Corona charging device

#1. Field of the Invention

#The present invention relates to corona charging devices and, more particularly, corona charging devices that are used in electrophotographic reproduction apparatus to give the photoconductive surfaces an electrostatic charge prior to light exposure.

#2. Technical Considerations and Prior Art

#FIG. 1 is a perspective view schematically illustrating a prior art type corona charge device of the type of which the instant invention is an improvement.

#FIG. 2 is a perspective view of one end of the device of FIG. 1 showing how a corona charging wire is mounted.

#FIG. 3 is a perspective view of the opposite end of the device of FIG. 1 showing how the other end of the corona charging wire is mounted.

#Referring now to FIG. 1, there is schematically shown a corona charging device, designated generally by the numeral 10, which is illustrative of the apparatus of the prior art. In this device, a corona charging wire 11 is bent into a U-shape and fitted around a projection 12 at its closed end 13. The projection 12 extends from an insulating block 14 which is made of a material such as nylon. The corona charging wire 11 has two legs 16 and 17 which have their free ends contained in slots 19 and 20, respectively, which are formed in a second insulating block 21. The blocks 14 and 21 are contained in a metal channel 22 which is grounded by a wire 23 wrapped around a pin 24 extending from the channel. This prior art embodiment is subject to all of the deficiencies set forth in the discussion of the prior art above.

#Referring now to FIGS. 2 and 4, an embodiment of the instant invention is shown where the projection 12 is no longer integral with the block 14. Rather, as seen in FIG. 4, the projection 12 is slidably mounted in a retainer 26 which projects from the block 14. The projection 12 is biased outwardly by a spring 28 having one end which abuts a shoulder 29 in the retainer and an inside end 31 of the projection. The two legs 16 and 17 extend past the retainer 26 through a pair of slots 32 in block 14.

#Referring now to FIGS. 3, 5 and 6, there is shown an embodiment illustrating how the legs 16 and 17 of the corona charging wire 11 are secured to the insulating block 21 in accordance with the principles of the instant invention. As seen in FIGS. 3 and 5, the legs 16 and 17 have bent portions 40 and 41 which fit over the exterior surface 42 of the insulating block 21. As seen specifically in FIG. 5, the bent portion 40 projects from a straight portion 44 which is parallel to the leg 16. The bent portion 41 projects from a similar parallel portion 45 which is shown in FIG. 6. The parallel portions 44 and 45 are joined to the legs 16 and 17 by U-shaped portions 47 which cooperate with bent portion 40 to fit around a shoulder or lip 48 projecting up from the block 21.