Abstract: A retractable indicator assembly 10 may be mounted on a container C which transmits air through the container and removes deleterious gases with an activated charcoal medium M in the container. An elongate indicator housing 12 has a chamber 20 therein. A male adaptor 14 has external threads 16 for sealing engagement with the container. A plug 40 is provided at the upper end of the housing 12. Housing 12 includes a transparent wall portion 28 for viewing at least a portion of the chamber 20. A litmus indicator 42 is moveable by a retractable rod 54 from a retracted position within the container to an extended position within the chamber 20 of the housing 12. An outer housing 64 is secured to the upper end of the rod 54, and protects the indicator housing 12 while the litmus indicator 42 is in its normally retracted position.

Abstract: A liquid injector has a tubular body surrounding and shielding a glass tube. The body and tube are sealed at opposing ends by a valve coupler and an end fill cap, each with there own O-ring seals. There are three openings through the body to allow for viewing of the contents of the tube, and to allow for light to pass into the tube. The injector is connected at the valve coupler through a hose and an on-off valve to the low side of an air conditioning system. It is connected through the end fill cap to a refrigerant charging system. The valve is shut off and the end fill cap is removed. The body is held upright and the liquid to be injected is poured into the glass tube. The fill end cap is replaced and the valve turned on. The charging system propels the liquid into the air conditioning system. The tube can be viewed through the openings to determined that a sufficient quantity of the liquid has been propelled from the injector.

Abstract: A sight glass assembly (1) is provided which is securable to a pressure vessel (V). The sight glass assembly includes a body (3) having top, bottom, front, back, and side walls defining a chamber (25) which is in fluid communication with the interior of the vessel. A glass (7) is secured in the sight glass body by a cover (11) to permit viewing of the vessel contents and sensors in the sight glass chamber. A baffle (29) in the sight glass body divides the chamber into a front chamber (33) and a back chamber (31). The baffle causes steam foam or bubbles from the vessel to condense in the back chamber so that only liquid enters the front chamber. The sensors are placed in the front chamber where they cannot be contacted by the foam or bubbles. By preventing foam or bubbles from entering the front chamber, and thus from contacting the sensing devices and the glass, the possibility of false readings by the devices and etching of the glass during operational use of the assembly is reduced.

Abstract: A fuel dispensing nozzle is provided with a view glass/fuel flow indicator that are disposed between the main fuel valve and a downstream check valve. The view glass/flow indicator means comprise a pair of horizontally aligned view glasses. A plurality of embodiments illustrate the use of different sub-assemblies in providing the view glass/flow indicator functions, as well as different provisions for obtaining a seal that prevents leakage of fuel at the view glass units.

Abstract: An in-line sight indicator structure for a fluid system wherein a chamber defining flow-through sight housing includes a sight glass in one wall portion thereof and a support member extending from an opposite wall portion in spaced relation to the sight glass to support an indicator element mounted thereon within a fluid stream passed through the chamber, the housing being hermetically sealed from ambient.

Abstract: A cooling medium charge amount detector capable of detecting whether or not an actual amount of a cooling medium is a desired amount in comparison with the amount of the cooling medium necessary for a desired degree of supercooling on an inlet side of an expansion valve in a refrigeration circulation system, without using a sensor or computation means. A cooling medium on the inlet side of an expansion valve 23 in a refrigeration circulation system 20 is allowed to flow into a cooling medium charge amount detector 40. Throttles 41, 42, 43 are disposed in this cooling medium charge amount detector 40, and sight glasses 44, 45, 46 are disposed at both ends of the throttles 41, 42, 43 to detect a gas-liquid condition of the cooling medium. When the cooling medium flows into this cooling medium charge amount detector, the shift of the cooling medium from a liquid condition to a two-phase gas-liquid condition is checked upstream or downstream of any throttle to match the load condition at that time.

Abstract: A sight flow apparatus includes a body designed to be connected in-line to fluid pipes within a manufacturing plant or other facility. One or more window assemblies are removably mounted on the sides or ends of the body to allow visual inspection of fluid flow through the body cavity. A fluid indicator device i.e., a flapper assembly or a rotor assembly, is mounted within the body cavity and supported by an axle extending between the windows, between the body itself, or between a pair of alignment washers located within the body. The rotor assembly includes a plurality of planar blades which are interconnected to form generally radially extending vanes. An enlarged indicator cap is coupled to each end of the rotor assembly to improve visual examination of fluid flow effects, to lock the interconnected blades together and to prevent the blades from contacting the windows, alignment washer or body.

Abstract: Apparatus and methods for periodically testing emergency wash units which involve the use of a transparent splash containment device which is positioned over an emergency wash unit and optionally attached thereto. The transparent splash containment device diverts and directs water flow to the drain of the emergency wash unit. An alignment indicator including sighting marks is provided to determine the alignment of the water flow. The sighting marks are provided with grid scales which can be used to estimate the velocity of the water flow.

Abstract: A sight flow product includes a body having a fluid inlet and a fluid outlet. The fluid inlet and fluid outlet are designed to be connected in-line to fluid pipes within a manufacturing plant or other facility. A cartridge can be located within and conform substantially to a cavity in the body. One or more window assemblies are removably mounted on sides or ends of the body to retain and locate the cartridge within the body cavity. The cartridge can be removed from the body and replaced when either of the window assemblies has been removed. Each of the window assemblies includes a transparent window to allow visual inspection of fluid flow through the sight flow product. A fluid sensing device e.g., a flapper, rotor or condensation drip tube, can be mounted within the cartridge by connection to the cartridge itself or by connection to opposed alignment washers in the window assemblies to facilitate visually inspecting the fluid flow in the sight flow product.

Abstract: This invention is directed to a sight glass structure positioned in conduit means connecting a suction accumulator and compressor in a refrigeration system. The sight glass structure herein provided may take the form of bushing means rigidly attached to the conduit means and threadably or otherwise receiving an axially passaged sight glass member providing visual communication with the interior of the conduit means, thereby permitting the detection or observation of any slugs of vaporized refrigerant passing from the suction accumulator to the compressor. Another form of the invention includes diametrally opposed bushing means affixed to the conduit means, and each bushing means is similarly equipped with sight glass members of like construction. Either form of the invention, if desired, may include within the sight glass member means impeding movement of the slugs or droplets, thereby improving the detection or observation thereof.

Abstract: A sanitary sight indicator for viewing the contents of a production process is provided. The sanitary sight indicator includes a body, an optical unit, and a sanitary connection between the body and the optical unit. The body includes a process-interfacing portion which is adapted to interface with the production process and an optical-interfacing portion which interfaces with the optical unit. The optical unit includes a viewing portion for viewing the contents of the production process and a body-interfacing portion which interfaces with the optical-interfacing portion of the body. The sanitary connection includes a sanitary gasket having a substantially flat annular portion, and first and second annular projections which are approximately semi-circular in cross-sectional shape and which extend outwardly from opposite sides of the annular portion. The sanitary connection further includes a sanitary gasket-groove in each of the optical unit-interfacing portion and the body-interfacing portion.

Abstract: A vapor recovery process signals to customers the presence of flow of gasoline or other liquid fuel and the return flow of vapors. In the preferred process, a customer's tank is fueled with a vapor recovery nozzle. Vapors emitted during fueling are collected by the nozzle and passed to a vapor return hose and then into a storage tank. A vapor flow indicator on the nozzle signals flow of vapors passing through the nozzle. A separate fuel flow indicator in the nozzle signals fueling, i.e., passing a fuel through the nozzle into the customer's tank.

Abstract: A system is provided for determining the presence, or absence of a component on the end of a vacuum pickup device. A monitor having a transparent body portion and plural air flow passageways is provided. An indicator is provided for each vacuum pickup device and contained within the air flow passageway intermediate a vacuum source and the vacuum pickup device. The position of the indicators within the flow passage is dependent upon the presence, or absence of a component on the end of the vacuum pickup device. With a component present on the pickup device, air flow through the passageway, due to the application of the vacuum source, is minimal and the indicator will be biased in a first direction. However, when a component is absent the pickup device, substantial air flow occurs through the passageway, thereby biasing the indicator in a second direction.

Abstract: A simple and compact fluid pressure indicator comprising a housing having a passage communicating with the pressure to be monitored leading to an interior chamber, a flexible diaphragm sealing and dividing the chamber into two parts, a colored indicator area on one side of the diaphragm, a light transmitting viewing window axially aligned with and parallel to the indicator area, and a sealed flexible envelope of light-absorbing fluid interposed between the indicator area and viewing window. A change in the monitored pressure causes the diaphragm to flex and the indicator area to be displaced, altering the thickness of the absorbing fluid envelope, and therefore the amount of light reflected from the indicator area. Thus a very small change in pressure will result in a dramatic color change displayed in the viewing window, providing a sensitive pressure indication.

Abstract: The visual monitoring apparatus includes a transparent tube section with coupling flanges at each end for coupling to adjacent conduit sections carrying a stream of conditioned sludge which includes agglomerated solid bodies. Control rods extend between the coupling flanges to strengthen the tube. A strobe light is mounted in a housing which is mountable alongside the tube and closely conforms to the shape thereof for confining the strobe light to a predetermined area of the tube and isolating that area from ambient light. The housing accommodates the control rods therethrough and contains a mirror which directs light reflected from the illuminated contents of the tube along a viewing path through a view port in the housing which is closed by a door or hatch. The frequency of the strobe can be adjusted to correspond to the flow rate of the fluid in the tube for creating the visual impression of substantially stopping the movement of the solid bodies in the tube.

Abstract: A sight glass includes a solid acrylic ring-shaped body with a glass tubular liner mounted to the interior cylindrical surface of the body with a fuel and fuel-additive resistant sealant. The liner has a diameter slightly less than the interior diameter of the body so as to form an annular air space therebetween. The sealant is also an adhesive which connects the liner to the body. O-rings at the forward and rearward edges of the liner maintian the annular air space between the liner and body. The adhesive/sealant is a flexible resilient material which will permit the liner to move slightly longitudinally.

Abstract: A self cleaning device for rotatable sight glass equipped visual flow indicators (for visually indicating fluid flow therethrough) that includes several stationary wiper implements that each include a wiper holder fixedly mounting a wiper in the form of a tube of compressible material that is in compressed wiping engagement with the inside surfacing of the sight glass, for improved wiping away of foreign materials when the sight glass is rotated for this purpose.

Abstract: An ink level sensor (18, 18', 18") is provided for detecting the level of ink in an ink cartridge (10) containing a capillary reservoir (14), such as foam, therein. The ink level sensor is a binary fluidic indicator, which provides both a human and machine readable indication of the level of the ink. A plurality of embodiments are described, including a two-port sensor (20), a one-port sensor (22), and a pair of fluidically-connected needles of different length (24).

Abstract: This invention is directed to a novel method of removably securing a sight glass member to a refrigeration vessel in hermetically sealed relation therewith. In accordance with the method concept, a ferrule or like tubular mounting means is fixedly attached to the vessel through an opening therein, and one end of the sight glass is located within the ferrule. Brazing metal is then positioned in contact with the sight glass member and ferrule, and the metal, member, and ferrule are heated by electromagnetic induction to melt the brazing metal and form a hermetic bond between the ferrule and sight glass member. By this method, leakage associated with threaded connections, and damage to the sight glass and extreme difficulty of removing the sight glass member when resistance or arc welding methods are used, are herein substantially entirely eliminated.

Abstract: A fluid flow indicator for use with light transmitting conduits having end fittings which include a bore. The flow indicator includes a base defined by a coiled wire closely received within the fitting bore and an axially extending indicator support which extends from the base into the conduit includes a rotatable flag whose rotation can be exteriorly observed or sensed as fluid flow occurs. The coiled wire base includes an abutment engaging with fitting structure for axially positioning the indicator relative to the fitting and conduit.

Abstract: A liquid level sight gauge useful in the fuel tank of a recreational vehicle such as a snowmobile is molded in two parts and can be installed without special tools in simple cylindrical holes provided in the wall of the tank or container. The gauge has a tubular body communicating with projecting cylindrical spigots which are passed through sleeves of a resilient gasket which sleeves secure them in the holes of the container wall.

Abstract: The device includes a main receptacle (1) having an overflow pipe (2) and a secondary receptacle (9) mounted so as to be freely movable in the vertical direction inside the main receptacle (1). The inner space of the secondary receptacle (9) communicates with a drainage pipe (8) for fluid lost by the hydraulic installation. The secondary receptacle (9) floats in the fluid contained in the main receptacle (1). The immersion level of the secondary receptacle (9) increases, depending on the amount of lost fluid received by the secondary receptacle (9), and the supply of fluid from the main receptacle (1) is caused by the immersion of the secondary receptacle (9).

Abstract: A sight flow indicator for visually indicating fluid flow through a conduit including a housing that has an inlet and an outlet and defines a flow passage between the two, the flow passage including a sighting region and a downstream restricted region that has a smaller flow area than said sighting region, a window in the housing providing viewing of the sighting region, and an elongated member that is located in the sighting region that is too long to move from the sighting region into the restricted region and is sufficiently smaller than the sighting region so as to be capable of vibrating about in the sighting region in response to flow of fluid therethrough.

Abstract: A brake bleeder wrench is provided with a transparent bleeder tube having a magnifying lens along upper portion thereof to improve visibility of air bubbles leaving the bleeder valve when the wrench opens the bleeder valve. In a modified form the head of the wrench contains an interchangeable drive hex socket to compensate for different types of bleeder valves.

Abstract: A gauge or indicator (20) for providing a positive on/off visual indication comprises a lens (22) and a transition mount (24) with a resilient diaphragm (32) secured therebetween to define a sealed chamber therein. The chamber is filled with an opaque liquid (34) and a contrasting plug (36) which is secured to the diaphragm (32) and movable therewith responsive to an actuator stem (38) between an "off" position obscured by the liquid and an "on" position wherein the plug is visible behind the lens (22) upon displacement of the liquid. Additional embodiments (50, and 70) are also disclosed.

Abstract: A safety viewing window for observing the interior of a pressure vessel is the subject of this invention. This viewing window is made up of an optically clear window disc fused to a metal frame. A laminate is overcoated over the fused disc and frame to provide a corrosion resistant viewing window. The metal frame has attached to it brackets for securing the entire unit to the vessel in a pressure tight manner.

Abstract: A sight glass assembly comprising a housing adapted to be mounted on a wall, the housing having a bore therethrough, the housing bore having an enlarged section providing a shoulder, a lens disposed in the enlarged bore section and seated on the shoulder, at least one deformable O-ring mounted on the lens and disposed between a periphery of the lens and a wall of the enlarged bore section of the housing, a retainer member threadedly mounted on the housing, the retainer member having a bore therethrough disposed in alignment with the housing bore when the retainer member is threadedly munted on the housing, the retainer bore having an enlarged section providing a shoulder and the lens being disposed between the housing and the retainer shoulders, the retainer member having a member receivable within the enlarged housing bore section between the housing and the lens when the retainer member is threadedly mounted on the housing for compressing the O-ring against the housing shoulder and causing the O-ring to exp

Abstract: Apparatus for providing a sight glass in the lower gearcase of a marine engine wherein the gearcase has a circular opening in its side. The circular opening has three concentric segments, the outermost segment has the largest diameter and is internally threaded. The center segment is sized to accomodate a disc-shaped transparent sight glass. The innermost segment has a diameter less than the center segment and the surface between the center and innermost segments contains an annular groove. An O-ring or resilient waterproof material fits into the annular groove and the disc-shaped sight glass is fitted into the center segment of the opening in the grearcase with its outer edge pressed against the O-ring. A ring-shaped window cover is then threadedly fitted into the outermost segment of the opening in the gearcase and firmly pressed against the sight glass and locked in place by a lock nut screwed into a threaded hole in the adjoining edges of the window cover and the gearcase.

Abstract: A gauge or indicator (20) for providing a positive on/off visual indication comprises a lens (22) and a transition mount (24) with a resilient diaphragm (32) secured therebetween to define a sealed chamber therein. The chamber is filled with an opaque liquid (34) and a contrasting plug (36) which is secured to the diaphragm (32) and movable therewith responsive to an actuator stem (38) between an "off" position obscured by the liquid and an "on" position wherein the plug is visible behind the lens (22) upon displacement of the liquid.

Abstract: A fluid indicator for viewing the condition of refrigerant flowing therethrough includes a brass body (12) having a cylindrical extending portion (26). The cylindrical extending portion includes a recess (30) bounded by a deflectable wall (28). An aperture (14) which includes a transparent glass pane (36) surrounded by a steel ring (38) is mounted in the recess and fixed therein by braze material. Tubes (16, 18) are brazeable into coupling portions (20, 22) of the body, and the fluid tight character of the indicator is unaffected despite failure to use a chill block, wet rag or other cooling device during the brazing operations.

Abstract: A transparent drain plug for the submersible transmission case of an outboard marine engine. The transparency of the plug permits the lubricating oil in the transmission to be viewed to determine by its color whether and to what extent water has seeped into the transmission. The plug has a special configuration which provides it with a lens effect to enhance the visibility of the transmission case interior.

Abstract: The thermometer device enables the temperature of hot water or mixed hot and cold water to be read directly from the outlet of a tap or faucet or mixing tap or shower head. The thermometer device comprises a cylinder (1) including a conventional nozzle-type device (2) such as an anti-splash nozzle, a spray nozzle, an aerating nozzle, or a flow rate restricting nozzle. The outer circumference of the thermometer device is fitted with a liquid crystal temperature-sensitive sheet (3). This temperature-sensitive sheet is protected from ingress of water by a transparent resin envelope (4) which is sealed by a sealing ring (5). When water runs through the tap, its temperature is communicated to the temperature-sensitive sheet by conduction through the cylinder, and is then displayed thereon.

Abstract: A chest cavity evacuation apparatus is provided with an air meter which is capable of directly measuring the volume of removed air. Small volumes of evacuated air are collected and measured, and the volume meter is resettable by tilting of the apparatus.

Abstract: A water management system for heat exchange devices is disclosed which includes an aqueous based heat exchange liquid containing dissolved corrosion inhibitors and a fluorescent dye, conduit means adapted to circulate the heat exchange liquid between a source of heat, such as an engine, and a cooling device, such as a radiator, a liquid or solid concentrate containing measured amounts of the corrosion inhibitors and the fluorescent dye packaged in defined unit quantities, and a comparator calibrated to provide a visual indication of the concentration of the corrosion inhibitors in the liquid and, if the concentration falls below an established level, the number of units that must be added to restore the established level.

Abstract: A sight glass assembly for observing the lubricant in the lower gearcase of a marine engine. The assembly is designed to be bonded into a circular hole in the lower gearcase housing and includes a window retaining ring which is bonded to the gearcase housing and a lock ring located inside the gearcase, an annular O-ring of resilient water proof material fitted into an annular groove in the retaining ring, a cylindrical disc-shaped transparent sight glass one of whose two outer edges is pressed against the O-ring, and a window cover having a central void and an annular face which is pressed against the second outer edge of the sight glass. The window cover is threadedly joined to the window retaining ring and is preferably locked into place by a lock screw threaded into a hole in the adjoining edges of the window retaining ring and the window cover.

Abstract: A rotary sight flow indicator which provides a visual indication of fluid flow and of the flow direction by the rotation of a shrouded cross-flow rotor. The sight flow indicator consists of a housing with a cavity containing the rotor and its shroud, and at least one view window by means of which the fluid inside the housing and the motion of the rotor can be observed. The rotor comprises a number of radial blades attached to a rotatable shaft placed substantially normal to the flow direction. A stationary shroud is positioned around a section of the circumference of the blades which shields the rotor blades from flow impingement during a portion of rotation. The asymmetric flow impingement on the rotor blades so created causes an unbalanced torque and consequently causes the rotor to turn.

Abstract: A metering sight glass is provided by a body of a transparent glass-like material having its ends polished to provide opposite viewing faces, the body being provided intermediate its length with dual axially aligned transverse passages, one of which provides a metering orifice, and the other of which provides a cavitation chamber positioned adjacent the metering orifice.

Abstract: An automatic shut-off device for interrupting flow to a remote system in response to a flow fault associated with the remote system. The device generally includes a flow detection assembly, which senses the fluid flow through the remote system, and a fault detection assembly, which detects an interruption in the flow associated with the remote system and accordingly shuts-off fluid flow through the flow detection assembly. The flow and fault detection assemblies are remotely housed yet are mechanically connected by a common valve stem which connects the fault valve assembly with the flow interruption assembly. A metering assembly disposed in the flow detection assembly is responsive to the fluid flow and provides a visual indication of the flow rate through the system. Also provided are means for manually resetting the device in order to provide fluid flow upon correction of the fault.

Abstract: An alarm test device for a sprinkler system incorporates test and drain valves, together with a sight glass and a metering orifice into a single test valve, with the option of employing a plug valve as the test and drain valves, and the further option of employing a combined sight glass and metering orifice as the plug valve.

Abstract: A liquid level control responsive to the level of liquid in a vessel having visual verification of fluid level including a tubular body for attachment to an opening in a vessel, the body having aligned openings in opposite sides receiving a pivot shaft, a control box mounted on one side and receiving an extension of the pivot shaft, an arm having one end attached to the pivot shaft and extending out the end of the body into the vessel and having a float on the end which is responsive to the level of liquid within the vessel, a control system within the box actuated by rotation of the pivot arm, and a transparent sight glass sealably closing the end of the tubular body so that the operator can observe the liquid level in the vessel through the sight glass.

Abstract: A flow indicator and a method for monitoring the operation of a chemical feed pump are provided. This indicator includes a housing defining a flow chamber and having an inlet through one end and an outlet through the other end. The inlet and the outlet of the housing are in communication with the fluid conduit of the pump, and the flow chamber is a vertical component of the flow path of the fluid flowing through the conduit. The housing contains two freely movable balls in the flow chamber, one ball having a specific gravity greater than that of the fluid and the other having a lower specific gravity. It is at least partially transparent to enable the operator of the indicator to observe the movement of the balls. The method for monitoring the pump involves placing the two balls in the flow chamber, connecting the indicator to the fluid conduit, operating the pump, and observing the action of the balls.

Abstract: The invention is an improved safety sight for liquid level detection in containers of liquids. The safety sight provides a means for such detection of the liquid level in automobile radiators, water tanks, oil tanks and other such vessels. The safety sight is composed of an insert for the vessel containing the liquid, a transparent lens or window piece to observe the liquid level, a retainer to hold the lens or window piece in the insert in the vessel and a seal under the lens or window piece to prevent leaks.

Abstract: A fuel pipe joint for connecting fuel pipes through which fuel is supplied from a fuel tank to an internal combustion engine mounted on a portable power-driven machine such as a chain saw. The fuel pipe joint has a main body made of a transparent synthetic resinous material and mounted on an upper portion of the fuel tank. The main body is equipped with a first pipe connector portion projected from the lower side of the main body into the tank and connected to a fuel pipe for sucking the fuel from the fuel tank, a second pipe connector portion projected from one side of the main body and connected to another fuel pipe leading to the internal combustion engine, and a fuel passage formed in the main body and providing a communication between the first and second pipe connector portions. The user can visually confirm the proper supply of the fuel, especially in starting up the engine.

Abstract: An angulated indicator lens secured to the top portion of a relay valve for providing maximum refraction and dispersion of the several indicating colors on the valve stem indicating the operative or inoperative position of the valve. The lens is constructed of a unitary transparent body having an interior angulated, truncated surface of approximately 45.degree. to the horizontal, with an exterior angulated, truncated upper viewing surface of approximately 54.degree. to the vertical. The transparent lens body receives ambient colored light from the stem providing the maximum refraction of light onto the first interior angulated surface and directing the color to be indicated through the lens medium and onto the second exterior angulated truncated surface for maximum indicating area.

Abstract: A cooking appliance including a vat for containing food during cooking, having a lid for engaging the vat. The lid has a transparent portion forming a double window consisting exclusively of an upper window and a lower window congruently placed on top of each other and an air space sealed therebetween, such that the lower window is exposed to cooking vapors emanating from the vat and the upper window is exposed to the outside atmosphere. Improved visibility through the windows is obtained during cooking. The upper and lower windows comprise a single unitary closed shell surrounding the air space.

Abstract: A flow indicator has a pivoting flap fitted in ducting of a hydraulic installation which transports contaminated liquids. To permit the purge of a reservoir, the flap has an opening for air returning through the ducting. The opening prevents overpressure or vacuum in a circuit. The invention applies specifically to purge and vent circuits for nuclear power installations.

Abstract: Disclosed is a pair of check valves for a home solar heating apparatus, one check valve for the solar collector supply line and one for the return line. The check valves have a transparent portion and an impeller which rotates during water flow and is located in the transparent portion, providing a visual check on water flow. Further, the impeller in the collector supply line acts as a check valve element which is gravity closed due to the impeller's greater-than-water density. Analogously, the impeller in the solar collector return line acts as a check valve due to its less-than-water density, these check valves operating to permit the usual direction of flow powered by a circulating pump but impeding the opposite direction of flow powered by thermosyphoning.

Abstract: A fuel gauge for locomotives comprises a block adapted for attachment to the locomotive fuel tank near the bottom thereof, preferably by connection with a tank drain plug. First and second chambers in the block are joined by a passage connecting the lower ends thereof and serve as a reservoir for an indicator liquid having a density greater than that of the fuel to be gauged and being immiscible with respect thereto. Valve-controlled passage means connects the interior of the tank with the upper end of the first of said chambers, permitting fuel to enter the first chamber and form an interface with said indicator liquid. A gauge glass connected with the upper end of the second of said chambers in conjunction with a gauge scale provides a visual indication of the quantity of fuel in the tank.

Abstract: A suction bottle for evacuating secretions from wounds is disclosed. The bottle includes a vacuum indicator arrangement located over a pressure opening 6 in the bottle, a sealing tube 7, a return spring 9, and a graduated scale bearer 10. In response to changes in pressure within the bottle, abutment 8 is caused to travel within graduated scale bearer 10, thus indicating the pressure within the bottle.

Abstract: An improved air filter restriction indicating device is disclosed for use in connection with an internal combustion engine intake air filtration system. The improvement resides in a novel structure for resetting the indicating device which permits the indicating device to be reliably used in cold, wet environments and in particularly dirty, dusty environments.