Abstract: A remote operation device includes: a vibration detector to detect a plurality of vibration components in a plurality of directions different from each other, the vibration components being included in a vibration caused on an attachment; a transmission device; and a transmission control section that controls an operation of the transmission device. A vibration determination condition is set in advance, the vibration determination condition including a condition that an amplitude of a maximum vibration component largest in amplitude among the plurality of vibration components detected by the vibration detector is equal to or larger than a preset amplitude threshold. The transmission control section controls the operation of the transmission device to allow the vibration information to be transmitted to an operator only when the vibration determination condition is met.

Abstract: A laser marking system in one aspect of the present disclosure includes a laser marker, a beam receiving device, and a notifier. The laser marker includes a laser beam emitter. The beam receiving device includes a beam receiver and a transmitter. The beam receiver receives a laser beam emitted by the laser beam emitter. The transmitter transmits a first positional signal. The first positional signal indicates a receiving position of the laser beam in the beam receiver. The notifier notifies of the receiving position of the laser beam based on the first positional signal.

Abstract: A flexible tying member for a theftproof device which is adapted to give warning in response to a change in a photo signal transmitted in an optical fiber extending through the flexible tying member. The flexible tying member has a first layer including the optical fiber and at least one electric wire connected to at least one photoelectric element, and a second layer including a reinforcing member. The flexible tying member has a coaxial structure having an inner layer formed by the above first layer, and an outer layer formed by the above second layer, or a parallel structure in which the above first and second layers longitudinally extend parallel with each other.

Abstract: A theftproof device comprising a flexible tying member, an optical fiber extending through the flexible tying member, a light emission element arranged opposite an end of the optical fiber, a light receiving element arranged opposite the other end of the optical fiber, a fixture fixed to an object to be protected from theft, an electrical circuit arranged within the fixture, mechanical connector means for mechanically connecting the flexible tying member to the fixture, and electrical connector means for electrically connecting the light emission element and the light receiving element to the electrical circuit. The electrical circuit is responsive to a change in a photo signal generated by the light emission element and transmitted through the optical fiber, for performing a warning function.

Abstract: A flexible tying member for a theftproof device which is adapted to give warning in response to a change in a photo signal transmitted in an optical fiber extending through the flexible tying member. The flexible tying member has a first layer including the optical fiber and at least one electric wire connected to at least one optoelectric element, and a second layer including a reinforcing member. The flexible tying member has a coaxial structure having an inner layer formed by the above first layer, and an outer layer formed by the above second layer, or a parallel structure in which the above first and second layers longitudinally extend parallel with each other.

Abstract: A flexible tying member for a theftproof device which is adapted to give warning in response to a change in a photo signal transmitted in an optical fiber extending through the flexible tying member. The flexible tying member has a coaxial structure comprising a central layer including one of the optical fiber and at least one electric wire, an intermediate layer including the other of these two members, and an outer wall layer including a reinforcing member.

Abstract: A plastic foamed sheet of excellent quality is produced by preheating in a chamber including a conveyor means for continuously conveying a thermoplastic resin sheet containing a heat-decomposable blowing agent in the horizontally supported state and a heating means for heating the sheet to a temperature lower than the decomposition temperature of the blowing agent, and foaming in a foaming chamber connected to the preheating chamber and including a heating means for heat-foaming the sheet as it is continuously conveyed while being perpendicularly suspended from the terminal of the conveyor means.

Abstract: A process for producing a crosslinked and foamed resin sheet which comprises shaping a resinous mixture comprising a thermoplastic synthetic resin and a heat-decomposable blowing agent into a sheet form, applying a high-energy ionizing radiation to the resulting foamable resin sheet to crosslink the resin sheet, and then heating the resulting crosslinked foamable resin sheet to the decomposition temperature of the blowing agent or to a higher temperature; wherein the high-energy ionizing radiation has a range of at least 0.7 .rho.d g/cm.sup.2 in which d is the thickness in cm of the foamable resin sheet, and .rho. is the density in g/cm.sup.3 of the foamable resin sheet, and a low-energy ionizing radiation with a range of not more than 0.6 .rho.d g/cm.sup.2 in which d and .rho. are as defined is applied to the foamable resin sheet before, during or after the application of the high-energy ionizing radiation.

Abstract: A plastic foamed sheet of excellent quality is produced by using an apparatus comprising a preheating chamber including a conveyor means for continuously conveying a thermoplastic resin sheet containing a heat-decomposable blowing agent in the horizontally supported state and a heating means for heating the sheet to a temperature lower than the decomposition temperature of the blowing agent, and a foaming chamber connected to the preheating chamber and including a heating means for heat-foaming the sheet as it is continuously conveyed while being perpendicularly suspended from the terminal end portion of the conveyor means.