Abstract: A temperature control circuit is disclosed utilizing automatically either the electric heating (or cooling) element or a separate sensor to measure the instantaneous temperature of the thermal load device. Either a pulsating dc or an ac electric power source may be used with the temperature sensing occurring at near-zero points of the source voltage waveform. The sensor forms one element of a Wheatstone bridge which when unbalanced by a value lower than a chosen reference value, causes a monostable oscillator to flip for at least several cycles of the source power. This turns on a power SCR to feed electric current to the thermal load to increase its temperature (and resistance) until the bridge is again balanced to reverse the state of the monostable oscillator and turn off the SCR. A simple, reliable two step, user friendly calibration circuit is provided for the temperature selecting component.

Abstract: A solder-desolder system includes a hand held tool having an electrically heated soldering tip which is a hollow tube through which molten solder may be removed from the workpiece by a steady inward flow of air or by a strong impulse, vacuum stroke. Also supplied to the workpiece is a flow of solder melting hot gas which may be inert for improved soldering performance. The hot gas is directed over the heated soldering tube and may independently melt the solder or it may be utilized to preheat the work. In any event, the system provides in a compact hand held soldering tool a jet of hot air within which is a hot soldering tube tip within which a vacuum flow removes molten solder from the workpiece.A further aspect of the solder-desolder system is a trigger in the handle of the tool which selectively connects the hollow tube to an ambient air driven venturi to provide the vacuum stroke.

Abstract: A replaceable tip for a hand held vacuum stroke desoldering tool. The tip or nozzle element is retained in a bore, in the otherwise closed front end of the tool, by a rear retaining shoulder and a forward compressible skirt-like barb which when radially compressed permits the removal or insertion of the tip element.

Abstract: A automated, milk inclusive espresso coffee machine which includes a fully automatic coffee grinding and brewing apparatus and a steam generator for driving a venturi mixing device which draws ambient air and milk from a refrigerated source for making milk inclusive espresso beverages, all milk contacting surfaces being either refrigerated or steam cleaned with each beverage made and served. A novel microprocessor controls all operations including brewing, steam generating, water heating, refrigerating, operations parameters, measuring and monitoring, many "house-keeping" functions and others.

Abstract: A metallic soldering tip is disclosed having a forward, outer retaining rim and a rear inwardly tapered skirted end of the character to be fitted loosely over a ceramic rod heating element. The tip is axially slotted from its rear edge to a point forward of the retaining rim. An inner sheath over the rear portion of the ceramic rod has a flared forward end which engages the tapered skirted end of the soldering tip while the reduced diameter forward end of an outer retaining sheath engages the retaining rim of the soldering tip and is drawn forcefully rearwardly by a retaining nut threaded onto the handle or body of the soldering implement. The rearward displacement of the outer sheath forces the slotted skirted portion of the soldering tip to press inwardly against the ceramic heating element by virtue of the tapered relation between the inner sheath, the rear of the soldering tip, retaining rim and the forward end of the outer retaining sheath.

Abstract: In a soldering system which utilizes a fine jet of very hot gas for heating the work point the hot air may impinge directly on the work point or it may heat a soldering tip from within whereby it may be used in a more conventional mode of soldering or desoldering. A regulated flow of gas to the heater of the soldering instrument may be somewhat preheated by passing along the leads carrying the electric power to the heating element. The same supply of air may also be used to cool the handle of the handle of the soldering instrument for operator comfort and safety. The temperature of the heating element is remotely electronically controlled by a time share use of the power leads as temperature sensing and feedback.

Abstract: A desoldering system utilizes a hot air soldering instrument which includes a hollow elongated cylindrical heating element capable of generating a high temperature. The cold input air is forced to move about the outer surface of the heating element. It is then directed to move between the inner surface of the heating element and the outer surface of an inner tube, whereby a primary and a secondary heating chamber are provided. In each heating chamber an open coil form or spring may be disposed to further increase the tortuous path of the air, and the heated air exits from the inner tube into a soldering tip from it is discharged, thus to provide a very hot air jet for soldering or desoldering purposes. Various modified instruments are disclosed for permitting either a hot air jet tip or a conventional soldering tip to be used. Also, a permanent air connection is featured in another modification to obviate the necessity of disassembling the air hose and other connections.

Abstract: A hand held, spring actuated single stroke piston desoldering instrument having a removable, replaceable nozzle tip in combination with a novel removal tool which also serves as a holder for several spare tips is disclosed. The barrel of the desoldering instrument is one-piece molded and includes an end cap portion with a forwardly protruding nose portion having a nozzle retaining central bore therethrough. The novel replaceable nozzle element has two annular grooves formed about its periphery: the first mates with an annular reduced diameter shoulder within the retaining bore of the end cap; the second is normally disposed forwardly of an outside of the end cap where it may be gripped by a pair of flexible jaws on the removal tool.

Abstract: A portable vacuum pump for desoldering applications has a hollow cylindrical barrel forming a vacuum cylinder containing a plunger. The pump has a trigger housing containing a single compression spring. The spring is mounted outside the barrel. No separate return spring is required to hold the trigger in the latched position. The single trigger keeps the spring end out of the barrel and thus out of contact with the soldering debris. This allows more space for the plunger, producing a longer stroke and a higher vacuum.

Abstract: Thermocouple apparatus is disclosed, utilizing interlocked loops of dissimilar wire. Base means, spring mounted, are provided for tensioning the loops whereby their point of interlock, in compression, forms a non-metallurgically bonded thermocouple junction. The end of each loop opposite its interlocked end is electrically connected by similar-metal means to a meter unit.