Abstract: An injection molding apparatus has at least two mold clamping mechanisms for clamping respective molds. A hydraulic pressure supply source supplies hydraulic pressure to the at least two mold clamping mechanisms to clamp the respective molds. A a hydraulic-pressure-supply-destination selection section is configured to allow hydraulic pressure from the hydraulic pressure supply source to be selectively supplied to any one of the two mold clamping mechanisms. At least two injecting machines are configured to inject resin material to the respective molds clamped by the respective two mold clamping mechanisms. A non-hydraulic power supply source drives the at least two injecting machines to inject the resin material.

Abstract: An injection molding apparatus includes, as its drive sources, an electric power supply source, compressed air source and hydraulic pressure supply source. A hydraulic-pressure-supply-destination selection section supplies hydraulic pressure from the hydraulic pressure supply source to a selected one of first and second mold clamping cylinders. Necessary capacity of the hydraulic pressure supply source can be lowered as compared to a case where all of the mold clamping mechanisms and injecting machines are driven by hydraulic pressure. Because only a selected one of the mold clamping mechanisms is driven at a time, the necessary capacity of the hydraulic pressure supply source can be halved as compared to a case where the mold clamping mechanisms are driven simultaneously.

Abstract: The present invention relates to a rotary cutter for rounding the corners of a sheet cut from, for example, a continuous web. The rotary cutter is provided with two blades adapted to be brought into engagement with each other while each blade is rotated by a separate parallel shaft. The rotary cutter satisfies three conditions: the first and second blades have the same blade contours with respect to a common curved edge line defining a plane; each blade at each position of engagement satisfies the relationship of .beta. .gtoreq. .alpha., where .beta. is the relief angle of each blade and .alpha. is the nip angle of each blade; R.sub.1 /R.sub.2 =AA'/AA", where R.sub.1 is the radius of rotation of the first blade, R.sub.2 is the radius of rotation of the second blade, AA' is the edge line length of the first blade, and AA" is the edge line length of the second blade.