Abstract: The formation of a hermetic seal in an assembly resulting from the connection or encapsulation of one or more substrates such as cables by one or more dimensionally-recoverable covering members such as heat-recoverable sleeves is checked by detecting the increase in air pressure which occurs during heating of the assembly once a hermetic seal has been made. To this end, a covering member is provided with an aperture which communicates with a detection device such as a balloon or a manometer and with a space within the assembly in which there is a build up of air pressure.

Abstract: A whistle audibly responsive to extremely small pressure differentials is described. The whistle has a cylindrical inlet portion, a cylindrical outlet portion and a cylindrical constriction that form a passageway between said inlet and outlet portions. The whistle produces audible sound having an intensity of about 80 DB in response to a pressure differential, across the inlet and outlet portions, that is in the range of about 0.005 to 0.02 psi.

Abstract: A system for detecting changes in load on terrain and actuating an alarm in response thereto including a fluid system, a pressure-sensitive device in the fluid system having a first pressure signal output responsive to a load on a terrain, a second pressure signal output generating device responsive to said first pressure signal output, an alarm and a pressure-sensitive switch connected to said alarm, said switch being responsive to the second pressure signal output to actuate the alarm.

Abstract: Pressure drop detectors are provided which are suitable for use in pressurized fluid fire alarm systems. The pressure drop detectors have pressurized fluid circuits provided as channels in the surface of a block of material, including one channel connected to a source of fluid pressure. The channels are associated with valve regions by means of which, with a first diaphragm pressed thereagainst, a required one or more of the channels can be closed off.The pressure drop detectors have a normally pressurized region of the first diaphragm which by means of a first piston normally supports a mechanical linkage of the detector. If the pressure drops however on release of pressure in the circuit connected to the detector, the collapsing of the first diaphragm allows the mechanical linkage to be released thus actuating a fire alarm.

Abstract: A pressure monitoring device is disclosed which is adapted to couple a source of fluid with a tripping device. The tripping device includes a tripping switch movable between a first position in which a tripping signal is generated and a second position in which a tripping signal is not generated, and biasing means for biasing the tripping switch into the first position. The pressure monitoring device comprises pressure transmission means which is operable in a first mode and in a second mode, and coupling means having a first position and a second position. The pressure transmission means when operating in the first mode is responsive to the pressure of the fluid being monitored and when operating in the second mode is independent of the pressure of the fluid. The coupling means is operatively associated with the pressure transmission means and the tripping device for coupling the pressure transmission means to the tripping device.

Abstract: An alarm system to monitor pressure in tubes or containers that normally maintain (a) a constant pressure, i.e., a fixed pressure or a pressure of some steady or unchanging magnitude, (b) a periodic pressure, i.e., a pressure which oscillates with a regular interval a recognizable period or a pressure, the magnitude of which varies from some positive value to a value close to or less than zero and then returns to its original positive value in some regular interval of time, (c) or a fluctuating pressure, i.e., a pressure similar to a periodic pressure but differing by not having any fixed period of time for an oscillation; a pressure which shifts from positive to negative uncertainly, is described. This alarm system sets an audible or other signal should pressure in a monitored line fall for a longer than acceptable period.

Abstract: A low pressure warning cap for a pneumatic tire air valve including a generally cylindrical body having first and second ends, a cylinder adjacent the first end, a threaded connector for attachment to a conventional air valve stem of a pneumatic tire at the second end and an acting chamber connecting with and disposed intermediate the cylinder and the threaded connector, a piston disposed in the cylinder and resiliently biased toward the acting chamber, the cylinder having an opening at the first end, a deformable diaphragm disposed across the acting chamber between the threaded connector and the enlarged end, a perforated diaphragm disposed across the cylinder adjacent the opening, an elastic sack enveloping in air tight manner the first end including the opening, and a protuberance in the threaded connector to cooperate with the valve to open the valve upon attachment of the cap to valve, whereby, at a desired tire pressure, the deformable diaphragm is deformed by air from at the desired pressure to move th

Abstract: An acoustic alarm arrangement associatable with a pneumatic tire for generating a signal indicating that pressure of gas in the tire decreases from a predetermined magnitude, has a housing arranged to be connected with a tire and bounding an inner chamber, a signal element associated with the housing and actuated under the action of a strike, and a striking element movable in the inner chamber between an inoperative position in which it is spaced from the signal element and an operative position in which it approaches and strikes the latter. The striking element subdivides the inner chamber into a first compartment communicating with the interior of the tire, and a second compartment.

Abstract: A knob for a cooking vessel is a whistle which gives an audible signal that cooking temperature has been reached, and has a valve slide for shutting off the whistle. Supporting inside and outside knob parts incorporate halves of a resonance chamber, which makes the knob extremely simple to mold, assemble, clean, and disassemble. The valve slide rests in guides which make it impossible to assemble incorrectly, and overlaid by a knob cover.

Abstract: A breathing apparatus for supplying air to a helmet and/or protective clothing comprises a base plate; a core body secured to the base plate; an air driving device supported by the core body; an air inlet and an air outlet for the air driving device; an energy source secured to the base plate and connected to the air driving device for operating the same; an aerating hose coupled to the air outlet; and an air filter connected to the air inlet for filtering air driven through the air inlet, the air outlet and the aerating hose by the air driving device.

Abstract: A maintenance alarm actuator for a fluid filter actuates an alarm when contaminant has accumulated in the filter. The actuator is connected to fluid lines upstream and downstream of the filter. Included in the actuator are a valve and a biasing mechanism which biases the valve. The valve responds to the difference in the line pressures, and the actuator is initially triggered when the pressure of the upstream line exceeds that of the downstream line by an amount sufficient to overcome the force of the biasing mechanism. When initially triggered, the actuator vents the downstream line to the alarm, thereby increasing the difference in line pressure and causing itself to trigger completely.

Abstract: An enclosure, for example, a safety enclosure around noisy or potentially dangerous machinery, includes a door which, when opened, stops the operation of the machine to prevent injury to personnel who may examine or maintain the machine. A pneumatic safety system for the door includes, in series, a source of compressed air, an air regulator valve, a series of disconnectable air connectors and a transducer, such as an air pressure limit switch, which converts a decrease in air pressure into a control signal to stop the operation of the machine. One air connector member is mounted on the door and another on the door frame, so that they are automatically disconnected when the door is opened, thereby opening the pneumatic line and causing the air pressure to decrease. The connector members each have a flat face which meet in a flush relationship, one connector member having a round orifice and the other connector member having a multi-slotted orifice which leads to an internal air cavity.

Abstract: Early detection of cracks in nonpermeable, structural members subject to stress is effected before the cracks traverse the member by forming a plurality of cavities in the member or adjacent thereto in which a plurality of fluids at differing pressures are confined and monitored, such that a crack in the structural member penetrating between at least two cavities allows passage of fluid between the cavities and is thus detected by a pressure sensor. The apparatus and process is particularly applicable to early detection with vacuum of cracks in the heat affected zone adjacent to welds on critical stressed members of an offshore platform. A strain gauge system may be employed in conjunction with the crack detection system.

Abstract: An improved apparatus for removing lubricating compositions from crankcase oil pans of internal combustion engines through the oil dipstick well of the engine involves signalling means, acting in response to the amount of vapor flowing to the vacuum chamber of the apparatus to signal, preferably audibly signal, the completion of removal of lubricating composition from the crankcase oil pan.An improved method for removing lubricating composition from crankcase oil pans is also disclosed.

Abstract: An audible vibratory biased reed assembly having the properties of being activated or commencing vibration upon being subjected to a predetermined energy level. This assembly utilizes a straight, flat, elongated, closed or clapping reed, to produce a clatter or buzzing sound, with the reed being biased through application of a bias force to one edge to distort its flatness adjacent its free extremity. The bias force is applied by an angular transverse bridge which substantially triples the frequency of the mechanical clatter.

Abstract: The blockage indicator for an internal combustion engine air cleaner element has a cylindrical housing with ports provided in the cylindrical wall thereof. The housing accommodates an indicator drum which is carried on a stationary shaft mounted on the housing end wall. The cylindrical surface of the indicator drum has painted signalling areas. The indicator drum is fixed axially on the shaft and accommodates a spring adapted to turn the drum on the shaft.The indicator housing also accommodates a spring-loaded diaphragm which forms, in conjunction with the housing, a sealed-off chamber communicating with the cleaned-air chamber of the air cleaner involved. A locking device provides interaction between the diaphragm and the indicator drum whose bottom wall faces toward the diaphragm. This constructional arrangement reduces the overall dimensions of the indicator.

Abstract: A device including a chamber having two inlets and an outlet. One inlet is connected to an expiratory valve in a lung ventilator or like machine, the other inlet is in communication with a whistle and the outlet is connected to an aspirator. The device gives an intermittent audible signal when the ventilator is operating and saves the operator of the ventilator from having to look at the expiratory valve thereof to verify its correct operation.

Abstract: A differential pressure indicator including a remote sensing means is disclosed wherein a reference volume under predetermined pressure is employed as a standard, triggering an indicating mechanism when a second (measured) pressure falls above or below a predetermined threshold. The indicating mechanism may include a novel shaft which protrudes through the casing carrying thereon a source of radioactive material which is remotely monitored. Alternatively, the protrusion may be sensed as an impedance variation or additional visual indicator. In one embodiment, a plurality of the subject sensors are housed upon the blades of a helicopter. Upon sensing the changing pressure in the helicopter blade, the protruding element provides a radioactive source which is sensed in a conventional manner to provide a cockpit readout.

Abstract: A blood pressure indicator adapted for self-examination includes a blood pressure arm cuff having an inflatable bladder, and a pair of pressure sensing switches impinging on the bladder and set to audibly or visually indicate the maximum systolic and diastolic pressure permissible. The bladder is inflatable by a flexible bulb connected thereto through a hose and a unidirectional flow valve which maintains inflation of the bladder. As air leaks out of the bladder, the patient notes when the pulse returns to the brachial artery, in relation to the indications given by the switches to ascertain whether the blood pressure falls within the permissible tolerances.

Abstract: Apparatus for indicating a clogged condition of a fluid filter or the like. The apparatus includes an electrical switch structure and a pressure-responsive element carried within the chamber to be responsive to the fluid pressure differential existing across the filter. The switch includes a threaded screw element adapted to adjustably engage the fluid pressure-responsive element in the chamber which may comprise a snap action element providing a positive instantaneous indication of the pressure across the filter reaching the preselected elevated value indicative of undesirable clogging of the filter.

Abstract: An apparatus for monitoring the thickness of filter cake on a filter by using the difference in pressure between the inside of the filter apparatus and the inside of a hollow body spaced from a filter element to provide a signal of measurement.

Abstract: Method and apparatus for continuously detecting cracks in aircraft blades while in flight. A hollow blade is sealed with a pressure differential, either above or below atmospheric. A reduction in the pressure differential such as results from cracks, is detected by a pressure sensor having a member which moves between a high pressure differential position and a low pressure differential position. A radiation source, typically a beta source, is carried on the member and moves from a shielded position to an unshielded position when the pressure differential drops. A radiation detector is mounted on a fixed portion of the aircraft and detects radiation from the source when the member moves to the unshielded position. The detector output may be used to operate a go-no go indicator providing a warning signal when the pressure differential falls below a predetermined value, or to operate an analog indicator providing an output varying as a function of the pressure differential.

Abstract: The immersed hoses of a floating plant for charging and discharging mineral oil products comprise means for the immediate indication of impacts, partial damages and rupture of the hoses themselves. Said means consist of a hollow space provided in the wall of the hoses, filled with a fluid under pressure and connected to means for monitoring its variations.Impacts, partial damages and ruptures, originating a variation in the pressure of the fluid inside the hollow space, can be detected immediately.

Abstract: A fuel filter bypass valve assembly includes a valve body having inlet and opposite sides. A movable member is peripherally sealed to the opposite side, and moves toward and away therefrom to define a variable volume chamber. Port means extends past the valve body for establishing communication between such chamber and the valve body inlet side. Yieldable biasing means is connected with the movable member for normally biasing same toward the valve body opposite side and biasing the entire assembly in a direction for positioning the inlet side against a valve seat. Cooperating stop means between the movable member and valve body limits movement of such movable member away from the valve body opposite side. The movable member and valve body are proportioned so that the pressure required to move the movable member away from the valve body against the force of the biasing means is substantially less than the pressure required to move the valve body away from the valve seat against the force of the biasing means.

Abstract: A fluid filter has a fluid inlet, a fluid outlet, and a filter element in the fluid pathway, and is provided with a by-pass which includes a fluid pressure indicator. The by-pass comprises a cylinder attached to a cover and removable therewith. The cylinder has one aperture which provides fluid communication between the cylinder and the inlet and has another aperture which, when open, provides fluid communication between the cylinder and the outlet and hence provides a fluid pathway between the inlet and outlet which by-passes the filter element. A piston is movable within the cylinder responsively to fluid pressure from a first position where it closes the second aperture to a second position where the second aperture is open. The cylinder can be removed and mounted in a first position which provides both an indicating and a by-pass function or it can be rotated to a second position which provides only an indicating function.

Abstract: A switch apparatus for detecting an imbalance condition between a first fluid circuit and a second fluid circuit. The switch apparatus has a housing with a bore therein in which a sleeve is located. The sleeve has a peripheral section which is electrically non-conductive and a central bore therethrough with a first diameter and a second diameter. A first piston is located in the first diameter and a second piston is located in the second diameter. A pin is connected to the second piston to limit the movement thereof in the central bore. When a pressure imbalance occurs, the sleeve will move and allow a plunger to move off the non-conductive peripheral surface to complete an electric circuit to inform an operator of a potential brake system failure.

Abstract: Disclosed herein is a signal device for detecting the condition of a fluid line filter and automatically activating a signal indicating that the filter requires cleaning or replacement. The signal device may be built in or installed as an attachment in the fluid lines leading to and from a filter for removing moisture and/or contaminants from the line. The signal device comprises a piston housing containing a piston movable to signalling position in response to reduced fluid pressure adjacent one end of the piston resulting from reduced volume of fluid passing through the filter, locking means for retaining the piston in said signalling position, and signal actuating means activated by fluid pressure when the piston is in said signalling position. The signal may be visual or audible, actuated mechanically or electrically.

Abstract: A single differential area piston with annunciator flag and coacting malfunction indicia scale is capable of monitoring a relatively large number of malfunction or shut-down points on a compressor or the like. The annunciator piston responds to leakage of an operating fluid medium caused by venting to atmosphere of a particular malfunction sensor on a compressor or like machine with which the annunciator is connected. The annunciator or indicator additionally operates shut-down and start-up control instrumentalities for the monitored machine. A great simplification in tubing, tubing connections and venting means is obtained in comparison to the prior art.

Abstract: An air filtering apparatus is disclosed utilizing a prefilter at the inlet side and a HEPA type filter at the outlet side. The interior chamber of the apparatus is divided into two subchambers with a blower forceably pumping air from the inlet chamber to the outlet chamber. A first indicator means is responsive to a predetermined decrease in pressure in the inlet chamber for indicating when the prefilter needs changing, and a second indicator means is responsive to a predetermined increase in pressure in the outlet chamber indicating when the HEPA type filter requires changing. A plurality of the apparatuses may be utilized in an air filtering system controlled remotely by radio transmitting and receiving devices.

Abstract: An apparatus for intermittently sounding an audible alarm when the temperature within a deep freezer rises to a predetermined level which is less than the freezing temperature of most food products so that steps can be taken to prevent the food products from thawing. The apparatus includes a remote bulb element which intermittently opens and closes a container of liquefied gas which is permitted to expand and sound an alarm when the freezer malfunctions.

Abstract: A combination visual and audible differential pressure warning signal device for fluid power, that is, hydraulic and pneumatic systems such, for example, as those employed in mobile equipment, industrial machinery, or the like. Thus, in a typical use of the invention, when the pressure in the hydraulic system, as in an oil filter, drops below a desired and predetermined normal, due to clogging of the filter, or for other reasons, the hydraulic pressure from the source, such as an oil pump, overcomes the combined pressure or force of the oil entering the signal device from the filter and the force of a resetting coil spring in the signal device, to actuate magnetic means which raises a normally concealed colored (red) visual warning signal into a position in which it may be seen through a window in the body of the signal device while, at the same time, closing an electrical circuit to an audio or audio-visual warning signal device.

Abstract: Pressurized operating fluid, such as oil for hydrostatic fluid bearings, is directed into a chamber against a plunger urging the plunger into a first position. A monitoring pressure force slightly less than the force of the operating fluid when the operating fluid is at a minimum working pressure is exerted against the plunger tending to move the plunger from this first to a second position. Thus, when the pressure of the operating fluid drops below the minimum working pressure, the plunger is moved to its second position and such movement is sensed, thereby sensing the malfunction.

Abstract: A can structure suitable for packaging beer or the like includes an indicator formed integral with one end wall. The indicator provides visual, tactile and audible indication of the quality of the product in the can. Various specific indicator structures are disclosed.