Joint mechanism and image forming apparatus using the same

Patent metadata

Field	Value
Publication number	US-10280982-B2
Application number	US-201815987305-A
Country	US
Kind code	B2
Filing date	May 23, 2018
Priority date	May 31, 2017
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

The joint mechanism includes an engagement pin; a first coupling having a pair of projections with engagement recessed portions formed respectively, the engagement recessed portions with which both end portions of the engagement pin are freely engaged or disengaged; a second coupling including a circumferential wall having an opening portion and a pair of projecting pieces; and a biasing member. The pair of projecting pieces are arranged in the engagement recessed portions so as to be opposed, on an upstream side in a rotation direction, to opening defining surfaces of the pair of projections, with the second coupling attached to the first coupling. Both end portions of the engagement pins are engaged with the engagement recessed portions so as to be each sandwiched between each of the pair of projecting pieces being applied a biasing force of the biasing member and each opening defining surface of the pair of projections.

First claim

The invention claimed is:

1. A joint mechanism which links a drive shaft and a follower shaft on the same axis along an axis direction and is capable of transmitting a rotation driving force of the drive shaft to the follower shaft, the drive shaft being driven to rotate in a predetermined rotation direction by a driving force from a driving source, and the follower shaft rotating in the rotation direction accompanying rotation of the drive shaft, the joint mechanism comprising:
an engagement pin provided at a front end portion of the drive shaft and having both end portions projecting from a circumference surface of the drive shaft in a radial direction;
a first coupling supported at a front end portion of the follower shaft so as to be rotatable following the follower shaft on the same axis and having a pair of projections with engagement recessed portions formed respectively, the engagement recessed portions with which both end portions of the engagement pin are freely engaged or disengaged;
a second coupling including a top wall and a circumferential wall and is attached to the first coupling so as to cover the pair of projections, the top wall having an opening portion into which the drive shaft provided with the engagement pin is allowed to be inserted, and the circumferential wall extending from an outer circumference edge of the top wall along the axis direction and having a pair of projecting pieces projecting inwardly from an inner circumference surface; and
a biasing member which biases the second coupling attached to the first coupling in the rotation direction with respect to the first coupling, wherein
the pair of projecting pieces are arranged in the engagement recessed portions, in a state where the second coupling is attached to the first coupling, so as to be opposed, on an upstream side in the rotation direction, to opening defining surfaces of the pair of projections, the opening defining surfaces defining an opening side end portion of each of the engagement recessed portions on a downstream side in the rotation direction, and
both end portions of the engagement pin inserted from the opening portion of the top wall are engaged with the respective engagement recessed portions so as to be each sandwiched between each of the pair of projecting pieces being applied an biasing force of the biasing member and each of the opening defining surfaces of the pair of projections.

2. The joint mechanism according to claim 1 , wherein
the biasing member is a torsion coil spring configured to include:
a coil portion to be inserted into the circumferential wall of the second coupling;
a first arm portion connected to one end of the coil portion and having a front end engaged with the second coupling; and
a second arm portion connected to the other end of the coil portion and having a front end engaged with the first coupling.

3. The joint mechanism according to claim 2 , wherein
the opening portion of the top wall includes:
a first opening into which the drive shaft is allowed to be inserted; and
a pair of second openings which communicate from the first opening in the radial direction and into which both end portions of the engagement pin are allowed to be inserted;

the top wall has a pair of guide slant surfaces which each slant from an opening edge, on the upstream side in the rotation direction, of each of the pair of second openings to an outer side in the axis direction, and guide both end portions of the engagement pin to be inserted into the pair of second openings, and
the second coupling attached to the first coupling
rotates in a direction reverse to the rotation direction against the biasing force of the biasing member such that the pair of projecting pieces separate from the opening defining surfaces of the pair of projections in the engagement recessed portions when both end portions of the engagement pin come into contact with the pair of guide slant surfaces and are inserted into the pair of second openings, and
rotates in the rotation direction due to the biasing force of the biasing member such that the pair of projecting pieces come close to the opening defining surfaces of the pair of projections in the engagement recessed portions when both end portions of the engagement pin pass the pair of guide slant surfaces to be engaged with the engagement recessed portions.

4. The joint mechanism according to claim 3 , further comprising:
a drive transmission gear that transmits the driving force from the driving source to the drive shaft and that is provided on the drive shaft on the same axis via a one-way clutch.

5. An image forming apparatus comprising:
a drive shaft driven to rotate in a predetermined rotation direction by a driving force from a driving source;
a roller member which has a follower shaft that rotates accompanying rotation of the drive shaft in the rotation direction and which transports a sheet by the rotation of the follower shaft;
an image forming portion which forms an image on a sheet transported by the roller member; and
the joint mechanism according to claim 1 which links the drive shaft and the follower shaft on the same axis along an axis direction.

Assignees

• Kyocera Document Solutions Inc

Inventors

• Ueno Daijiro

Classifications

• G03G21/1864

  associated with a positioning function · CPC title

• G03G21/186

  Axial couplings · CPC title

• G03G21/1857 Primary

  for transmitting mechanical drive power to the process cartridge, drive mechanisms, gears, couplings, braking mechanisms · CPC title

• G03G21/1647

  Mechanical connection means · CPC title

• B65H2403/721

  Positive-contact clutches, jaw clutches · CPC title