Abstract: A damper device comprises first and second cylinders which are adjacent and rotatable with respect to each other and have respective hinge pieces, a piston operation member provided in the first and second cylinders in such a manner that it is rotatable with respect to the first cylinder, a piston member to which is fitted a pressure control member which is provided with a multithread section on the outer wall thereof and with a through-hole in the central portion thereof and a through-hole having a check valve, and a plurality of chambers provided in the second cylinder the chambers being divided into the upper and lower chambers by the piston operation member. These chambers are communicated with the through-holes, and a cylinder with a bottom is fitted to the piston member.

Abstract: A door closer comprises: first and second cylinders provided with respective hinge pieces, the cylinders being rotatable with respect to each other about one and the same axis and being in contact with each other in the axial direction thereof; a support shaft inserted into the two cylinders substantially over the entire length thereof, one end portion of the support shaft being non-rotatably secured to the end portion of the second cylinder while the other end portion thereof being rotatably supported in the first cylinder; an intermediate rotary cylinder member provided rotatably with respect to the support shaft and the first cylinder between one end portion of the support shaft and the inner wall of the first cylinder; and a coil spring surrounding substantially the entire length of the support shaft in such a manner that both end portions thereof are non-rotatably secured to the intermediate rotary cylinder member and the lower end portion of the second cylinder, respectively.