# US 2017/0255156 A1 · Sheet stacking apparatus and an image forming apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0255156 A1 - Document ID: US20170255156A1 - Status: Published application - Kind: A1 - Application number: 15/437,832 - Filed: 2017-02-21 - Published: 2017-09-07 - Earliest claimed: 2016-03-01 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Naoto Tokuma - Web page: https://patentgrep.com/patent/US20170255156A1 ## CPC - G03G 15/6552: {Means for discharging uncollated sheet copy material, e.g. discharging rollers, exit trays} - B65H 31/02: with stationary end support against which pile accumulates - B65H 31/20: adjustable for different article sizes - B65H 31/22: removable or interchangeable - B65H 2301/4212: of articles substantially horizontal - B65H 2402/30: Supports; Subassemblies; Mountings thereof - B65H 2402/60: Coupling, adapter or locking means - B65H 2405/11164: Rear portion extensible in parallel to transport direction - B65H 2405/1119: Areas with particular deformation properties, e.g. flexible, elastic - B65H 2405/121: Locking means - B65H 2701/11312: large formats, i.e. above A3 - B65H 2801/06: Office-type machines, e.g. photocopiers - B65H 2801/27: Devices located downstream of office-type machines - G03G 2215/00421: Discharging tray, e.g. devices stabilising the quality of the copy medium, postfixing-treatment, inverting, sorting - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES ## Abstract Disclosed is a sheet stacking apparatus which includes a first stacking portion on which a sheet is stacked, a second stacking portion which is movable with respect to the first stacking portion, a third stacking portion which is detachably attachable to the first stacking portion or the second stacking portion and a restricting portion which restricts disengagement of the third stacking portion which has been attached. The second stacking portion is movable such that the second stacking portion is located at a first position where the restricting portion does not restrict disengagement of the third stacking portion and a second position where the restricting portion restricts disengagement of the third stacking portion which has been attached. ## Claims ### Claim 1 A sheet stacking apparatus, comprising: a first stacking portion on which a sheet is stacked; a second stacking portion on which a sheet is stacked, the second stacking portion being movable with respect to the first stacking portion; a third stacking portion on which a sheet is stacked, the third stacking portion being detachably attachable to the first stacking portion or the second stacking portion; and a restricting portion which restricts disengagement of the third stacking portion which has been attached, wherein the second stacking portion is movable such that the second stacking portion is located at a first position and a second position; and wherein the restricting portion does not restrict disengagement of the third stacking portion when the second stacking portion is located at the first position and the restricting portion restricts disengagement of the third stacking portion which has been attached when the second stacking portion is located at the second position. ### Claim 2 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the restricting portion restricts movement of the third stacking portion which has been attached in a direction of disengagement of the third stacking portion which has been attached when the second stacking portion is located at the second position. ### Claim 3 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the second stacking portion is provided on the first stacking portion such that the second stacking portion is slidable in a direction in which a sheet stacking surface extends. ### Claim 4 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the restricting portion is provided on the second stacking portion. ### Claim 5 (depends on 4) The sheet stacking apparatus according to claim 4, wherein the third stacking portion is made of an elastically deformable wire rod member; and wherein the restricting portion includes a protruding portion which restricts deformation of the wire rod member when the second stacking portion is located at the second position. ### Claim 6 (depends on 4) The sheet stacking apparatus according to claim 4, wherein the first stacking portion includes an engaging portion; wherein the third stacking portion includes an engaged portion which can be engaged with the engaging portion; and wherein the restricting portion which is provided on the second stacking portion restricts release of engagement of the engaging portion with the engaged portion when the second stacking portion is located at the second position and can release engagement of the engaging portion with the engaged portion when the second stacking portion is located at the first position. ### Claim 7 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the restricting portion is provided on the first stacking portion. ### Claim 8 (depends on 7) The sheet stacking apparatus according to claim 7, wherein the third stacking portion includes an engaging portion which can engage with the restricting portion when the second stacking portion is located at the second position, and which does not engage with the restricting portion when the second stacking portion is located at the first position. ### Claim 9 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the restricting portion does not protrude from a sheet stacking surface. ### Claim 10 (depends on 1) The sheet stacking apparatus according to claim 1, wherein angles of a sheet stacking surface of the first stacking portion, a sheet stacking surface of the second stacking portion and a sheet stacking surface of the third stacking portion are different each other. ### Claim 11 (depends on 1) The sheet stacking apparatus according to claim 1, wherein the second stacking portion is movable to a storage position at which the second stacking portion is stored in the first stacking portion. ### Claim 12 (depends on 11) The sheet stacking apparatus according to claim 11, wherein a gap between the first stacking portion and the second stacking portion, formed when the second stacking portion is located at the storage position is smaller than that formed when the second stacking portion is located at the first position or the second position. ### Claim 13 (depends on 1) An image forming apparatus, comprising: an image forming portion which forms an image on a sheet; and the sheet stacking apparatus according to claim 1, which stacks a sheet on which an image is formed by the image forming portion.