# US 8,739,468 B2 · Door opening and closing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,468 B2 - Document ID: US8739468B2 - Status: Granted - Kind: B2 - Application number: 13/391,536 - Filed: 2010-05-14 - Published: 2012-12-20 - Granted: 2014-06-03 - Earliest claimed: 2009-08-20 - Assignees: Sugatsune Kogyo Co., Ltd. - Applicants: Koushi Yamaguchi; Kazuaki Kashiwaguma; Mitsuru Sugiura - Inventors: Koushi Yamaguchi; Kazuaki Kashiwaguma; Mitsuru Sugiura - Web page: https://patentgrep.com/patent/US8739468B2 ## CPC - E05F 3/106: {with crank-arm transmission between driving shaft and piston within the closer housing} - E05F 1/14: with double-acting springs, e.g. for closing and opening or checking and closing {no material} - E05F 1/16: for sliding wings - E05F 5/003: {for sliding wings (Fasteners specially adapted for holding sliding wings open E05D13/04)} - E05F 3/02: with pneumatic piston brakes (rotary type E05F3/14) - E05F 3/227: {mounted at the top of wings, e.g. details related to closer housings, covers, end caps or rails therefor} - E05F 5/027: {with closing action} - E05Y 2201/624: Arms - E05Y 2900/132: Doors - E05Y 2900/20: for furniture, e.g. cabinets - E05F: DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING - E05Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES E05D AND E05F, RELATING TO CONSTRUCTION ELEMENTS, ELECTRIC CONTROL, POWER SUPPLY, POWER SIGNAL OR TRANSMISSION, USER INTERFACES, MOUNTING OR COUPLING, DETAILS, ACCESSORIES, AUXILIARY OPERATIONS NOT OTHERWISE PROVIDED FOR, APPLICATION THEREOF ## Abstract Provided is a door opening and closing device wherein the device width can be made small and wherein the movement of a retraction arm can be stabilized. In a body case (102) which is slender and extends in one direction, there is provided an arm block (121) for a retraction arm (104) which rotates from the open state to the closed state. On one side of the body case (102), there is provided a first slider (134) which, being interlocked with the rotation of the arm block (121), makes linear movements in one direction. In the body case (102), there is provided an arm shaft (105) which serves as the center of rotation of the arm block (121). A second slider (131) which, being interlocked with the rotation of the arm block (121), makes linear movements in one direction, is provided opposite the first slider (134), in such a way as to have the arm shaft (105) held between the first and second sliders (134, 131). On one side of the body case (102), there is provided a force applying member (128) which applies force on the first slider (134) in one direction. On the opposite side of the body case (102), there is provided a damper which resists the linear movement of the second slider (131). ## Claims ### Claim 1 A door opening and closing device comprising: a body case elongated in one direction; a retractable arm which is provided rotatable in the body case, rotates from an open state to a closed state, and has an arm axis as a rotational center thereof; a first slider which is provided at one side of the arm axis in the one direction in the body case and moves linearly in the one direction in conjunction with rotation of the retractable arm; a first link which is rotatable and directly connected to the retractable arm at an off-center position from the arm axis and is rotatable and directly connected to the first slider; a second slider which is provided at an opposite side of the arm axis in the one direction in the body case in such a way that the arm axis is located between the first slider and the second slider and which moves linearly in the one direction in conjunction with rotation of the retractable arm; a biasing member which is provided at the one side of the body case and biases the first slider in the one direction; and a damper which is provided at the opposite side of the body case and resists linear movement of the second slider, wherein the biasing member gives the retractable arm in the open state a biasing force in an opening direction, and when the retractable arm in the open state is rotated in a closing direction by a predetermined angle or more, the biasing member gives the retractable arm a biasing force in the closing direction, and when the retractable arm is rotated in the closing direction, the damper damps rotation of the retractable arm. ### Claim 2 (depends on 1) The door opening and closing device of claim 1, further comprising a second link which is connected to the retractable arm at an off-center position from the arm axis and is connected rotatable to the second slider. ### Claim 3 (depends on 1) The door opening and closing device of claim 1, wherein the biasing member is a compression spring. ### Claim 4 (depends on 3) The door opening and closing device of claim 3, further comprising: a spring catch which is provided at the one side of the arm axis in the body case for catching the compression spring; and position adjusting means for adjusting a position of the spring catch in the one direction relative to the body case, wherein the position of the spring catch is adjusted thereby to adjust the biasing force of the compression spring sandwiched between the first slider and the spring catch. ### Claim 5 (depends on 1) The door opening and closing device of claim 1, wherein the second slider is removably connected to the damper, and the second slider and the damper are away from each other so as to prevent the damper from damping rotation of the retractable arm when the retractable arm is rotated in the opening direction. ### Claim 6 (depends on 1) The door opening and closing device of claim 1, wherein the body case has at least one opening, the door opening and closing device further comprises an arm base having a first wall part which is installed in the body case via the opening for supporting an end of the arm axis, a second wall part for supporting an opposite end of the arm axis and a linking part for linking the first wall part to the second wall part, and the retractable arm is sandwiched between the first wall part and the second wall part of the arm base. ### Claim 7 (depends on 6) The door opening and closing device of claim 6, wherein the opposite end of the arm axis is supported by the second wall part of the arm base and a side wall of the body case superimposed on the second wall part. ### Claim 8 (depends on 1) The door opening and closing device of claim 1, further comprising a second link which is connected to the retractable arm at an off-center position from the arm axis and is connected rotatable to the second slider. ### Claim 9 (depends on 1) The door opening and closing device of claim 1, wherein the biasing member is a compression spring. ### Claim 10 (depends on 2) The door opening and closing device of claim 2, wherein the biasing member is a compression spring. ### Claim 11 (depends on 2) The door opening and closing device of claim 2, wherein the second slider is removably connected to the damper, and the second slider and the damper are away from each other so as to prevent the damper from damping rotation of the retractable arm when the retractable arm is rotated in the opening direction. ### Claim 12 (depends on 3) The door opening and closing device of claim 3, wherein the second slider is removably connected to the damper, and the second slider and the damper are away from each other so as to prevent the damper from damping rotation of the retractable arm when the retractable arm is rotated in the opening direction. ### Claim 13 (depends on 4) The door opening and closing device of claim 4, wherein the second slider is removably connected to the damper, and the second slider and the damper are away from each other so as to prevent the damper from damping rotation of the retractable arm when the retractable arm is rotated in the opening direction.