Abstract: A device for sealing off and monitoring a volume includes two seals. Support elements space the seals apart from one another. At least one conduit is disposed between the seals and the support elements. The at least one conduit has an inlet opening and an outlet opening for a medium. At least one sensor is associated with the outlet line. The two seals have edges being tightly joined to one another leaving the inlet and outlet openings of the at least one conduit free. The support elements are formed of a flow-hindering material. At least two devices may be tightly joined together to form a field, with the outlet opening of the at least one conduit of one of the at least two devices being connected to the inlet opening of the at least one conduit of another of the at least two devices.

Abstract: Pesticidal substituted pyridazinones of the formula ##STR1## in which R.sup.1 represents alkyl or halogenoalkyl, or represents optionally substituted cycloalkyl, or represents optionally substituted cycloalkylalkyl, or represents optionally substituted aralkyl,R.sup.2 represents halogen or alkyl,R.sup.3 and R.sup.4 independently of one another each represents hydrogen or alkyl,R.sup.5, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 independently of one another each represents hydrogen, halogen, alkyl, halogenoalkyl, alkoxy, halogenoalkoxy, alkylthio or halogenoalkylthio,X represents oxygen or sulphur andZ represents a radical of the formula --CH.dbd.CH--, --CH.sub.2 --O--, --O-- or --S--.

Abstract: The invention relates to acetals of the formula CH.sub.3 --CO--CH.dbd.C(OR).sub.2 where R is --(CH.sub.2).sub.n --OR' where n is 2 or 3 and R' is C.sub.1 -C.sub.5 -alkyl.In addition, the invention relates to a process for the preparation of acetals of the formula CH.sub.3 --CO--CH.dbd.C(OR).sub.2 where R is C.sub.1 -C.sub.12 -alkyl or R is --(CH.sub.2).sub.n --OR' where n is 2 or 3 and R' is C.sub.1 -C.sub.5 -alkyl. The process comprises reacting diketene with an alcohol of the formula ROH where R has the meaning indicated, in the presence of an acidic catalyst.

Abstract: Herbicidal pyrimidine derivatives of the formula ##STR1## in which R.sup.1 stands for optionally substituted alkyl,R.sup.2 stands for an optionally substituted radical from the group consisting of alkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl and heteroarylalkyl, andstands for halogen, amino, cyanoamino or for an optionally substituted radical from the series comprising alkoxy, alkylthio, alkylamino and dialkylamino.Intermediates of the formula ##STR2## in which R.sup.3 is optionally substituted alkyl or benzyl, and n is 0 or 2,are also new.

Abstract: Herbicidal substituted triazines of the formula ##STR1## in which A.sup.1 represents optionally branched and optionally aryl-substituted alkanediyl,A.sup.2 represents optionally branched alkanediyl,Q represents oxygen, sulphur, NH or N-alkyl,R.sup.1 represents hydrogen, hydroxyl, nitro, cyano, cyanoamino, azido, halogen, alkoxy, alkylthio (which is optionally substituted by halogen or cyano), alkyl, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, amino, alkylamino or dialkylamino,R.sup.2 represents hydrogen, alkyl, alkenyl or alkinyl,R.sup.3 represents optionally substituted aryl or heteroaryl,R.sup.4 represents hydrogen, alkyl, alkenyl or alkinyl andR.sup.5 represents hydrogen or alkyl.

Abstract: The invention relates to a process for the preparation of acetylketene dialkyl acetals of the formula CH.sub.3 CO--CH.dbd.C(OR.sup.2).sub.2 in which R.sup.2 can be an alkyl radical with 1 to 12 carbon atoms, and also these compounds themselves, providing that R.sup.2 is an alkyl radical with 3 to 12 carbon atoms. In the preparation process an alkyl acetoacetate of the formula CH.sub.3 CO--CH.sub.2 COOR.sup.1 is reacted with a saturated primary or secondary alcohol R.sup.2 OH in the presence of an acid catalyst, in which R.sup.2 has the abovementioned meaning and in which R.sup.2 OH or is higher boiling than R.sup.1 OH.

Abstract: To detect if a tool bit, such as a drill, a saw blade, or the like, upon being worked into a wall, meets a metallic obstruction, such as a conduit, reinforcement rod, hydraulic pipe or the like, an alternating voltage, preferably between 2 and 20 kHz, is coupled through a coupling capacitor (9) to the tool bit, and current flow to the tool bit is detected by a current measurement stage (10; 31, 32) to disconnect energy to the drive motor (5), for example by disabling firing of a thyristor (15), or closing a valve of a compressed-air tool. The coupling capacitor should have a capacity small enough to provide high impedance to network power frequency, and to insure a substantial change in current being supplied to the tool bit holder, typically a chuck, if the tool bit meets a metallic object in the wall.

Abstract: A low-voltage circuit breaker of compact design has a housing of insulating material with several parallel disposed chambers. A switching mechanism designed as a structural unit is provided in one of the chambers. The other chambers comprise compartments for switching path contacts. The switching mechanism comprises a U-shaped carrier for all moving parts. In particular, a drive shaft with a coupling part, such as a key, as well as a tripping shaft, likewise having a coupling part such as a slot, are provided. A pole control shaft is provided for actuating the switch contacts and is provided at its end with a coupling part such as a slot which comes into engagement with the coupling part of the drive shaft of the switching mechanism if the latter is built into the switch gear.

Abstract: To permit operation of the power tool only if both hands of an operator are engaged, the tool is formed with a handle portion which has a sensing surface thereon, electrically coupled to a current flow sensing circuit, preferably including an opto-coupler or a field-effect transistor (FET) circuit which permits firing of a triac, thyristor, or the like only if current flows over the sensing surface by area contact therewith. The sensing surface is energized, preferably, from a resistive or capacitative voltage divider; the capacitative voltage divider has the advantage that the triac firing circuit can cause the triac to fire during null or zero crossings of ac supplied power. If a locking-type switch is used, two handles or touch-areas are needed; if a spring-loaded switch is provided, it can function as one safety element, and a touch-area sensing surface as the other.

Abstract: A low-voltage circuit breaker has a fixed contact and a movable contact which is attached to a pivoted contact carrier. Between the contact carrier and the movable contact, a contact pressure spring is arranged, which is designed as a coil compression spring. The contact carrier has an arm which extends to the vicinity of the contact-making end of the movable contact. The arm carries a setscrew which is positioned to act centrally with respect to a contact overlay of the movable contact. The setscrew limits the lifting of the movable contact or the contact overlay to the desired small extent, when a large current flows through the circuit breaker and exerts electrodynamic force on the movable contact.

Abstract: A low voltage circuit breaker having a housing of insulating material separated into an upper part and a lower part. A slot is provided one side wall of the lower part beginning at the parting line and extending to the lower edge of the lower part in which wires leading to an auxiliary device can be installed. An outlet is provided at the separation for these wires. The slot makes it possible to arrange several identical low voltage circuit breakers with connected auxiliary wires directly next to each other.

Abstract: A writing element is detachably, or non-detachably, connected to an elongate holder which can be bent by hand into any desired shape to remain in that shape. The holder consists of a core made of a flexible metal such as lead and is covered with a flexible covering such as a covering of a plastics material.