摘要:
The invention is aimed at the provision of an automatic releasing-type rolling head for forming a tapered thread on a pipe in which the shock generated at the end of the thread rolling operation is alleviated and a thread automatic rolling roller retracting mechanism is not damaged. The rolling head includes shaft bearing plates 33 which are slidably supported in a plurality of guide grooves 36 radially provided on inner surfaces of the front and rear closures of the housing 30 and which are provided on their outer surfaces in the radial directions with oblique surfaces 33b, thread rolling rollers 35 rotatably supported by the shaft bearing plates 33, a cam ring 31 which rotates in the housing 30 and has cam oblique surfaces 31a opposed to the oblique surfaces 33b of the shaft bearing plates 33, a lever 44 which abuts at its oblique surface against a cam member 45 to prevent movement thereof in association with the cam ring 31 and an abutment member 41 which is pressed and moved by a thread-rolled pipe. When the to-be-rolled pipe is thread-rolled to a predetermined length, the oblique surface of the lever 44 moving in association with the movement of the abutment member 41 is gradually moved away from the cam member 45. The cam ring 31 is rotated and the shaft bearing plates 33 and the thread rolling rollers 35 are moved in radial and outward directions and released from the to-be-rolled pipe.
摘要:
The invention is aimed at the provision of an automatic releasing-type rolling head for forming a tapered thread on a pipe in which the shock generated at the end of the thread rolling operation is alleviated and a thread automatic rolling roller retracting mechanism is not damaged. The rolling head includes shaft bearing plates 33 which are slidably supported in a plurality of guide grooves 36 radially provided on inner surfaces of the front and rear closures of the housing 30 and which are provided on their outer surfaces in the radial directions with oblique surfaces 33b, thread rolling rollers 35 rotatably supported by the shaft bearing plates 33, a cam ring 31 which rotates in the housing 30 and has cam oblique surfaces 31a opposed to the oblique surfaces 33b of the shaft bearing plates 33, a lever 44 which abuts at its oblique surface against a cam member 45 to prevent movement thereof in association with the cam ring 31 and an abutment member 41 which is pressed and moved by a thread-rolled pipe. When the to-be-rolled pipe is thread-rolled to a predetermined length, the oblique surface of the lever 44 moving in association with the movement of the abutment member 41 is gradually moved away from the cam member 45. The cam ring 31 is rotated and the shaft bearing plates 33 and the thread rolling rollers 35 are moved in radial and outward directions and released from the to-be-rolled pipe.
摘要:
A motor and a power transmitting mechanism are accommodated and supported in a two-piece housing unit separable into first and second housings. An air tank is defined by an outer surface of the second housing and an inside surface of a third housing provided on a recessed outer surface of the second housing.
摘要:
A combustion gas powered tool includes a member defining a part of cylindrical combustion chamber having an axis. A piston is movable in a direction along the axis of the combustion chamber. The piston defines the combustion chamber in conjunction with the member. A mixture of air and fuel is generated in the combustion chamber. The air-fuel mixture in the combustion chamber is burned to drive the piston. An orifice grille extends in the combustion chamber, and is parallel to the axis of the combustion chamber.
摘要:
In a mowing machine having an engine for driving a rotary blade via a centrifugal clutch, a shaft and a reduction gear assembly, the outer diameter of the shaft is selected such that the torsional natural vibration frequency of the rotational system extending from the engine to the rotary blade is less than one third of a rotational frequency above which the centrifugal clutch starts transmitting the engine output torque to the shaft. As a result, the torsional natural vibration frequency of the rotational system does not equal the rotational frequency or the half or one third of the rotational frequency of the engine so that undesirable resonance phenomenon will not occur.
摘要:
A retro-focus wide angle photographic lens system comprises a front lens group including first and third negative meniscus lenses each having one surface greater in curvature than the other and oriented toward an image, and a second positive lens, and a rear lens group including a fourth positive lens, a fifth negative lens, and sixth and seventh positive lenses each having one surface greater in curvature than the other and oriented toward the image. The various lens system parameters are selected within the limits of and to satisfy a plurality of mathematical expressions, in order to optimize miniaturization while still retaining satisfactory optical characteristics.
摘要:
An air compression system for supplying a compressed air into a pneumatically operated tool. The system includes an air compressor and air accumulator connected to the compressor and having a first accumulator and a second accumulators separate therefrom. A relief valve is connected between the first and second accumulators for allowing the compressed air to flow from the first accumulator to the second accumulator when a pressure of the compressed air accumulated in the first accumulator increases to a predetermined pressure. A check valve is provided between the first and second accumulators and in parallel to the relief valve for allowing the compressed air to flow from the second accumulator to the first accumulator. The accumulator is connected to the pneumatically operated too. If the tool requires small amount of compressed air for operation, the compressed air supply into the first accumulator is only necessary to reduce recharging period.
摘要:
A combustion gas powered fastener driving tool includes inlet and outlet openings through which the combustion gases are discharged from a combustion chamber. These openings are located above the uppermost driving position (top dead center) of a slidable piston, so that an air and fuel mixture is fully trapped in the combustion chamber until after it is combusted. Since an outflow of the unburnt air and fuel mixture is completely prevented, the rate of fuel consumption of the fastener driving tool is high and there is no danger of accidental explosion of unburned fuel even when the fastener driving tool is used in a badly ventilated working place or site. An electric fan for forcing fresh air into the combustion chamber is disposed outside the cylinder and isolated from high temperatures. The fan is durable in structure and reliable in operation.
摘要:
An automatic nailing apparatus includes a housing having a piston driving system for driving a piston, a percussion rod having a concave at only the tip thereof, a nosepiece having a round channel being provided with a pair of nail head guide rails, and a nail magazine for supplying interconnected nails. The forefront nail of the interconnected nails can be nailed in a direction normal to a workpiece because a point of application on nailing exists on the center axis of the forefront nail.
摘要:
A miniaturized telephoto camera lens assembly comprises a first positive lens, a second negative lens, and a third positive meniscus lens having a higher object side curvature. These lenses are disposed close together, and relatively remote from closely spaced fourth and fifth positive and negative meniscus lenses, respectively, each having higher object side curvatures. The optical parameters of the lens assembly are chosen to satisfy seven specified conditions relating to composite focal distances, spacing distances, Abbe numbers, and refractive index to optimize miniaturization while still achieving a high level of optical performance.