US2646504A - Extensible antenna with two-way acting fluid driving means - Google Patents

Extensible antenna with two-way acting fluid driving means Download PDF

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Publication number
US2646504A
US2646504A US198626A US19862650A US2646504A US 2646504 A US2646504 A US 2646504A US 198626 A US198626 A US 198626A US 19862650 A US19862650 A US 19862650A US 2646504 A US2646504 A US 2646504A
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Prior art keywords
antenna
chamber
section
sections
piston
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US198626A
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Frederick V Gosline
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PIONEER SPECIALTY Co
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PIONEER SPECIALTY Co
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/18Combined units comprising both motor and pump
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01QANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00Details of, or arrangements associated with, antennas
    • H01Q1/08Means for collapsing antennas or parts thereof
    • H01Q1/10Telescopic elements
    • H01Q1/103Latching means; ensuring extension or retraction thereof

Definitions

  • This invention relates to extensible and retractable radio antennas and actuating means therefor, and more particularly to antennas adapted for installation in vehicles where it is desired to control the movement of the antenna from a point remote from its mounting.
  • It is another object to provide an improved antenna comprising a pluralityof sections which may be mounted on a vehicle body panel or the like, the antenna being actuatable by a uid pressure system directlyV connected to the sections in a limited space below the mounting panel, and which may be controlled by electrical means remote from the mounting area.
  • Figure 1 is an elevational View, partly in crosssection and with parts broken away, showing the operative portions of the antenna sections together with the hydraulic actuating means;
  • Fig. 2 is a fragmentary elevational view, partly in cross-section, showing the details of the hydraulic actuating means and its connection to the antenna.
  • the antenna proper is of the telescopic type having a plurality of Sections I2, I3 and I4. It will be understood that While only three sections are shown in the illustrated embodiment, the principles of the invention contemplatepthe use of any desirable number ofV sections.V As will later appear, these sections form part of a fluid pressure system' ment; .this securing means may comprise an insulatingblockll of annular shape which is secured to an intermediate portion of section I4 n and in which the 'lead-in connection (not shown) may be mounted. This insulating block is held within a cylindrical shell I8 which extends through an opening (not designated) in the body panel, a dome-nut I9, neck piece 2
  • IAntenna section comprises two cylindrical members 23 and 24 which are held in rigid concentric relation. Outer cylinder 24 is directly secured to the body panel I6 by the means above described, and extends above and below said panel.V
  • a head 25 is secured within the upper end 26 of outer cylinder 24 and this vhead is provided with an annular groove (not designated) in which is held the upper edge portion 21 of inner cylinder 23.
  • the lower edge portions of these two cylindrical members V are held in rigid relation by a head 28 of electricallyinsulative material, this head also being connected with the hydraulic pump mechanism to be later described.
  • the lower chamber 29 Vformed by the inner cylindrical member 23 below its cooperating piston, serves to conduct the hydraulic fluid when the antenna sections are being moved to their extended position.
  • VThe annular Space 3l between cylindrical members 23 and 24 serves to conduct the hydraulic fluid when the sections are being rctraeted.
  • inner cylinder 23 is provided with an aperture 32 immediately below head 25, and the lower head 28 is provided Vwith an aperture 33 leading to chamber 29 and an aperture 34 connected with chamber 3
  • the purposes and functions of apertures 32, 33 and 34 will appearhereinafter in the description of the operation of the device.
  • Intermediate antenna section I3 is slidably mounted within outer section I4 and is of generally similar construction to the latter section.
  • section I3 is provided with an inner cylindrical member 35 and an outer cylindrical member 36 in rigid concentric relation.
  • the lower ends of these cylindrical members support a piston 31 which is slidably disposed within cylinder 23.
  • the piston 31 is preferably fabricated of a metallic or other electrically conductive material, and the t of the piston in cylinder 23 is such that the peripheral surfaces thereof are in conductive contact with the cylinder.
  • An annular packing member 38 is provided in piston 31 to prevent hydraulic fluid from passing the piston. It will be noted that piston 31 divides the cylinder 23 into lower chamber 29 and an upper chamber 39.
  • the piston 3T is provided with a centrally located aperture 4I which connects chamber 29 to a lower chamber 42 vformed by inner cylinder 35 of intermediate antenna section I3 and its cooperating piston. Chamber 42 thus also forms a part of the iiuid pressure system for extending the antenna sections.
  • the annular chamber 43 which is formed between cylinders 35 and 36 is connected to upper chamber 39 of the lower antenna section by an aperture 44 in cylinder 36 immediately above piston 3'I. Since, as stated previously, aperture 32 connects annular chamber 3I to chamber 39, it will be seen that chambers 3l, 39 and 43 all form a part of the uid pressure system for retracting the antenna.
  • the head 25 is provided with a clearance aperture 45 through which antenna section I3 extends, and the fluid in chamber 39 is prevented from leaking past this aperture by a packing gland 45. It will be understood that while only one intermediate antenna section I3 is shown, the antenna may comprise a plurality of such sections.
  • antenna I3 The upper end of antenna I3 is provided with a head 4l which holds cylinders 35 and 35 in concentric relation.
  • Upper antenna section I2 which is preferably of solid cylindrical construction, is slidably mounted within cylinder 35 and extends upwardly through head 41, a packing gland 4B being provided in the head to prevent leakage.
  • a piston 49 is formed at the lower end of antenna section I2, and this piston is constructed of electrically conductive material similar to piston 4I, having a sliding contacting t with the cylinder 35. The piston 49 thus divides cylinder 35 into lower chamber 42 and an upper chamber 5I, a packing 52 being provided in the piston to prevent leakage.
  • Upper chamber 5I is connected to annular chamber 43 by means of a passageway 53 formed in head 4T.
  • the illustrated system is reversible and comprises in general an electric motor 54 which drives pump I5 in either direction.
  • the pump may be of conventional positive displacement type comprising rotary gears 55, the pump chamber being connected by passageways 56 and 5l to a reservoir comprising two chambers 58 and 59. These chambers are sealed from each other by a parting wall SI, passageway 56 being connected to chamber 58 and pasageway 5'I to chamber 59.
  • Chamber 58 is connected by a standpipe 52 to port 33 which, as previously stated, leads to antenna-extending chamber 29.
  • Chamber 59 is likewise connected by a standpipe to port 34, leading to antenna-retracting chamber 3E.
  • the motor 54 is preferably of the reversible type and is connected by leads 34 and 65 to a reversible switch 5G connected to a battery 6l. Since it may be desirable to ground the motor casing, head 28 as stated previously is preferably constructed of material having electric insulating properties so as to prevent grounding of the antenna.
  • the antenna sections may be retracted by actuating pump I5 in such a direction as to force fluid upwardly through port 34 into chamber 3I.
  • the hydraulic fluid will pass upwardly through annular chamber 3
  • hydraulic iiuid will be withdrawn from chamber 29 through port 33.
  • Air spaces 68 are preferably left in chambers 58 and 59 to allow for differences in volume of fluid flow.
  • the fluid entering chamber 39 will react on the upper side of piston 3i' to force antenna section I3 downwardly within section I4.
  • antenna sections I2 and I3 will thus be forced into chambers 29 and 42, reacting against the undersides of pistons Si and 49 to extend antenna sections I2 and I3. It will be noted that due to the arrangement of the parts the fact that the antenna sections are part of the hydraulic system will in no way interfere with their electrical functions. It will also be observed that by stopping motor 54 the antenna sections may be stopped in any intermediate position, and will be held in such position by friction as well as by the effect of the trapped fluid. It is important to observe that because of the continuous electrical contact between heads 33 and 49 and their corresponding cylinders, no impairment of the electrical function of the antenna will occur in any of its intermediate positions.
  • An antenna of the extensible type comprising a section secured to a stationary support, said section comprising' concentric inner and outer spaced cylinders forming an annular chamber therebetween, a movable section slidably mounted within said stationary section, said movable section having a piston slidable within the inner cylinder of said stationary section and dividing said inner cylinder into upper and lower chambers, saidl movable section further comprising a pair of concentric inner and outer spaced cylinders forming an annular chamber therebetween, an uppersection slidable within said movable section, said upper section having a piston within the inner cylinder 'of said movable section and dividing said cylinder intoupper and lower chambers, a iiuid connection between the lower chambers-of said stationary and movable sections, ⁇ additional fluid connections leading from the upper chamber of said stationary section to the annular chambers of said stationary and movable sections, an apertured portion forming a passage connecting the annular and upper chambers of said movable section, and means
  • a iirst section secured rto a stationary support, said section comprising concentric inner and outer spaced cylinders forming an annular chamber therebetween, a movable section slidably mounted within said rst section, said movable section having a piston slidable within the inner cylinder of said rst section and dividing chamber.
  • said pump being secured to the underside of said reservoirs and adapted to pump fluid in either direction between said pump chambers,

Description

EXTENSIBLE ANTENNA WITH TWO- WAY ACTING FLUID DRIVING MEANS Filed Dec. l, 1950 l BY Y Y Trav/KEYS.
atenteci . ulry 2,1, 19753 EXTENSIBLE ANTENNA WITH TWO-WAY ACTING FLUID DRIVING MEANS Frederick v. Gosline, Detroit, Mich., assignr, byY mesne assignments, to Pioneer Specialty Company, a corporation of Michigan Application December 1, 1950,'Serial No. 198,626
4 claims. (c1. 250433) This invention relates to extensible and retractable radio antennas and actuating means therefor, and more particularly to antennas adapted for installation in vehicles where it is desired to control the movement of the antenna from a point remote from its mounting.
It is an object of the present invention to provideVV such an antenna which is operable underl the iniiuence of control means located at a point remote from the antenna mounting and in which the actuating mechanism for the antenna is directly connected to the antenna proper and occupies a relatively small space. More particularly, it is an object to provide an improved antenna of the indicated character havingA a fluid pressure system for extending or retracting the antenna sections, in which the antenna sections themselves form a part of said iiuid pressure system and in which the iiuid pressure reacts directly upon these sections.
It is another object to provide an improved antenna comprising a pluralityof sections which may be mounted on a vehicle body panel or the like, the antenna being actuatable by a uid pressure system directlyV connected to the sections in a limited space below the mounting panel, and which may be controlled by electrical means remote from the mounting area.
. It is a further object to provide an extensible antenna as described, which is driven by a re- .versible uid pressure system of which the antenna sections themselves form a part, the hydraulic system in no way interfering with the electrical functions ofthe antenna sections, and in which the sections may be stopped and positively held in any intremediate position.
Other objects, features, and advantages of the present invention will become apparent from the I subsequent description taken in conjunction with the accompanying drawing.
In the drawing:
Figure 1 is an elevational View, partly in crosssection and with parts broken away, showing the operative portions of the antenna sections together with the hydraulic actuating means; and
Fig. 2 is a fragmentary elevational view, partly in cross-section, showing the details of the hydraulic actuating means and its connection to the antenna.
The antenna proper, generally indicated at II, is of the telescopic type havinga plurality of Sections I2, I3 and I4. It will be understood that While only three sections are shown in the illustrated embodiment, the principles of the invention contemplatepthe use of any desirable number ofV sections.V As will later appear, these sections form part of a fluid pressure system' ment; .this securing means may comprise an insulatingblockll of annular shape which is secured to an intermediate portion of section I4 n and in which the 'lead-in connection (not shown) may be mounted. This insulating block is held within a cylindrical shell I8 which extends through an opening (not designated) in the body panel, a dome-nut I9, neck piece 2| and spacer 22 securing shell I8 to the body panel.
IAntenna section comprises two cylindrical members 23 and 24 which are held in rigid concentric relation. Outer cylinder 24 is directly secured to the body panel I6 by the means above described, and extends above and below said panel.V
A head 25 is secured within the upper end 26 of outer cylinder 24 and this vhead is provided with an annular groove (not designated) in which is held the upper edge portion 21 of inner cylinder 23. The lower edge portions of these two cylindrical members V,are held in rigid relation by a head 28 of electricallyinsulative material, this head also being connected with the hydraulic pump mechanism to be later described. The lower chamber 29 Vformed by the inner cylindrical member 23 below its cooperating piston, serves to conduct the hydraulic fluid when the antenna sections are being moved to their extended position. VThe annular Space 3l between cylindrical members 23 and 24 serves to conduct the hydraulic fluid when the sections are being rctraeted. For this-purpose, inner cylinder 23 is provided with an aperture 32 immediately below head 25, and the lower head 28 is provided Vwith an aperture 33 leading to chamber 29 and an aperture 34 connected with chamber 3|. The purposes and functions of apertures 32, 33 and 34 will appearhereinafter in the description of the operation of the device.
Intermediate antenna section I3 is slidably mounted within outer section I4 and is of generally similar construction to the latter section. In particular, section I3 is provided with an inner cylindrical member 35 and an outer cylindrical member 36 in rigid concentric relation. The lower ends of these cylindrical members support a piston 31 which is slidably disposed within cylinder 23. The piston 31 is preferably fabricated of a metallic or other electrically conductive material, and the t of the piston in cylinder 23 is such that the peripheral surfaces thereof are in conductive contact with the cylinder. An annular packing member 38 is provided in piston 31 to prevent hydraulic fluid from passing the piston. It will be noted that piston 31 divides the cylinder 23 into lower chamber 29 and an upper chamber 39. The piston 3T is provided with a centrally located aperture 4I which connects chamber 29 to a lower chamber 42 vformed by inner cylinder 35 of intermediate antenna section I3 and its cooperating piston. Chamber 42 thus also forms a part of the iiuid pressure system for extending the antenna sections. The annular chamber 43 which is formed between cylinders 35 and 36 is connected to upper chamber 39 of the lower antenna section by an aperture 44 in cylinder 36 immediately above piston 3'I. Since, as stated previously, aperture 32 connects annular chamber 3I to chamber 39, it will be seen that chambers 3l, 39 and 43 all form a part of the uid pressure system for retracting the antenna. The head 25 is provided with a clearance aperture 45 through which antenna section I3 extends, and the fluid in chamber 39 is prevented from leaking past this aperture by a packing gland 45. It will be understood that while only one intermediate antenna section I3 is shown, the antenna may comprise a plurality of such sections.
The upper end of antenna I3 is provided with a head 4l which holds cylinders 35 and 35 in concentric relation. Upper antenna section I2, which is preferably of solid cylindrical construction, is slidably mounted within cylinder 35 and extends upwardly through head 41, a packing gland 4B being provided in the head to prevent leakage. A piston 49 is formed at the lower end of antenna section I2, and this piston is constructed of electrically conductive material similar to piston 4I, having a sliding contacting t with the cylinder 35. The piston 49 thus divides cylinder 35 into lower chamber 42 and an upper chamber 5I, a packing 52 being provided in the piston to prevent leakage. Upper chamber 5I is connected to annular chamber 43 by means of a passageway 53 formed in head 4T.
for the hydraulic system reacts directly on the antenna structure and is mounted immediately below fixed antenna section I4. It will be understood that while the particular fluid driving means shown in the illustrated embodiment is that which is preferred, other and similar driving means and mounting arrangements are contemplated by the principles of the invention. The illustrated system is reversible and comprises in general an electric motor 54 which drives pump I5 in either direction. The pump may be of conventional positive displacement type comprising rotary gears 55, the pump chamber being connected by passageways 56 and 5l to a reservoir comprising two chambers 58 and 59. These chambers are sealed from each other by a parting wall SI, passageway 56 being connected to chamber 58 and pasageway 5'I to chamber 59. Chamber 58 is connected by a standpipe 52 to port 33 which, as previously stated, leads to antenna-extending chamber 29. Chamber 59 is likewise connected by a standpipe to port 34, leading to antenna-retracting chamber 3E. The motor 54 is preferably of the reversible type and is connected by leads 34 and 65 to a reversible switch 5G connected to a battery 6l. Since it may be desirable to ground the motor casing, head 28 as stated previously is preferably constructed of material having electric insulating properties so as to prevent grounding of the antenna.
In operation, assuming an initial position in which the antenna II is fully extended, the antenna sections may be retracted by actuating pump I5 in such a direction as to force fluid upwardly through port 34 into chamber 3I. The hydraulic fluid will pass upwardly through annular chamber 3|, through aperture 32 and into upper chamber 33 of antenna 'section I4. Simultaneously with this action, hydraulic iiuid will be withdrawn from chamber 29 through port 33. Air spaces 68 are preferably left in chambers 58 and 59 to allow for differences in volume of fluid flow. The fluid entering chamber 39 will react on the upper side of piston 3i' to force antenna section I3 downwardly within section I4. At the same time, the fluid will pass through aperture 4G, upwardly through annular chamber 43 and through aperture 53 into upper chamber 5l of the antenna section i3. This fluid will force piston 49 of antenna section I2 downwardly, the fluid in chamber 42 passing into chamber 29 through aperture 4I. This action will continue until both antenna sections I3 and I3 are fully retracted within section I4. At this time, piston 3i will abut head 28 and knob 50 will abut head 4l, stopping the retracting movement. When it is desired to extend the antenna sections, the switch S3 will be reversed, driving iiuid upwardly 'through port 33 and downwardly through port 34. The iiuid will thus be forced into chambers 29 and 42, reacting against the undersides of pistons Si and 49 to extend antenna sections I2 and I3. It will be noted that due to the arrangement of the parts the fact that the antenna sections are part of the hydraulic system will in no way interfere with their electrical functions. It will also be observed that by stopping motor 54 the antenna sections may be stopped in any intermediate position, and will be held in such position by friction as well as by the effect of the trapped fluid. It is important to observe that because of the continuous electrical contact between heads 33 and 49 and their corresponding cylinders, no impairment of the electrical function of the antenna will occur in any of its intermediate positions.
While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.
I claim:
l. An antenna of the extensible type comprising a section secured to a stationary support, said section comprising' concentric inner and outer spaced cylinders forming an annular chamber therebetween, a movable section slidably mounted within said stationary section, said movable section having a piston slidable within the inner cylinder of said stationary section and dividing said inner cylinder into upper and lower chambers, saidl movable section further comprising a pair of concentric inner and outer spaced cylinders forming an annular chamber therebetween, an uppersection slidable within said movable section, said upper section having a piston within the inner cylinder 'of said movable section and dividing said cylinder intoupper and lower chambers, a iiuid connection between the lower chambers-of said stationary and movable sections,` additional fluid connections leading from the upper chamber of said stationary section to the annular chambers of said stationary and movable sections, an apertured portion forming a passage connecting the annular and upper chambers of said movable section, and means for connecting a source of fluid pressure to the lower and annular chambers of said stationary section, whereby fluid pressure may be selectively applied to yeither the upper or lower sides of said pistons.
2. The combination according to claim 1, fur- Ather provided with a head'secured to said sta- 6 said inner cylinder into upper and lower chambers, a fluid connection between said annular chamber and said upper inner chamber, a head secured to and enclosing the lower endsA of said annular chamber and said lower inner chamber, a reversible pump with a motor therefor sup--v ported directly by anddepending below said head in substantial alignment with said stationary andfmovable antenna sections, a fluid connection from one side of said pump extending through said head to said lower inner chamber, and a fluid connectionfrornY the other side of said pumpextending' throughsaid head to said annular chamber.
4. The combination according to claim 3, further provided with a reservoir comprising two separate chambers secured to the underside of tionary section, said head being constructed of Y 3. An antenna of the extensible type com.
prising a iirst section secured rto a stationary support, said section comprising concentric inner and outer spaced cylinders forming an annular chamber therebetween, a movable section slidably mounted within said rst section, said movable section having a piston slidable within the inner cylinder of said rst section and dividing chamber.
said head, said pump being secured to the underside of said reservoirs and adapted to pump fluid in either direction between said pump chambers,
the iiuid connections which extend through said head connecting said reservoir chambers with said lower inner Y FREDERICK V. GOSLINE.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,232,693 Dow Feb. 25, 1941 2,343,944 Wagenknecht Mar. 14, 1944 chamber and said annularV
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918795A (en) * 1955-09-06 1959-12-29 Ramsey Corp Electro-hydraulic actuating cylinder
US2961837A (en) * 1956-09-28 1960-11-29 Delong Corp Supporting leg assembly for marine platform
US3098229A (en) * 1959-06-17 1963-07-16 Gen Mills Inc Transmission line erected by pressurized plastic
US3430541A (en) * 1967-03-28 1969-03-04 Us Army Compression rod actuator
US3439326A (en) * 1967-01-20 1969-04-15 Henry F Boudin Vehicle emergency signal light
US3444511A (en) * 1962-01-02 1969-05-13 Ltv Aerospace Corp Transducer array and erecting means
US3584884A (en) * 1968-09-10 1971-06-15 Western Electric Co Pressure elongatable support apparatus
FR2061538A1 (en) * 1969-05-07 1971-06-25 Commissariat Energie Atomique
US3788196A (en) * 1971-08-09 1974-01-29 Ultramation Inc Linear thruster
US3877348A (en) * 1971-08-09 1975-04-15 William C Sandlin Linear thruster
US4137535A (en) * 1976-09-17 1979-01-30 Walter Rupprecht Telescoping antenna mast
US4375781A (en) * 1979-11-12 1983-03-08 Michio Bessho Double-acting hydraulic press
US5132696A (en) * 1990-10-18 1992-07-21 Hughes Aircraft Company Pneumatic extendable antenna for water deployable buoy
US5850713A (en) * 1996-12-20 1998-12-22 Yuasa Koki Co., Ltd Device raising and lowering apparatus
US7165504B1 (en) * 2004-12-20 2007-01-23 The United States Of America As Represented By The Secretary Of The Navy. Antenna linear extension and retraction apparatus for a submersible device, and method of use

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232693A (en) * 1937-03-18 1941-02-25 Jennings B Dow Antenna system
US2343944A (en) * 1941-03-17 1944-03-14 Zenith Radio Corp Extensible antenna

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232693A (en) * 1937-03-18 1941-02-25 Jennings B Dow Antenna system
US2343944A (en) * 1941-03-17 1944-03-14 Zenith Radio Corp Extensible antenna

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2918795A (en) * 1955-09-06 1959-12-29 Ramsey Corp Electro-hydraulic actuating cylinder
US2961837A (en) * 1956-09-28 1960-11-29 Delong Corp Supporting leg assembly for marine platform
US3098229A (en) * 1959-06-17 1963-07-16 Gen Mills Inc Transmission line erected by pressurized plastic
US3444511A (en) * 1962-01-02 1969-05-13 Ltv Aerospace Corp Transducer array and erecting means
US3439326A (en) * 1967-01-20 1969-04-15 Henry F Boudin Vehicle emergency signal light
US3430541A (en) * 1967-03-28 1969-03-04 Us Army Compression rod actuator
US3584884A (en) * 1968-09-10 1971-06-15 Western Electric Co Pressure elongatable support apparatus
FR2061538A1 (en) * 1969-05-07 1971-06-25 Commissariat Energie Atomique
US3788196A (en) * 1971-08-09 1974-01-29 Ultramation Inc Linear thruster
US3877348A (en) * 1971-08-09 1975-04-15 William C Sandlin Linear thruster
US4137535A (en) * 1976-09-17 1979-01-30 Walter Rupprecht Telescoping antenna mast
US4375781A (en) * 1979-11-12 1983-03-08 Michio Bessho Double-acting hydraulic press
US5132696A (en) * 1990-10-18 1992-07-21 Hughes Aircraft Company Pneumatic extendable antenna for water deployable buoy
US5850713A (en) * 1996-12-20 1998-12-22 Yuasa Koki Co., Ltd Device raising and lowering apparatus
US7165504B1 (en) * 2004-12-20 2007-01-23 The United States Of America As Represented By The Secretary Of The Navy. Antenna linear extension and retraction apparatus for a submersible device, and method of use

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