Abstract: A seal structure in which a hole (5) is defined by a metal base member (4) as a partition member for partitioning the regions on the opposite sides thereof to a gas tight or liquid tight state and a member passes through the hole (5) and extends therefrom. The member passing through the hole (5) may be an electric conductor (2), a pipe member for flowing gas or liquid, a heat pipe for flowing a heat medium, an optical fiber for transferring an optical signal, or the like, and the structure is arranged such that the member passing through the hole is disposed through a synthetic resin seal member (3) and the hole (5) is sealed based on the confinement effected by the plastic deforming action of the base member (4) and the deforming action of the seal member (3) effected by making use of the elastic plasticity thereof, whereby the structure exhibits an excellent pressure resistive performance and can effectively seal the hole (5).

Abstract: A pressure sensor has a thin plate diaphragm having a strain detecting section thereon, and a support member for receiving and properly positioning the diaphragm within a stepped bore structure. The pressure sensor with which the strain detecting section is formed on the diaphragm surface is formed by the use of semiconductor manufacture technology by making the diaphragm of the pressure sensor in the form of a thin plate member. The diaphragm and the support member are joined together by diffusion bonding, and heat treatment for this diffusion bonding is also utilized to crystallize the semiconductor strain gauges.

Abstract: A vibration generating apparatus including a support body having a first center axis, a first spherical joint element provided at a forward end of the support body and having the center of a sphere located on the first center axis, a vibrating body having a second center axis passing through the sphere center, a second spherical joint element provided on the vibrating body and concentric complementary with the first spherical joint element to cooperate therewith to allow the vibrating body to be supported on the support member for universal movement, a rotary shaft coaxially rotatably supported within the vibrating body, a pair of eccentric weights mounted on the rotary shaft with a phase deviation of 180 degrees and in a manner symmetrical with respect to the sphere center, and a drive motor connected to the rotary shaft for driving same for rotation whereby the pair of eccentric weights are rotated about the second center axis to cause the vibrating body to move in conical motion vibration such that the sec

Abstract: A pipe laying apparatus including an excavator propulsion unit located in a starting pit. The excavator includes an excavator body having a first axis, an excavating tool having a second axis and located at a forward end portion of the excavator body, and injection ports formed in the excavating tool for injecting a viscosity imparting liquid into soil as excavated.