Abstract: A guard for protective use over a guy wire of a utility pole or the like is provided as a long tubular body of weather and impact resistant plastic material formed with oppositely disposed longitudinal edge portions that protrude and converge laterally along a slit through which a guy wire can enter the body. The body is secured on the wire by bolts which pass transversely through holes in the body between the wire and the slit and hold the edge portions pressed together. The guard will cushion impacts, and it is difficult to vandalize.

Abstract: An anchor for a building which is temporarily located upon the ground without a permanent foundation. The building has base plates at its margins which rest upon ground plates anchored in the earth and carrying locater members engaged by the base plates. Elongated auger type earth penetrating anchors are located at spaced points adjacent the base plates and carry adapters pivotally mounting locking members each having an end overlying a base plate. An adjustable member on each adapter urges the associated locking member into firm overlying anchoring engagement with a base plate.

Abstract: A multi-layered skylight having an outer element with a central domed portion and a downwardly extending circumferential skirt portion, said outer element comprising a monolayer of a synthetic resin which transmits light, and an inner element of one-piece construction with a central domed portion and a substantially planar circumferential edge portion, said inner element comprising at least two sheets of a synthetic resin which transmits light, said sheets being substantially parallel to one another and having a plurality of supporting elements extending therebetween, said elements being arranged with the planar edge portion of said inner element being within and surrounded by the circumferential skirt portion of said outer element and with the central domed portions of said inner and outer elements being in a substantially parallel spaced relationship to one another.

Abstract: A doorframe assembly for partition wall construction is disclosed and comprises metal backer jamb members adapted for attachment to opposite sides of a door opening, vinyl jamb members snap-engaged with the metal backer jamb members, hinge plate means for supporting a door attached along a longitudinal recess portion of a vinyl jamb member at one side of the door opening, strike plate means adapted for receiving door locking means attached along a longitudinal recess of a vinyl jamb member at the opposite side of the door opening, and, mortising vinyl trim adhered along remaining open portions of the vinyl jamb members at both sides of the door opening and having a thickness substantially the same as the hinge plate means and strike plate means providing a mortised generally planar finished surface along the vinyl jamb members.

Abstract: A prestressed steel support structure and method of erecting the same having bearing supports and containing at least one tension element having at least one hollow profile member extending in a catenary configuration between support locations and within which there is arranged at least one prestressing cable. The hollow profile member is provided with a filler and the prestressing cable forms a connection with the hollow profile member by means of such filler.

Abstract: A pressure vessel susceptible to high temperatures, especially for containment of a nuclear-reactor core, is constituted of a cylindrical shell from a cast material such as cast steel, cast iron or concrete, and is prestressed by vertical cables which extend parallel to generatrices of the shell. Peripheral (circumferential) prestressing cables are provided around the shell which can be externally insulated. The peripheral tensioning cables are exposed externally of the insulation material and bear upon the shell of the vessel with heat-resistant elements of high compressive strength which extend through the external insulation.

Abstract: A method of coupling the strands 2, 5 of adjacent sections of a stressing tendon in a multi-span post-tensioned concrete structure comprises tensioning strands 2 of a first section of the tendon, anchoring the strands 2 in an anchorage member 1 using wedges 3, and then joining the strands 2 of the first section to strands 5 of a second section of the tendon in end-to-end relation by compressing metal sleeves 6 around the strands. The sleeve 6 may have hardened metal inserts 7. The outer strands 5 may be gradually directed inwards by a first collar 9 and a second collar 11 may be provided so as to gradually direct the strands 5 into a duct 10 for the second section of the tendon.

Abstract: The invention contemplates an improved construction of the reinforced ends of flexible sheet-metal panels used in defining the basic generally cylindrical wall to be lined with flexible material in the erection of a prefabricated swimming pool. The end-reinforcement structure uses substantially thinner-gage material than heretofore, and yet a secured joint of two lapped panel ends has the hoop-tension resistance of the best of previous constructions without presenting any ambiguity regarding the sense (i.e., overlapped relation of parts) at the overlap.

Abstract: The invention relates to a decorative stained glass insert unit which is attachable to an existing window unit to create an esthetically pleasing window treatment effect.

Abstract: A prefabricated building panel capable of bearing weight supporting loads, comprised of a pair of spaced apart rectangular metal frame members which are joined along one side by fastening bolts holding them in rigid relationship with respect to each other, and which have on their opposite side a locking means for locking one pair of panel frame members to the fastening bolts of another pair of frame members, and having the interior panel space defined by the frame members filled with an expandable polymeric insulative material which is molded directly to the panel frame members. As a result, load bearing steel stud frame members can be provided with insulation already installed at the factory, thereby eliminating separate insulating steps at the job site.

Abstract: In a self-supporting concrete form of foamed polymeric material, a one piece transverse connecting member is provided which mechanically holds fastening members inserted into the form providing mechanical support for finish material such as furring strips, paneling, etc. The connecting member is formed from one piece of sheet material, preferably cold rolled steel, and comprises a central connecting web portion extending between and embedded in sidewall members of the form and first and second imperforate flat attachment flange portions extending perpendicularly from the web portion and embedded near the outer surfaces of the sidewall members for supportably receiving fastening members penetrating the sidewall members. The web portion of the connecting member comprises an array of relatively large openings to permit the flow of concrete through the form units and to provide a high strength web of metal.

Abstract: A panel adapted for mounting on a building, the panel being formed from a plurality of thin panels of a selected stone facing material, such as granite or marble, backed and interconnected by fiberglass-strengthened concrete underlaying the plurality of thin panels and covering and engaging anchor means mounted in the backs of the stone panels. The method of forming the building panel involves placing the granite or marble panels face down in a form, mounting anchor means in the backs thereof, and overlaying both the plurality of thin panels and the anchor means with a fiberglass-strengthened concrete mixture, and curing the mixture both within and without a support form.

Abstract: Upstanding polysurfaced male and female lips are provided along confronting edges of adjacent elements, such as building panels. The female lip is engaged over the male lip and when rotated about the male lip is snap-fitted into interlocked relation therewith. The lips provide an upstanding joint which secures the adjacent elements in fixed angular relation to each other. The lips are interengaged along plural angularly spaced-apart regions and are overlapped such that vertical and lateral disengagement of either lip relative to the other is precluded along the entire length of the joint.

Abstract: An interlocking frame assembly for constructing and supporting a wall system, wherein a plurality of substantially H-shaped support sections are each formed with a pair of flange members extending substantially perpendicularly from a side thereof, with each pair of flange members having a pair of inwardly directed projections and each pair of leg members forming the H-shaped support section also having a pair of inwardly directed projections. A plurality of connecting sections are selectively positionable to engage the inwardly projecting projections of separate support sections to interconnect said support sections in perpendicular or parallel arrangement relative to one another.

Abstract: Apparatus for fastening building construction insulating panels to a supporting wall structure comprising a slotted channel member and an anchoring clip. The channel has flanges by which it is secured to a supporting wall structure and a slotted mounting surface spaced from the supporting wall a preselected distance to provide improved insulation. The anchoring clip has opposed flanges on one end for engaging the edges of adjacent insulating wall panels and an anchor on the opposite end for engaging the slot in the channel and thereby holding the insulated panel to the supporting wall with the preselected spacing.

Abstract: A framework in particular an arch comprising at least one frame member and wherein the framework extends in at least two dimensions, a linkage system associated with the framework and attached thereto at at least three non-collinear positions on the framework, said linkage system embodying two tension members, one of which extends from each of the two outer positions of said three non-collinear positions to the central position thereof where the tension members are each attached to one of two spaced points on a swivel member which is at least swivelable in the plane of the framework and is attached to the framework at the said central position by a connection operable in use, to allow at least limited rotation about a point offset from the line of the tension members and thereby ensure that a change in tension in one of said tension members results in a rotation of the swivel member which causes a change in tension in the other tension member.

Abstract: An aluminum-wood composite pole which comprises an elongated hollow aluminum member having a rectangular cross-section with front and back surfaces integral with oppositely facing recessed connecting sides. Bolted in the recesses are wooden facings to allow gripping thereof by jump jacks used on scaffolding.

Abstract: A chub packaging machine, or the like, incorporates a double-knife cut-off or severing device of the invention. Chub packages are elongate tubular packages which are gathered at their opposed ends and have metal clips clinched therearound to close those ends. The double-knife cut-off device is mounted on the closure head assembly of a conventional chub packaging machine, with appropriate modification, and produces a shorter and cleaner stub end on a chub package than heretofore available. The appreciable amounts of product trapped in the stub ends of chub packages formed on conventional chub machines are substantially eliminated by shortening the stub ends to approximately one-third the usual length. The double knife cut-off device severs a short gathered portion of the tubing between two packages at two spaced apart positions rather than in the center of the portion as heretofore known.

Abstract: A package preferably of cube shape is supported and moved by a series of notched rollers (5-9) and a film (F) is disposed in overlying relation to the package with its leading part (FL) underneath the leading part of the package and a movable tucking bar (23) is arranged to move into engagement with the trailing part (FT) of the film and movable in sequence through the notches (11, 25, 27, 29, 31) in the rollers so as to tuck the trailing part (FT) of the film (F) underneath the trailing part of the package and in overlapping relation with respect to the leading part (FL) of the film (F).

Abstract: A machine for filling a cloth bag with cloth filling material having a series of elongated fingers and a hollow spout mounted on a rectangular frame in registry with one another for movement relative to one another along the frame such that the fingers advance into and retract out of the passageway. A cloth filler material is spread upon the fingers and the bag to be filled is draped over the spout so that the inside bottom of the bag is facing the fingers. An air operated double acting cylinder is actuated to drive an endless cable which cable may either be operatively connected to a roller assembly connected to a rear end portion of the fingers or to the spout depending upon whether it is desired to move the fingers into and out of the spout or move the spout along and over the fingers. Movement of the fingers into the spout or vice versa forces the bottom of the bag through the spout and extends the bag over the fingers and the filler material spread thereon.

Abstract: A severing device for use in a semiautomatic machine for facilitating the wrapping of an article with thermoplastic film material. The device is designed as an adapter to fit into a presently known machine to permit the removal of the hot wire presently used in such machines for severing the film and to replace such hot wire by a mechanical device for this purpose whose location and operation will not appreciably, if any, require alteration of the manual sequence previously known for effecting such wrapping. The device includes a knife and knife bed assembly which is relatively movable by electrical means. At least one limit switch is positioned adjacent the meeting zone of the knife and knife bed assembly so that upon movement of the thermoplastic film downwardly by the same motion as previously placed same against the hot wire for severing, the film will contact and actuate the limit switch and thereby actuate the knife and knife bed assembly for effecting such severing.

Abstract: A method is proposed for packaging products, particularly food products, and sterilizing them in an alternating high-frequency electromagnetic field. The product is first introduced into trough-like, preferably interconnected containers provided with a metallic layer; then the containers are closed with a synthetic film, brought within the range of an alternating high-frequency electromagnetic field, and finally sealed with a foil having a metallic lamina which covers the synthetic film.

Abstract: Packaging apparatus for making hermetically sealed vacuum packages from two continuous webs of plastic packaging material supplied as roll stock. The lower web is formed into product receptacles, and the upper web is applied over the receptacles to serve as the top. The apparatus includes a single-station evacuate-and-seal head where the two webs are initially sealed together around the flanges of the receptacle. The resulting package is then evacuated through a slit in the lower web, and the evacuation slit is sealed off to complete the package. During evacuation, the upper web is shifted up to engage a heated plate to raise the web temperature to a level permitting forming of the plastic material. After final sealing, the spaces above and below the packages are sequentially vented to atmosphere so as to control the formation of the upper web to produce a crowned effect, wherein a portion of the product extends upwardly a small distance above the flanges of the package.

Abstract: An improved knife section for reciprocating mower is disclosed wherein the improved knife section is constructed from less material than a standard knife section. The thickness of the improved knife section is made substantially equal to the thickness of the material of a standard knife section by forming convolutions in the body. A reinforcing ridge parallel to the cutting edge further improves the rigidity and strength of the improved knife section. The reinforcing ridge extends rearwardly beyond the cutting edge to encircle the rivet holes to allow for the inclusion of countersunk areas permitting the rivet heads to fit within the plane of the knife section, thereby producing a substantially uniform top surface. An extension of the countersunk area below the bottom surface of the knife section can interfit an embossed depression formed around the rivet hole in the support bar, resulting in an interlock between the knife section and support bar to reduce shearing stresses within the rivet.

Abstract: Mounting for a tree shaker having a pair of mounting brackets secured to respective sides of the tractor, a guide extending transversely beneath the tractor chassis, and supporting a slide which is coupled to the near side mounting bracket by means of a piston/cylinder assembly whereby the slide is movable in a transverse direction with respect to the tractor, the slide carrying on it a tree shaker.

Abstract: An improved knotter primarily for use with a crop baling machine is disclosed. As is known in the art, a quantity of compacted crop material is encircled with a length of twine, or similar binding material, and a knot is tied in primary and secondary portions thereof to produce a discrete package of material. The improved knotter includes a rotatable twine holder for gripping the primary and secondary portions of twine and holding them in a side-by-side relationship extending along a predetermined path. A rotatable billhook is mounted adjacent the twine holder and positioned to intersect the predetermined path. Drive means interconnecting the twine holder and billhook rotate the two elements in timed relation such that during a first cycle of the billhook the twine portions are positioned thereabout, and during a second cycle of the billhook a knot is tied therein.

Abstract: A method and apparatus for the elimination of an irregularity in a yarn being produced on an open end spinning machine and drawn off therefrom by a pair of draw-off rollers and wound on a bobbin. The yarn is deflected into an N-shaped run so that a knotting mechanism can knot the parallel portion of the yarn together so as to remove the irregularity in the yarn. Yarn guides are provided on the knotting mechanism for displacing an oblique portion of the yarn out of the knotting mechanism when in use.

Abstract: An elongated suction air nozzle provided for forming a thread reserve in the form of a loop in thread running past the mouth thereof. A constriction is provided in the nozzle and extends for the whole length of the expected loop size. The constriction divides the cross-sectional area of the nozzle into two partial areas resulting in air flow in the central region of the nozzle being of a greater velocity than in the two partial remote areas.

Abstract: A false twisting machine which includes a frame having racks of thread supply spools on opposite sides with centrally disposed bobbin supporting take-up mechanisms therebetween defining corridors on opposite sides thereof with thread heaters and false twisting members disposed horizontally across the top of the machine, together with thread transport mechanisms for stretching the threads and for advancing the threads vertically upward from the thread supply spools on opposite sides of the machine across the top of the machine in a horizontal path with virtually no deviation therefrom through the heaters and false twisters and then downwardly onto the take-up bobbins for ultimate removal of the wound thread packages from the machine thereby providing a machine of greatly reduced height and capable of easy maintenance.

Abstract: A bulk yarn formed from a plurality of multi-filament yarns having alternating compact and open segments. The compact segments include first and second plaited portions which are twisted in opposite directions. The open segments of the yarn are defined by loosely bundled multi-filament yarn. The apparatus for bulking the yarn includes an elongated housing having a longitudinal bore extending therethrough. Pressurized air passes through diametrically opposed passages for contacting the yarn as it passes through the bore for producing the bulking effect thereon.

Abstract: A wristwatch movement has a back cover formed with a battery replacement hole, and a base plate formed with a battery compartment in a substantially axial alignment with the battery replacement hole. An actuating lever has one end selectively engageable with a setting lever engaging with a winding stem extending through a radial bore of the base plate, and another end formed with a handling portion extending toward the battery compartment such that the handling portion can be manipulated through the battery replacement hole to cause the one end of the setting lever to disengage from the winding stem, to allow the winding stem to be pulled out of the radial bore.

Abstract: An electronic timepiece having a reversible stepping motor to actuate time-indicating hands to provide a time display, which comprises a driver circuit to produce driving current pulses composed of compound pulses appearing each time unit. A rotor of the stepping motor rotates a plurality of steps during each time unit to cause one of the time-indicating hands to advance through unequal intervals to provide a modulated display.

Abstract: An electronic analog wristwatch includes an alarm which is set by rapidly, electromechanically driving the watch hands forward proximate to the desired alarm time, slowly advancing the hands electromechanically to the exact alarm setting, and then rapidly returning, by electromechanically driving, the hands to the actual present time. A counter records the number of drive pulses required to advance the hands to the alarm setting, while another counter records the time elapsed, measured in pulses, in setting the alarm including advancement and return of the hands. The number of pulses required for hand advancement is stored in memory. The pulses required for hand return are counted until the sum of the hand returning pulses and the elapsed time pulses equals the number of pulses which were required for advancing the hands, as stored in memory.

Abstract: A quartz oscillation circuit used for a time standard of an electronic timepiece, which includes an inverter operating as an amplifier, an input capacitor and an output capacitor, the capacitors having the opposite temperature characteristics to compensate changes in oscillation frequency with the variation of temperature without any increase of the power consumption.

Abstract: A timepiece having chronograph features has an electronic digital display pable of displaying six digits. In the chronograph operating mode these are normally minutes, seconds and hundredths of seconds. Should the instrument run for more than one hour prior to a stop or split operation, then during such operation a detector and a timer will cause hours alone to be displayed alternating with the remaining information (minutes, seconds, hundredths of seconds). Thus a six digit display may be employed for eight digit information.

Abstract: An electronic timepiece comprises an oscillator, a frequency divider for frequency dividing the output signal of the oscillator to generate 100 Hz output pulse signals, time count circuits having a plurality of counters cascade-connected to count the output pulse signals of the frequency divider, a decoder circuit for decoding the output signal of the time count circuits to generate a display signal and a display device for displaying data corresponding to the output display signal of the decoder circuit, in which a stopwatch display mode and a normal time display mode may be selected by the operation of a switch. The electronic timepiece further includes a control circuit connected between the decoder circuit and display device and adapted to inhibit normal time display data from being supplied to the display device in response to the operation of the switch which sets the electronic timepiece into the stopwatch display mode.

Abstract: A retaining spring for fixedly retaining a case band and a back cover of a wristwatch case, which retaining spring comprises a fixing portion secured to one of the case band and the back cover, a weakened or torsionable portion extending from the fixing portion, and an engaging portion connected to the fixing portion through the weakened or torsionable portion and engaging with the other one of said case band and said back cover.

Abstract: A unidirectional gear transmission of reduced axial thickness advantageou employed in timepieces is adapted to be driven by a stepping motor. The driving gear is provided with an alternating pattern of teeth having a first thickness and spacing and sets of two teeth having greater thickness and spacing. The driven gear is provided with an alternating pattern of teeth corresponding to the first thickness teeth of the driving gear and two spaces corresponding to the greater thickness teeth of the driving gear separated by a single tooth. Regular stepping rotation in either sense can be transmitted from the driving gear to the driven gear, but transmission of rotation from driven to driving gear is prevented.

Abstract: An improved combined cycle gas turbine and steam turbine power plant is disclosed in which the energy source for both the steam turbine portion of the system and the gas turbine portion is a pressurized fluidized bed combustor fueled by a carbonaceous fuel such as coal. Combustion gas discharged from the pressurized combustor is processed for minimal cleanup and temperature conditioning prior to passage through a heat exchanger to heat a stream of pressurized air for driving an air-gas turbine. Following the loss of sensible heat energy through the heat exchanger, the lower temperature combustion gas is expanded through a second, combustion gas turbine so that a portion of the remaining energy is extracted at a lower temperature, avoiding problems of hot gas corrosion and fouling within the turbine. A compressor, driven by one or both gas turbines, provides both the pressurized air supply for fluidization of the bed and the stream of air to the air-gas turbine.

Abstract: A method of operating a liquid fuel rocket engine having at least first and second propellant component pumps, driven by a gas turbine which is connected to discharge its turbine propulsion gases through a secondary thrust nozzle, includes a main engine having a combustion chamber with a thrust nozzle, an initial expansion portion with an expansion corresponding to ground pressure and a final expansion portion connected to the initial expansion portion and terminating in a thrust discharge operating substantially at vacuum and with means for circulating at least one propellant component through cooling channels of the walls of both expansion portions, comprises, directing a first component into the combustion chamber, and directing at least a first portion of a second propellant component into the walls of the initial expansion portion and then into the combustion chamber and directing a second portion of the second propellant component into the walls of the final expansion portion so that they are heated the

Abstract: A device of the type wherein a gas pressure is converted into an oil pressure and the resulting oil pressure is exerted to drive an actuator. A pair of gas-oil reservoirs are coupled with each other via a conduit wherein an automatic oil level control valve is disposed to close the conduit when the actuator is in operation and the gas pressure in the reservoirs are not balanced and open the conduit when the actuator is not in operation.

Abstract: A hydromechanical/hydrostatic automotive energy management system comprising two hydraulic units, the system adapted to provide: An efficient, continuously variable optimal transmission ratio, an intermittent optimal engine operation in city traffic and regenerative braking, thereby, the system is able to reduce a car's fuel consumption by as much as one half while improving drivability.

Abstract: A device for the power-assisted control of a hydraulic transmitter is disclosed which includes a transmitter cylinder having a first and second bore provided therein, a main piston with a bore hole, disposed in the cylinder, valve means disposed in the bore of the cylinder, a fluid source communicated with the cylinder, a control piston movably disposed in the second bore and having a control section and a second section formed thereon wherein the control section of the control piston is larger than the second section of the control piston.

Abstract: Internal combustion engines are turbocharged by operating a turbocompressor with exhaust gases from an internal combustion engine. Compressed air is fed from the turbocompressor to the engine at a rate such that all the air compressed by the turbocompressor is fed to the engine when the engine is at the highest altitude for which the engine is designed and is operating at full load and is running at its lowest normal operating speed. But when the engine is operating at lower altitude and/or higher speed and/or at less than full load, then some of the air compressed by the turbocompressor is automatically discharged.

Abstract: This air conditioning system includes low pressure water vaporization, transfer and absorption, both in a solution concentrating section using solar radiation or other heat input and in a solution diluting section where heat exchange with ambient fan blown air subsequently permits cooling or heating enclosure air. The fan blown enclosure air is cooled or heated in passing through the same heat exchanger by changing the flow paths of the solutions passing to and from the two unique vapor exchangers, which are described in detail. The solutions are separated but contained in a sealed system with storage volume to give a large heat capacity potential by changing the solution concentration to either cool or heat the enclosure air.The various system operational modes are described in detail, with the functioning of the vapor exchangers and heat exchangers in concert with the flows through pipes and ducts as generated by pumps and fans together with control by valves.

Abstract: The subject invention relates to method and apparatus for controlling or manipulating a body of crude, refined, or used petroleum as, for example: in the herding and recovery of an oil spill in a body of water; in temporarily stopping a leak in an oil tanker caused by a cracked hull; in recovering oil inadvertently spilled on a beach front; in plugging an oil casing pipe to control an oil fire at sea on a drilling platform; in effecting preliminary refinement of oil at the oil rig site; in transporting oil from the Arctic or Antarctic region without resorting to complicated and costly apparatus; and in many other applications. The method basically comprises exposing a body of crude, refined, or used petroleum mass either to a transient atmosphere or environment of a freezing, sub-freezing, or cryogenics temperature, or contacting the petroleum with a substance or mechanism exhibiting freezing, sub-freezing, or cryogenics temperatures.

Abstract: An air cooled centrifugal water chiller is disclosed which may be operable (1) under conditions of low outdoor ambient temperature, requiring flooding of the air cooled condenser in order to reduce its capacity and maintain proper system operation; or (2) in a heat recovery mode through the provision of a liquid cooled heat recovery condenser which thereby accommodates a portion of or all the condensing load, also requiring reduction in the capacity of the air cooled condenser through flooding. In order to provide sufficient refrigerant within the system to accommodate flooding under the conditions enumerated above, a refrigerant storage vessel is provided in communication with the shell of the evaporator of the system for receiving and storing excess liquid refrigerant during those operating conditions when it is not required in order to flood the air cooled condenser.

Abstract: An improved refrigerator partition bottom closure support frame assembly comprising a pair of side wall sections and a rear wall section whereby the closure may be slidably removed and reinstalled without removal of the closure support. The support frame provides concealed adjustment gaps compensating for tolerance and manufacturing variations so as to reduce assembly time and improve the appearance of the refrigerator.

Abstract: Apparatus and method are disclosed for absorbing a subject vapor in an absorbent liquid wherein an additive is provided which exists in at least a vapor phase concurrently with the subject vapor, which additive is effective to reduce the surface tension of the absorbent liquid upon contact therewith. A heat transfer member is provided having a first surface over which absorbent liquid is passed such that a film is formed thereon, and a second surface over which a heat transfer fluid is passed in order to remove heat from the absorption process. Means are provided associated with the first surface of the heat transfer member for promoting interfacial turbulence between the film of absorbent liquid and the subject vapor such that a series of preferential absorption sites is established along the first surface.

Abstract: A cryostat for maintaining an inventory of a liquefied cryogen including a vacuum jacketed reservoir (Dewar) containing heat shields in the vacuum jacket, the heat shields cooled to different temperatures and a cryogen recondenser cooled by a cryogenic refrigerator. Included in the cryostat is an access passage to place objects in the cryogen and to support the refrigerator, the access passage including means to remove the refrigerator without opening the liquid cryogen to ambient atmosphere.