US3582730A - Static electricity pinning method - Google Patents

Abstract

Static electricity apparatus is provided including a device in the form of a wand coupled to a source of unidirectional potential for temporarily mounting a layer being worked onto a vertical or horizontal layer of high dielectric material. The layer being worked on is between a grounded substrate and the dielectric material. When the wand is moved over the layers, the layers are pinned together by static electricity. The substrate is of ground potential and provides a reference or basis for the electrical charge taken by the dielectric material.

Description

I United States Patent 13582,730

[72] lnv entor Anthony Q Teston 2,934,649 4/1960 Walkup 310/64 Lansdale 3,172,657 3/1965 Brandt 101/232 [21] Appl. N0. 695,219 3,174,748 3/1965 Roberts et al 101/232UX [22] Filed Jan. 2, 1968 3,448,000 6/1969 Paquin et a1. l56/272X [45] Patented June 1, 1971 FOREIGN 7 T t El i l 3] Ass'gnee j f' lz f Cmpmm 707,734 4/1965 Canada 156/272 923,457 4/1963 Great Britain 156/275 Primar Examinr-Reuben Epstein 541 STATIC ELECTRICITY PINNING METHOD mwmeywhavinea Cantor & Reich 3 Claims, 4 Drawing Figs.

[52] US. Cl 317/262, ABSTRACT; Static electricity apparatus is provided including 156/272 a device in the form of a wand coupled to a source of [51 l llll. Cl B321) 31/28 idirectional potential for temporarily mounting a layer [50] Field of Search 156/1, 272, being worked onto a vertical or horizontal layer of high dielec- 317/262 tric' material. The layer being Worked on is between a 56 R f ed grounded substrate and the dielectric material. When the l e erences wand is moved over the layers, the layers are pinned together UNITED STATES PATENTS by static electricity. The substrate is of ground potential and 3,359,469 12/1967 Levy et al. 317/262 provides a reference 01' basis for the electrical charge taken by 3,194,131 7/1965 Robinson 317/262 the dielectric material.

PATENTED JUN 1 I97! mwswron ANTHQNPO; fits-m 5 er W STATIC ELECTRICITY PINNING METHOD This invention relates to a static electricity apparatus useful in pinning a layer of material to a layer of high dielectric material while being between a substrate and the dielectric material. The layers are pinned together by static electricity. Such apparatus is useful in silk screening techniques wherein the layer of material to be worked on has heretofore been held in place by use ofa vacuum frame, adhesives, or tape. It is also useful in place of. wet stripping of film in the publishing field and tape used in the printing field.

The apparatus is preferably portable, and is completely dependable. The size of the layer of material being worked on can vary to any desired size. The apparatus may be vertical or horizontal. When vertical, the apparatus materially reduces the floor space and does not require any special tables or supports.

The apparatus of the present invention utilizes a substrate. The substrate may be in the form of an ordinary aluminum household mesh screen painted black. Instead of a screen, the substrate could be a plate or a special transparent working surface, i.e., a fogged glass plate clamped to a grounded wire screen mounted on a plexiglass base. The size of the substrate determines the maximum size of the work that can be processed. The screen is preferably aluminum and it must be grounded. The substrate may have a size which bears no relationship to the size of the material worked on except that the substrate must be at least as large as the material being worked on.

A layer of material having a high dielectric constant is juxtaposed to the substrate. Such material may be in for form of a layer of plastic material such as acetate or Mylar having one side attached to the substrate or adjacent thereof. The material being worked on is disposed between the dielectric layer and the substrate. By passing the wand over the layers, the dielectric layer and the material being worked on are electrostatically pinned together.

The wand is preferably provided with a handle so that it may be portable and is coupled to a source of unidirectional potential. A switch which may be hand or foot operated is provided. The wand is moved over the juxtaposed layers. In doing so, the material being worked on is pinned to the dielectric layer. Until the layers are physically separated, they will remain in that position for a period of several hours.

It is an object of the present invention to provide a novel static electricity apparatus for electrostatically pinning material to be worked on to a layer of other material which may be vertical or horizontal.

It is another object of the present invention to provide an electrostatic pinning device so that layers being worked on may be maintained in a predetermined position without the use of adhesives, vacuum, tape, etc.

It is another object of the present invention to provide a novel method for supporting and maintaining layers of material being worked on in the predetermined position by use of electrostatics.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is'a perspective view of the apparatus of the present invention and illustrating the electrostatic pinning device.

FIG. 2 is a side elevation view of the apparatus shown in FIG. 1 with parts broken away.

FIG. 3 is a perspective view of the apparatus in accordance with another embodiment of the present invention.

FIG. 4 is a side elevation view of the apparatus shown in FIG. 3.

Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIG. 1 an apparatus in accordance with one embodiment of the present invention designated generally as and having associated therewith an electrostatic pinning device designated generally as 12.

Theapparatus 10 includes asubstrate 14. Thesubstrate 14 may be a grounded aluminum mesh screen, a grounded stainless steel screen, a grounded plate, or a special surface. A layer of highdielectric material 16 of any configuration overlies thesubstrate 14. High in this regard is excess of about 2.2 at 10 cycles per-second and at room temperature and/or a surface resistivity of l0' megohms per square. The physical size of the dielectric material is unimportant.Layer 16 is preferably secured to thesubstrate 14 along one edge such as the top edge as illustrated. The apparatus is preferably used in a vertical position. If the apparatus is used horizontally, the side edge of thelayer 16 may be secured to the substrate [4.Layer 16 may be a layer of polymeric material such as an acetate having a thickness of about three one-thousandths of an inch.

Whileapparatus 10 may be utilized for mounting various types of material such as drawings in an art department, for the purposes of this disclosure, it will be assumed that theapparatus 10 is being used in a silk screening process. Thus, a positive 20 overlies astencil film 18. The positive 20, in ac cordance with conventional silk screening practice, is a sheet plastic material having thereon a photographically produced positive image. Thestencil film 18 is a sheet of plastic, commonly Mylar or acetate, having a photosensitive emulsion thereon which is to be exposed to a light source to thereby receive the image of positive 20.Film 18 and positive 20 are positioned betweensubstrate 14 andlayer 16 with the positive being in contact with thelayer 16. In order to electrostatically pin elements l4, 16, 18 and 20 together it is only necessary to movewand 26 of the electrostatic pinning device 12 over the various elements.

The electrostatic pinning device 12 includes aunidirectional power supply 22 having a voltage such as l5,000volts. Power supply 22 may, for example, be a conventional direct current source of potential. Thewand 26 may be removably connected to and supported byhandle 24.Wand 26 has sharp stainless steel or monel points at three'fourths inch intervals on an aluminum tube so as to have overlapping ionization patterns.Wand 26 is coupled to the source ofpotential 22 by an electrical conductor extending through the wand to an electrical socket in thehandle 24 wherein it is electrically coupled to the cord extending tosource 22. The polarity ofwand 26 is unidirectional to that of thegrounded substrate 14.

Thewand 26 and discharge points thereon are spaced from thelayer 16 by means ofbushings 28 and 30.Bushings 28 and 30 assure that the wand will be a uniform distance from thelayer 16 at all times and facilitate the ease with which the wand will be moved relative tolayer 16.Handle 24 is an electrically insulated handle and may be made from plexiglass.Bushings 28 and 30 likewise may be made from electrical insulation material. Coupling of current fromsource 22 to thewand 26 may be effected by afoot switch 32.

With the stencil film and positive being thusly pinned to thelayer 16, the light source (not shown) may be turned on so that burning or exposure will commence. In the case of large screens or substrates, the light source may have to be moved and several burns made.

Thelayer 16, positive 20,stencil film 18 are all held tightly to thesubstrate 14 and to each other by static electricity so that no undercutting will take place when the light source moves from place to place for more than one burn as is in the case of large positives. Unless the elements are physically pulled apart, the electrostatic lamination will hold together for many hours. While the time period will vary with humidity conditions, the minimum holding time is usually over one hour.

The above description and the illustration in FIGS. 1 and 2 may be referred to as an indirect method of preparing a screen in screen process printing. A direct method is shown in FIGS. 3 and 4 wherein the apparatus is identical with that described above except as will be made clear hereinafter. Hence, corresponding elements are provided with corresponding primed numerals. The identical electrostatic pin device will be used with the apparatus Theapparatus 10 includes awooden frame 36 to which is secured a groundedsurface 38 of a substrate such as a metal plate. Thephotosensitive screen 18 is directly against thesurface 38 and may be mounted on a separate frame which is larger thanframe 36. The screen 18' may be silk, nylon or dacron coated in conventional manner with a photosensitive layer. The positive 20' is disposed between the photosensitive screen 18' and the layer ofdielectric material 16'.

it is preferable when preparing the photosensitive screen 18' for the direct method that the work be done in the vertical position. However, the screen 18', positive 20' andlayer 16 of dielectric material may be pinned together while in the horizontal position and then secured to thesurface 38 of groundedsubstrate 14 for processing with the elements in a vertical position.

The pinning device is preferably a portable unit for ease of handling and for ease of transportation. It will be appreciated that thewand 26 whether it is used in the direct or indirect method is of opposite polarity with respect to thescreen 18 andsurface 38.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

lclaim:

l. A static electricity pinning method for closely adhering together a film having photosensitive emulsion thereon and an image bearing sheet for exposure to a light source without "undercuttingcomprising:

superimposing a said film, a said sheet and a layer of high dielectric strength material onto a grounded conductive substrate,

with said film and said sheet between said layer and said substrate, and at least one of said substrate and layer being light transmitting,

and electrostatically pinning together said superimposed layers by moving a wand having ionizing points connected to a source of direct current over and in juxtaposition to said superimposed layers.

2. The method of claim 1, said layer of high dielectric strength material being transparent.

3. The method of claim 1, said sheet being adjacent said substrate.

Claims (3)

1. A static electricity pinning method for closely adhering together a film having photosensitive emulsion thereon and an image bearing sheet for exposure to a light source without ''''undercutting'''' comprising: superimposing a said film, a said sheet and a layer of high dielectric strength material onto a grounded conductive substrate, with said film and said sheet between said layer and said substrate, and at least one of said substrate and layer being light transmitting, and electrostatically pinning together said superimposed layers by moving a wand having ionizing points connected to a source of direct current over and in juxtaposition to said superimposed layers.

2. The method of claim 1, said layer of high dielectric strength material being transparent.

3. The method of claim 1, said sheet being adjacent said substrate.

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