Arm rotating device and image forming apparatus provided with the same

The elastic force of a spring 41 in a direction of an arrow X is applied to an end 51A of a coil spring 5A in a direction of an arrow Y through a holding plate 42. The end 52A of the coil spring 5A is engaged with a holding hole 12 and regulated from moving in the direction of the arrow Y. The elastic force of the spring 41 in the direction of the arrow X is constantly applied to the coil spring 5A in a direction in which the peripheral surface of the support post 3 is tightened.

CROSS REFERENCE

This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2013-190063 filed in Japan on Sep. 13, 2013, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an arm rotating device having an arm with a free end and a fixed end and rotatably supporting the arm around a support post that is fixed on the side of the fixed end, the arm being configured to enable an operating body, such as an operating device and a display operating device, to be mounted on the side of the free end, and also relates to an image forming apparatus provided with such an arm rotating device.

An exemplary operating portion of an image forming apparatus includes a display operating device in which a touch panel is arranged on a surface of a display that displays an operating state and the like of the apparatus. In recent years, in accordance with multi-functionalization of image forming apparatuses, the amount of information to be displayed has increased and thus a display and a touch panel have become large in size. In addition, due to the enlargement of the size of a recording medium that can be subjected to an image forming process or diversification of processes to a recording medium, a feed path has become longer, so that the standing position of an operator to an image forming apparatus has not been fixed.

For this reason, for example, as disclosed in Japanese Patent Laid-Open Publication No. 2011-081059, some conventional image forming apparatuses are configured to rotatably support a display operating device with respect to the apparatus through an arm and a support post and enable the display operating device to be operated in an arbitrary position within a predetermined range. The display operating device receives a pressing operation by an operator in a switch arranged in the front face of the display operating device, or from a touch panel on the surface of a display.

As the arm becomes larger to cope with the increase in weight associated with the enlargement of a display, the pressing operation of the touch panel has easily generated vibration in the display operating device. In order to suppress this vibration, as the easiest way, measures in which a coil spring is wound around the peripheral surface of the support post and a load is applied to the rotating operation of the support post by the elastic force of the coil spring have been taken.

However, while the load to be applied increases as the arm becomes larger, if the winding force of the coil spring to the peripheral surface of the support post is increased, scraping occurs in the peripheral surface of the support post and the internal peripheral portion of the coil spring due to the repetition of the rotation of the arm and thus the load to be applied to the support post may be decreased. In addition, if the winding force of the coil spring is made too large, the load to the support post may be greatly decreased due to the error of component precision or assembly precision.

In any case, the decrease in load to the support post raises a problem that interferes with the pressing operation of the display operating device. This problem occurs similarly when an operating device other than the display operating device is mounted on the side of a free end of the arm.

An object of the present invention is to provide an arm rotating device capable of preventing a load to a support post from being decreased by causing a biasing force in a direction in which the elastic force of a coil spring is increased to be constantly applied to at least one end of the coil spring that is wounded around the support post and also capable of exactly performing a pressing operation with respect to an operating body, and to provide an image forming apparatus provided with such an arm rotating device.

SUMMARY OF THE INVENTION

An arm rotating device of the present invention is equipped with a support post, an arm, a coil spring, and a holding portion. The support post is rotatably supported within a predetermined angle of rotation. The arm has a fixed end and a free end, the arm being fixed to the support post on the side of the fixed end and configured to enable an operating body to be mounted on the side of the free end. The coil spring is wound around the peripheral surface of the support post. The holding portion holds at least one end of the coil spring in a movable manner while biasing the one end of the coil spring in a direction in which the elastic force of the coil spring is increased.

An image forming apparatus of the present invention includes: the above described arm rotating device; and an operating body that is mounted on the side of the free end of the arm of the arm rotating device and receives an input operation of information related to an image forming process.

The foregoing and other features and attendant advantages of the present invention will become more apparent from the reading of the following detailed description of the invention in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an arm rotating device according to a preferred embodiment of the present invention will be described with reference to the drawings. As shown inFIG. 1, an arm rotating device10according to a first preferred embodiment of the present invention is applied to an image forming apparatus100as an example. The arm rotating device10is equipped with a support post unit101and an arm unit102. The support post unit101extends upward from the rear side of the upper surface of the image forming apparatus100. The arm unit102includes a fixed end and a free end and is fixed to the upper end of the support post unit101on the side of the fixed end and configured to enable a display200to be mounted on the side of the free end. The display200is an operation body of the m present invention and displays information related to an image forming process in the image forming apparatus100. On the surface of the display200, a touch panel that receives an input operation by an operator is arranged.

The support post unit101rotatably supports the arm unit102around a central axis. By rotating the arm unit102around the central axis of the support post unit101, the display200moves from side to side. An operator who executes an operation to the image forming apparatus100can move the display200to a position in which the operator can easily operate the touch panel, according to a standing position with respect to the image forming apparatus100.

As shown inFIG. 2, the arm rotating device10, in a state in which a cover is removed, is equipped with a main body1and an arm2. The main body1is stored in the cover of the support post unit101and rotatably supports a support post3. The arm2is stored in the cover of the arm unit102, and a fixed end21of the arm2is fixed to the upper end of the support post3. The main body1has a rectangular tube shape as an example and is equipped with two upper and lower holding portion4on one side surface.

As shown inFIG. 3, within the main body1, bearings13and that rotatably support upper and lower ends of the support post3are fixed. Around the peripheral surface of the support post3, upper and lower two coil springs5A and5B are wound. The coil springs5A and5B, by winding the peripheral surface of the support post3, cause a load to be applied to the rotation of the support post3. Each of the coil springs5A and5B is arranged in a state in which first ends51A and51B are vertically spaced away from each other and second ends52A and52B are vertically close to each other.

As shown inFIG. 4, two of the holding portions4are vertically and symmetrically arranged on the side surface1A of the main body1. Each of the holding portions4is equipped with a spring41and a holding plate42. According to this preferred embodiment, each of the holding portions4is equipped with two of the springs41as an example. The spring41includes a first end411that is engaged with the holding plate42, and a second end412that is engaged with an engagement portion11of the main body1.

The holding plate42is an inelastic member defined by the present invention, and the ends51A and51B of the coil springs5A and5B together with the first end411of the spring41are engaged with the holding plate42. The holding plate42is held so as to be horizontally movable on the side surface1A. Specifically, a projection61that is fitted into a long hole421of the holding plate42and a projection62that contacts a side surface422parallel to the moving direction in the holding plate42are formed on the side surface1A. The projections61and62are equivalent to the contact member as a regulating member of the present invention. Since having a part that contacts the long hole421and the side surface422and that is formed into an arc shape and dot contacting the long hole421and the side surface422, the projections61and62can move the holding plate42smoothly.

It is to be noted the holding plate42is provided so as to reliably move mainly the ends51A and51B of the coil springs5A and5B, and the spring41only in a direction in which the elastic force of the coil springs5A and5B is increased and decreased. Therefore, if the ends51A and51B of the coil springs5A and5B, and the spring41can be reliably moved only in the direction in which the elastic force of the coil springs5A and5B is increased and decreased, the holding plate42can be eliminated. For example, it is also possible to form a horizontally directed long hole into which the ends51A and51B on the side surface1A of the main body1are fitted and to cause the end of the spring41to be directly engaged with the ends51A and51B that penetrate the long hole and are exposed to the outside of the main body1.

In addition, the shape of the main body1is not limited to the rectangular tube shape. On condition that the ends51A and51B of the coil springs5A and5B, and the spring41can be smoothly moved in the direction in which the elastic force of the coil springs5A and5B is increased and decreased, the main body1can be formed into an arbitrary shape.

As shown inFIG. 5, on a side surface1B opposite to the side surface1A in the main body1, a holding hole12is formed. With the holding hole12, the ends52A and52B of the coil springs5A and5B shown inFIG. 3are engaged.

The holding hole12need not be necessarily formed on the side surface1B. According to the positional relationship between the ends51A and51B and the ends52A and52B in the coil springs51A and5B in a plan view, the holding hole12can be formed on other side surfaces including the side surface1A of the main body1. It may be possible to improve workability in assembling by forming the holding hole12on the side surface1A equipped with the holding portion4.

As shown inFIG. 6, the elastic force of the spring41in a direction of an arrow X is applied to the end51A of the coil spring5A in a direction of an arrow Y through the holding plate42. The end52A of the coil spring5A is engaged with the holding hole12and regulated from moving in the direction of the arrow Y. Therefore, the elastic force of the spring41in the direction of the arrow X is constantly applied to the coil spring5A in a tightening direction in which the peripheral surface of the support post3is tightened. The same may be applied to the coil spring5B.

Even when variation occurs in dimensional precision and attachment precision of the support post3, the coil springs5A and5B, each portion of the main body1, and the like, the rotational load of the support post3can be maintained at a proper value by the coil springs5A and5B. Moreover, even when scraping occurs in the peripheral surface of the support post3and the internal peripheral surface of the coil springs5A and5B due to the repetition of the rotation of the support post3, the rotational load of the support post3can also be maintained at a proper value by the coil springs5A and5B.

By reversing the tightening direction with respect to the peripheral surface of the support post3by the coil spring5A and the coil spring5B, even when the support post3rotates in either the clockwise direction or the counterclockwise direction inFIG. 6, a load with respect to the support post3can be made constant. For example, the support post3and the coil springs5A and5B are arranged so that the coil spring5A tightens the peripheral surface of the support post3when the support post3rotates in the clockwise direction and the coil spring5B tightens the peripheral surface of the support post3when the support post3rotates in the counterclockwise direction. This can be realized by reversing the winding directions of the coil spring5A and the coil spring5B or by reversing the positions of the ends51A and51B and the ends52A and52B.

It should be noted while the arm rotating device10is equipped with two coil springs5A and5B, the arm rotating device10can also be equipped with only a single coil spring or three or more coil springs on the condition that the rotational load with respect to the support post3can be properly maintained.

As shown inFIG. 7, an arm rotating device110according to a second preferred embodiment of the present invention is different from the arm rotating device10in that the holding portion4includes a cover401, and the other configurations are in common with the configurations of the arm rotating device10. The cover401is mounted on the side surface1A and covers the both ends of the spring41in the holding portion4together with the holding plate42. This, at a time of the assembly of the arm rotating device110, prevents the spring41and the holding plate42from being flipped away by the elastic force of the spring41or the coil springs5A and5B.

As shown inFIG. 8, an arm rotating device120according to a third preferred embodiment of the present invention is different from the arm rotating device10in that a stopper43is provided on the upstream of the moving direction (arrow X direction) of the holding plate42by the spring41, and the other configurations are in common with the configurations of the arm rotating device10. In a case in which the load to the support post3during rotation in the clockwise direction of the support post3is different from the load to the support post3during rotation in the counterclockwise direction of the support post3, when the support post3rotates in the clockwise direction or the counterclockwise rotation, one of the coil springs5A and5B (only the coil spring5A is shown inFIG. 8) may be excessively deformed in a loosening direction. Accordingly, the stopper43regulates the excessive movement of the holding plate42in the loosening direction of the coil springs5A and5B and prevents the rotational load of the support post3from being remarkably decreased.

As a fourth preferred embodiment of the present invention, the projection62as a contact member may be formed of a rotating body such as a roller, which can reduce frictional resistance with the side surface422of the holding plate42and can move the holding plate42further smoothly.

The arm rotating device of the present invention is applicable not only to an image forming apparatus but also similarly to other devices that support an operation body in a movable manner.

The foregoing preferred embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the following claims, not by the foregoing embodiments. Further, the scope of the present invention is intended to include the scopes of the claims and all possible changes and modifications within the senses and scopes of equivalents.