Abstract: An energy absorber having a bar movable along a longitudinal axis by a tensile force. First and second energy absorbers extend along the longitudinal axis. A coupling mechanism couples the second energy absorber to the bar. The first energy absorber activates upon movement of the bar along the longitudinal axis. The coupling mechanism has a force transferring element to transfer force from the bar to the second energy absorber upon activation by a trigger. The trigger is subjected to a trigger load that is proportional to the bar's velocity along the longitudinal axis. The trigger is displaceable from its unloaded position upon loading and, simultaneously, constrained from displacing by a constraining force acting in opposite direction of the trigger load. The trigger displaces to activate the force transferring element to activate the second energy absorber when the velocity of the bar is above first pre-determined non-zero amount.

Abstract: An energy absorber with a bar extending and movable along a longitudinal axis, and first and second energy absorbers. The first energy absorber activates upon movement of the bar along the axis. A mechanism couples the second energy absorber to the bar, and has a force transferring element to transfer force from the bar to the second energy absorber upon activation by a trigger. The trigger receives a trigger load as the bar is moved along the axis, the load being proportional to the velocity of the bar such that a higher velocity results in a higher trigger load. The trigger is displaceable relative to its unloaded position and simultaneously constrained from displacing by a constraining force acting in a direction opposite the trigger load. Displacing the trigger activates the force transferring element to couple and activate the second energy absorber when the bar velocity exceeds a first amount.

Abstract: Method and system for producing holes of various dimensions and configurations in a workpiece (42) using a portable orbital drilling machine (44), wherein said workpiece has attached thereto a template (10) with preformed guide holes (12-40) located in a pattern corresponding to the positions of the holes to be formed in the workpiece. Each guide hole (12-40) is provided with a readable information carrier (12i-40i) containing an identification of the respective guide hole. When fixating the drilling machine (44) in a guide hole, the latter is identified by a hole database (48) by sensing the respective information carrier. A control unit (50) associated with the hole database (48) controls the drilling machine (44) to perform a relevant hole-cutting process in the workpiece.

Abstract: Method and system for producing holes of various dimensions and configurations in a workpiece (42) using a portable orbital drilling machine (44), wherein said workpiece has attached thereto a template (10) with preformed guide holes (12-40) located in a pattern corresponding to the positions of the holes to be formed in the workpiece. Each guide hole (12-40) is provided with a readable information carrier (12i-40i) containing an identification of the respective guide hole. When fixating the drilling machine (44) in a guide hole, the latter is identified by a hole database (48) by sensing the respective information carrier. A control unit (50) associated with the hole database (48) controls the drilling machine (44) to perform a relevant hole-cutting process in the workpiece.

Abstract: A fastener assembly is inserted into a throughhole of a composite laminate to thereby fasten the composite laminate together. The throughhole has a length extending from a first outer surface of the composite laminate to a second outer surface of the composite laminate. The throughhole has a first width at the first outer surface, a second width at the second outer surface, and a third width at a point along the length of the throughhole between the first outer surface and the second outer surface. The third width is less than each of the first width and the second width. The fastener assembly includes a substantially annular fastener device having an axial opening and a peripheral surface substantially conforming to the inner surface of the throughhole.

Abstract: A method and cutting tool for producing a hole or a recess in a workpiece which includes flat or curved sheets of fiber-reinforced composite material, metal or combinations thereof. The cutting tool has a shaft with a longitudinal axis and an axial cutting surface and at least one cutting edge disposed on the axial cutting surface and extending radially from the longitudinal axis with a gap between the radial inner extent of the cutting edge and the longitudinal axis. The method of use includes rotating the cutting tool about its longitudinal axis and also translating the cutting tool during rotation.

Abstract: An apparatus for grinding and/or polishing a surface of a wall element includes a first elongate guide device oriented substantially parallel to the surface of the wall element. A second elongate guide device is movably coupled to the first elongate guide device and oriented orthogonally relative thereto. The second elongate guide device is oriented substantially parallel to the surface of the wall element and moves along the first elongate guide device. A polishing device is movably coupled to the second elongate guide device. The polishing device moves along the second guide device and polishes the surface of the wall element at a plurality of locations along the second guide device and along the first guide device.

Abstract: A method and cutting tool for producing a hole or a recess in a workpiece which includes flat or curved sheets of fiber-reinforced composite material, metal or combinations thereof. The cutting tool has a shaft with a longitudinal axis and an axial cutting surface and at least one cutting edge disposed on the axial cutting surface and extending radially from the longitudinal axis with a gap between the radial inner extent of the cutting edge and the longitudinal axis. The method of use includes rotating the cutting tool about its longitudinal axis and also translating the cutting tool during rotation.

Abstract: A fastener assembly is inserted into a throughhole of a composite laminate to thereby fasten the composite laminate together. The throughhole has a length extending from a first outer surface of the composite laminate to a second outer surface of the composite laminate. The throughhole has a first width at the first outer surface, a second width at the second outer surface, and a third width at a point along the length of the throughhole between the first outer surface and the second outer surface. The third width is less than each of the first width and the second width. The fastener assembly includes a substantially annular fastener device having an axial opening and a peripheral surface substantially conforming to the inner surface of the throughhole.

Abstract: A fastener assembly is inserted into a throughhole of a composite laminate to thereby fasten the composite laminate together. The throughhole has a length extending from a first outer surface of the composite laminate to a second outer surface of the composite laminate. The throughhole has a first width at the first outer surface, a second width at the second outer surface, and a third width at a point along the length of the throughhole between the first outer surface and the second outer surface. The third width is less than each of the first width and the second width. The fastener assembly includes a substantially annular fastener device having an axial opening and a peripheral surface substantially conforming to the inner surface of the throughhole.

Abstract: The invention relates to a method for machining and forming transcurrent openings in fibre-reinforced composite materials. Openings with damage-free edges can be formed with high precision by positioning a rotating grinding tool in a preformed hole. In conjunction with this the material is arranged in such a way that the axis of rotation of the grinding tool is essentially perpendicular to the longitudinal direction of the fibres at the edge of the hole. The opening is machined and formed by causing the grinding tool on the one hand to rotate about its own axis and on the other hand to describe an orbital motion relative to the edge of the hole. Any damage/defects caused in the course of preforming are removed in this way.

Abstract: Paper or paper board is made by adding cationic polymeric retention aid to a cellulosic supension, shearing the suspension to degrade the resultant flocs, aggregating the suspension by adding an aqueous composition of bentonite or other anionic bridging coagulant in the presence of anionic dye, pigment or optical brightening agent, and forming paper from the aggregated suspension.

Abstract: A method of producing a hole in a fiber reinforced composite material workpiece includes the step of providing a cutting tool having a shaft, a cutting head, and an axis of rotation. The cutting head has a diameter which is substantially smaller than the diameter of the hole that is produced. The shaft has a diameter which is substantially smaller than the diameter of the cutting head. The cutting head has a height which is substantially smaller than the depth of the hole that is produced. The cutting tool is oriented such that the axis of rotation of the cutting tool is substantially orthogonal to the surface of the workpiece. The workpiece is simultaneously machined in both an axial and a radial direction relative to the longitudinal axis of the hole, by simultaneously rotating the cutting tool around the axis of rotation, moving the cutting tool in an axial direction, and moving the cutting tool eccentrically around the longitudinal axis of the hole.

Abstract: The invention relates to a method for producing a hole in a workpiece consisting of a fibre-reinforced composite material. The central axis of the hole passes through a predetermined point on the surface of the workpiece and is oriented in a certain determined direction in relation to the longitudinal directions of the fibres in the immediate vicinity of the point. The material is machined simultaneously in both an axial and a radial sense by causing the tool to describe an axial motion and to rotate not only about its own axis (5), but also eccentrically about the central axis.

Abstract: A blood vessel prosthesis, comprising a tubular element of an inert, completely or partially non-resorbable material having no adverse tissue reaction. To the inside of the tubular element an interior wall construction of a resorbable material with no adverse tissue reaction is fixed, which wall construction has such a structure that passage of blood cells, such as erythrocytes and thrombocytes, into or through the same is permitted.