US3890033A - Adjustable-spring attenuator for radiated beams - Google Patents

Adjustable-spring attenuator for radiated beams Download PDF

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US3890033A
US3890033A US441991A US44199174A US3890033A US 3890033 A US3890033 A US 3890033A US 441991 A US441991 A US 441991A US 44199174 A US44199174 A US 44199174A US 3890033 A US3890033 A US 3890033A
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spring
coil spring
cylindrical
coil
helical
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US441991A
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Kevin Mcgee
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Rolls Royce Power Engineering PLC
Sir Howard Grubb Parsons and Co Ltd
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Sir Howard Grubb Parsons and Co Ltd
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G21K1/10—Scattering devices; Absorbing devices; Ionising radiation filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
    • G01J1/20—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle
    • G01J1/22—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means
    • G01J1/24—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void intensity of the measured or reference value being varied to equalise their effects at the detectors, e.g. by varying incidence angle using a variable element in the light-path, e.g. filter, polarising means using electric radiation detectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/02—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the intensity of light

Definitions

  • a variable attenuator for use in a radiation beam path comprising at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiation beam path in which it is placed to a greater or lesser degree, there being further provided control means for providing gradual variation in the physical form of the element.
  • This invention relates to attenuators for radiation beams such as optical beams.
  • Attenuators for instruments such as gas analysers. for example. have generally involved the use of wedge combs or shutters placed in the optical beam. calling for carriages and guides manufactured to a high degree of accuracy.
  • Previously known precision attenuators have. therefore, tended to be costly and somewhat complex.
  • the object of the present invention is to provide a variable attenuator for the purpose described which. whilst capable of precise adjustment. is both of simple construction and inexpensive.
  • a variable attenuator for use in a radiation beam path comprises at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiation beam path in which it is placed to a greater or lesser degree.
  • control means for producing gradual variation in the physical form ofthe element.
  • a variable attenuator includes a helical coil spring which is placed in the beam path to be attenuated, the coil density of the spring in the beam path being controllable by means of a spring take-up arrangement which may be automatically or hand-operated.
  • the spring is prefera bly placed across the full height or full width of the beam to be attenuated and variation of the spring coil density alters the number of turns met by the beam thus altering the degree of obscuration.
  • the spring may be a compression spring but is preferably an extension spring continuously under tension for all settings of the attenuator. It is also possible. however, to use a coil spring varying between compression and extension over the operating range of the attenuator.
  • FIG. 1 shows a simple perspective view of an optical beam path attenuator according to the present inven tion.
  • FIG. 2 shows a sectional front elevation of a spring take-up arrangement of the attenuator shown in FIG. 1, and
  • FIG. 3 shows a side elevation of the spring take-up arrangement shown in FIGS. I and 2.
  • the attenuator shown comprises a spring wire coil 1 supported by a bracket 2 such that several of the spring coils may interrupt a light beam indicated by arrow A.
  • I'he coil I is fixed at its lower end to bracket 2 by screws 3. the upper end of the coil being arranged to wind onto the cylinder 4 of a coil take-up arrangement.
  • the latter arrangement comprises. in addition to cylinder 4,11 knurled operating knob S, a shaft 6 and a transverse pin 7, in fixed relationship to one another and arranged to rotate together by means of the shaft 6 being mounted in a hole in an end wall at the top of cylinder 4.
  • the extreme upper end of the coil is fixed between the cylinder 4 and the bracket 2, cylinder 4 being rigidly held by the bracket.
  • the arrangement shown enables the number of turns of coil 1 passing through a fixed beam area. or path. to be varied by turning the knob 5 and thus taking up a greater or lesser number of the coil turns on to cylinder 4.
  • the attenuator described in addition to being generally mechanically simple and robust. is particularly suitable for use in locations subject to vibration since. al though the coil may vibrate in such circumstances. the overall attenuating effect of the coil remains constant to a surprisingly high degree.
  • the invention is not limited to the use of coil springs as attenuating elements.
  • Alternative forms may comprise, for example, a plurality of elements of leaf-spring shape, or a deformable strip of zig-zag configuration.
  • a further possible embodiment may employ a body of material capable of transmitting radiation. the change in form of the body being arranged to alter the path length of radiation through the body, and thus vary the attenuation of the beam.
  • the invention is not limited to attenuators for optical beams but may also be applied to attenuators for alternative forms of radiation. for example. infra-red radiation.
  • a variable attenuator for use in a radiated beam path comprising at least one obturating element which element is capable of varying its physical form. whereby according to the degree of such variation the element may of itself, or in combination with other ele ments, attenuate a radiated beam path in which it is placed to a greater or lesser degree; and control means operatively connected to said obturating element for providing gradual variation in the physical form of the element, said obturating element comprising an elongated.
  • cylindrical helical coil spring for location with the longitudinal axis of the coil spring normal to the beam path being attenuated.
  • the coil density of the spring in the beam path being substantially infinitely controllable within the physical distortion limits of the 3 cylindrical, helical coil spring, the spring defining a cyl inder in elevation for disposition across the full height or width of the beam to be attenuated and variations of the spring coil density causing an alteration in the number of turns of the spring met by the beam and thus altering the degree of the obscuration.
  • said coil spring heing fixedly anchored at one end. and said control means comprising a cylinder element connected axially to the other end ofthe coil spring. said coil spring being continuously under stress.
  • a variable attenuator for use in combination with a radiated beam for adjustahly-attenuating the beam path in relation to the physical extension or detention of an ohturating element comprising:
  • support means having spaced portions defining the general area for which a radiated beam to be attenuated will pass; at least one. elongated, axially-deformable ohturating element anchored between said support portions in intercepting relation to said area through which the beam will pass; and means for adjusting the axial length of said obturating element axially between said spaced support portions.
  • said obturating element comprising a cylindrical, helical coil spring continuously stressed be tween said space support portions during all positions of adjustment.
  • variable attenuator as claimed in claim 2 in which said cylindrical. helical coil spring is terminally anchored at one end on one support portion, said other support portion including a cylindrical drum telescopically and fixedly connected to the other end of said helical coil spring whereby axial extension and detention of said coil spring uniformly changes the shape of each of the helical coils and the diameter of the cylindrical coil as well as the distance between adjacent helical coils of the spring.
  • variable attenuator as claimed in claim 3 in which said cylindrical drum is journaled in said other support portion and is rotatably adjustahly mounted thereon, means for rotating the cylindrical drum and the cylindrical coil spring for imposing torque along the longitudinal axis of the cylindrical coil spring and adjustahly winding the helical coils of the coil spring into an adjusted obturating relationship normal to the path of the radiated beam being attenuated.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Optics & Photonics (AREA)
  • Springs (AREA)

Abstract

A variable attenuator for use in a radiation beam path comprising at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiation beam path in which it is placed to a greater or lesser degree, there being further provided control means for providing gradual variation in the physical form of the element.

Description

United States Patent [1 1 McGee ADJUSTABLE-SPRING ATTENUATOR FOR RADIATED BEAMS [75] Inventor: KevinMcGee,Newcastle-upon- Tyne, England [73] Assignee: Sir Howard Grubb Parsons 8L Co..
Limited, Newcastle-upon-Tyne, England [22] Filed: Feb. 13, 1974 [21] Appl. No.: 441,991
[30] Foreign Application Priority Data Feb. 13, I973 United Kingdom 6961/73 [52] US. Cl. 350/266; 350/270; 350/27l [51] Int. Cl. G02f 1/28 [58] Field of Search 350/266, 267, 269, 270,
350/27l; 356/225; 313/l l7; 250/229 [56] References Cited UNlTED STATES PATENTS 3,447,862 6/l969 Elpern 350/266 June 17, 1975 3.610.740 l0/l97l 3.756700 9/l973 Aparicin 350/278 Saxe 350/267 Primary Examiner-Vincent P. McGraw Attorney, Agent, or Firm--Holman & Stern 5 7 1 ABSTRACT A variable attenuator for use in a radiation beam path comprising at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiation beam path in which it is placed to a greater or lesser degree, there being further provided control means for providing gradual variation in the physical form of the element.
4 Claims, 3 Drawing Figures ADJUSTABLE-SPRING ATTENUATOR FOR RADIATEI) BEAMS FIELD OF THE INVENTION This invention relates to attenuators for radiation beams such as optical beams.
BACKGROUND OF THE INVENTION Many optical instruments require attenuating det ices capable of giving precise control ofvarying attenuation of an optical beam path. Attenuators for instruments such as gas analysers. for example. have generally involved the use of wedge combs or shutters placed in the optical beam. calling for carriages and guides manufactured to a high degree of accuracy. Previously known precision attenuators have. therefore, tended to be costly and somewhat complex.
SUMMARY OF THE INVENTION The object of the present invention is to provide a variable attenuator for the purpose described which. whilst capable of precise adjustment. is both of simple construction and inexpensive.
According to the present invention a variable attenuator for use in a radiation beam path comprises at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiation beam path in which it is placed to a greater or lesser degree. there being further provided control means for producing gradual variation in the physical form ofthe element.
In the preferred form of the invention, a variable attenuator includes a helical coil spring which is placed in the beam path to be attenuated, the coil density of the spring in the beam path being controllable by means of a spring take-up arrangement which may be automatically or hand-operated. The spring is prefera bly placed across the full height or full width of the beam to be attenuated and variation of the spring coil density alters the number of turns met by the beam thus altering the degree of obscuration.
The spring may be a compression spring but is preferably an extension spring continuously under tension for all settings of the attenuator. It is also possible. however, to use a coil spring varying between compression and extension over the operating range of the attenuator.
One embodiment of the invention will now be de scribed with reference to the accompanying drawing in which:
DESCRIPTION OF THE DRAWING FIG. 1 shows a simple perspective view of an optical beam path attenuator according to the present inven tion.
FIG. 2 shows a sectional front elevation of a spring take-up arrangement of the attenuator shown in FIG. 1, and
FIG. 3 shows a side elevation of the spring take-up arrangement shown in FIGS. I and 2.
DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing. the attenuator shown comprises a spring wire coil 1 supported by a bracket 2 such that several of the spring coils may interrupt a light beam indicated by arrow A.
I'he coil I is fixed at its lower end to bracket 2 by screws 3. the upper end of the coil being arranged to wind onto the cylinder 4 of a coil take-up arrangement. The latter arrangement comprises. in addition to cylinder 4,11 knurled operating knob S, a shaft 6 and a transverse pin 7, in fixed relationship to one another and arranged to rotate together by means of the shaft 6 being mounted in a hole in an end wall at the top of cylinder 4. The extreme upper end of the coil is fixed between the cylinder 4 and the bracket 2, cylinder 4 being rigidly held by the bracket.
The arrangement shown enables the number of turns of coil 1 passing through a fixed beam area. or path. to be varied by turning the knob 5 and thus taking up a greater or lesser number of the coil turns on to cylinder 4.
Typical dimensions for the attenuator shown are as follows:
25 X 40 mm rectangle.
Beam palch' si/e:
S i r approxlniately.
12 thousandths of an inch.
The attenuator described. in addition to being generally mechanically simple and robust. is particularly suitable for use in locations subject to vibration since. al though the coil may vibrate in such circumstances. the overall attenuating effect of the coil remains constant to a surprisingly high degree.
The invention is not limited to the use of coil springs as attenuating elements. Alternative forms may comprise, for example, a plurality of elements of leaf-spring shape, or a deformable strip of zig-zag configuration. A further possible embodiment may employ a body of material capable of transmitting radiation. the change in form of the body being arranged to alter the path length of radiation through the body, and thus vary the attenuation of the beam.
It will be appreciated that the invention is not limited to attenuators for optical beams but may also be applied to attenuators for alternative forms of radiation. for example. infra-red radiation.
I claim:
I. A variable attenuator for use in a radiated beam path comprising at least one obturating element which element is capable of varying its physical form. whereby according to the degree of such variation the element may of itself, or in combination with other ele ments, attenuate a radiated beam path in which it is placed to a greater or lesser degree; and control means operatively connected to said obturating element for providing gradual variation in the physical form of the element, said obturating element comprising an elongated. cylindrical helical coil spring for location with the longitudinal axis of the coil spring normal to the beam path being attenuated. the coil density of the spring in the beam path being substantially infinitely controllable within the physical distortion limits of the 3 cylindrical, helical coil spring, the spring defining a cyl inder in elevation for disposition across the full height or width of the beam to be attenuated and variations of the spring coil density causing an alteration in the number of turns of the spring met by the beam and thus altering the degree of the obscuration. said coil spring heing fixedly anchored at one end. and said control means comprising a cylinder element connected axially to the other end ofthe coil spring. said coil spring being continuously under stress. and means for adjustahly rotating the cylinder to impose torque on the individual helical coils of the spring for altering the diameter of the cylindrical coil and the spacing between adjacent helical coils of the springv 2. A variable attenuator for use in combination with a radiated beam for adjustahly-attenuating the beam path in relation to the physical extension or detention of an ohturating element comprising:
support means having spaced portions defining the general area for which a radiated beam to be attenuated will pass; at least one. elongated, axially-deformable ohturating element anchored between said support portions in intercepting relation to said area through which the beam will pass; and means for adjusting the axial length of said obturating element axially between said spaced support portions. said obturating element comprising a cylindrical, helical coil spring continuously stressed be tween said space support portions during all positions of adjustment.
3. The variable attenuator as claimed in claim 2 in which said cylindrical. helical coil spring is terminally anchored at one end on one support portion, said other support portion including a cylindrical drum telescopically and fixedly connected to the other end of said helical coil spring whereby axial extension and detention of said coil spring uniformly changes the shape of each of the helical coils and the diameter of the cylindrical coil as well as the distance between adjacent helical coils of the spring.
4. The variable attenuator as claimed in claim 3 in which said cylindrical drum is journaled in said other support portion and is rotatably adjustahly mounted thereon, means for rotating the cylindrical drum and the cylindrical coil spring for imposing torque along the longitudinal axis of the cylindrical coil spring and adjustahly winding the helical coils of the coil spring into an adjusted obturating relationship normal to the path of the radiated beam being attenuated.

Claims (4)

1. A variable attenuator for use in a radiated beam path comprising at least one obturating element which element is capable of varying its physical form, whereby according to the degree of such variation the element may of itself, or in combination with other elements, attenuate a radiated beam path in which it is placed to a greater or lesser degree; and control means operatively connected to said obturating element for providing gradual variation in the physical form of the element, said obturating element comprising an elongated, cylindrical helical coil spring for location with the longitudinal axis of the coil spring normal to the beam path being attenuated, the coil density of the spring in the beam path being substantially infinitely controllable within the physical distortion limits of the cylindrical, helical coil spring, the spring defining a cylinder in elevation for disposition across the full height or width of the beam to be attenuated and variations of the spring coil density causing an alteration in the number of turns of the spring met by the beam and thus altering the degree of the obscuration, said coil spring being fixedly anchored at one end, and said control means comprising a cylinder element connected axially to the other end of the coil spring, said coil spring being continuously under stress, and means for adjustably rotating the cylinder to impose torque on the individual helical coils of the spring for altering the diameter of the cylindrical coil and the spacing between adjacent helical coils of the spring.
2. A variable attenuator for use in combination with a radiated beam for adjustably-attenuating the beam path in relation to the physical extension or detention of an obturating element comprising: support means having spaced portions defining the general area for which a radiated beam to be attenuated will pass; at least one, elongated, axially-deformable obturating element anchored betWeen said support portions in intercepting relation to said area through which the beam will pass; and means for adjusting the axial length of said obturating element axially between said spaced support portions, said obturating element comprising a cylindrical, helical coil spring continuously stressed between said space support portions during all positions of adjustment.
3. The variable attenuator as claimed in claim 2 in which said cylindrical, helical coil spring is terminally anchored at one end on one support portion, said other support portion including a cylindrical drum telescopically and fixedly connected to the other end of said helical coil spring whereby axial extension and detention of said coil spring uniformly changes the shape of each of the helical coils and the diameter of the cylindrical coil as well as the distance between adjacent helical coils of the spring.
4. The variable attenuator as claimed in claim 3 in which said cylindrical drum is journaled in said other support portion and is rotatably adjustably mounted thereon, means for rotating the cylindrical drum and the cylindrical coil spring for imposing torque along the longitudinal axis of the cylindrical coil spring and adjustably winding the helical coils of the coil spring into an adjusted obturating relationship normal to the path of the radiated beam being attenuated.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4070681A (en) * 1975-02-07 1978-01-24 Canon Kabushiki Kaisha Modulated laser
US6997584B1 (en) * 2002-12-12 2006-02-14 Russell Rothan Bicycle lamp
US20070206901A1 (en) * 2006-03-02 2007-09-06 Bonitatibus Michael H Sunlight simulator apparatus
US7928859B1 (en) 2008-11-21 2011-04-19 Yazaki North America, Inc. Full angle laser illuminate instrument cluster
US7954965B1 (en) 2009-04-13 2011-06-07 Yazaki North America, Inc. Method for multiple gauges in a scanning laser based display device
US8026827B1 (en) 2009-05-04 2011-09-27 Yazaki North America, Inc. Virtual push button switch

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3447862A (en) * 1966-08-19 1969-06-03 Marlin Elpern Light valve system
US3610740A (en) * 1968-10-07 1971-10-05 Luis R Aparicio Variable light filters
US3756700A (en) * 1972-02-09 1973-09-04 Research Frontiers Inc Method and apparatus for increasing optical density ratios of light valves

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3447862A (en) * 1966-08-19 1969-06-03 Marlin Elpern Light valve system
US3610740A (en) * 1968-10-07 1971-10-05 Luis R Aparicio Variable light filters
US3756700A (en) * 1972-02-09 1973-09-04 Research Frontiers Inc Method and apparatus for increasing optical density ratios of light valves

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4070681A (en) * 1975-02-07 1978-01-24 Canon Kabushiki Kaisha Modulated laser
US6997584B1 (en) * 2002-12-12 2006-02-14 Russell Rothan Bicycle lamp
US20070206901A1 (en) * 2006-03-02 2007-09-06 Bonitatibus Michael H Sunlight simulator apparatus
WO2007103019A3 (en) * 2006-03-02 2008-05-02 Solar Light Company Inc Sunlight simulator apparatus
US7657147B2 (en) 2006-03-02 2010-02-02 Solar Light Company, Inc. Sunlight simulator apparatus
US20100158468A1 (en) * 2006-03-02 2010-06-24 Bonitatibus Michael H Sunlight Simulator Apparatus
US8571374B2 (en) 2006-03-02 2013-10-29 Solar Light Company, Inc. Attenuator apparatus
US7928859B1 (en) 2008-11-21 2011-04-19 Yazaki North America, Inc. Full angle laser illuminate instrument cluster
US7954965B1 (en) 2009-04-13 2011-06-07 Yazaki North America, Inc. Method for multiple gauges in a scanning laser based display device
US8026827B1 (en) 2009-05-04 2011-09-27 Yazaki North America, Inc. Virtual push button switch

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