摘要:
To ensure that a biodegradable medical implement dissolves in vivo at an appropriate dissolution rate. The biodegradable medical implement of the present invention is formed of a magnesium material, and, at least in one transverse section, a layer of magnesium crystal grains in which a (0001) plane in a hexagonal crystal structure is oriented toward a surface side is continuous over an entire circumference.
摘要:
A locking screw including a male screw and a female screw, the male screw being screwed into the female screw, the male screw including male threads and the female screw comprising female threads, wherein a male thread comprises a crest side flank surface and a root side flank surface connecting the crest side flank surface and a root of the male thread, a slope of the crest side flank surface is smaller than a slope of a female flank surface of the female thread, a slope of the root side flank surface is larger than the slope of the female flank surface, a connected portion of the crest side flank surface and the root side flank surface interferes with the female thread, and a clearance is formed between the root side flank surface and the female screw when the connected portion interferes with the female thread.
摘要:
[Object] To provide a self-tapping screw which is the most suitable for tightening a workpiece made of a soft material such as a resin or an aluminum alloy.[Solution] In the self-tapping screw 1 including a normal thread 10 and a female screw molding thread 12 having a larger diameter than that of the normal thread 10, out of pitches of the normal thread 10 positioned in a head portion side from the female screw molding thread 12, any one pitch is set to be larger than other pitches. The self-tapping screw 1 not only reduces driving torques but also improves fastening force, and thus can be applied to various workpieces made of the soft material as well as a hard material.
摘要:
A power tool holding assembly includes a first direction guiding unit that has a piston-cylinder construction and a linear movement guiding unit that includes a ball spline and is connected via ball bearings to a piston rod of the piston-cylinder construction so as to be freely rotatable. A power tool is mounted onto one end of the spline shaft of the linear movement guiding unit. A space inside the cylinder of the piston-cylinder construction below the piston is connected via a hose coupling and hose to an air compressor that fills the space with compressed air. The air pressure of the compressed air fed into the space is regulated by a pressure regulating valve provided on the hose and so is maintained at a value that keeps the rod stationary.
摘要:
An automatic screw fastening machine embodied by the invention transmits the rotating force of a motor to a driver bit via a differential planetary mechanism consisting of an input disc, a plurality of planetary cones, a cam disc, and a variable-speed ring. The automatic screw fastening machine causes a resilient supporting unit to restrict the variable-speed ring from shifting itself in the axial direction. Furthermore, the machine is provided with a torque detection unit capable of detecting the torque of reaction force applied to the variable-speed ring by effect of the load applied to the driver bit. As soon as the detect-signal value correctly matches a specific value corresponding to the predetermined fastening torque, supply of power to the motor is discontinued. In consequence, when fully completing a screw fastening process, rotation of the driver bit is substantially reduced to zero so that no rotating force can be transmitted to the driver bit. This in turn prevents the driver bit from adversely being affected by own inertia. This permits the driver bit to fully stop own movement simultaneous with the completion of the screw fastening process, the automatic screw fastening machine thus offers incomparable capability to execute every screw fastening process by securely applying the desired fastening torque.
摘要:
This invention relates to an improvement of a thread forming screw including driven head, cylindrically formed shanks rolled type thread which has a following flank angle smaller than a progresssive flank angle and is interrupted by plural slot recesses locating in one revolution of the thread and being pretendedly formed as helical slot recesses. One of the recesses is formed by a duly inclined leading edge of an interrupted thread, a nearly perpendicular rearward edge of the one located at its leading side and a flat-like bottom located betweenthere. This configuration of the shank enable it to be easily driven into a workpiece because of the decreasing the engagement between the interrupted screw thread and the female thread formed thereby. And it can prevent the fastener from rotating in such directions that it can loose because the following flanks of the interrupted threads depress the female thread swaged thereby and the materials are deformed, flown and dropped into the recesses nearby in an axial tension and the drops of the material prevent the threads from sliding back along the female thread.
摘要:
This invention relates to an improvement of thread-forming fasteners comprising driving heads, shanks, work entering end portions without a thread and continuous rolled type threads on both the said shank and the said work entering end portions, the shanks being of arcuate triangular configuration in cross section which is characterized by three equally spaced lobes separated by relatively broad arcuate sides. The shanks are formed so that the radii of the lobes are gradually increased while the radii of the sides are gradually decreased toward the heads. And beside one of the threads in longitudinal section is of anti-symmetric triangular shape so that a slipping torque along the female thread formed thereby can be increased for easy entry in a workpiece in adding axial load during fastening operation and a slipping torque along the female thread can be decreased in axial loaded condition after it is seated on the workpiece. The above configuration of the fastener enables it to be easily driven into a thin workpiece with low driving torque on account of the less engagement between the screw thread and the female thread formed in the workpiece. And it enables it steadily secured to the workpiece with high stripping torque by the peripheral engagement between the screw thread and the female thread when it is seated.
摘要:
Automatic electrode shaping apparatus comprising a grinding tool adapted to come in contact with the points of electrode tips attached to the tips of arms of a welding machine for grinding said points, a judging device for judging the shaping condition of said points of the electrode tips, and a tip holding mechanism for holding the electrode tips with the grinding tool coming in contact with the electrode tips, the grinding tool and the judging device being movable with respect to the electrode tips and alternatively located in the position opposite to the electrode tips.According to the automatic electrode shaping apparatus, the electrode tips are held by the tip holding mechanism, and ground and shaped with the grinding tool in a stable manner. After the electrode tips have been shaped, the shaping condition of the electrode tips can be judged whether it is good or bad, without moving the electrode tips.
摘要:
A power operated screwdriver having a head at an end thereof. The head includes a body having a bit passageway and a screw passageway. The bit and screw passageways intersect in an inclined manner. A pair of screw holding jaws are pivotally mounted in a detachable manner on the head. A spring is provided for each of the screw holding jaws for biasing the screw holding jaws towards one another for holding screws in a driving position after the screws exit from the screw passageway. Stop jaw mounting openings are provided at an end of each of the holding jaws and pass completely through the holding jaws. A pair of stop jaws are pivotally mounted in a detachable manner within each of the mounting openings. A spring is provided for each of the stop jaws for biasing the stop jaws towards one another. Both the holding jaws and the stop jaws pivotally swing in the same plane.