Abstract: The rate of speed of thread being fed to a sewing machine needle is monitored so that when the thread speed decreases, indicating one or more malfunctions in the sewing operation, the operation of the sewing machine is automatically terminated.

Abstract: A low inertia drive mechanism is disclosed for imparting translational movement to a sewing machine fabric clamp. The drive mechanism comprises a first and second rigid tables mounted on guide rods for independent translational movements in mutually perpendicular straight paths. The second table carries a pair of transverse rods on which a third rigid table is slidably mounted which may move in any direction in a plane parallel to the planes of said first and second tables. The drive mechanism also comprises stationary motors not carried by any of the tables for imparting reciprocatory motion to the first and second rigid tables. The mechanism further includes means for connecting the fabric clamp to the third rigid table.Also disclosed is a fabric clamp for supporting and guiding fabric for use with a variable translation fabric feeding mechanism.

Abstract: Apparatus for guiding work through a sewing machine in which the work, as it is fed through the machine, is biased laterally into engagement with an edge guide by a vacuum-induced flow of air. The apparatus is particularly useful for guiding superposed plies of material as they are fed through the machine and aligning the edges of the plies along which they are stitched by the machine.

Abstract: A system is disclosed in which a first information carrying member with multiple pieces of bight information recorded thereon to control the position of lateral oscillation of a needle, and a second information carrying member with multiple pieces of feed information recorded thereon to control the length and direction of feed movement of a feed dog are driven individually by a single step motor with a substantially fixed phase difference in timed relation to rotation of the main shaft of a sewing machine. One information carrying member is secured to the output shaft of the step motor, while the other information carrying member is fitted thereto loosely. Holding means normally functions to hold the two information carrying members at given relative angular positions, and permits said other information carrying member to rotate relatively to said one in both forward and reverse directions from said given angular position within a predetermined angular range.

Abstract: A method and apparatus for forming a continuous chain of stitches between pieces of material on a double needle sewing machine which includes a sensing device for detecting the presence of material in the sewing area and connected to the sensing device elements are provided for releasing the tension on one of the needle threads upon indication of absence of material in the sewing area. Additionally an auxiliary feed device functioning in cooperation with the machine's feed dog and needle plate is effective in simultaneously advancing the untensioned needle thread with the single chain of stitches being formed.

Abstract: An automatic color bobbin changer for attachment to a sewing machine, the automatic color bobbin changer having first and second grasping fingers to cooperate together and detach a first bobbin case from a sewing machine and deliver the first bobbin case to a storage area for further use or discarding. The first and second grasping fingers also function in the preferred embodiment to pick up a second bobbin case having thread of the same or different color from the storage area and deliver the second bobbin case into operative engagement with the sewing machine.

Abstract: There is disclosed an easy-opening convenience end for generally cylindrical containers in which an end closure has a push tab or gate panel formed out of the thickness of the end closure and displaced beneath the plane of the end closure with a folded protective edge circumscribing the outer periphery of the gate panel, except for a limited portion which defines a hinge section between the gate panel and end closure. The folded edge tapers or otherwise merges into the thickness of the end closure adjacent to the hinge section, and a line of weakening or separation is formed between the fold and gate panel by a metal shearing operation so as to permit opening of the end closure by depression of the tab inwardly about its hinge section.Modified forms of ends incorporate relatively broad reinforcing areas in the closure surrounding opposite sides of the gate panel to facilitate initial separation of the gate panel away from the end.

Abstract: Method and apparatus for reducing torpedo drag in which polymer drag redug material is carried by the torpedo in concentrated form, ambient water is ingested and mixed with the concentrated polymer to produce a seawater-polymer solution of predetermined concentration, and the solution is ejected from the torpedo nose to be swept rearwardly in intimate contact with the exterior surface of the torpedo under torpedo forward motion.

Abstract: A skate sail is rigged with leading edge spars set by manipulation of a cruciform frame. The sail and frame assembly is suitable for mounting on a boat or vehicle as well as for being hand held, and is collapsible for compact stowing. When provided with a cinch line the sail assembly can be used for hang gliding. Rigging is set by joining separable lengths of a mast and advancing a transverse brace along the mast toward the mast head to deploy by toggle-like action head spars to which the sail is lashed thereby spreading and drawing taut a trapezium configuration of sail foil which is anchored to the foot of the mast. Laterally extendable wings may be provided and deployed separately to provide troughs which catch air spilling from the main sail foil and ease handling of the sail and enhance the ability of a user to trim the sail readily.

Abstract: 1. Apparatus for decreasing the intensity of cosmic rays at a selected dince beneath a relatively empty displacement volume in an otherwise uniformly loaded ship floating on a body of water comprising in combination,a ship having a relatively empty displacement volume, andmeans for establishing in vertical alinement with said volume a charged particle deflecting field having a strength and configuration effective to divert from a region at said selected distance directly beneath said volume a major fraction of the charged particles which would be prevented from reaching said region by absorption in water displaced by said volume.

Abstract: A bell and clapper assembly is provided comprising a transparent glass bell housing and hollow handle integral therewith wherein a clapper having an aesthetic appearance of selected design motif is removably mounted in the bell housing. A clapper of selected design may readily be suspended in the bell by the supplier, the retailer or at a subsequent time by the purchaser by virtue of the fact that the clapper is carried by a flexible chain having a sleeve at the upper end thereof which aligns with an opening at the top of the handle and removably receives the threaded post of a decorative rosette fastener engaging the top surface of the bell handle.

Abstract: A sheet of opaque plastic the shape and dimensions of a book page, with an arrow cutout shaped in the sheet extending beyond the page on the right edge as viewed when a book is opened, to indicate as to whether it is the upper or lower part of either page where the user's reading was interrupted. Also, a self-adhesive movable arrow label positioned on the right or left edge of the opaque plastic sheet to indicate the exact line on either page where reading was interrupted. This enables a reader to locate the exact line where reading was interrupted without looking over approximately eighty lines on two pages by glancing at both arrows. In addition, by viewing only five lines through an elongated rectangular cutout, eye strain is reduced.

Abstract: An apparatus for performing vapor deposition processes on a substrate includes essential housing having a centrally located reaction chamber, with the housing having a pair of opposed openings in opposed sides thereof. Cover means are removably secured to the housing for closing the opening and they define coolant chambers therein. Reaction gases are supplied and exhausted from the reaction chamber through a ducting system, and the housing includes at least one additional coolant chamber therein about periphery of the reaction chamber between the cover plates. Coolant is supplied to and exhausted from the coolant chambers in order to cool the reaction chamber, and support means are provided in the reaction chamber supporting a substrate thereon upon which vapor deposition is to occur. Heat is supplied in the reaction chamber on the side of the support means opposite the substrate to heat the substrate.

Abstract: An apparatus is disclosed for applying a plastic filament on the periphery of a face of a glass sheet which is adapted for use in the production of a multiple window pane unit. The apparatus includes an extrusion device for extruding on the glass sheet a plastic material having a viscosity greater than 115.degree. Mooney at the end of an 8 minute test at 40.degree. C. as measured by a Mooney consistometer, and support means defining a surface for supporting a glass sheet. The extrusion device includes a body portion and head member and an extrusion nozzle carried by the head member for extruding the plastic material. The nozzle extends from the head at right angles to the longitudinal axis of the device and the head is rotatable relative to the body portion about the longitudinal axis of the device to permit orientation of the nozzle at an angle of about between 15.degree. and 45.degree. with respect to the plane of the face of the glass sheet which is supported by the supporting means.

Abstract: A prosthetic spur for fighting cocks made of aluminum and provided with a socket adapted to fit onto an existing stump of the fighting cock where its natural spur would grow and having a pointed arcuate shape.

Abstract: A method is disclosed in which cultchless young oysters of a selected size taken from seed stock are placed in a first set of foraminous cribs and the first set of foraminous cribs are then placed on a shelf within an open top receptacle where the young oysters are protectively housed within the receptacle intermediate the top and bottom of the receptacle. Immature oysters of a larger size than the oysters placed in the first set of cribs are placed in a second set of foraminous cribs and the second set of foraminous cribs are placed across the open top of the receptacle above the first set of cribs. The second set of cribs are lashed to the top of the receptacle, whereupon the receptacle with its oyster containing cribs supported thereon are lowered to the bottom of a body of water where it is allowed to remain for a predetermined oyster growth period.

Abstract: A restraining device for cattle particularly suited for restraining a cow during delivery of a calf, the device includes an elongated bar having a pair of telescoping segments and a bolt extending therethrough for releasably securing the segments in a fixed relationship, a pair of cuffs pivotally connected to the opposite ends of the bar, each being adapted individually to receive a leg of a cow, a pair of stirrups suspended from the bar adapted to receive a pair of human feet, and a pair of eyes affixed to the bar adapted with a pair of spikes extended therethrough for securing the bar to the ground.

Abstract: A sling is provided for supporting horses and other large four legged animals in an upright position for short or extended periods of time while in a stationary or traveling mode. The sling includes three major parts: a T-shaped member which conforms to the sternum and shoulders of the animal; a belly band or sternum abdominal band attached to the T-member; and a tail piece attached to the abdominal band by six adjustable straps. If desired, straps can be connected to a halter and to the sternum abdominal band to provide support for the animal's head. Straps are attached to the abdominal sternum support band which can be detachably secured to a sling support for raising and lowering of the sling, and if desired, moving the animal along a track from one location to another. The entire sling is formed of an easily cleaned fabric.

Abstract: An animal grooming tethering device in which a safety break-away clip is used, having two generally resilient parallel arms connected to one another at one end, and a band slidable on the arms to adjust the clip to release the tether at a predetermined force corresponding to the weight of the animal. The device is intended for use as a leash on a grooming table, and will prevent injury to the animal in the event the animal jumps or falls from the table.

Abstract: A disabling circuit for a closed loop fuel controlled internal combustion engines of the type wherein fuel is completely cut off during deceleration includes a circuit for generating an electrical signal of a duration corresponding to the duration of fueld cut-off. A timing circuit respectively insensitive and sensitive to electrical signals of short and long durations derives a disabling signal which clamps the feedback signal to a suitable control voltage until the end of the electrical signal. The timing circuit is responsive to the end of the electrical signal to introduce a delay time to prolong the disabling signal and prevent the lean mixture fuel cut-off periods from adversely affecting control system when it resumes closed loop operation.

Abstract: A compression ignition internal combustion engine having a swirl chamber and a primary combustion chamber both of which are fluid-connected by a primary communicating passage has a recess portion at the fuel impinged portion of the swirl chamber for producing a plurality of small swirls. A pair of second communicating passages connecting the swirl chamber and the primary combustion chamber are so designed as to be directed to the center of the swirl chamber whereby the separation of fuel and air is prevented and the harmful components within the exhaust gas are effectively reduced without deteriorating the combustibility of the mixture.

Abstract: A water-cooled internal combustion engine for motor vehicles, particularly a diesel engine, with a cooling system comprising two separate cooling units, each of them consisting of a radiator and a fan, the first cooling unit being arranged forwardly of the engine receiving drive from the engine by mechanical transmission means, the fan of the second cooling unit receiving drive from the engine itself via transmission means, the first cooling unit dissipating at least 60% of maximum heat output and the second unit coming into action additionally to the first by means of temperature control.

Abstract: A jacket conduit which surrounds the exhaust gas at a portion equipped with an engine exhaust gas component sensor and is spaced from the exhaust gas conduit to define an air chamber on same and is formed with an air inlet opening which opens from the atmosphere into the air chamber for admitting atmospheric air thereinto and a flow control valve for controlling the ramming atmospheric air into the air chamber in accordance with the exhaust gas temperature and preferably one of the atmospheric temperature and the engine coolant temperature.

Abstract: An intake pipe arrangement for internal combustions is provided which includes an intake manifold and intake pipes arranged symmetrically pairwise at opposite sides thereof. In order to reduce the mutual vibrational influence of the intake pipes, the intake pipes are connected at the intake manifold with the end segments of the intake pipes approaching the intake manifold extending diagonally with respect to one another so that their imaginary extensions intersect in the intake manifold.

Abstract: An improved tubular composite for transmitting substantial thrust forces has a tubular core of continuous reinforcing fibers in a resin matrix unidirectionally and longitudinally oriented. Integral with the core is a sheath of resin impregnated continuous fibers oriented at about .+-.40.degree. to about .+-.60.degree. with respect to the longitudinal axis of the core.

Abstract: Disclosed is a device for promoting the purification of exhaust gas in an internal combustion engine at the time of warm-up. The opening degree of the throttle valve of the carburetor is temporarily maintained open at about 20 degrees immediately after the engine is started. After this, the throttle valve is closed stepwise to its idling position as the temperature of the engine is increased. When the gear shift of the transmission is shifted from neutral to, for example, low gear, for driving a vehicle in the case wherein the opening degree of the throttle valve is being held open at about 20 degrees, the throttle valve is automatically closed to an opening degree which is smaller than 20 degrees.

Abstract: A restriction is formed in a branch passage of the exhaust gas passageway of an engine having a plurality of combustion chambers, which passage communicates at its upstream end with only a part of the combustion chambers of the engine, to divide the branch passage into upstream and downstream sections, and the EGR passageway connects the upstream section and the induction passageway of the engine, and the EGR rate is controlled by controlling a vacuum for operating the EGR control valve in accordance with the pressure differential between the upstream and downstream sections and/or a venturi vacuum to control the degree of opening of the EGR control valve and therefore the pressure differential between the sections and therefore the flow rate of exhaust gases passing through the restriction.

Abstract: An exhaust gas recirculation system comprises a valve assembly for controlling the recirculation of exhaust gases in such a manner as to maintain a difference between a first and second pressure at a predetermined value. The first pressure is a pressure in a zone in an air induction passage between a throttle valve therein and a flow restrictor disposed therein downstream of the throttle valve, while the second pressure is a pressure in a zone in an exhaust gas recirculation passage between an exhaust gas recirculation flow control valve member and a second flow restrictor disposed therein downstream of the valve member.

Abstract: A low leakage integrator used in a carburetor feedback control system is disclosed. The integrator comprises an operational amplifier having a feedback capacitor coupled between its output and its inverting input terminal. Input voltages are coupled through a resistor to the inverting input terminal and a pair of controllable gates are utilized to implement an integrate and hold mode of operation for the integrator while minimizing the drift of the integrator output due to leakage currents during the hold mode of the integrator.The carburetor control system utilizes the above integrator in combination with a fuel mixture sensor and an engine position sensor to produce an output voltage related to the sensed fuel mixture. This output voltage is utilized to control a solenoid that adjusts the setting of a carburetor valve to thereby alter the carburetor fuel mixture as desired.

Abstract: To effect EGR in an internal combustion engine with the maintenance of adequate balance between the suppression of NO.sub.x formation and preservation of stable engine operation, the condition of combustion in the engine is taken as the basis of feedback control of the volume of recirculated exhaust gas so as to correct a deviation of the total amount of the recirculated exhaust gas and unexhausted combustion gas in the combustion chamber from a desired amount. The intensity of an ionic current produced upon combustion in each combustion chamber, the magnitude of mechanical vibration of the engine or the frequency of misfire in a combustion chamber is detected as an exact indication of the condition of combustion.

Abstract: A transducer modifies a subatmospheric pressure signal to create an operating pressure which positions an exhaust gas recirculation control valve. A regulating unit senses subatmospheric induction passage pressure to provide the pressure signal and prevents the pressure signal from dropping below a lower limit to thereby establish the maximum exhaust gas recirculation area produced by the control valve.

Abstract: A switching member simultaneously establishes a reference pressure and selects the pressure in one of two zones of a recirculation passage to create a control pressure, and a transducer regulates an operating pressure which positions a control valve to provide exhaust gas recirculation at rates which establish the pressures in the zones necessary to maintain the control pressure equal to the reference pressure. Exhaust gas recirculation thus varies with engine exhaust backpressure and accordingly is a proportion of induction air flow with the proportion being ruled by the switching member.

Abstract: An installation for preheating the suction or intake mixture of a carburetor internal combustion engine by means of an exhaust gas branch line branching off from an exhaust gas pipe system that is equipped with an exhaust gas manifold, and extending along parts of the suction pipe system in heat-exchanging relationship therewith, and which also includes a closure valve controlling the exhaust gas partial stream flowing through the branch line; a part of the exhaust gas pipe system is constructed as Venturi pipe of a gas jet pump and the exhaust gas branch line is connected downstream of the heat-exchange area with an annular space of the gas jet pump surrounding the Venturi pipe so that by the suction in the gas jet pump the branched-off exhaust gas partial stream is sucked back into the remaining exhaust gas stream, while the closure valve is arranged in the exhaust gas branch line.

Abstract: An installation for preheating the suction mixture of a carburetor internal combustion engine with a heat pipe extending from a place of the exhaust gas line system to a place of the suction pipe system and with a heat-absorption zone, on the one hand, and a heat emission zone on the other; the heat pipe leads from its heat-absorption zone to a lower part of the suction pipe directly adjoining the carburetor outlet and in its heat emission zone partly surrounds with its flat condenser jacket from below the flow channel of this pipe along a wall surface area while leaving free the main part of the pipe cross section.

Abstract: Several embodiments of induction systems for internal combustion engines including a relatively large main induction passage and a relatively small sub or auxiliary induction passage. The sub-intake passage is sized so that the charge issuing from it into the combustion chamber enters the chamber at a high velocity to improve flame propagation and combustion. Throttle valves are provided for diverting substantially all of the engines idle and low-speed charge requirements into the chamber through the sub-intake passage. In accordance with each embodiment of the invention, means are provided for causing a small amount of the charge flow during these idle and low-speed conditions also to pass through the main induction passage to minimize the effects of fuel condensation during transition from off-idle to high-speed operation. This arrangement also minimizes the likelihood of lean running during idle and low-speed operation as might also be caused by fuel condensation.

Abstract: A fuel economizer system for an internal combustion engine comprising a fuel supply tank, a main fuel supply line connecting the tank to the carburetor of the engine, and a fuel pump in the supply line for delivering fuel to the carburetor, an adjustable fuel metering valve positioned in the fuel supply line between the fuel pump and the carburetor, and means for automatically adjusting the metering valve in response to changes in load conditions on the engine to provide minimum fuel pressure and fuel to the carburetor inlet during idle and no-load conditions, while increasing the fuel pressure and amount of fuel supplied to the carburetor in response to increases in the load condition on the engine.

Abstract: A fuel injection apparatus with wetting action for use on a spark ignition internal combustion engine has a fuel injector positioned coaxially above the upstream end of an associated upstanding cylindrical throttle bore in a throttle body so as to discharge liquid fuel in a pulsed spray pattern toward the bore wall above the circular disc type throttle valve pivotably supported in the throttle bore to control air flow therethrough. The spray pattern is such that at closed or nearly closed throttle liquid fuel droplets will travel to the bore wall and collect on the same so as to gravitate downward toward the small openings between opposite sides of the throttle and bore wall for pick up and vaporization by the then substantially sonic air flow through these openings and, under open throttle conditions, the fuel droplets are dispersed in the airstream flowing through the throttle bore before any substantial quantity can reach the bore wall.

Abstract: To lock an internal combustion engine ignition distributor in the initial angular setting, the hold-down clamp member is provided with a tang portion that is accommodated in close tolerance fit by a complementary notch in the distributor mounting flange when the hold-down clamp is mounted upon the engine in a manner to securely clamp the distributor housing in place at the initial angular setting.

Abstract: An anti-theft device for an automotive vehicle or any internal combustion engine turned over by a starter, in which electrical energy is connected to the starter only at such times as several rotatable digital members are arranged in selected positions. The digital control means may be positioned in either of two alternative coded positions to energize the starter depending upon the position of a hidden switch which the user manipulates according to the particular code he desires.The digital means are connected to the starter such that an unauthorized "hot wire" creates a short circuit for the thief. Similarly, the ignition coil is so wired as to provide a short circuit if the thief should attempt to hot wire the ignition coil.

Abstract: An ignition arrangement with speed limitation for internal combustion engines in which a trigger pulse actuates a switch for generating a high ignition voltage, particularly a capacitor ignition device with thyristor control. A timing circuit is triggered by a pulse for preventing renewed actuation of the switch by a trigger pulse within a predetermined reference time interval of the timing circuit. The timing circuit, furthermore, short-circuits the control part of the switch. Each trigger pulse actuates the timing circuit only after the switch for generating the high voltage. A transistor is connected in parallel with the control path of the switch, and the transistor's control electrode is connected to the output of the timing circuit switched by the trigger pulse. An electronic discharge switch actuated by the trigger pulse, is connected in parallel to a time-determining capacitor of the timing circuit. Upon reaching a predetermined voltage across the capacitor, the latter resets the timing circuit.

Abstract: The invention contemplates a capacitor-discharge ignition system which includes a particular low-resistance, low-inductance, wire-wound circuit element at the spark plug which is operative with the spark plug and with the rest of the ignition system to materially suppress RFI generated at the spark gap. In application to high-speed, high-power two-cycle engines, use of the invention does not adversely affect engine performance.

Abstract: An internal combustion ignition system includes a switching transistor, an ignition transformer, a ballast resistor and a current sensing resistor. The primary winding of the transformer, and these two resistors are in series with the collector emitter path of the switching transistor across a supply. A sensing transistor has its base-emitter across the current sensing resistor and its collector connected to control a by-pass transistor with its collector-emitter across the ballast resistor. The transistor is on whenever the current in the sensing resistor is below a set level, thereby allowing a rapid current build up when the switching transistor is switched on.

Abstract: An internal combustion engine has an engine block, an oil pan and a sound insulating capsule shrouding the engine block. The engine block and the oil pan have circumferential mounting faces oriented towards one another. A mounting arrangement includes a sound dampening intermediate layer situated between the mounting faces for a noise-dampened connection of the oil pan with the engine block and with a lower terminal zone of the capsule. The oil pan is held by the lower terminal zone of the capsule and the capsule is supported by a component other than the internal combustion engine. The intermediate layer is constituted by a gasket which has at least one fold to take up relative motions between the engine block and the oil pan during operation of the internal combustion engine.

Abstract: A split engine operation of a multi-cylinder internal combustion engine having a closed loop or feed back control system is disclosed. At split engine operation mode, the feed back control will be suspended, and at full cylinder engine operation mode, the feed back control will be resumed. A relay is provided to suspend the supply of output from a PI detector to a fuel injection control unit. The relay is circuited with a cylinder selector unit via a counter so that the resumption of the supply of the output from the PI detector to the fuel injection control unit will take place when a predetermined time duration has past after the engine operating condition switched into full cylinder engine operation mode from split engine operation mode.

Abstract: A portable campfire grill employing three identical elongate members constructed of steel or like heat resistant material. Each of the elongate members has a pair of slots, one slot being formed adjacent each end and the respective slots being oriented in opposite directions. The slots have a depth half the width of the member so that when the elongate members are engaged by interengagement at the slots, the opposite surfaces of the elongate members are in coplanar relation thereby forming a triangular shaped grill structure having a flat surface. The slots have a dimension in a direction longitudinally of the members such that the members must be stressed to effect such interengagement so that the triangular structure formed by assembling the three members is retained in assembled, operative condition.

Abstract: A wood burning stove having an enclosure in which is located a first, V-shaped baffle plate extending horizontally from the front wall of the enclosure but spaced from the rear wall thereof, a second flat baffle plate having a rear edge in engagement with the rear wall of the stove enclosure and extending across the enclosure with the front edge thereof spaced from the interior of the front wall of the stove to define a vent space leading from the rear of the enclosure over the top of the V-shaped baffle plate, up the front wall and then back towards the rear wall over the top of the second, flat baffle plate to a flue opening, side air channels are provided to heat room air.

Abstract: Fire preventing shielding and air circulation apparatus for use with a box-type stove includes means for forming a chamber bounded at its top by the bottom of the firebox of the stove using a flat panel and upwardly extending apertured sides. A preferred embodiment also includes a stack formed on and bounded by the rear side of the stove and connected to communicate with the chamber.

Abstract: A device for supplying cold outside air of controlled volume and direction to a fireplace. The device includes a housing carrying an adjustable volume damper and direction damper for controlling the volume and direction of air flow from the device. Means are provided for maintaining the desired position of the direction damper and for limiting the directionality thereof.

Abstract: A solar heating panel, wherein the moving fluid is air, has a plurality of U-shaped flow paths from the inlet to the outlet. The flow paths are defined by L-shaped collectors which extend between a base sheet and a cover sheet. The cover is transparent to solar energy.

Abstract: The apparatus of the invention includes a heat collector which utilizes a dark-colored, conductive, fibrous heat absorber positioned to receive the sun's rays and to absorb heat therefrom. The apparatus also includes heat-transfer means which passes through or flows over the fibrous heat collector and absorbs heat therefrom. The fibrous heat absorber is a large-area sheet, and it is supported so that it has a generally corrugated contour to increase its effective surface area. The heat transfer means may be air or a fluid.The apparatus of the invention also includes a heat storage apparatus, which comprises essentially a container of metal-coated material such as eutectic crystals which are in liquid form when the heat of fusion has been absorbed and which are crystalline in form when the heat of fusion is given up and the crystals cool.