providing a squeegee for said silk screen, d. causing one dimension of said printing area to be less than the circumference of the exterior cylindrical surface of said cylinder by an amount which is greater than the width of the working edge of said squeegee, e. flooding said printing area with a film-forming resistive material, f. moving said printing area toward said cylinder and in a direction parallel to said one dimension while maintaining said screen in stRaight-line contact with said surface, and simultaneously effecting rotation of said cylinder about its own axis at a speed corresponding to the speed of movement of said screen, whereby rolling contact is effected between said surface and said screen, g. maintaining said working edge of said squeegee in contact with the side portion of said screen opposite the straight-line region of contact between said screen and said surface, whereby said resistive material in the shape of said serpentine area is screened onto said cylindrical surface, h. stopping said movement of said screen after all of said serpentine shape has been screened onto said surface, and before any overlapping occurs, i. removing the coated cylinder from contact with said screen without first reversing substantially the direction of screen movement, and j. providing termination means at opposite ends of said cylinder and in electrical contact with the coating of resistive material.
Claim 8
Dependent Claim
101 words
The invention as claimed in claim 5, in which said method further comprises causing said one dimension to be such that the bends or turns at one side of said serpentine shape are the first things coated onto said surface, and the bends or turns at the other side of said shape are the last things coated onto said surface, whereby the screened reproduction of said shape has bends or turns on opposite sides of a gap in the coating on said cylinder, said gap extending parallel to the cylinder axis along the full length of one side of said cylinder.
Claim 9
Dependent Claim
78 words
The invention as claimed in claim 5, in which said film-forming material is adapted to provide adherently a resistive film directly on said surface, and in which said step (j) of said method further comprises providing highly conductive films on the ends of said cylinder and in electrical contact with the ends of said resistive film, and additionally comprises providing conductive end caps over said conductive films, said conductive films and said end caps forming said termination means.
Claim 10
Dependent Claim
82 words
The invention as claimed in claim 5, in which said method further comprises causing the width of the line forming said serpentine shape to be in the range from about 0.008 inch to about 0.100 inch, causing the spaces between adjacent portions of said serpentine shape to be in the range of about 0.008 inch to about 0.100 inch, and causing the width of the gap between the edges of the coated regions of said surface to be at least 0.015 inch.
Claim 11
Dependent Claim
40 words
The invention as claimed in claim 8, in which said method further comprises causing the maximum thickness of said line, in a direction radial to said cylinder, to be in the range from about 0.0005 inch to about 0.002 inch.
Claim 12
Independent Claim
245 words
A method of manufacturing cylindrical film-type resistors, which comprises: a. providing an elongated cylindrical substrate, b. supporting said substrate by engaging a first roller means with the exterior cylindrical surface region at one end of said substrate, and by engaging a second roller means with the exterior cylindrical surface region at the other end thereof, and causing the intermediate exterior cylindrical surface regions of said substrate between said roller means to be free of support means, c. providing a silk screen having a pervious pattern portion of predetermined shape, (d) providing a squeegee on the side of said screen opposite said substrate, e. flooding said screen with a resistive ink, f. pressing the working edge of said squeegee against said screen and engaging said screen with said substrate at the opposite side of said substrate from said roller means, g. moving said screen in such direction that said pattern portion thereof moves between said squeegee edge and said substrate, said screen movement operating frictionally to create a force which causes rotation of said substrate on said roller means about the longitudinal axis of said substrate, said force being the sole driving force causinG said rotation, h. moving said working edge of said squeegee away from said screen and causing said screen to separate from said substrate, i. removing said substrate with the silk-screened resistive coating thereon, j. drying said resistive ink, and k. providing termination means at opposite portions of the resulting silk-screened resistive film.
Claim 13
Independent Claim
245 words
A method of manufacturing cylindrical film-type resistors, which comprises: a. providing an elongated cylindrical substrate, b. supporting said substrate by engaging a first roller means with the exterior cylindrical surface region at one end of said substrate, and by engaging a second roller means with the exterior cylindrical surface region at the other end thereof, and causing the intermediate exterior cylindrical surface regions of said substrate between said roller means to be free of support means, c. providing a silk screen having a pervious pattern portion of predetermined shape, (d) providing a squeegee on the side of said screen opposite said substrate, e. flooding said screen with a resistive ink, f. pressing the working edge of said squeegee against said screen and engaging said screen with said substrate at the opposite side of said substrate from said roller means, g. moving said screen in such direction that said pattern portion thereof moves between said squeegee edge and said substrate, said screen movement operating frictionally to create a force which causes rotation of said substrate on said roller means about the longitudinal axis of said substrate, said force being the sole driving force causinG said rotation, h. moving said working edge of said squeegee away from said screen and causing said screen to separate from said substrate, i. removing said substrate with the silk-screened resistive coating thereon, j. drying said resistive ink, and k. providing termination means at opposite portions of the resulting silk-screened resistive film.
Claim 14
Dependent Claim
102 words
The invention as claimed in claim 10, in which said method further comprises causing the dimension of said pervious pattern portion which is parallel to said direction of said movement of said screen to be less than the circumference of said substrate by an amount at least equal to the thickness of said working edge of said squeegee, whereby a gap is provided in the resistive coating on said substrate after said pattern portion moves past said squeegee edge, and in which said method step recited in clause (h) is caused to occur while said squeegee edge is registered with said gap.
Claim 15
Dependent Claim
41 words
The invention as claimed in claim 11, in which said method step recited in clause (h) is caused to be smooth and jerk-free, and to be such that said squeegee edge moves substantially radially to the cylindrical surface of said substrate.
Claim 16
Dependent Claim
37 words
The invention as claimed in claim 11, in which said method further comprises stabilizing the location of said working edge of said squeegee to prevent any portion of said working edge from moving to any considerable extent.
Claim 17
Dependent Claim
25 words
The invention as claimed in claim 11, in which said method further comprises causing the width of said gap to be at least 0.015 inch.
Claim 18
Dependent Claim
24 words
The invention as claimed in claim 11, in which said method further comprises causing said pervious pattern portion to consist of an elongated line.
Claim 19
Dependent Claim
47 words
The invention as claimed in claim 15, in which said method further comprises causing said line to be serpentine and to have a multiplicity of elongated arm portions disposed adjacent other arm portions through which current is flowing in the opposite directions, whereby to provide inductance-cancellation effects.
Claim 20
Dependent Claim
87 words
The invention as claimed in claim 16, in which said method further comprises causing the width of said line to be in the range of about 0.008 inch to about 0.1 inch, causing the spacing between adjacent arm portions of said line to be in the range of about 0.008 inch to about 0.05 inch, and causing the maximum thickness of said line in a direction radial to the cylindrical surface of said substrate to be in the range of about 0.0005 inch to about 0.002 inch.
Claim 21
Dependent Claim
121 words
The invention as claimed in claim 11, in which said method further comprises causing said pervious pattern portion to be serpentine and to have ends extending generally longitudinally of said substrate to substantially the ends of said substrate, in which said method further comprises orienting said pervious pattern portion and said squeegee edge in such manner that said ends of said pattern are generally the last pattern portions which pass beneath said squeegee edge during the screening step of clause (g), and in which said method further comprises terminating rotation of said substrate as soon as said pattern ends pass beneath said squeegee edge whereby to prevent the resulting screened ends of the screened-on pattern from smearing on said roller means.
Claim 22
Dependent Claim
55 words
The invention as claimed in claim 18, in which said method further comprises causing said ends of said pattern to be substantially axial to said substrate, and causing said serpentine pattern to be so oriented that the bends therein are adjacent opposite sides of said gap and the arms thereof extend circumferentially of said substrate.
Claim 23
Dependent Claim
40 words
The invention as claimed in claim 10, in which said method further comprises causing said cylindrical substrate to be ceramic, to be solid, and to have no end recesses, and to have a diameter ranging down to about 0.060 inch.
Claim 24
Dependent Claim
52 words
The invention as claimed in claim 10, in which said method further comprises moving said roller means with said Substrate supported thereon longitudinally of said screen, to and from a load-unload station which is not beneath said screen whereby to facilitate loading and unloading of said substrate relative to said roller means.
Claim 25
Dependent Claim
26 words
The invention as claimed in claim 10, in which said method further comprises performing an additional step to insure separation of said substrate from said screen.
Claim 26
Dependent Claim
36 words
The invention as claimed in claim 22, in which said additional step comprises directing a jet of air between adjacent regions of said screen and said substrate after at least partial completion of said step (h).
Claim 27
Independent Claim
169 words
A method of silk-screening cylindrical parts, which comprises: a. providing a silk screen having ink thereon, b. supporting a cylindrical part adjacent said silk screen without effecting spindling of said part, c. providing a squeegee on the opposite side of said screen from said part, d. relatively moving said squeegee in a direction toward said part to thus press said screen into pressure contact with said supported part, e. effecting relative movement of said screen to cause silk-screening of said part accompanied by rotation thereof, said rotation of said part being about the longitudinal axis thereof and being caused by said relative screen movement, f. relatively moving said screen in a direction away from said part to thereby tend to cause said screen and said part to separate from each other, and g. directing an air jet between said screen and said part to insure said separation, whereby said part is engaged solely with the part-supporting means and may be withdrawn to a load-unload position remote from said screen.
Claim 28
Independent Claim
169 words
A method of silk-screening cylindrical parts, which comprises: a. providing a silk screen having ink thereon, b. supporting a cylindrical part adjacent said silk screen without effecting spindling of said part, c. providing a squeegee on the opposite side of said screen from said part, d. relatively moving said squeegee in a direction toward said part to thus press said screen into pressure contact with said supported part, e. effecting relative movement of said screen to cause silk-screening of said part accompanied by rotation thereof, said rotation of said part being about the longitudinal axis thereof and being caused by said relative screen movement, f. relatively moving said screen in a direction away from said part to thereby tend to cause said screen and said part to separate from each other, and g. directing an air jet between said screen and said part to insure said separation, whereby said part is engaged solely with the part-supporting means and may be withdrawn to a load-unload position remote from said screen.
Claim 29
Dependent Claim
69 words
The invention as claimed in claim 24, in which said method further comprises causing the pervious portion of said screen to be sufficiently large, and causing the amount of said relative movement of said screen to be sufficiently great, that a pervious region of said screen is adjacent said part during performance of said step (f), whereby the ink tends to effect adherence of said part to said screen.
Claim 30
Dependent Claim
23 words
The invention as claimed in claim 24, in which the diameter of said part is very small whereby said part is very light.
Claim 31
Dependent Claim
37 words
The invention as claimed in claim 26, in which said part is a ceramic cylinder having a diameter in the range of about 0.060 inch to about 0.120 inch, and in which said ink is resistive ink.
Claim 32
Dependent Claim
47 words
The invention as claimed in claim 24, in which said supporting is effected by engaging a first roller means with the exterior cylindrical surface at one end of said part, and by engaging a second roller means with the exterior cylindrical surface at the other end thereof.
Claim 33
Dependent Claim
54 words
The invention as claimed in claim 24, in which said method further comprises causing said air jet to be in the form of an air curtain the major dimension of which, in a direction transverse to the direction of air flow, is parallel to the region of contact between said part and said screen.
Claim 34
Dependent Claim
32 words
The invention as claimed in claim 24, in which said method further comprises varying the air pressure, which is employed to create said jet, in accordance with the size of said part.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |