JPH04105397A - Electromagnetic shielding shield for rotary/reciprocating shaft - Google Patents

Abstract

PURPOSE: To improve electromagnetic shielding characteristic by providing an elastic coil spring means of garter type, enabling the coil spring means to have a plurality of individual coils, and making independent a coil spring means within the deflection range of the individual coil means for the coil means. CONSTITUTION: An electromagnetic shielding gasket 210 has a garter-type axial- direction spring 212 with a plurality of coils 214 provided in an annular seal 216, and the annular seal supports the coil spring 212 with elasticity in the axial direction of a garter type without interference in a preselected direction and controls the elastic characteristic of the coil spring. Then, a large load is obtained by a winding angle, the number of coils per unit length is increased, using a thin wire and a stress generated at the seal is decreased when the load has been received, and at the same time the shielding effect of the gasket 210 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates generally to electromagnetic shielding devices, and more particularly to electrically conductive gaskets or seals, which resist the forces exerted on the gasket or seal. Rotating or reciprocating shafts or rotating and reciprocating shafts can be mounted so that no electromagnetic energy is transmitted or leaked through them, regardless of the

[Prior Art and Its Problems] Electronic devices are often used in restraint systems for power plants. In this regard, it becomes necessary to connect the mechanical power via the area where the microwaves are generated to the area which must be shielded from the microwaves.

Problems with unnecessary electromagnetic energy leakage and interference have long been recognized, and it will be readily appreciated that reciprocating or rotating shafts present unique electromagnetic shielding problems.

Traditionally, electromagnetic shielding for rotating/reciprocating shafts has been provided by conductive elastomer or braided cables (
It was formed by a braided cable). Electrically conductive elastomers provide some electromagnetic shielding, but undergo permanent set when loaded. That is, such elastomers deform when a load is applied, and then a change in load creates a gap or separation through which electromagnetic energy is transmitted.

The above problem becomes more pronounced when the gasket is exposed to periodic heat. The repeated heating and cooling applied to the gasket by movement of the shaft causes significant slack to form a gap through which electromagnetic energy passes.

Irregularities or surface deformation or wear of the shafts, housings, etc. on which the gaskets and the like are mounted may cause them to no longer come into close contact with each other, thereby creating certain electromagnetic shielding problems. Regarding the frequency of electromagnetic energy, commercial microwave bands are approximately 100 MHz to IGHz, and military microwave bands are IGHz to 300 GHz. The term electromagnetic energy as used herein is a generic term encompassing the entire spectrum of electromagnetic energy frequencies; the terms electromagnetic interference (EMI) and radio frequency interference (RF I) used below are interchangeable. , both terms refer to interference or interference caused by unwanted electromagnetic or radio frequency energy entering a particular piece of equipment. In general, the ability to shield electromagnetic energy from equipment is often referred to as shielding effectiveness.

[Technical problem to be solved by the invention] The most important factor in electromagnetic shielding is the frequency of electromagnetic energy, that is, its wavelength. It is known that total -C electromagnetic waves consist of two essential components: a magnetic field and an electric field. These two fields are perpendicular to each other and the direction of wave propagation is perpendicular to the plane containing these two elements. The relative strength between the magnetic field (formerly) and the electric field (E) depends on the distance of the wave from its source, and also on the properties of the wave's source. The ratio E/H is the wave impedance Z1 and Called.

It will therefore be appreciated that the shielding effectiveness for a particular gasket will vary depending on whether the electromagnetic energy is generated within the gasket or in equipment remote from the gas furnace.

If the source has a large current compared to the voltage, such as a ring line, transformer, or power line, then
It is called a current magnetic source or a low impedance source and has a small E/H value. Conversely, if the source operates at a high voltage and low current, the impedance of the source is high and the waves are commonly referred to as an electric field.

At a point very far from the source, the ratio E/H is the same for all waves, regardless of their direction. In this case, the wave is called a plane wave and the wave impedance is 377 ohms, which is the natural impedance of free space.

It is known that when the conductivity of a metal approaches infinity, its intrinsic impedance approaches zero. Due to the large difference between the intrinsic impedance of the metal and the intrinsic impedance of free space, waves from sources remote from the metal receptor are largely reflected by it and little passes through. Conversely, in the case of magnetic or low impedance fields where little energy is reflected, there is more absorption and shielding against the magnetic field is more difficult. Since magnetic shields do not have infinite conductivity, a portion of the field passes through a region corresponding to the thickness of the metal shield.

Another major factor in shielding effectiveness is the gaps that exist in the shield. A gap in the shield allows electromagnetic fields to radiate through the shield unless continuity of current across the gap is maintained. Therefore, the function of EMI is to maintain continuity of current within the shield.

Of course, the significance of the gap depends on the frequency of the impinging electromagnetic energy. For example, electromagnetic energy with a frequency of IGHz has a wavelength of approximately 29.5cm, and 100GHz
The electromagnetic energy of z has a wavelength of about 3111111 degrees. As a general rule, for effective shielding used commercially, the gap size should be 2 times the wavelength of the electromagnetic energy.
For avionics applications, the gap size should be less than 50 times smaller than the wavelength of the electromagnetic energy.
Must be smaller than 1/1.

Other factors that directly affect the size of the gap and therefore the shielding effectiveness are the surface finish of the gap parts to be sealed, and the ability to withstand changes in the surrounding environment with no or little change in conductivity due to corrosion cell action, etc. The ability of the shielding material to maintain dimensional stability against a constant load over the lifetime of the gasket provided between the assembled parts is unacceptable from the viewpoint of shielding effectiveness. It is important to prevent changes and gap gaps.

SUMMARY OF THE INVENTION The gasket shield of the present invention provides effective electromagnetic shielding by using a gradient coil type spring with closely spaced coils. The coil flexes under load to provide a substantially uniform force between cooperating points or surfaces, thereby providing high electrical conductivity and therefore high shielding effectiveness within a range of practical temperature and cycling conditions. The gasket shield of the present invention also provides sufficient flexibility to follow fluctuations caused by torque, eccentricity, irregularities, or other factors, while maintaining the desired load and low clearance area to provide Effective shielding can be achieved over very high frequencies.

The electromagnetic shield for a rotating/reciprocating shaft of the present invention comprises elastic coil spring means of the type for preventing the propagation of electromagnetic waves, the coil spring means comprising a plurality of individual coil means. , the coil means are such that the coil spring means prevent the propagation of electromagnetic waves independently of the compression of the coil spring means within the deflection of the individual coil means.

The individual coil means are also adapted to be inclined along their center line, and to determine the orientation of the trailing portion of each coil means with respect to a line perpendicular to said center line, and to It has back angle means for determining the deflection characteristics and front angle means for determining the orientation of the leading portion of each coil means with respect to said perpendicular line.

the front angle means is made larger than the back angle means;
The coil means are interconnected to form a garter type elastic coil spring.

Further, means are provided for supporting the garter type elastic coil spring between the shaft and a housing surrounding the shaft.
The garter type elastic coil spring means are connected to each other to form an axially or radially elastic coil spring, and a conductive elastomer is disposed within the garter type elastic coil spring means.

The means for supporting said garter-type elastic coil spring means may include a groove formed in the housing or shaft, and may further include an axial force on said garter-type elastic coil spring when a radial load is applied thereto. means for applying a load, thereby reducing the spacing between the coils and improving the electromagnetic shielding properties of the elastic coil spring. The axial loading means may be a groove with tapered walls for axially compressing the elastic coil spring when a radial load is applied by the shaft.

[Example] Referring to FIG. 1, there is shown an example of a load-deflection curve 10 for showing the characteristics of a diagonally wound elastic coil spring suitable for the electromagnetic shield of the present invention. .

As shown in FIG. 1, when a spring is loaded, the spring will move through the straight section 12 until it reaches a minimum at its load point 14.
It deflects in a substantially straight line as shown by . The load point minimum represents the point at which the load begins to be approximately constant after the initial deflection. For axially elastic garter-type springs described below, the load is applied in the axial direction, and for radially elastic garter-type springs described below, the load is applied radially. Note that the direction is added.

Between the minimum load point 14 and the maximum load point 16, the load -
The deflection curve is either constant or shows a slight increase as shown in FIG. The area between the minimum load point 14 and the maximum load point 16 is known as the service deflection area 18.

Seals, for both sealing and electromagnetic shielding purposes
In a typical spring used in conjunction with a gasket or the like, the spring is normally loaded within the area indicated by point 20. Loading the spring beyond the maximum load point 16 causes the spring to deflect rapidly until it reaches the abutment point 22, thereby creating a permanent set in the spring as a result of the overload. Also shown in FIG. 1 is the total deflection area 24, which may be defined as the deflection between the unloaded spring deflection and the deflection at the maximum load point 16.

2a and 2b show a circular welded spring 30 of the present invention. These drawings are oriented clockwise (arrow 3
Figure 4 shows a plurality of coils 32 wound around the coils 32, which are tilted clockwise along their centerlines 36. It will be appreciated that the spring can also have a coil angled counterclockwise along the centerline 36 of the spring.

Also, wind the spring counterclockwise (SeriesRF-
RF), the coil can also be tilted clockwise at a real angle on the inner diameter of the spring.

As shown more clearly in Figure 2b, each coil has a trailing section 4.
2 and a leading portion 40. The trailing section has a real angle of 48, which for each coil: 32
Determining the alignment of trailing portion 42 with respect to standard line 50 provides a means for determining the operating elastic range of spring 30, as will be explained in detail below.

The front angle 54 also provides a means for determining the alignment of the nose/10 of the coil 32 with respect to the standard line. .

The spring 30 has a trailing portion 42 that has an inner diameter 58 (second a) of the spring 30.
FIG. 4 and along the outer diameter 60 of the leading portion 40 and the spring 30 by interconnecting the coils 32 so as to form a garter-type coiled spring with some elasticity in the axial direction.

As shown most clearly in FIG. 2b, the spring 3 of the present invention
0 has a leading portion 40 that is always arranged at a forward angle 54 that is greater than the actual angle 48 that defines the trailing portion 42 .

That is, when the coil is wound in a circular shape about centerline 36, each turn has a trailing portion and a leading portion, the leading portion being larger than the trailing portion 42 of the coil 32 as it progresses along centerline 36. Proceed along center line 36. This definition of leading and trailing parts of the coil applies both in the case of clockwise or counterclockwise winding, and the leading part can be located on the outside or inside of the spring.

Figures 3a and 3b show a circular welded spring 6 of the present invention.
8 is shown. This spring 68 is shown in FIGS. 2a and 2b.
It has a physical diameter and wire size similar to the spring 30 shown and is wound clockwise (arrow 70
reference). In this regard, the spring 68 has a plurality of coils 72
, each coil having a leading portion 74 and a trailing portion 76 defined by a real angle 80 and a leading angle 82, respectively, as shown in Figure 3b. This coil can also be tilted clockwise along the centerline, but it is also possible to wind the spring counterclockwise (Series F) and tilt the coil counterclockwise at a real angle on the outer diameter of the spring. You will understand what you can do.

Similar to the spring 30, the coil 72 of the spring 68 is a garter-type coil spring 6 that is elastic in the axial direction with a leading portion along the inner diameter 68 and a trailing portion along the outer diameter 84 of the spring 68.
are connected to each other to form 8.

Curve A in FIG. 4 represents the characteristics of spring 68, and curve B represents spring 3.
0 characteristics. The two springs exhibit nearly identical load-deflection characteristics in their service deflection ranges, but the maximum load points have a variation of about 40%.

According to the invention, it has been found that it is possible to vary the actual angle between 1° and 35°, as long as the forward angle 54 is greater than the actual angle and its value is greater than 20' and less than 55°. . Changes in the actual angle of the spring have a significant effect on the elastic properties of the spring, which are independent of the front angle. This is illustrated in FIG. 5, which shows the load-deflection curves for springs C and D with the spring parameters shown in Table 1. It should be noted that the spring parameters mentioned here are presented only to show the effect of the actual spring angle and trailing arrangement. Actual spring parameters will depend on desired spring size, load and application.

Springs C and D are identical springs with identical wire diameters, spring inner diameters, and coil heights, and nearly identical front angles, but with different back corner polishing and corresponding coil spacing. ing.

As shown in FIG. 5, the working deflection of spring D is approximately 45%, while the working deflection of spring D is 50%. This is a matter independent of the anterior angle.

Therefore, using springs with the same wire diameter, internal diameter, and coil height, the force required to deflect the spring, which was previously possible only by varying the forward angle of the spring, can be reduced. Springs can be designed to have varying elastic properties.

Table 1 21.3 4.1 10.5 1.1 0.56 21.3 4.1 16, 25 0.81 Table 2 E O,4121,64,111,21F O
,4121,,64,12738G O,4121
, 6/1.1 34 450.41 0.41 As mentioned above, improved load-deflection characteristics can be effectively used in combination with unlunt or gasket materials, in which case the spring cavity is This spring cavity determines the inner diameter of the spring and the height of the coil.

If the spacing between the coils is kept constant, the actual angle and front angle can be varied to design a spring with elastic properties depending on the application. For example, decreasing the actual angle increases the force required to deflect the spring, as illustrated in FIG. 6, which shows the load-deflection curves for springs E, F, and G shown in Table 2. This allows the spring to be formed from small diameter wire and the coils to be closely spaced.

Conversely, increasing the actual angle will increase the service deflection if the coil spacing is held constant.

Characteristics 1 are important and make the coil springs of the present invention effective as electromagnetic shielding gaskets, either by themselves or in combination with conductive elastomers as described below.

Referring to FIGS. 7a and 7b, a circular clockwise welded spring 100 of the present invention is shown having a plurality of coils 102 that extend along its centerline 104. is tilted counterclockwise along the line.

As shown in more detail in Figure 7b, each coil 1
02 has a trailing part 110 and a leading part 108,
The trailing portion is a standard line 114 of the trailing portion 110 of each coil 102.
the actual angle 112 which provides a means for determining the orientation relative to the
have.

Front angle 116 also provides a means for determining the orientation of leading portion 108 of coil 102 with respect to standard line 114 .

The spring 100 has a trailing portion 110 having an outer diameter 120 of the spring 100.
(See Figure 7a) Also along the leading portion 108 and the spring 100
The coils 102 are interconnected to form a garter-type coil spring that is elastic in the axial direction along the inner diameter 122 of the coil spring.

As shown most clearly in FIG. 7b, the spring 1 of the present invention
00 has a leading portion 108 that is always arranged at a forward angle 116 that is greater than the actual angle 112 that defines the trailing portion 110. That is, when the coil is wound circularly about centerline 104 , each turn has a trailing section 110 and a leading section 108 , where the leading section follows the trailing section 110 of coil 102 rather than along centerline 104 . Larger center line 10
Proceed along 4.

As mentioned above, the inner full-angle coil spring 30 of FIG. 2a has similar general load-deflection characteristics as the outer full-angle coil spring 68 of FIG. 3a; , the specific load-deflection characteristics of each spring are different. For example, an inside back angle slanted coil spring 30 having the same wire size and dimensions as an outside back angle slanted coil spring 68 is similar to an outside back angle slanted coil spring (FIG. 1). It has a lower maximum load point (curve A in FIG. 1) than curve B).

Referring to FIG. 8, the electromagnetic shielding gasket 21 of the present invention
0 is shown, and this gasket has an annular seal 21
6 includes a garter-type axial spring 212 having a plurality of coils 214 disposed in the coils 214 . The annular seal non-interferentially supports the garter-type axially elastic coil spring 212 in a preselected orientation to control the elastic properties of the coil spring, as will be described in detail below. Although the gasket 210 can be made of plastic, plastic alone cannot provide electromagnetic shielding capability without the use of a metal filter, which is preferably used. Conversely, the electromagnetic shielding ability can be enhanced by forming the gasket from a suitable metal material.

FIG. 9 shows, for comparison purposes, load-deflection curves A illustrating the characteristics of springs 30 and 100, which will be described below. A load-deflection curve B is also shown to illustrate the characteristics of the spring.

The load-deflection curve B shows the spring 2 formed according to the invention.
12, and a linear load-deflection portion 236 is shown until a peak load point 238 is reached. In the section 240 after the peak load point 238,
The load decreases with deflection. This creates a saddle-shaped deflection area between peak load point 238 and butt point 242.

This type of load-deflection characteristic has a special effect on electromagnetic spring seals, where the tension created by the spring locks the seal in place within a groove or the like. In this regard, the spring produces a relatively constant load over a predetermined use deflection area 244, but exhibits a sharp increase in load beyond the use area limit at points 246,248. This results in self-centering in the spring knoll grooves, etc.

FIG. 10 schematically shows a cross section of the diagonal coil spring of the present invention, and this coil spring 212 has the coil springs 11a, b, and c.
, as shown in figure d, the winding angle θ, the measured coil width CW,
It has a measuring coil height CH and a measuring spring height H.

The winding angle can be clockwise (indicated by the solid line) or counterclockwise (indicated by the dashed line).

As shown in FIG. 11c, the axially flat spring 212 can be wound counterclockwise at 30°, for example as in FIG. 11b, and as in FIGS. It can be wound clockwise with winding angles of 30° and 60°, respectively. Although the spring is shown as circular, it may have other shapes, such as elliptical or rectangular, depending on the shape of the cooperating component into which spring 212 or seal 216 is inserted.

As shown, the winding angle θ is defined as the angle formed by a substantially circular spring that forms a conical or inverted conical shape depending on the position of the spring, and the angle θ is measured from the horizontal to the center of the valley cone or inverted cone. It is measured as the angle between the lines of intersection passing through the lines. By varying the winding angle θ, different loads can be obtained and the extent of the load depends on the winding angle θ. That is, as explained below, as the winding angle θ increases, the generated load increases. The force produced by the load is unaffected by whether the spring has a conical shape as shown in FIG. 11b or an inverted conical shape as shown in FIG. 11d. That is, the springs in FIG. 11b and FIG. 1id exhibit the same behavior.

Curves A, B, C, and D in Figure 12 have angles θ of 0.
Figure 3 shows the load-deflection characteristics of a series of springs varying from 90° to 90° and having the spring specifications listed in Table 3. Each spring A, B, C and D has the same requirements except for the winding angle θ.

Curve A in FIG. 12 represents a spring 212 with a wrap angle of 00, which would represent a spring 30 or 100. Curve B shows a spring 212 with a winding angle of 15° and shows the critical rise 268 of a spring formed according to the invention.
It clearly shows the characteristics of This gradual rise or peak load characteristic is more clearly illustrated by curves CD and E corresponding to springs C, D and E in Table 3.

As shown in FIG. 12, as the winding angle θ increases, the load reaches its maximum value at about 90°. The important point is that after the peak loads shown at 270, 272, and 274, respectively, the force drops rapidly to near the forces shown by springs A and B. Therefore, these springs have an area of use between the unwound spring A and the road 276, 278, 28.
0, but these areas of use are demarcated by abrupt load-deflection characteristics, as shown in FIG. The spring of the present invention has advantages in a variety of applications as described above. As mentioned above, although the illustrated spring is generally circular in shape, other shapes can be used for other applications. That is, the spring can be easily processed into shapes other than a circle.

Front spring winding angle (0) Peak load value (Kg) Increase over standard load (%) As shown in Figure 3, the peak load is sufficiently larger than the standard load, and in fact, if the winding angle is 90', it will be 1725. %
has reached. In this way, high loads can be obtained by using the winding angle. Ultimately, as mentioned above, by using thinner wire and increasing the number of coils per unit length, the stress on the seal under load is reduced.
In addition, the shielding effect of the gasket 210 can be enhanced.

Also, as pointed out above, curves CD and E in FIG.
The spring of the present invention, which exhibits a Kerr deflection curve as shown by curve A in FIG. be able to.

Referring now to FIG. 13, an electromagnetic shielding gasket 310 having a radially resilient coil spring 312 of the present invention is shown. The radially elastic spring 312 has a plurality of coils 314 disposed within an annular seal, the annular seal being of a radially elastic garter type, as described in detail below. The coil spring 312 is non-interferentially supported in a preselected orientation to provide a means for controlling the elastic properties of the spring. Spring 3
The load-deflection curve for 12 is shown in FIG.

The load-deflection characteristics can be determined using a test jig 330 shown in FIG. A radially resilient spring 332 is retained within the housing by a fixture 336, which constrains the spring 332 within a cavity 338. Splash 3 using circumferential spacer 340
The outer circumference of 32 is loaded, and the plug 342 is connected to the spring 332.
Measure the force required to pass it through the inner circumference of the

The spring 312 having elasticity in the radial direction is, for example, a first
At 30' as shown in Figure 1b, No. 11a.

It is oriented counter-clockwise as shown in Figures b, c and d, but alternatively it can be oriented clockwise, for example with a winding angle of 30' or 60' as shown in Figures 11d or 11e, respectively. Although the spring is shown as circular in shape, it will be appreciated that it may have other shapes, such as an elliptical or rectangular shape, depending on the shape of the cooperating component into which the spring 312 or seal 316 is inserted.

As shown, the winding angle θ is defined as the angle formed by a substantially circular spring that forms a conical or inverted cone depending on the position of the spring, and the angle θ is measured from the horizontal to the center of each cone or inverted cone. It is measured as the angle between the lines of intersection passing through the lines. By changing the winding angle θ, a load of W can be obtained, and the degree of the load depends on the winding angle θ. That is, as explained below, as the winding angle θ increases, the generated force increases. The force produced by the load is not affected by whether the spring has a conical shape as shown in Figure 11b or an inverted conical shape as shown in Figure 1id.

That is, the springs in FIG. 11b and FIG. 1id exhibit the same behavior.

Spring 312 also has a trailing portion defined by the back angle mentioned above and a leading portion defined by the front angle.

When a load is applied to the spring 312 in the radial direction, the winding angle becomes Oo.
A larger load is exhibited when the winding angle is 90° than in the case of Oo, and such a load gradually increases from Oo to 90°. Also, a spring 312 with a back angle or trailing portion along the outer diameter of the spring will have a significantly greater force than a spring with the same wrap angle but with a back angle or trailing portion along the inner diameter of the spring. 1°, which allows for great compatibility. That is, a larger range of wire sizes and coil spacings can be used to produce forces responsive to the same or larger deflections. This is particularly advantageous when the spring is combined with a 7-hole for electromagnetic shielding, as described above.

With respect to the various canted coil springs described above that are suitable for use as electromagnetic shields, reference is now made to FIG.
A typical application example of a spring shield 400 provided between As shown in FIG.
0 has elasticity in the radial direction as described above.

Another example of a shield is shown in FIG. 16, in which a spring 410 is filled with a conductive elastomer 412 and is provided by a groove 418 between a shaft 414 and a housing 416.

A further embodiment of the invention is shown in FIG. 17, in which a spring shield 4 with radial elasticity
20 is the shaft 422 and housing 4 by g426
24.

FIG. 18 shows a spring 430 having elasticity in the axial direction, which is an embodiment of the pond of the present invention, and this spring has the following characteristics:
It is located in a sloped skin 436 between shaft 432 and housing 434 . The slope of the groove is determined by the spring 43.
0 produces an axial loading of the spring 430 when loaded radially between the shaft 432 and the bottom of the groove.
It has an angle θ of about 0° to 5°.

FIG. 19 shows yet another embodiment of the invention in which an axial spring 440 is attached to a shaft 440.
2 and housing 444, the spring shield 440 has a wrap angle γ as previously described in connection with the spring characteristics of springs suitable for use in the present invention.

Microwave shielding is achieved by flexing the coils radially or axially so that they almost abut, and minimizing the space or open area between them due to eccentricity and tolerance variations. .

Figure 20a is a top view of the spring in an unloaded state, and Figure 20b is a top view of the spring with both axial and radial loads exhibiting axial and radial deflection 462. It is a diagram. As shown in Figure 20b,
The coil is compressed to its near abutting condition and is provided between the shaft 432 and the housing 434 to enhance electromagnetic and spring shielding capabilities under load.

The springs of the present invention can be coated with an elastomer to increase their electrical conductivity, including, for example, copper particles or other electrically conductive metallic materials. The springs of the present invention can also be plated or coated with soft metals, such as tin, gold or silver, to increase electrical conductivity. The springs themselves can be formed from beryllium copper for high conductivity, or from stainless steel or monel alloys as specific examples.

Although specific electromagnetic shields of the present invention have been described above to illustrate modes of effective use of the present invention, the present invention is not limited to these specific embodiments. It is understood that any changes, modifications or equivalent constructions to these embodiments that can be made by those skilled in the art are within the scope of the present invention.

[Brief explanation of drawings]

FIG. 1 is a graph showing load-deflection curves showing various parameters of the elastic coil spring of the present invention, where curve A has a real angle on the inside of the spring, and curve B has a real angle on the outside of the spring. This shows the case where the Figures 2a and b are top and side views, respectively, of a clockwise wound circular welded spring (SeriesRF-RF) according to the invention, which spring defines a trailing section along the inner diameter of the spring; and a leading angle defining a leading portion along the outer diameter of the spring. Figures 3a and b are top and side views, respectively, of a clockwise wound circular spring according to the present invention having the same physical dimensions as the spring shown in Figures 2a and b;
The spring has a real angle defining a trailing portion along the outer diameter of the spring and a leading angle defining a leading portion along the inner diameter of the spring. FIG. 4 is a graph showing the load-deflection curve of the spring shown in FIGS. 2 and 3. FIG. FIG. 5 is a graph showing load-deflection curves for various springs subjected to axial loading having a trailing portion along the inner diameter (5eries RF-RF) and having the spring dimensions shown in Table 1. FIG. 6 is a graph showing load-deflection curves for axial springs with different actual angles. FIGS. 7a and 7b are top and side views, respectively, of a clockwise wound circular welded spring according to the invention, which spring has a forward angle along the inner diameter of the spring and an outer diameter of the spring; It has a real angle along. FIG. 8 is a perspective view of an electromagnetic shielding gasket of the present invention having an annular coil of axial elasticity, which gaskets are interconnected to form a garter-type axially elastic coil spring; a plurality of coils arranged as an annular seal with preselected winding angles to control its elastic properties; independent action, thereby providing a preselected concentration of force on the sealing portion of the seal. FIG. 9 is a graph illustrating load-deflection curves for springs formed in accordance with the present invention. FIG. 10 is a diagram schematically showing an axially inclined coil spring with a winding angle θ and explains how the winding angle θ is calculated. Figures 11a, b, c, d and e show axial springs with different winding angles. FIG. 12 is a graph showing load-deflection curves for axially elastic annular coil springs having different winding angles. FIG. 13 is a perspective view of an electromagnetic shielding gasket of the present invention having radially loaded coil spring knolls interconnected to form a radially elastic angled coil spring; a plurality of coils arranged as an annular seal with preselected winding angles to control its elastic properties; independent action, thereby providing a preselected concentration of force on the sealing portion of the seal. FIG. 14 is a sectional view showing a test jig for determining load-deflection characteristics. FIG. 15 is a cross-sectional view of an electromagnetic shielding radial spring provided between a shaft and a grooved housing. FIG. 16 is a cross-sectional view of another embodiment of the electromagnetically shielded radial spring of the present invention, showing the spring being filled with an electrically conductive elastomer. FIG. 1.gamma. is a sectional view of an embodiment of the song according to the present invention, showing a state in which a shield is provided in the groove of the noyaft. FIG. 18 is a cross-sectional view of an embodiment of the present invention, in which an electromagnetic shielding axial spring is provided in a tapered skin to allow the spring to be axially compressed by a radial load. It shows. FIG. 19 is a cross-sectional view of another embodiment of the invention, showing a shield spring with a winding angle installed in a groove in the housing. Figures 20a, b and c are cross-sectional views of the spring shield in an unloaded condition with axial loading and axial and radial loading alignment. [Explanation of main symbols] 48, 80.112 Back angle means, 50, 114
: Right angle line, 54, 82.116 : Front angle means, 84, 120
Outer diameter, 86, 122: Inner diameter, 402, 414.422.432.442 revolutions/'
Reciprocating noyaft, 404, 416.434.444
Housing, 406.418.436.446:
ft. 412: conductive elastomer,

Claims (10)

[Claims] 1. Rotating/reciprocating shaft (402, 414, 422,
432, 442), comprising garter-type elastic coil spring means (30, 68, 100, 212, 312,
322, 400, 410, 420, 430, 440), and the coil spring means (30, 68, 100, 212
,312,322,400,410,420,430,
440) comprises a plurality of individual coil means (32, 72, 1
02,214,314), and these coil means are:
Individual coil means (32, 72, 102, 214, 31
4) within the range of deflection of said coil spring means (3).
0,68,100,212,312,322,400,
410, 420, 430, 440), the coil spring means are adapted to prevent the propagation of electromagnetic waves, and the individual coil means (32, 72, 102, 2
14, 314) are made to be inclined along their center lines (36, 104) and each coil means (3
2,72,102,214,314) subsequent part (42,
determining the orientation of the coil spring means (30, 68, 100, 212, 312, 322, 400, 41
0,420,430,440) for determining force-deflection characteristics (48,80,112), and each coil means (32,72,102,214,314)
The perpendicular line (50
, 114) and a front angle means (5) larger than the back angle means (48, 80, 112).
4, 82, 116), and the coil means (32, 72, 102, 214, 314).
) is a garter type elastic coil spring (68,100)
The outer diameter (84, 100) of a garter type coil spring (68, 100) is
20) and the leading portion (74, 108) is along the inner diameter (86, 122) of the garter type elastic coil spring or the opposite (spring 30); The elastic coil springs (400, 410, 430, 440) are connected to the shaft (40
2,414,422,432,442) and the shaft (
402, 414, 422, 432, 442) and a housing (404, 416, 434, 444) surrounding the electromagnetic shield. 2. Electromagnetic shield according to claim 1, characterized in that the coil means (32, 72, 102, 214, 314) are interconnected to form an axially elastic coil spring. 3. Electromagnetic shield according to claim 1, characterized in that the coil means (32, 72, 102, 214, 314) are connected to each other so as to form a radially elastic coil spring. 4. Electromagnetic shield according to any one of claims 1 to 3, further comprising an electrically conductive elastomer (412) provided within said garter-type elastic coil spring means (410). 5. In any one of claims 1 to 4, the garter type elastic coil spring (400, 410, 430, 44
means for supporting said housing (404)
, 416, 434, 444) provided in the groove (406,
418, 436, 446). 6. Electromagnetic shield according to any one of claims 1 to 4, characterized in that the means for supporting the garter-type elastic coil spring (420) comprises a groove (426) provided in the shaft (422). 7. In claim 5 or 6, when a radial load is applied to the garter type elastic coil spring (400, 410, 430, 440), an axial load is generated on the elastic coil spring, thereby reducing the coil spacing. An electromagnetic shield further comprising means for enhancing the electromagnetic shielding characteristics of the elastic coil spring. 8. According to claim 7, the elastic coil spring (430)
An electromagnetic shield characterized in that the means for producing an axial load comprises means for tapering the walls of the groove and thereby compressing said elastic coil spring (430) in the axial direction. 9. According to claim 8, said individual coil means are adapted to be compressed into substantially abutting relation by said tapered groove wall when said resilient coil spring (430) is subjected to a radial load. An electromagnetic shield characterized by: 10. According to any of claims 1 to 9, said back angle means (48, 80, 112) is greater than about 1° and less than about 40°, and said front angle means is about 15°.
An electromagnetic shield characterized in that the angle is larger than 55° and smaller than about 55°.