CA1050749A - Resilient rollers - Google Patents
Resilient rollersInfo
- Publication number
- CA1050749A CA1050749A CA202,841A CA202841A CA1050749A CA 1050749 A CA1050749 A CA 1050749A CA 202841 A CA202841 A CA 202841A CA 1050749 A CA1050749 A CA 1050749A
- Authority
- CA
- Canada
- Prior art keywords
- roller
- resilient member
- flexible sleeve
- resilient
- rigid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/10—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
- G03G15/101—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material
- G03G15/102—Apparatus for electrographic processes using a charge pattern for developing using a liquid developer for wetting the recording material for differentially wetting the recording material
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Rolls And Other Rotary Bodies (AREA)
- Wet Developing In Electrophotography (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
Abstract
Abstract of the Disclosure A roller having a uniform surface resiliency sufficient to maintain substantial contact along a line of axial tangency with a co-operating surface comprises a central roller and a flexible sleeve spaced apart by resilient means.
Description
``
~5(:i 79~
The present invention relates generally to a roller having a resilient surface and to a method for making such a roller The resilient surface of the roller allows it to maintain substantial contact along the length of its axial tangency, with a more rigid surface with which it co-operates.
U.S. Patent 3,084,043 teaches an apparatus and method for the liquid development of electrostatic latent images wherein the liquid developer is presented to a photo-receptor having an electrostatic latent image on its surface,said presentation being by means of an applicator comprising lands and valleys such that a liquid developer is contained in the valleys out of contact with the photoreceptor, while the surfacesof the lands are in contact with the photo-receptor. In such an arrangement, the liquid developer is attracted from the valleys to the electrostatic latent-image in image configuration. A -typical example of such an arrangement is an electrostatographic copying apparatus wherein the applicator is a rigid cylindrical member having on its surface a pattern of grooves and ridges which comprises lands and valleys, respectively. ~ liquid developer is maintained in the valleys below the surface of the lands.
The applicator is positioned to come into contact with a photoreceptor bearing on its surface an electrostatic latent image. In a typical electrostatographic copying apparatus the photoreceptor is also a cylindrical member comprising a conductive substrate and a photoconductive coating which supports the electrostatic latent image. The electrostatic /
.
~5~
latent image is typically produced by first char~ing the entire surface of the photoreceptor in the dark and then by exposing the charged surface to imagewise radiation.
The portions of the charged photoreceptor surfaces which are struck by the radiation are discharged, leaving an image patterns of charge on the photoreceptor surface in the non-radiation-struck areas.
The photoreceptor surface bearing the electrostatic latent image and the applicator are brought into moving contact during which the liquid developer is drawn to the photo-receptor from the valleys o~ the applicator roller by the charges which form the electrostatic latent image.
Typically the image is then transferred to an image receiving member such as paper by pressure contact between the photo-receptor and a roller.
Although both of the surfaces may be flat, it is more common for at least one of the surfaces to be arcuate to facilitate the moving of the applicator past sequential points on the photoreceptor while the two are in contact.
In compact electrostatographic copying devices the surfaces are typically small diameter cylinders to facilitate the co-operative movement of the surfaces in a confined space.
Such movement typically occurs at speeds of about four inches per second, although moving contact resulting in the transfer of li~uid developer from the applicator to the photoreceptor occurs at speeds ranging generally from about two to about 70 inches per second.
l~S~74~
Although ~isible and recognizable images can be produced by such an apparatus and method, they have been found to lack uniform density and to be characterized by spots and streaks where no image is developed. Typically, areas of the image which have the same shade of color or density in the original have areas of thle greatly varying density in the developed image and final copy. Further, the final copy typically has areas of streaks and spots where ho image was developed to correspond to solid areas of the original image. Such typical characteristics of the developed image are generally considered unsatisfactory, not pleasing to the eye, and as indices o~ unaccepkab:Le copy quality.
In our copending Canadian application Serial No. 206,g55 filed August 12, 1974, we have described an arrangement in which a cooperating roller has a deformable surface, such a roller may be for example the surface of a photoreceptor or applicator~
The use of the deformable surface, either the applicator surface or the photoreceptor surface in such an electrostatographic development apparatus or method when at least one of such surfaces is arcuate provides substantially uniform contact and a substantially uniform nip width between the surfaces.
~56~7~9 In the copending application we described how we have found that substantially uniform contact between the surfaces is achieved whenever the gap distance between adjacent portions of the surfaces while they are main-tained in contact is less than about 0.0005 inch along the line of tangency between the surfaces. In one embodiment a rigid applicator surface has an overalL variation along its line of tangency with the photoreceptor of not more than about 0.002 inch and a variation from land to land of not more than about 0.0~05 inch. A deformable photo-receptor having a hardness of about 30 as measured on a Shore A durometer contacts the land surfaces. The gap between the deformable photoreceptor surface and the lands of the rigid applicator surface in such an arrangement is maintained at about 0.0005 inch or less to provide sub-stantial contact between the surfaces.
The nip width in that exemplary embodiment is the zone of substantial contact between -the two surfaces. Sub-stantially uniform nip width we have found is achievedwhenever the zone of substantial contact between the sur~aces varies not more than about ten fold. A preferred nip width variation is about + 50~.
~S~749 In the embodiment described just above, the photo-receptor is the deformable member. ~owever, it is to be understood that the applicator may be the deformable memb~r.
The deformable member may have a hardness of up to about las measured on a Shore A durometer). For producing copies of consistent sharpness and clarity a preferred hardness is from about 40 to about 70, and optimum print quality is achieved from about 50 to about 60 .
An important aspect of the copending application is the ability of the deformable surface to maintain its func-tional integrity during deformation. That is, the deformable ember, whether the applicator or the photoreceptor, must continue to provide its intended function during deformation.
The establishing of a substantially uniform nip width and of substantial contact as the surfaces move in operative contact provides substantially uniform periods of time during which the liquid developer is able to move from the applicator valleys to the photoreceptor surface across a substantially uniform gap which is never in excess of 0.0005 inch. Thus, substantially uniform amounts of liquid developer are transferred to the photoreceptor in response to substantially equally charged portions of the image.
~5697~
According to another aspect of the invention there is provided a method for assembling a roller having a uniform surface resilience and comprising a rigid central roller and .
a flexible sleeve spaced apart by a layer of resilient material in compression, said method comprising the steps of: (i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member; (ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the xesilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
Photoreceptor members and applicator rolls in the form of resilient rollers formed in accordance with the teach-ing of the present invention provide for the development of electrostatic latent images of similar or equal potential by the application or deposition of substantially equal amounts of developer for respective image potentials. Preferably, the nip width in cooperating use is not more than about ten fold, the resilient roller has a linear variation along its l.ine of tangency of not more than 0.0~2 inches and a .~ - 7 -~S~374~
variation from land to land of not more than 0.0005 inches, and its surface hardness is in the range 40 to 70 , and optimumly about 55.
Enbodiments of the invention will now be described with reference to the accompanying drawiIlgs, in which:
Fig. 1 is a view of the elements comprising a resilient roller prior to assembly in a sealed container;
Fig. 2 is a cross-sectioned view along lines 2-Z
of Fig. 1 showing an assembled resilient roller;
Fig. 3 shows a greatly enlarged resilient roller in contact with an uneven surface with which it co-operates;
and Figs. 4A and 4B depict an alternate method of assembling the resilient roller of the present invention.
Referring now to the drawin~s, in Fig. 1, there is shown a rigid roller 1 which may be made of any non-fLexible material such as metal, wood, or hardened plastic. Also shown in Fig. 1 is sleeve 3 which is comprised of a material and a thickness which allows it to be flexible. For example, the sleeve has an outside diameter of 4.77 inches and a thick-ness of 0.0045 inch and is formed of an extruded brass substrate 4 coated with selenium 5. The photoreceptor may comprise any suitable photoconductive material coated on any suitable conductive metal base. Any suitable photo-conductive material and substrate may be emp:Loyed. Typical photoconductors are selenium, selenium aLloys and haLlogen ~opeclselenium.
Typical substrates are nickel, brass and alw~um. If desired there may be an interface layer between the photoconductive material and the substrate to provide selected adhesive or electrical properties and there may be an insulating coating over the photoreceptor.
Flexible sleeve 3 has an inside diameter which is sufficiently larger than the outside diameter of the rigid roller 1 that flexible sleeve 3 will slip over rigid roller 1 leaving a free space between all points on the inside diameter of flexible sleeve 3 and the outside diameter of rigid roller 1.
Although not illustrated, the flexible sleeve may be an applicator means which is sought to be made sufficiently resilient to co-operate with a rigid photoreceptor surface.
Also shown in Fig. 1 is resilient material 6 which is comprised of a closed cell, flexible, sponge-like material.
Any such material is acceptable. Typical of such materials are polyurethane foams, cellulose acetate, epoxy, poly-ethylene, poly(vinylchloride) and rubber foams.
The resilient material is in the form of a cylinder having an uncompressed wall thickness greater than the free space that is available between the inside diameter of the -flexible sleeve 3 and the outside diameter of the rigid roller 1. :
The elements described above are contained in a sealed chamber 7 which has a port 8 for pumping a fluid in and out of the chamber 7. Any suitable fluia may be used. Typical ~ 10 5~7~
fluids are air, water and hydrocaxbon fxactions. In Fig. 1, air is pumped into fluid-tight chamber 7 through port 8 until an internal pressure sufficient to collapse resilient member 6 is achieved. The resilient member 6 collapses when the pressure inside the sealed chamber 7 exceeds the pressure of the trapped fluid inside the closed cells of the resilient member 6 to a sufficient degree that the walls of the closed cells cannot support the cells in their normal position. In Fig. 1, a pressure of 35 p.s.i. is required to collapse a poly-urethane foam resilient member 6, having a thickness of 0.5inch, sufficient to allow the collapsed resilient member 6 to be slipped into the free space between the inside diameter of the flexible sleeve 3 and the outside diameter of the rigid roller 1.
Following assembly the fluid pressure is then removed by releasing the air from the inside of sealed chamber 7 through port 8. As the fluid press~lre is reduced, the pressure differential between the atmosphere inside the sealed chamber and the fluid inside the closed cells approaches 2ero, and the closed-cell foam becomes self supporting but remains under at least some compression.
Referring more specifically now to Fig. 2 there is shown the completed resilient roller 9 as it appears after assembly by the method described above. The resilient material 6 is uniformly distributed to evenly space apart the rigid roller 1 and the flexible sleeve 3 and to exert a uniform outward pressure on the inside diameter oE the flexible sleeve 3.
Referring more specifically now to Fig. 3, there is shown resilient roller 9 as assembled above working in cooperation ~5~74~
with li~uid developer applicator roll 10 which is formed from a hard material so that is has grooves 11 and ridges 12 on its operati~e surface which act, repsectively, as valleys and lands. A liquid developer solution 13 is contained in the valleys and upon coopexative motion of the photoreceptor the liquid developer solution 13 is presented to the photoreceptor 5 to develop any electrostatic latent image thereon. As shown in Fig~ 3, the line of axial contact between the resilient roller 9 and the lands 12, the applicator roller 10 is uneven However the resilient properties of the resilient roller 9 allow contact between the surface of the resilient roller 9 and the uneven lands 12 without sufficient distortion oE the photoreceptor 5 to affect its operation.
It will be appreciated with reference to Fig. 3 that the applicator roller may be the resilient roller, and the photoreceptor surface may be rigid. In such a configuration the resilient surface of the applicator roll would flex to maintain a contact between its lands and the uneven surface of the photoreceptor.
Referring more specifically now to Fig. 4A, there is sho~n a rigia core 1 having a number of apertures 14 in its surface. The core is covered by a tube of resilient material 6. Also shown is flexible sleeve 2 which has on its surface valleys and lands, shown for example respectively at 11 and 12. The flexible sleeve 2 may be made of any flexible material which will support the land-and-valley surface configuration while it functions as a resilient applicator roller. Typical such materials are steel and plast:ic.
~3507~
The resilient applicator roller is assembled by first positioning the resilient tube 6 on the rigid core 1 as in Fig. 4A. The pressure on the resi]ient tube 6 is provided by evacuating air from the inside of the rigid roller 1 through port 8. A partial vacuum is thus created by means of aperture 14 in the surface of rigid core 1 thus causing the resilient member 6 at least partially to collapse, as shown in Fig. ~B. The flexible sleeve 2 is then slipped into position over the collapsed resilient member 6 (in Fig.
4B, the sleeve is shown nearly in position) and the partial vacuum which has been maintained at the port 8 is relaxed to allow the resilient member 6 to expand, thus spacing apart the flexible sleeve 2 and the rigid roller 1 with uniform pressure to achieve a resilient applicator roll.
In this arrangement the resilient member 6 can be conveniently formed of any of the materials mentioned in relation to resilient member 6 of Figs. 1 and 2 but preferably having a very open cell structure.
. .
.
~5(:i 79~
The present invention relates generally to a roller having a resilient surface and to a method for making such a roller The resilient surface of the roller allows it to maintain substantial contact along the length of its axial tangency, with a more rigid surface with which it co-operates.
U.S. Patent 3,084,043 teaches an apparatus and method for the liquid development of electrostatic latent images wherein the liquid developer is presented to a photo-receptor having an electrostatic latent image on its surface,said presentation being by means of an applicator comprising lands and valleys such that a liquid developer is contained in the valleys out of contact with the photoreceptor, while the surfacesof the lands are in contact with the photo-receptor. In such an arrangement, the liquid developer is attracted from the valleys to the electrostatic latent-image in image configuration. A -typical example of such an arrangement is an electrostatographic copying apparatus wherein the applicator is a rigid cylindrical member having on its surface a pattern of grooves and ridges which comprises lands and valleys, respectively. ~ liquid developer is maintained in the valleys below the surface of the lands.
The applicator is positioned to come into contact with a photoreceptor bearing on its surface an electrostatic latent image. In a typical electrostatographic copying apparatus the photoreceptor is also a cylindrical member comprising a conductive substrate and a photoconductive coating which supports the electrostatic latent image. The electrostatic /
.
~5~
latent image is typically produced by first char~ing the entire surface of the photoreceptor in the dark and then by exposing the charged surface to imagewise radiation.
The portions of the charged photoreceptor surfaces which are struck by the radiation are discharged, leaving an image patterns of charge on the photoreceptor surface in the non-radiation-struck areas.
The photoreceptor surface bearing the electrostatic latent image and the applicator are brought into moving contact during which the liquid developer is drawn to the photo-receptor from the valleys o~ the applicator roller by the charges which form the electrostatic latent image.
Typically the image is then transferred to an image receiving member such as paper by pressure contact between the photo-receptor and a roller.
Although both of the surfaces may be flat, it is more common for at least one of the surfaces to be arcuate to facilitate the moving of the applicator past sequential points on the photoreceptor while the two are in contact.
In compact electrostatographic copying devices the surfaces are typically small diameter cylinders to facilitate the co-operative movement of the surfaces in a confined space.
Such movement typically occurs at speeds of about four inches per second, although moving contact resulting in the transfer of li~uid developer from the applicator to the photoreceptor occurs at speeds ranging generally from about two to about 70 inches per second.
l~S~74~
Although ~isible and recognizable images can be produced by such an apparatus and method, they have been found to lack uniform density and to be characterized by spots and streaks where no image is developed. Typically, areas of the image which have the same shade of color or density in the original have areas of thle greatly varying density in the developed image and final copy. Further, the final copy typically has areas of streaks and spots where ho image was developed to correspond to solid areas of the original image. Such typical characteristics of the developed image are generally considered unsatisfactory, not pleasing to the eye, and as indices o~ unaccepkab:Le copy quality.
In our copending Canadian application Serial No. 206,g55 filed August 12, 1974, we have described an arrangement in which a cooperating roller has a deformable surface, such a roller may be for example the surface of a photoreceptor or applicator~
The use of the deformable surface, either the applicator surface or the photoreceptor surface in such an electrostatographic development apparatus or method when at least one of such surfaces is arcuate provides substantially uniform contact and a substantially uniform nip width between the surfaces.
~56~7~9 In the copending application we described how we have found that substantially uniform contact between the surfaces is achieved whenever the gap distance between adjacent portions of the surfaces while they are main-tained in contact is less than about 0.0005 inch along the line of tangency between the surfaces. In one embodiment a rigid applicator surface has an overalL variation along its line of tangency with the photoreceptor of not more than about 0.002 inch and a variation from land to land of not more than about 0.0~05 inch. A deformable photo-receptor having a hardness of about 30 as measured on a Shore A durometer contacts the land surfaces. The gap between the deformable photoreceptor surface and the lands of the rigid applicator surface in such an arrangement is maintained at about 0.0005 inch or less to provide sub-stantial contact between the surfaces.
The nip width in that exemplary embodiment is the zone of substantial contact between -the two surfaces. Sub-stantially uniform nip width we have found is achievedwhenever the zone of substantial contact between the sur~aces varies not more than about ten fold. A preferred nip width variation is about + 50~.
~S~749 In the embodiment described just above, the photo-receptor is the deformable member. ~owever, it is to be understood that the applicator may be the deformable memb~r.
The deformable member may have a hardness of up to about las measured on a Shore A durometer). For producing copies of consistent sharpness and clarity a preferred hardness is from about 40 to about 70, and optimum print quality is achieved from about 50 to about 60 .
An important aspect of the copending application is the ability of the deformable surface to maintain its func-tional integrity during deformation. That is, the deformable ember, whether the applicator or the photoreceptor, must continue to provide its intended function during deformation.
The establishing of a substantially uniform nip width and of substantial contact as the surfaces move in operative contact provides substantially uniform periods of time during which the liquid developer is able to move from the applicator valleys to the photoreceptor surface across a substantially uniform gap which is never in excess of 0.0005 inch. Thus, substantially uniform amounts of liquid developer are transferred to the photoreceptor in response to substantially equally charged portions of the image.
~5697~
According to another aspect of the invention there is provided a method for assembling a roller having a uniform surface resilience and comprising a rigid central roller and .
a flexible sleeve spaced apart by a layer of resilient material in compression, said method comprising the steps of: (i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member; (ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the xesilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
Photoreceptor members and applicator rolls in the form of resilient rollers formed in accordance with the teach-ing of the present invention provide for the development of electrostatic latent images of similar or equal potential by the application or deposition of substantially equal amounts of developer for respective image potentials. Preferably, the nip width in cooperating use is not more than about ten fold, the resilient roller has a linear variation along its l.ine of tangency of not more than 0.0~2 inches and a .~ - 7 -~S~374~
variation from land to land of not more than 0.0005 inches, and its surface hardness is in the range 40 to 70 , and optimumly about 55.
Enbodiments of the invention will now be described with reference to the accompanying drawiIlgs, in which:
Fig. 1 is a view of the elements comprising a resilient roller prior to assembly in a sealed container;
Fig. 2 is a cross-sectioned view along lines 2-Z
of Fig. 1 showing an assembled resilient roller;
Fig. 3 shows a greatly enlarged resilient roller in contact with an uneven surface with which it co-operates;
and Figs. 4A and 4B depict an alternate method of assembling the resilient roller of the present invention.
Referring now to the drawin~s, in Fig. 1, there is shown a rigid roller 1 which may be made of any non-fLexible material such as metal, wood, or hardened plastic. Also shown in Fig. 1 is sleeve 3 which is comprised of a material and a thickness which allows it to be flexible. For example, the sleeve has an outside diameter of 4.77 inches and a thick-ness of 0.0045 inch and is formed of an extruded brass substrate 4 coated with selenium 5. The photoreceptor may comprise any suitable photoconductive material coated on any suitable conductive metal base. Any suitable photo-conductive material and substrate may be emp:Loyed. Typical photoconductors are selenium, selenium aLloys and haLlogen ~opeclselenium.
Typical substrates are nickel, brass and alw~um. If desired there may be an interface layer between the photoconductive material and the substrate to provide selected adhesive or electrical properties and there may be an insulating coating over the photoreceptor.
Flexible sleeve 3 has an inside diameter which is sufficiently larger than the outside diameter of the rigid roller 1 that flexible sleeve 3 will slip over rigid roller 1 leaving a free space between all points on the inside diameter of flexible sleeve 3 and the outside diameter of rigid roller 1.
Although not illustrated, the flexible sleeve may be an applicator means which is sought to be made sufficiently resilient to co-operate with a rigid photoreceptor surface.
Also shown in Fig. 1 is resilient material 6 which is comprised of a closed cell, flexible, sponge-like material.
Any such material is acceptable. Typical of such materials are polyurethane foams, cellulose acetate, epoxy, poly-ethylene, poly(vinylchloride) and rubber foams.
The resilient material is in the form of a cylinder having an uncompressed wall thickness greater than the free space that is available between the inside diameter of the -flexible sleeve 3 and the outside diameter of the rigid roller 1. :
The elements described above are contained in a sealed chamber 7 which has a port 8 for pumping a fluid in and out of the chamber 7. Any suitable fluia may be used. Typical ~ 10 5~7~
fluids are air, water and hydrocaxbon fxactions. In Fig. 1, air is pumped into fluid-tight chamber 7 through port 8 until an internal pressure sufficient to collapse resilient member 6 is achieved. The resilient member 6 collapses when the pressure inside the sealed chamber 7 exceeds the pressure of the trapped fluid inside the closed cells of the resilient member 6 to a sufficient degree that the walls of the closed cells cannot support the cells in their normal position. In Fig. 1, a pressure of 35 p.s.i. is required to collapse a poly-urethane foam resilient member 6, having a thickness of 0.5inch, sufficient to allow the collapsed resilient member 6 to be slipped into the free space between the inside diameter of the flexible sleeve 3 and the outside diameter of the rigid roller 1.
Following assembly the fluid pressure is then removed by releasing the air from the inside of sealed chamber 7 through port 8. As the fluid press~lre is reduced, the pressure differential between the atmosphere inside the sealed chamber and the fluid inside the closed cells approaches 2ero, and the closed-cell foam becomes self supporting but remains under at least some compression.
Referring more specifically now to Fig. 2 there is shown the completed resilient roller 9 as it appears after assembly by the method described above. The resilient material 6 is uniformly distributed to evenly space apart the rigid roller 1 and the flexible sleeve 3 and to exert a uniform outward pressure on the inside diameter oE the flexible sleeve 3.
Referring more specifically now to Fig. 3, there is shown resilient roller 9 as assembled above working in cooperation ~5~74~
with li~uid developer applicator roll 10 which is formed from a hard material so that is has grooves 11 and ridges 12 on its operati~e surface which act, repsectively, as valleys and lands. A liquid developer solution 13 is contained in the valleys and upon coopexative motion of the photoreceptor the liquid developer solution 13 is presented to the photoreceptor 5 to develop any electrostatic latent image thereon. As shown in Fig~ 3, the line of axial contact between the resilient roller 9 and the lands 12, the applicator roller 10 is uneven However the resilient properties of the resilient roller 9 allow contact between the surface of the resilient roller 9 and the uneven lands 12 without sufficient distortion oE the photoreceptor 5 to affect its operation.
It will be appreciated with reference to Fig. 3 that the applicator roller may be the resilient roller, and the photoreceptor surface may be rigid. In such a configuration the resilient surface of the applicator roll would flex to maintain a contact between its lands and the uneven surface of the photoreceptor.
Referring more specifically now to Fig. 4A, there is sho~n a rigia core 1 having a number of apertures 14 in its surface. The core is covered by a tube of resilient material 6. Also shown is flexible sleeve 2 which has on its surface valleys and lands, shown for example respectively at 11 and 12. The flexible sleeve 2 may be made of any flexible material which will support the land-and-valley surface configuration while it functions as a resilient applicator roller. Typical such materials are steel and plast:ic.
~3507~
The resilient applicator roller is assembled by first positioning the resilient tube 6 on the rigid core 1 as in Fig. 4A. The pressure on the resi]ient tube 6 is provided by evacuating air from the inside of the rigid roller 1 through port 8. A partial vacuum is thus created by means of aperture 14 in the surface of rigid core 1 thus causing the resilient member 6 at least partially to collapse, as shown in Fig. ~B. The flexible sleeve 2 is then slipped into position over the collapsed resilient member 6 (in Fig.
4B, the sleeve is shown nearly in position) and the partial vacuum which has been maintained at the port 8 is relaxed to allow the resilient member 6 to expand, thus spacing apart the flexible sleeve 2 and the rigid roller 1 with uniform pressure to achieve a resilient applicator roll.
In this arrangement the resilient member 6 can be conveniently formed of any of the materials mentioned in relation to resilient member 6 of Figs. 1 and 2 but preferably having a very open cell structure.
. .
.
Claims (6)
1. A method for assembling a roller having a uniform surface resilience and comprising a rigid central roller and a flexible sleeve spaced apart by a layer of resilient material in compression, said method comprising the steps of:
(i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member;
(ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the resilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
(i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member;
(ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the resilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
2. The method of claim 1, wherein the steps (i) and (ii) are carried out in a pressurized container and said resilient member is formed of material having a closed-cell structure.
3. The method of claim 1, wherein the pressure is applied by evacuating air from the interface of the surface of the rigid central roller and the resilient member and said resilient member is formed of material having a very open cell structure.
4. The method of claim 1 or 2, wherein the flexible sleeve is a conductive metal coated on its outer surface with a photoconductive material.
5. The method of claim 1 or 2, wherein the flexible sleeve comprises a flexible metal having a land and valley pattern on its surface.
6. A method for assembling a roller having a uniform surface resilience and comprising a rigid central roller and a flexible sleeve spaced apart by a layer of resilient material in compression, said method comprising the steps of:
(i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member;
(ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the resilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
(i) placing said resilient member under sufficient pressure to reduce the thickness of the resilient member;
(ii) assembling the rigid roller, flexible sleeve and resilient member so that the resilient member lies between the rigid roller and the flexible sleeve; and (iii) reducing the pressure so that the resilient member increases in thickness, thus spacing apart the rigid central roller and the flexible sleeve.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4218473A GB1427948A (en) | 1973-09-07 | 1973-09-07 | Resilient rollers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1050749A true CA1050749A (en) | 1979-03-20 |
Family
ID=10423216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA202,841A Expired CA1050749A (en) | 1973-09-07 | 1974-06-19 | Resilient rollers |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5056950A (en) |
| CA (1) | CA1050749A (en) |
| GB (1) | GB1427948A (en) |
| NL (1) | NL7411976A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5642114U (en) * | 1979-09-07 | 1981-04-17 | ||
| JPS5937580A (en) * | 1982-08-25 | 1984-03-01 | Canon Inc | Fixation device |
| JPS5961864A (en) * | 1982-09-30 | 1984-04-09 | Canon Inc | Heat fixation device |
-
1973
- 1973-09-07 GB GB4218473A patent/GB1427948A/en not_active Expired
-
1974
- 1974-06-19 CA CA202,841A patent/CA1050749A/en not_active Expired
- 1974-09-02 JP JP10079874A patent/JPS5056950A/ja active Pending
- 1974-09-09 NL NL7411976A patent/NL7411976A/xx not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| NL7411976A (en) | 1974-11-25 |
| GB1427948A (en) | 1976-03-10 |
| JPS5056950A (en) | 1975-05-19 |
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