Patent Application
20200361740
Disclosed is an improved system for repositioning sheets conveyed to a sheet stacker tray or other output device for set stapling or the like.
In a typical electrostatographic printing process, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charges thereon in the irradiated areas. This records an electrostatic latent image on the photoconductive member corresponding to the information areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules to the latent image forming a toner powder image on the photoconductive member. The toner powder image is then transferred from the photoconductive member to a copy sheet. The toner particles are heated to permanently affix the powder image to the copy sheet.
Generally, printing machines employing this process or an ink jet process utilize cut sheets of paper advanced though the printing machine, one sheet at a time, for suitable processing therein. Frequently, sheets are advanced through the printing machine by transport subsystems that include mechanisms for aligning the sheet output in multiple sets. To keep each set separated, the registration assembly offsets the sets so that they will stack in the output tray offset from each other, alternately in an inboard and then in an outboard direction, the separation distance being great enough to allow the operator to separate the sets easily. It has been usual in the past for the output stacker to use a paddle wheel to urge the sheets against the moveable registration edge. For each set, the edge is moved to a new position, thereby guaranteeing that each set of sheets will be easily differentiated from the next for the benefit of the operator. One problem frequently encountered is that, as a sheet enters the offsetting area, for some skew angles, speeds and registration positions, the paddle wheels do not exert the proper force on the sheets to guarantee registration. This results in a scattering of the sheets or in a percentage of the sheets still being angled after reaching the output tray, depending on the sheet weight and type, resulting in poor offset definition for successive sets of sheets. What is required is that offset registration be accomplished while the sheets are in motion. Prior systems have been able to accomplish registration without corner damage, but only by bringing the sheet to a stop before registration. One attempt at registering sheets “on-the-fly” is shown in U.S. Pat. No. 4,786,045.
Obviously, there is still a need for offset registering of sheets for stacking “on-the-fly.”
Accordingly, in answer to this need, disclosed herein is a four bar linkage that is adjustable to variably position a paper edge registration guide. The linkage geometry maintains parallelism of the edge registration guide to the paper path direction. The motion of the four bar linkage can be generated either by rotating one of two links with a suitable actuator or by use of a linear force acting normal to the edge registration guide.
Various of the above-mentioned and further features and advantages will be apparent to those skilled in the art from the specific article or methods described in the example(s) below, and the claims. Thus, they will be better understood from this description of these specific embodiment(s), including the drawing figures (which are approximately to scale) wherein:
For a general understanding of the features of the disclosure, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to identify identical elements.
In accordance with the present disclosure, an improved edge registration apparatus 10 is disclosed in
A cam like device 20 is shown positioned between movable registration edge 18 and fixed rail 16 in
Parallel link edge registration offset enablement at multiple location is shown in
In practice, sheet edge registration apparatus 10 provides quick response time, precise location, simpler manufacturing, a single entrance point height and robust alignment for registering sheets “on-the-fly.” The edge registration apparatus includes a single narrow channel 19 mounted to a set of linked arms 12 and 14 which when moved in the process direction (upstream-downstream) articulate in a cross-process direction (inboard-outboard) to register sheets 11 at various locations for stacking, offsetting or finish processing. The linked arms keep the channel parallel to the paper path at all times regardless of inboard-outboard offset. The channel has a lead in angle and ramp (not shown) in order to prevent sheet stubbing when entering the channel. The movable rail 18 and the links 12 and 14 which keep the movable and fixed rails parallel are actuated by conventional devices, such as, a stepper motor mounted on a link or solenoids. Additionally, small stepper motor driven cams can be used between the rails for spacing purposes. Regardless of the method used, the rail guide position would be maintained until the next job and the offset it requires passes through. Sheet count would determine the timing.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
