Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; a drive for periodically moving the exciting piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and exciting piston. The stroke is selected as a function of a maximum length of the pneumatic chamber such that the periodic movement of the flying mass on the path between an impact on the impact surface and a minimum approach of the exciting piston intermittently has a velocity of zero.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism includes: a flying mass; an impact surface which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston which limits a movement of the flying mass opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; and a drive for periodically moving the exciting piston with a stroke along the impact axis.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; and a drive for periodically moving the exciting piston with a stroke along the impact axis. The flying mass is excited to a periodic movement between the impact surface and a minimum approach of the exciting piston. A length ratio of the maximum length of the pneumatic chamber to the stroke is selected as less than 1.55.

Abstract: A hand-held power tool includes a motor-driven percussion mechanism. The percussion mechanism includes a guide tube (21) and a reciprocating driving member (22) displaceable in the guide tube (21) for driving, via a gas spring, an impact member (23) likewise displaceable in the guide tube (21). The percussion mechanism further includes a motor-driven eccentric wheel (17) rotatable about an axis (D) which is spaced from the percussion mechanism axis (S) in a direction perpendicular to the percussion mechanism axis (S) by a distance (X). A connection rod (29) is eccentrically supported on the eccentric wheel (17) and connected to the driving member (22) for converting a rotational movement of the eccentric wheel (17) into a reciprocating movement of the driving member (22).

Abstract: A hand-held power tool includes a percussion power tool includes a percussion piston (5) for applying blows to an anvil (8) axially displaceable in a guide tube (6) within limits defined by two, spaced from each other, stops (9a, 9b) arranged in the guide tube (6), a pneumatic percussion mechanism (2) for driving the percussion piston (5), an air spring (3) for connecting the percussion piston (5) with the percussion mechanism (2), and an impact ring (12) arranged coaxially with the anvil (8) outwardly thereof and having spaced from each other, inner radical flanks (14) located on opposite axial sides of the outer radial collar (11) provided on the anvil (8), with the impact ring (12) freely axially displaceable, within limits, relative to the outer radial collar (11) and having an outer diameter smaller than a guiding inner diameter of the guide tuber (6), and with a mass ratio of the impact ring (12) to the anvil (8) being equal at least 0.25.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; a hammer piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and hammer piston; a drive for periodically moving the hammer piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and hammer piston. The stroke is selected as a function of a maximum length of the pneumatic chamber such that the periodic movement of the flying mass on the path between an impact on the impact surface and a minimum approach of the hammer piston intermittently has a velocity of zero.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; a hammer piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and hammer piston; and a drive for periodically moving the hammer piston with a stroke along the impact axis. The flying mass is excited to a periodic movement between the impact surface and a minimum approach of the hammer piston. A length ratio of the maximum length of the pneumatic chamber to the stroke is selected as less than 1.55.

Abstract: A pneumatic hammer mechanism is disclosed. The hammer mechanism includes: a flying mass; an impact surface which limits a movement of the flying mass along the impact axis in the impact direction; a hammer piston which limits a movement of the flying mass opposite from the impact direction; a pneumatic chamber between the flying mass and hammer piston; and a drive for periodically moving the hammer piston with a stroke along the impact axis.

Abstract: A hand-held power tool includes a motor-driven percussion mechanism including a guide tube (21), a reciprocating driving member (22) displaceable in the guide tube (21) for driving, via a gas spring, an impact member (23) likewise displaceable in the guide tube (21) a motor-driven eccentric wheel (17) rotatable about an axis (D) which is spaced from the percussion mechanism axis (S) in a direction perpendicular to the percussion mechanism axis (S) by a distance (X), and a connection rod (29) eccentrically supported on the eccentric wheel (17) and connected to the driving member (22) for converting a rotational movement of the eccentric wheel (17) into a reciprocating movement of the driving member (22).

Abstract: A hand-held power tool includes a percussion power tool includes a percussion piston (5) for applying blows to an anvil (8) axially displaceable in a guide tube (6) within limits defined by two, spaced from each other, stops (9a, 9b) arranged in the guide tube (6), a pneumatic percussion mechanism (2) for driving the percussion piston (5), an air spring (3) for connecting the percussion piston (5) with the percussion mechanism (2), and an impact ring (12) arranged coaxially with the anvil (8) outwardly thereof and having spaced from each other, inner radical flanks (14) located on opposite axial sides of the outer radial collar (11) provided on the anvil (8), with the impact ring (12) freely axially displaceable, within limits, relative to the outer radial collar (11) and having an outer diameter smaller than a guiding inner diameter of the guide tuber (6), and with a mass ratio of the impact ring (12) to the anvil (8) being equal at least 0.25.

Abstract: A hand-held power tool has a air spring percussion mechanism which is suitable to provide for generating axial impacts by an impact piston reciprocating along an impact axis and which is driven by a crank pin (4) of a rotatably supported eccentric (5) whose mass distribution with respect to an eccentric axis (E) has an unbalance (U) which is offset in the eccentric plane extending perpendicular to the eccentric axis (E) by an angle of unbalance (?) in the range of 70° to 90° relative to the crank pin (4) which is spaced from the eccentric axis (A) by a distance equal to the crank radius (K).

Abstract: A cup-shaped drill head with an inner conical surface (2) for force-locking connection with an exterior conical surface (3) of a driving drill shaft (4), which at the leading end changes over into a cup base (5) with a center point (P), whereby in the change over from the cup base (5) to the inner conical surface (2) a lesser curvature (K) is present than at the center point (P).

Abstract: A cup-shaped drill head with an inner conical surface (2) for force-locking connection with an exterior conical surface (3) of a driving drill shaft (4), which at the leading end changes over into a cup base (5) with a center point (P), whereby in the change over from the cup base (5) to the inner conical surface (2) a lesser curvature (K) is present than at the center point (P).

Abstract: Radiation-sensitive compositions comprising

Abstract: Radiation-sensitive compositions comprising (a1) a cationically or acid-catalytically polymerisable or crosslinkable compound or (a2) a compound that increases its solubility in a developer under the action of acid; and (b) at least one diaryliodonium salt of formula I X is branched C3-C20alkyl or C3-C8cycloalkyl; X1 is hydrogen, linear C1-C20alkyl, branched C3-C20alkyl or C3-C8cycloalkyl; with the proviso that the sum of the carbon atoms in X and X1 is at least 4; Y is linear C1-C10alkyl, branched C3-C10alkyl or C3-C8cycloalkyl; A− is a non-nucleophilic anion, selected from the group (BF4)−, (SbF6)−, (PF6)−, (B(C6F5))4−, C1-C20alkylsulfonate, C2-C20haloalkylsulfonate, unsubstituted C6-C10arylsulfonate, camphorsulfonate, and C6-C10arylsulfonate substituted by halogen, NO2, C1-C12alkyl, C1-C12halo-alkyl, C1-C12alkoxy or by COOR1; and R1 is C1-C20alkyl, phenyl, benzyl; or phenyl mono- or poly-substituted by C1-C12alkyl, C1-C12alkoxy or by halogen; with the

Abstract: A tool for drilling and/or chiseling has a striking mechanism (6) within a guide tube (9) for reciprocating a first piston (7) and, via an air cushion, for reciprocating a second piston (19) within the guide tube. The second piston drives a driving anvil (17) in the driving direction. Between the first and second pistons (7, 19) the guide tube (9) has a series of radially extending first air passages (10) arranged in a first plane (E1) extending perpendicularly of the driving direction. A control body can be shifted over the guide tube (9) and is connected to the driving anvil (17). The guide tube (9) has a second series of radially extending second air passages (11) therethrough arranged in a second plane (E2) spaced from the first plane (E1) at a distance (A) opposite to the driving direction.

Abstract: A manually operable tool, such as a hammer drill, for drilling and/or removing material in at least one of brittle material and low ductile material, has a continuously rotatable chuck (8) and a motor driven striking mechanism (1) for transmitting impulse-like blows to a tool bit (9) held in the chuck (8). The tool includes members (5) for transmitting impulse-like blows composed of superimposed axially-directed blows and torsional blows to the tool bit (9) in the chuck for forming drilling blows. Further, an adaptor can be provided for attachment to the hammer drill containing the members (5) for affording the superimposed blows.

Abstract: The invention relates to the use of oxime sulfonates of formula 1 ##STR1## wherein R is naphthyl, ##STR2## Ar is an unsubstituted aryl group or an aryl group which carries one or more than one substituent selected from the group consisting of nitro, chloro, bromo, hydroxyl, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 perfluoroalkyl, C.sub.1 -C.sub.4 alkoxy and acid degradable substituent;R.sub.0 is either a R.sub.1 -X group or R.sub.2 ;X is an oxygen or a sulfur atom;R.sub.1 is hydrogen, C.sub.1 -C.sub.4 alkyl or unsubstituted phenyl or phenyl which is substituted by a member selected from the group consisting of chloro, bromo, C.sub.1 -C.sub.4 alkyl and C.sub.1 -C.sub.4 alkoxy, andR.sub.2 is hydrogen, C.sub.1 -C.sub.

Abstract: The invention relates to a chemically amplified negative photoresist which can be developed in aqueous alkaline media, which contains a radiation-sensitive acid generator and a compound which reduces the solubility of the resist in aqueous alkaline solutions in the presence of acid, and a polyhydroxyl compound of the formula I ##STR1## in which n is an integer between 2 and 6,R is hydrogen, halogen, C.sub.1 -C.sub.4 alkoxy or C.sub.1 -C.sub.4 alkyl, andZ is an n-valent radical which is unsubstituted or substituted by one or more substituents from the group consisting of hydroxyl, halogen and C.sub.1 -C.sub.4 alkoxy, and is selected from the group consisting of:a) aliphatic radicals having 1 to 12 carbon atoms,b) cycloaliphatic radicals having 5 to 20 carbon atoms,c) aromatic radicals having 6 to 20 carbon atoms andd) radicals having 7 to 30 carbon atoms which comprise at least two different structural units selected from aliphatic, cycloaliphatic or aromatic groups.

Abstract: The invention relates to the use of oxime sulfonates of formula 1 ##STR1## wherein R is naphthyl, ##STR2## Ar is an unsubstituted aryl group or an aryl group which carries one or more than one substituent selected from the group consisting of nitro, chloro, bromo, hydroxyl, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 perfluoroalkyl, C.sub.1 -C.sub.4 alkoxy and acid degradable substituents;R.sub.0 is either a R.sub.1 --X group or R.sub.2 ;X is an oxygen or a sulfur atom;R.sub.1 is hydrogen, C.sub.1 -C.sub.4 alkyl or unsubstituted phenyl or phenyl which is substituted by a member selected from the group consisting of chloro, bromo, C.sub.1 -C.sub.4 alkyl and C.sub.1 -C.sub.4 alkoxy, andR.sub.2 is hydrogen, C.sub.1 -C.sub.