baber/WOPTO huggingface dataset:
Patent WO-03038986-A1 (WO)
Title: Schaltungsanordnung zum betreiben eines elektromotors
Inventor: KNAB NORBERT
IPC: H02P29/00
Filed: 2002-10-14
Abstract: Es wird eine Schaltungsanordnung zum Betreiben eines Elektromotors (46) vorgeschlagen, die einen Zeitgeber (22) enthält. Ein Regler stellt in Abhängigkeit von einem ersten Differenzsignal (15) zwischen einem Sollwertsignal (11) and einem Istwertsignal (14) ein erstes Schaltsignal (20) zur Bestromung des Elektromotors (46) bereit. Gleichzeitig wird der Zeitgeber (22) gestartet, der das Bestromungssignal (45) auf eine vorgegebene Maximalzeit (Tmax) begrenzt. Eine Detektionsanordnung (37) stellt eine Änderung des Sollwertsignals (11) fest und gibt daraufhin ein zweites Schaltsignal (38) ab, das ebenfalls den Zeitgeber (22) startet and die Bestromung des Elektromotors (46) veranlassen kann. Die Schaltungsanordnung schützt einerseits den Elektromotor (46) vor einer thermischen Überlastung und ermöglicht andererseits die Bestromung des Elektromotors (46) bei einer Sollwertänderung. Die erfindungsgemässe Schaltungsanordnung ist zum Einsatz in einem Verstellantrieb geeignet.
Patent WO-03071729-A1 (WO)
Inventor: SPETH MICHAEL
IPC: H04L1/00
Filed: 2003-01-24
Abstract: The invention relates to a device that (1) issues an input data block (10) comprising several bits as an output data block (13) with at least one puncturing or at least one repetition of at least one bit. The device (1) comprises an allocation unit (3) for allocating the bits of the input data block (10) to the bits of the output data block (13), with the aid of a modifiable puncturing or repetition model (incw(k)). The allocation unit (3) is in the form of a hardware circuit, which is designed to execute both puncturing and repetitive coding.
Patent WO-2004004957-A1 (WO)
Inventor: DIENER MARK
IPC: B23D53/04
Filed: 2003-06-21
Abstract: The invention relates to a metal-cutting band saw comprising a main carrier (3) to which an intermediate carrier (4) can be pivotably fixed. The saw frame (5), which can be set on the workpiece (16), is arranged on the intermediate carrier by means of a pivoting bearing or a parallel guide. The pivoting bearing (21) which interconnects the main carrier and the intermediate carrier is located above the workpiece to be machined.
Patent WO-2004026432-A1 (WO)
Title: Vorrichtung zum filtrieren eines fluids, insbesondere für kunststoffverarbeitende anlagen
Inventor: MIDDLER ROBERT
IPC: B29C48/03
Filed: 2003-07-18
Abstract: Die Erfindung betrifft eine Vorrichtung zum Filtrieren eines Fluids, insbesondere eines verflüssigten Kunststoffes mit einem Gehäuse mit einem Zufuhrkanal, einem Abfuhrkanal und ggf. Rückspülkanälen, wobei im Strömungsweg des Fluids in einem quer zur Strömungsrichtung verschieblich gelagerten Siebträger mindestens zwei Filterelemente in entsprechenden Siebräumen angeordnet und mit dem Zufuhrkanal und dem Abfuhrkanal in Verbindung bringbar sind, wobei jeder Siebraum zwei im Siebträger oder Gehäuse ausgearbeitete Zufuhrteilkanäle aufweist, die vom Siebraum zum Abfuhrkanal hin gerichtet sind, der Abfuhrkanal Gehäuseteilkanäle mit den Gehäuseteilkanälen durch Verschieben des Siebträgers miteinander zur Führung des Fluids verbindbar sind und dass ggf. Durch Verschieben des Siebträgers die Siebräume mit den Rückspülkanälen verbindbar sind.
Patent WO-2004048763-A1 (WO)
Title: Verfahren und vorrichtung zum betrieb eines einspritzsystems einer brennkraftmaschine
Inventor: RUEGER JOHANNES-JOERG
IPC: F02D41/24
Filed: 2003-11-04
Abstract: Bei einem Verfahren und einer Vorrichtung zum Betrieb eines Einspritzsystems einer Brennkraftmaschine (10), wobei eine Ansteuerung (215) eines Einspritzaktors (104) anhand wenigstens einer Zustandsgrösse des Einspritzsystems durchgeführt wird, ist zur Erhöhung der Mengengenauigkeit an zugemessenem Kraftstoff vorgesehen, dass die wenigstens eine Zustandsgröße erfasst und zwischengespeichert wird, dass der wenigstens eine Einspritzaktor (104) mit einem Ansteuerimpuls vorgebbarer Impulsdauer und vorgebbarer Ausgangsimpulshöhe angesteuert wird (520), dass bei der Ansteuerung (520) des wenigstens einen Einspritzaktors (104) eine Einspritzerkennung durchgeführt wird (525), dass die Impulshöhe des Ansteuerimpulses in vorgebbaren Schritten bei der vorgegebenen Impulsdauer so lange inkrementiert wird (535), bis eine Einspritzung erkannt wird (525), und dass im Falle einer erkannten Einspritzung die Impulshöhe des die Einspritzung bewirkenden Ansteuerimpulses als Funktion der erfassten Zustandsgrösse dauerhaft abgespeichert (530) und im zukünftigen Betrieb des Einspritzsystems bei der Ansteuerung des wenigstens einen Einspritzaktors zugrunde gelegt wird.
Patent WO-2004054746-A1 (WO)
Inventor: GERBER BEAT
IPC: B23D51/10
Filed: 2003-11-18
Abstract: L'invention concerne une scie à mouvement alternatif (10) qui comporte : une tige de piston (24) allongée, effectuant un mouvement alternatif ; et une lame de scie (27) qui est sensiblement parallèle à la tige de piston, qui peut être tendue au moyen d'un dispositif tendeur (32) supporté par l'extrémité de tige de piston (30) et qui présente une extrémité de fixation (28). L'objectif de l'invention est de simplifier la conception de cette scie à mouvement alternatif et de rendre sa production plus économique. A cet effet, le dispositif tendeur (32) est formé uniquement par l'extrémité de tige de piston (30) et les pièces (33, 38, 39, 40) qui sont montées dans cette dernière de manière à effectuer un coulissement rectiligne, notamment un mouvement alternatif, sans aucune autre pièce auxiliaire. Le dispositif tendeur de cette scie à mouvement alternatif présente une fiabilité de fonctionnement, une qualité et une robustesse excellentes.
Patent WO-2004060149-A1 (WO)
Title: Hygieneschutz für endoskope
Inventor: KRESS JUERGEN
IPC: A61B1/012
Filed: 2003-12-05
Abstract: Endoskop mit Hygieneschutz, der aus einer Hülle, die am distalen Ende geschlossen sowie zumindest stirnseitig für optische Informationen durchlässig ist, und die in Achsrichtung des Endoskops kondomartig aufrollbar ist, und aus einem oder mehreren parallel zum Endoskop verlaufenden Arbeitskanälen, die am distalen Ende der Hülle offen enden, wobei die Arbeitskanäle nur mit dem distalen Ende der Hülle verbunden sind, neben den Arbeitskanälen ein oder mehrere Vakuumkanäle mit einer oder mehreren Öffnungen, die auf der vom Patienten abgewandten Seite der Hülle enden, vorgesehen sind und die Arbeitskanäle zwischen der Außenseite des Endoskops und der Innenseite der Hülle positioniert sind. Die Erfindung betrifft ausserdem ein Verfahren zum Anlegen eines Endoskopschutzes, wobei zwischen Endoskop und Schutzhülle ein Unterdruck angelegt wird.
Patent DE-1805198-A1 (DE)
Title: Coating contg. a polyester and an N-methylol polymer
Inventor: FRANZ RIEMHOFER DR
IPC: C09D167/00
Filed: 1968-10-25
Abstract: Coating materials giving high flexibility with excellent hardness, consist of 50 to 10% of polymers or oligomers containing N-methylol ether groups and 50-90% of specified polyesters of mol.wt. 600-3000 (pref. 800-2500 eps. 1000-2000). The polyesters are made from polyols consisting of 1 to 40% (pref. 10 to 30 %) aliphatic polyols with 3 or 4 hydroxyl groups and 3 to 6 C atoms, the remainder being a mixture of 70 to 30 mol.% (pref. 60 to 40 mol.%) propane diol-(1,2) with diethylene glycol and/or di-propylene glycol. The acid component comprises 91 to 40 ml.% (pref. 75-60 mol.%) aromatic or cycloaliphatic dicarboxylic acids the remainder being aliphatic dicarboxylic acids with 4 to 12 C atoms.
Patent DE-1813418-A1 (DE)
Title: Safeguarding fuse against premature - ignition
Inventor: GRAF VON LUETTICHAU HARALD
IPC: F42C15/24
Filed: 1968-12-07
Abstract: Oscillating system is used as switching device; its frequency is adjustable in relation to max. value, and acceleration in given time interval, of the charge.
Patent DE-1813820-A1 (DE)
Title: Rotating cover for reactor with a sodium - vapour convection barrier
Inventor: HELMUT ROTHFUSS
IPC: G21C13/073
Filed: 1968-12-11
Abstract: The cover is for a liq. metal cooled reactor and the convection barrier prevents egress of the sodium vapour into the gap between the cover and the reactor pressure vessel. The cover, which may be raised and lowered, is mounted on a flange ring in the reactor pressure vessel. This ring is located above the level of the liquid metal coolant but is held at a temp. above solidifying temp. of the liq. metal.
Patent DE-1901169-A1 (DE)
Title: Polymerisation initiator containing two chelates of
Inventor: CHABERT HENRI
IPC: C08F4/70
Filed: 1969-01-10
Abstract: Initiator system for the polymerisation of ethylenically unsaturated monomer(s) at -30 deg. to 100 deg.C, contain (a) organic or inorganic oxidising agent, (b) a chelate derived from a ligand (at least bidentate) and a metal from groups (Ib), (IIb), (IVb), (Vb), (VIb), (IIIa), (IVa), (Va) and (VIII); the metal is capable of accepting one or more electron pairs from a donor, (c) an electron donor in an amount sufficient to complex all the medal of the chelate, and (d) one or more chelates, complexes, or salts of metals from the afore mentioned groups, the degree of coordination being different from that of the chelate (b).
Patent DE-1908357-A1 (DE)
Title: Switching arrangement for controlling - the cooling of furnaces and single workpieces
Inventor: EIERMANN DIPL-PHYS DR KURT
IPC: G05B19/07
Filed: 1969-02-20
Abstract: The temp. is measured with an electrical thermometer whose tension, increased by an amplifier is fed to comparator amplifiers which operate the control elements of the controlled system, such as output contactors, solenoids. The latters' command variable for the cooling is attained by the initial and end temp. of the cooling being present by the initial voltage of two potentiometers, and by the nominal value of the temp. during cooling being present by the initial tention of an operational amplifier in integrating circuit. The tapping of the potentiometer for the end temp. is connected via a variable resistance to the non-inverting input of the operational amplifier, and the tapping of the potentiometer for the initial temp. is connected to the inverting input.
Patent DE-1910308-A1 (DE)
Title: Butt welding of thermoplastic profiles
Inventor: BERNDT WOLFGANG
IPC: B29C65/20
Filed: 1969-02-28
Abstract: Butt welding of thermoplastic profiles. The purpose of this invention is to eliminate the overflow bead which is formed on pressing together heated ends of thermoplastic components. This arrangement is used especially for external mitred corners of a rectangular frame. When the corners are pressed together after withdrawal of the heating plate suitably shaped blocks are pressed simultaneously against the external and internal corners. This way the bead is suppressed and a smooth exterior appearance is obtained.
Patent DE-1916047-A1 (DE)
Title: Coating textiles wood by curtain spray
Inventor: LEHMANN FRIEDRICH
IPC: B05C19/04
Filed: 1969-03-28
Abstract: Powdered or granulated thermoplastic glue is sprinkled onto the workpiece and then fused under heat. The glue is best applied as a curtain onto the workpieces moving through, possibly using a spray and ports mounted along a tunnel, with bowls fitted to collect surplus or spillage glue. Used for coatings of textiles, wood, etc.
Patent DE-1917964-A1 (DE)
Title: High frequency welding of plastics
Inventor: GAUDLITZ GUSTAV
IPC: B29C33/16
Filed: 1969-04-09
Abstract: Pressure knife has a die insert, and dies for perforation, embossing, seam imitation, hollow punching etc. All the parts belonging to the knife or to a die are held in position magnetically or are cemented together by a solidifying fluid filler, preferably a synthesis resin.
Patent DE-1919053-A1 (DE)
Title: Controlling the circulation rate in a metal - desulphurisation bath
IPC: F27D27/00
Filed: 1969-04-15
Abstract: The bath is contained in two chambers which are under different pressure caused by gas or gas-forming substances, and separated by a tubular wall whose lower edge is spaced from the chamber floor. due to the difference in pressure, gas flows through the gap from one chamber to the other and into the space between the tubes. The pressure difference and the depth of immersion of the tube are such that the metal surface is below the upper tube apertures and, with an increased difference in pressure, is lowered to the lower tube edge. This results in two different rates of flow of the metal cycle.
Patent DE-1927310-A1 (DE)
Title: Anthraquinone dyestuffs for polyester - dyeing
Inventor: WILLIAM GREENHALGH COLIN
IPC: C09B1/473
Filed: 1969-05-29
Abstract: Anthraquinone dyestuffs of formula: in which X is hydroxy or amino, R is hydroxy, alkoxy, mercapto- or alkyl mercapto- groups, Z is a phenylene or naphthalene radical, which may be further substituted, and the rings A and B may be substituted, may be prepared by reacting an anthraquinone, in the presence of an acid catalyst, with a compound of formula HZR, (Z and R as defined above). The dyestuffs e.g. 1-amino-2-(4'-hydroxybenzyl)-anthraquinone and 1-hydroxy-2-(4'-hydroxybenzyl) anthraquinone, are useful for colouring synthetic textiles e.g. polyester fibres.
Patent DE-1928495-A1 (DE)
Title: Punch for extra deep pressings
Inventor: ANTON MAYER DIPL-ING
IPC: B21D37/10
Filed: 1969-06-04
Abstract: The punch is made up of three or more segments which have circumferential grooves on the outside and are mounted on a conical shaft. In operation, as the punch is pressed into the disc of metal, the segments are pushed upwards on the shaft so that their diameter increases by about 0.1 mm compared with that of the punch end. Thus more of the forming pressure is transferred via the teeth to the sides of the 'cup' and deeper drawings can be made without interstage annealing. On withdrawal, the segments retract to the smaller diameter. Minute corrugations formed inside the can are not detrimental.
Patent DE-1965167-A1 (DE)
Title: Etherified, acid-curable, phenol-formalde- - hyde resins
IPC: C08G8/28
Filed: 1969-12-27
Abstract: Condensation products of any phenol(s) with 1, 2, or 3 mol. formaldehyde, the condensates having been obtained in alkaline soln., are etherified with esters of formula:- The symbols have the following meaning:- m and n are zero to 10; X is O, S, SO2, NR, alkene or alkyne (opt. substd.) with one or more unsatd. bonds, arylene (mono- or polynuclear, opt. substd.); R1-8 are H, OH, halogen, -OSO3H, -OPO3H2, -NO2, alkyl, alkyne, alkene, aryl, in a variety of combinations and substitutions; keto-, alcoholic or aldehyde-gps. may be present. The products may be used as alkali-resistant putties, mortars, coating or castings.
Patent DE-2002015-A1 (DE)
Title: Longitudinal welding of tubes
IPC: B23K37/053
Filed: 1970-01-17
Abstract: Several clamping shoes press the workpiece, in the vicinity of the seam which is to be welded, against a support beam which serves as an electrode. A lifting device is provided for raising the workpiece, and comprises a table which can be raised and lowered and which has a bearing facilitating longitudinal and/or rotational movement of the workpiece.
Patent DE-2013578-A1 (DE)
Title: Chlorine pentafluoride prodn under modera-te -
IPC: B01J27/06
Filed: 1970-03-21
Abstract: ClF5 is produced by reacting ClF3 and/or ClF with at least stoichiometric amount of F2 at 60-200 degrees C and 80 atm in presence of catalyst of alkaline earth) and/or Ag fluoride on inert carrier, activated by treating with ClF3/F2 mixture to 60-200 degrees C. Product finds use as fluorinating agent and also, increasingly, as high energy oxidant in rocket technology, having better stability in storage than F2 or OF 2 and greater oxidising power than ClF3. process is suitable for (dis)continuous operation and can give quantitative ClF5 yields, in spite of moderate conditions used.
Patent DE-2024280-A1 (DE)
Title: Anti-flame agent for textile material - com prising dialkoxyphos - phonoalkyl-carbamates
IPC: D06M13/288
Filed: 1970-05-19
Abstract: Anti-flame agent for textile material is cpd of formula (where R1 and R2 are 1-4C alkyl or together form a 2-3C alkylene radical, R3 is H, 1-3C alkyl, methylol or 2-4C alkoxymethyl, R4 is H, methylol or alkoxymethyl with 2-4C, and A is alkylene with 2-6C). Above substances have advantage that they have no disagreeable odour and are toxic.
Patent DE-2025574-A1 (DE)
Title: New nitrophenanthrene carboxylic acids - increasing phagocytosic capability of human
IPC: C07D317/70
Filed: 1970-05-26
Abstract: New cpds. of formula: (where R1 to R8 and R10 independent of one another are H or 1-10C alkoxy, or R2 and R3, R3 and R4, R5 and R6 or R6 and R7 together represent a methylenedioxy group, in which however one of R1 to R8 or R10 is NO2; and R9 is H, 1-10C alkyl or a cation). A pref. cpd. is 6-methoxy-2,3-methylenedioxy-5-nitrophenanthrene-9-carboxylic acid methyl ester.
Patent DE-2026166-A1 (DE)
Title: Vehicle safety mirror - with foamed plastics filling
IPC: B60R1/04
Filed: 1970-05-29
Abstract: Corrosion-protected safety mirror for vehicles has the space between the mirror insert and the housing which encloses it filled with foamed polystyrene, plasticised PVC, silicone rubber, or soft or mid-hard polyurethane. Specifically, cellular polyethylene may also be used.
Patent DE-2034035-A1 (DE)
Title: Candle hot melt mould roller - composed of negative die of ornament rotated in contact with candle turning opposite way
IPC: C11C5/02
Filed: 1970-07-09
Abstract: Negative mould or ornament to be applied to the candle is placed on a shaft and rotated slowly, being heated during this process by oil pumped up and round from a tank below. The candle is rotated the opposite way and contacted ith the roller mould so that the ornament is melted into the outside of the candle. Process time is greatly reduced.
Patent DE-2034805-A1 (DE)
Title: Card feed hopper incorporating pneumatic conveyor, perforated - drum fibre supply and level control
IPC: D01G23/02
Filed: 1970-07-14
Abstract: Loose stock supplied from an opening plant by a pneumatic conveyor system is fed to the hopper feed of a carding machine. At the top of the hopper feed the supply of stock is controlled by a perforated drum divided at its periphery into four compartments by comb plates. Air is extracted from the centre of the drum. The action of a vibrator plate in the hopper is controlled by a cam and spring sensing the pressure of material in the hopper. A level control governs the speed of rotation of the perforated drum which may be intermittently driven. Several drum and hopper units may be connected in series to the pneumatic conveyor system.
Patent DE-2036312-A1 (DE)
Title: N-sulphamoyl-n'-carboxy-urea derivs - plastics assistants and intermediates for plant protection agents
IPC: A01N47/42
Filed: 1970-07-22
Abstract: Cpds. of formula R1NHSO2-N=CX-NR1-COOR2 and the tautomeric keto forms (where R1 is opt. substd. (ar)aliphatic; R2 is opt. substd. (ar)aliphatic or aromaticf X=OR3, SR3, NHR3 or NHNR3R4; R3 is H or as R2; R4 is COR3 or R3) are plastics assistants and intermediates for plant protection agents, and may be prepd. by reacting a cpd. of formula with HX at - 70 to 200 degrees C, pref. -50 to 70 degrees C pref. in the presence of base and solvent.
Patent DE-2054531-A1 (DE)
Title: Compressed respiration air purifier - with air heater in line between stages
IPC: B01D53/04
Filed: 1970-11-05
Abstract: A compressed air purification plant, for air respiration, esp. for divers, fire fighting units etc. consisting of a series of individual chambers connected in a particular sequence and containing silica gel, Hopcalite and chemical adsorber, is constructed with separate vessels containing the silica gel, hopcalite and chemical adsorber, and interconnected by pipes; the pipe connecting the silica gel vessel to the Hopcalite vessel contains an air preheater and a non-return valve. the advantage of the arrangement is that improved purification is achieved in the last, adsorbing stage.
Patent DE-2059792-A1 (DE)
Title: Amylase determination in body fluids
Inventor: P HENSON CARL
IPC: C12Q1/40
Filed: 1970-12-04
Abstract: An indicator compn. comprises (a) a tetrazole salt pref. of formula: where R1 is phenyl, naphthyl, p-iodophenyl or 3-methoxyphenyl; R2 and R3 are H or NO2; n is 1 or 2 (when n = 2, the two halves of the molecule are identical and when n = 1, R1 is linked to H), and (b) a PH 12-12.5 buffer. A prefd. indicator is neotetrazolium chloride.
Patent DE-2062465-A1 (DE)
Title: Scouring agent - for dish washing machines, contg aminopolycarboxylic acid and alkali silicate
IPC: C11D3/08
Filed: 1970-12-18
Abstract: Dish cleaning agent, useful as substitute for phosphate cleaners, contains (a) 5-90wt.% aminopolycarboxylic acid or salts, (b) 90-5wt.% soluble alkali silicate (esp. with alkali oxide:SiO2 1:0.5-3.5 ratio (c) 0-5wt.% alkali hydroxide or carbonate, (d) 0-10 wt.% weakly foaming non-ionogenic tenside e.g. alkylene oxide adducts on higher fatty alcohols or 12-18C alkylphenols or on polypropylene glycols of 900-4000 mol.wt., (e) 0-10 wt.% active Cl-yielding cpd. esp. K di-chloroisocyanurate, (f) 0.5wt.% enzyme(s) such as hydrolases, esp. amylases, proteases and lipases, (g) 0-10wt.% complexing agents, e.g. hydroxypolycarboxylic, aminopolyphosphonic and hydroxyalkanephosphonic acids, and their water-soluble salts; composn. pH being 7-12 (8-11 in dilute aq. soln.). Liquid composn. esp. contains 10-50 wt.% (a), 2-20wt.% (b), 2-20 wt.% alkali hydroxide, 30-86 wt.% water. Composns. opt. contain, as (a), EDTA, aminotriacetic acid or their salts, and pref. (b):(a) ratio is 1-0.5 to 18.
Patent DE-2062995-A1 (DE)
Title: Acrylic contact lens prod by hydrophilising sheet material with alkal
IPC: C08J7/12
Filed: 1970-12-21
Abstract: Hydrophilic copolymer is prod. by (a) forming a copolymerisable mixt. of 75 - 92% MMA and 8 - 25% acrylic acid (b) transporting the mixt. into a mould (c) heating the mixt. to 40 - 65 degrees C (d) removing the copolymer with a soln. contng. 0.1 - 5 wt.% base for not longer than 48 hrs. The method is directed to the prodn. of contact lenses which combine the good optical props. of acrylics with non-irritation to corneal surfaces without adversely affecting clarity or increasing the risk of bacterial infection.
Patent DE-2101232-A1 (DE)
Title: Plastic welding - with pivoted lifter and curved pivoted welding pads to work all films
IPC: B29C65/00
Filed: 1971-01-12
Abstract: The use of pivots on the operating lifters, and on the curved welding heads allows the setting of an infinite range of welding pressures and welding lengths in bonding thermoplastic film to thermoplastic tubular films according to the material's welding characteristics and its thickness, in a simply-constructed welding unit.
Patent DE-2121844-A1 (DE)
Title: Porous reaction cell - with parallel continuous capillaries and separate channels for phases of different wettability
IPC: C10K1/14
Filed: 1971-05-04
Abstract: A porous reaction body is used for chemical or electrochemical reactions or exchange reactions between phases of different wetability which are not completely miscible, inside a porous body. Patent no. DT 1541456 is improved by replacing the system of large pores by parallel contiguous capillaries of equal dia., with separate inlet and outlet for phases of different wettability.
Patent DE-2134721-A1 (DE)
Title: Power station cooling system - with reduced overall thermal losses to increase thermal efficiency
Inventor: EIGNER OTTO
IPC: F01K17/00
Filed: 1971-07-12
Abstract: The working fluid in either a thermal or nuclear power station is recondensed in the normal way and the heat energy given up to the cooling water is extracted by cascaded heat pumps the resultant high level heat energy being either fed back into the steam raising etc. system (e.g. feed water heating) or used externally e.g. district heating system so that there is maximum use made of the heat energy fed into the system initially and minimum disturbance to the environment. Cooling towers and heat engines for energy conversion may be associated with the heat pumps.