Abstract: A watertight testing device includes a cylindrical core fit into a pipe joint part, a first seal member for sealing between the outer surface of the core and the inner surface of one pipe, a second seal member for sealing between the outer surface of the core and the inner surface of the other pipe, a first pressing member for pressing and compressing the first seal member into a first seal-member insertion space, a second pressing member for pressing and compressing the second seal member into a second seal-member insertion space, a moving device for moving the first and second pressing members in a pipe axial direction, and a test fluid feeder for feeding a test fluid into a test space.

Abstract: In a variable-scale photocopying machine having a photosensitive medium, a light source, an optical system for projecting light from the source as an exposure light beam onto the medium, and a scale-varying mechanism, the width of the light beam is adjustable by an adjusting mechanism, which is actuated by a tensioned cord connected thereto when the cord is deflected by an adjusting member in response to movement of the scale-varying mechanism thereby to adjust the quantity of the exposure light to suit each scale of photocopying.

Abstract: An aperture-controlling device in a variable-scale photocopying machine having an optical system unit which is movable to vary the scale of the photocopy relative to the original comprises an aperture-adjusting member for adjusting the width of an exposure light beam projected on a photosensitive drum, a tensioned, flexible cord connected at one end to the aperture-adjusting member, and a member following movements of the optical system unit to displace the cord at a point thereof substantially perpendicularly to its longitudinal direction thereby to actuate the aperture-adjusting member and adjust the exposure light beam width. The other end of the cord is connected to an exposure member which is adjustably movable to move the cord in forward and return movements substantially in the longitudinal direction thereof thereby to adjust the exposure light beam width independently of the adjustment thereof due to scale-varying movement of the optical system unit.

Abstract: The apparatus comprises a projection optical system and a copying system. The projection optical system can project an image of an original either onto a screen or to an exposing position of the copying system by switching between two positions. The copying system comprises a plurality of chargers providing different charging conditions in accordance with the types and sizes of copy sheets, by utilizing a change-over switch. A plurality of switches adapted for use with copy sheets of different lengths are arranged along the path of movement of a sheet of paper and, when the switch corresponding to the particular length of copy sheet desired is actuated, the movement of the sheet of paper is stopped, so that the central portion of the copy sheet can be brought into alignment with the optical axis for exposing at all times regardless of the difference in the length of copy sheets.