JPS602542A - Jam detecting device in paper conveying path - Google Patents

Abstract

PURPOSE:To prevent a detecting lever from being broken and as well to the operator from being harmed, by providing such an arrangement that a support member is rotated upon removal of a jammed paper, to fall down a paper detecting lever so that the long side of the lever is made substantially parallel with a guide and baffle top board so that the lever is prevented from projecting into a paper guide path which has been opened. CONSTITUTION:In order to remove a jammed paper a guide and baffle top board 7 is rotated together with the rotary support shaft 8 of a paper detecting lever 9 to open a conveying path in the vicinity of a jam detecting device while a stopper 14 for retaining the detecting lever 9 in the vicinity of the rotary support shaft 8 in the rotating direction of the top board 7 is provided to maintain the relative relationship between the top board 7 and the detecting lever 9, for a moment in the condition before the opening of the paper conveying path. After this top board 7 rotates, exceeding a predetermined angle, the detecting lever 9 is fallen by its weight so that its long side or the edge orthogonal to the paper conveying path becomes in substantially parallel with the top board 7 without projecting into the opened paper conveying path, and therefore, interference between the detecting lever 9 and the paper or the hands of the operator who removes the jammed paper, is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mechanism for preventing damage to a jam detection device provided in a paper conveyance path of a copying machine or the like during jam removal and injury to an operator who removes the jam.

(Prior art) Conventionally, it has been common to use a microswitch or a photoelectric sensor to detect a jam in the paper conveyance path, but the former's actuator is easily broken by a collision with the paper lead edge, and the latter's actuator is prone to breakage due to paper dust, etc. There were problems such as deterioration of sensor sensitivity.

In order to avoid this, a paper detection sensor as shown in Figure 1 (al) and (bl) has been proposed. FIG. 2 is a schematic side view of the configuration, showing fixing rolls 1 and 2;
On the back of the paper kite hasoful bottom plate 3 at the exit of the
An optical sensor 6 with a light-emitting element 4 and a light-receiving element 5 facing each other as shown in the plan view is arranged at bl. - From the blade paper guide baffle top 1 7, a paper detection lever 9 supported swingably by a pin 8 hangs down through the guide bottom plate 3, and its tip is connected to the light emitting element 4 and the light receiving element 5.
It is something that is interposed between. 10 is the fixing roll 1
It is a peeling claw to peel off the paper that tries to wrap around the paper.
It is integrally supported by the support member 11 together with the guide/panful top plate 7, and the paper conveyance path can be opened by means of a rotating shaft I2.

As can be easily understood from this figure, the paper that has finished fixing passes while pushing up the paper detection lever 9.
During this time, the light receiving element 5 detects the light from the light emitting element 4, and the conveyance state of the paper can be determined from the time and timing.

On the other hand, if a jam occurs, the jammed paper can be removed by lifting the support member 11 to open the paper conveyance path as shown in FIG.

(Object of the Invention) However, as is clear from FIG. 2, when the paper conveyance path is opened, the tip of the paper detection lever 9 hangs down so as to point in the direction of the jammed paper in the paper conveyance path, and the operator can detect the jammed paper. When removing the paper, there is a drawback that the paper detection lever 9 may be damaged or the operator may be injured.

The present invention has been made to eliminate the above-mentioned drawbacks.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, the vicinity of the rotation support shaft 8 of the paper detection lever 9 is held down by a stopper in the rotational direction of the support member 11, and the paper detection lever 9 and the rotation support shaft 8 are held down by a stopper. The relative positional relationship with the support member 11 is temporarily maintained in the state before the paper conveyance path is opened, and after the support member 11 has rotated by a certain angle or more, the paper detection lever 9 collapses due to its own weight, and its long side touches the guide pan full top. To provide a jam detection device for a paper conveyance path that is substantially parallel to a plate 7.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIGS. 3 and 4 are schematic side views showing one embodiment of the jam detection device of the present invention, the former being in a normal state and the latter being in an open state for removing a jam.

In this figure, a protrusion 13 is provided near the rotary support shaft 8 of the paper detection lever 9, and the protrusion 13 is engaged with a stopper 14 fixed to the support member 11.

By doing this, when the support member 11 is rotated around its rotation axis 12 to open the paper conveyance path for removing a jam, the support member 11 is rotated to a nearly vertical position in the figure. During this period, the relative positional relationship between this and the paper detection lever 9 is the same as in the normal state, and when the support member 11 is further rotated to the position shown in FIG. The edge intersecting the paper transport path is approximately parallel to the paper guide/panful top plate 7 and does not protrude into the open paper transport path.

(Effects of the Invention) Since the present invention is constructed as described above, there is no risk that the operator will touch the paper detection lever 9 and be injured or damage the detection lever 9 during jam removal work. This makes it possible to remove jams from copying machines, etc. quickly and appropriately, reducing the burden on operators and reducing machine down time.

In the embodiment, a case has been described in which the device is provided with a peeling claw at the exit of the fixing device, but the present invention does not need to be limited to this, and can be applied to any desired location on the paper conveyance path. It goes without saying that it can be done.

[Brief explanation of drawings]

FIGS. 1(a) and (bl) are a schematic side view showing the arrangement of a conventional paper detection means and a plan view of the sensor, respectively; FIG. 3 and 4 are schematic side views of the jam detection device of the present invention, respectively, with the former showing the normal state and the latter showing the jam removing state. 3. Paper guide. Hasoful bottom plate, 6...
...Sensor, 7...Paper guide/full top plate, 8...Paper detection 'c Rotation support shaft, 9...
...Paper detection lever\, 14... Stopper 263- Fig. 3 1 B Fig. 4

Claims (2)

[Claims] (1) A sensor fixed to the back of the bottom plate of the guide/panful for paper conveyance, and a rotary support shaft above the top plate of the guide/panful, which hangs down to intersect with the paper conveyance path, and its tip indicates whether there is paper or not. In the jam detection device including a paper detection lever that swings toward or away from the sensor, the guide/panful top plate is rotated together with the rotary support shaft of the paper detection lever. At the same time as opening the paper conveyance path in the vicinity, a stop is provided that presses the vicinity of the rotation support shaft of the paper detection lever in the direction of rotation of the guide/baffle top plate. After the guide baffle top plate has rotated by a certain angle or more, the edge of the paper detection lever that intersects with the paper transport path is moved to the guide baffle. A jam in a paper transport path, characterized in that the paper is rotated by its own weight so as to be almost parallel to a top plate, thereby preventing interference between the paper detection lever, the hand of an operator who removes the jam, and the jammed paper when removing the paper jam. Detection device. (2) A paper transport path near a paper exit of a roll-type fixing device of an electrophotographic copying machine or the like is equipped with a paper peeling claw for preventing paper from wrapping around the fixing roll of the fixing device. The paper conveyance path jam detection device described above.