MX2007000910A - Driving force member - Google Patents

Abstract

A driving force member 10 having an external profile adapted to engage another driving force member of substantially similar size having either a twisted or non-twisted recess such that, when so engaged, rotational driving force can be transferred from one driving force member 10 to the other, the external profile having a least one tapered portion 20.

Description

GUIDANCE FORCE MEMBER FIELD OF THE INVENTION The invention relates to a member of driving force. The driving force member is particularly suitable for receiving a directing rotation force, transferred by means of an additional driving force member which takes the form of a twisted or non-twisted depression.

BACKGROUND OF THE INVENTION The following discussion on the background of the invention is intended to facilitate the understanding of the present invention. However, it should be noted that the discussion is not an acknowledgment or admission that any material of the aforementioned has been published, known or will form part of the general knowledge common in any jurisdiction, for the priority date of the request. Steering force members are commonly used in any situation where it is necessary to transfer a directing rotation force from one article to the components of another article. Typically, the two members of driving force are configured in such a way that the internal profile of one is complemented by the external profile of the other. This complementation often means an identical match. Recently, in the field of processing and development cartridges, the included force transmitting members for transferring the directing rotation force from an image processing apparatus to the photosensitive drum, or to similar components, had been implemented in the form of a crooked projection. to be received inside a crooked depression. While the use of guiding force members that have crooked profiles had produced benefits that resulted in the guiding force member being self-centering, and in that it also helps prevent the decoupling of the driving force members while the force is being applied guideline rotation, has also introduced other complications. For example: • Existing strength members that do not have a twisted profile can not be used, with a steering force member that does have a twisted profile, because the coupling point between the two steering force members is insufficient for facilitate the transfer of the directional rotation force. • A member of driving force that has a twisted profile requires additional accuracy in the training equipment to meet the exact tolerances of the twisted profile regulations; and • a member of driving force having a twisted profile has a tendency to break along its length, due to its twisted profile. When the break occurs, the components that fail have a driving force applied to them and, therefore, frequently cause damage to the other components that are close to the members of driving force. Therefore, it is an object of the present invention to create a driving force member that seeks to provide at least one of the advantages of a driving force member having a twisted profile, while resolving at least one of the disadvantages of a driving force member having a twisted profile, and which can be used with members of driving force having a twisted depression or a non-twisted depression profile. It will be appreciated that, although the following description is given in relation to image processing equipment, it is not restricted to that use, and can be used in any circumstance in which it is necessary to impart a directing rotation force from one component to another.

BRIEF DESCRIPTION OF THE INVENTION Throughout this document, unless otherwise indicated, the terms "comprising", "consisting of", and the like, shall be considered as non-exhaustive, or, in other words, meaning "including, but not including." limited to". According to a first aspect of the invention there is a guide force member having an external profile adapted to mate with another guide force member, of substantially the same size, having a twisted or uncrossed depression, such that when are coupled in this way, you can transfer the directional rotation force from one member of driving force to the other; the outer profile having at least one tapered portion. Ideally, when coupled, the directional rotation force facilitates self-centering of the driving force member within the other driving force member. The driving force member of the present invention is particularly suitable for coupling with another driving force member, substantially of similar size, having an untwisted depression or a crooked depression, with a degree of torsion within the range of 1 to 15. ° per mm of the axial length of the depression. From . preferably, the external profile of the driving force member is defined by a projection; the projection having a base, side walls and a triangular upper surface; the upper surface being substantially parallel to one floor of the depression of the other driving force member, when the driving force members are engaged. In its preferred form, the upper surface is substantially equal to an equilateral triangle. Alternatively, the external profile of the driving force member is defined by a projection; the projection having a base, side walls and a hexagonal top surface; the upper surface being substantially parallel to one floor of the depression of the other driving force member when the driving force members are engaged. In the preferred form. of this configuration, the upper surface is substantially the same as an irregular hexagon. Ideally, the at least one tapered portion is defined by the outer profiles of the side walls. The driving force member may also include a short cylindrical base; the short cylindrical base is connected to the projection on the base, and has a diameter greater than the maximum width of the upper surface. Alternatively, the driving force member may include an axial rod comprising a support member and an arrow; the axial rod being connected to the projection on the base, and where the size of the base is greater than the size of the supporting member, which is greater than the size of the arrow.

Preferably, the distance between each side wall and the axis of rotation of the driving force member increases along a predetermined length of the axis of rotation, which extends away from the base; the predetermined length being correlated with at least one segment of the at least one tapered portion. This increase in distance can be determined with reference to a nonlinear equation. For example, the gradient of the profile of the side wall with respect to the axis of rotation of the member (z) of driving force, can be between 0 and 0.2z + r; where r is the minimum approximate radius of the upper surface. However, in its most preferred embodiment, the distance (d) between each portion of the side wall and the axis of rotation of the driving force member (z) falls within the scale established by the equations: d = 0.0341 z2 + 0.0361 z + 4.081 2; d = 0.0406Z2 + 0.0589z + 4.1.093. Alternatively, the distance between each side wall and the axis of rotation of the driving force member decreases along a predetermined length of the axis of rotation, which extends away from the base; the predetermined section being correlated with at least one segment of at least one tapered portion. Again this decrease in the density can be determined with reference to a non-linear equation. It is more preferred that the angle of a line taken between the connection point of the side wall with the base and the connection point of the side wall with the top surface, with respect to the axis of rotation, vary from 5 ° to 25 °. The joints between the side walls can be bevelled. The joints between the side walls and the top surface can also be bevelled. The apices of the upper surface may also be rounded. Preferably the dividing line produced during the manufacture of the driving force member is parallel to the upper surface. The driving force member may include a conductive portion of electricity. According to a second aspect of the invention, there is a photosensitive drum including a guide force member, wherein the axis of rotation of the guide force member is concentric with the axis of rotation of the photosensitive drum. According to a third aspect of the invention there is a drum hub that includes a guide force member; the drum hub being adapted to engage with the photosensitive drum, such that the axis of rotation of the driving force member of the drum hub is concentric with the axis of rotation of the photosensitive drum. According to a fourth aspect of the invention there is a process cartridge including a photosensitive drum according to the second aspect of the invention, or a drum hub according to the third aspect of the invention. According to a fifth aspect of the invention there is a developer cartridge that includes a developer roller that includes a guide force member; the axis of rotation of the driving force member being concentric with the axis of rotation of the developing roller.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an isometric view of a driving force member, according to a first embodiment of the invention. Figure 2 is an isometric view of a driving force member according to a second embodiment of the invention. Figure 3 is a sectional view of a driving force member according to a fourth embodiment of the invention. Figure 4 is a plan view of the driving force member shown in Figure 3. Figure 5 is a sectional view of a drum hub including a driving force member according to a sixth embodiment. Figure 6 is an isometric view of a driving force member according to an eighth embodiment of the invention. Figure 7 is an isometric view of a driving force member according to a ninth embodiment of the invention. Figure 8 is a sectional view of the driving force member shown in Figure 7. Figure 9 is an isometric view of a process cartridge including a drum hub, modified to include a driving force member as shown in Figure 7. Figure 10 is an isometric view of the drum hub shown in Figure 9, but shown in isolation. Figure 1 a is an isometric view of a driving force member having the shape of a crooked depression. Figure 1 1 b is a sectional view of the driving force member shown in Figure 1 1 a. Figure 12 is a first schematic representation of the member of. guide force of Figure 9, received within the driving force member of Figure 1 1. Fig. 13 is a second schematic representation of the driving force member of Fig. 9, received within the driving force member of Fig. 11.

PREFERRED MODALITIES OF THE INVENTION According to a first embodiment of the invention, there is a guide force member 10. The driving force member 10 comprises a projection 12 and a short cylindrical base 14. The projection 12 is fixed to the base 14 in such a way that only the side walls 16a, 16b, 16c and the top face 18 are exposed. The diameter of the short cylindrical base 14 is larger than the diameter of the projection 12. The projection illustrated in Figure 1 is essentially defined by six apices. The apices ABC define the upper face 18. The side wall 16a is defined by the apexes ACDF. The side wall 16b is defined by the apices ABDE. The side wall 16c is defined by the apices BCEF. If so, the coordinates (x, y) of the apex A correspond substantially to the coordinates (x, y) of the apex D. A similar situation occurs with respect to the apex pair BE and the pair of apices CF. The apices ABC are equidistant from each other, and so are the apices DEF. The edge 20a defined by the apices AD is straight. Similarly, the edges 20b, 20c, defined by the apices BE and the apices CF, are also straight. The edges 22, 24, defined by the apices AB, AC, BC, DE, DF and EF, are slightly curved. In this way the plan form of each side wall 16a, 16b, 16c is. a trapezoid The parallel major side of. each trapezoid defines the boundaries of the upper face 18 (ie, they coincide with the edges 22). This means that the distance between the center point of the projection 12 and each edge 20, when taken within the xy plane, increases as it moves away from the base 14, along the z axis (the z axis being also the axis of rotation of the driving force member 10). According to a second embodiment of the invention, in which the same numbers refer to the same parts, there is a guide force member 100. The guide force member 100 is identical to the guide force member 10, except that the side greater parallel of each side wall 16a, 16b, 16c, defines the edges connecting the projection 12 with the base 14 (ie, they coincide with the edges 24). This means that the distance between the center point of the projection 12 and each edge 20, when taken within the xy plane, decreases as it moves away from the base 14, following the z-axis. According to a third embodiment of the invention, in which the same reference numbers refer to the same parts, there is a guide force member 200. The driving force member 200 is identical to the driving force member 10, except for the base 14 of the short cylinder. In this embodiment, the base 14 of the short cylinder is replaced by an axial rod 202. The axial rod 202 comprises a support member 204 and an arrow 206. The support member 204 and the arrow 206 are both cylindrical in shape. The diameter of the support member 204 is greater than the diameter of the arrow 206. The radius of the support member 204 is smaller than the distance between the center point of the projection 1 2 and each edge 20, when taken into the xy plane, where z = 0. The advantages of this third embodiment are that the manufacturing process of the driving force member 200 is simplified, while providing a weak point that does not cause the entire member to separate when there is a fault. To complicate, the increase in the overall size from the arrow 206 to the support member, with respect to most of the projection 12, allows most of the driving force member 200 to be manufactured in a first cavity. The rest of the guide force member 200 is manufactured in a second cavity. To complete the manufacture of the driving force member, the first and second cavities are placed so that they are coupled together, the resulting joint being represented by the dividing line P in figure 4. This dividing line P is also the one that also constitutes the dividing line P. weak point of the member 200 of driving force. Additionally, the use of the axial rod allows the driving force member to be included in subassemblies, for example, a gear part of a processing cartridge. According to a fourth embodiment of the invention, there is a photosensitive drum adapted to receive the driving force member 200 of the third embodiment therein. The center of the driving force member 200 is located on the axis of rotation of the photosensitive drum. The guide force member 200, in the embodiment shown, is formed integrally with the rotation arrow, which has its axis of rotation concentric with the axis of rotation of the photosensitive drum. Alternatively, and in accordance with a machine mode of the invention, there is a drum hub 300 adapted to receive the driving force member 200 of the third embodiment. A sectional view of this latter arrangement is shown in Figure 5. The drum hub 300 is further adapted to be coupled with a photosensitive drum 302. Again the center of the driving force member 200 is located on the axis of rotation of the photosensitive drum 302. According to a sixth embodiment of the invention, there is a developing cartridge that includes a developing roller adapted to have the driving force member 200 the third mode received therein The center of the driving force member 200 is located on the axis of rotation of the developing roller. The driving force member 200 is formed integrally with the rotation arrow, which has its axis of rotation concentric with the axis of rotation of the developing roller. As the developer cartridge is well known to anyone who has experience in the. technique, the other components that make up the developer cartridge will not be described here. However, the preferred implementation of this embodiment comprises a developer cartridge that includes the developer roller and the toner container. According to a seventh embodiment of the invention, there is a processing cartridge that includes a photosensitive drum according to the fourth embodiment of the invention, or a photosensitive drum bucket, according to the fifth embodiment of the invention. As the processing cartridge is well known to those skilled in the art, the other components making up the processing cartridge will not be described here. However, the preferred implementation of this embodiment comprises a processing cartridge that includes the photosensitive drum, or a photosensitive drum hub, such as those already mentioned, a toner container, a developer roller, a cleaning sheet, a loading roller yu na exploring unit. In an eighth embodiment of the invention there is a guide force member 300. The guide force member 300, which is illustrated in Figure 6, is essentially defined by twelve apices. The apices ABCDEF define the upper face 302. The side wall 304a is defined by the apices ABHG. The side wall 304b is defined by the apices BCI H. The side wall 304c is defined by the apexes CDIJ. The side wall 304d is defined by the apices DEJK. The side wall 304e is defined by the apices EFKL. The side wall 304f is defined by the AFGL apices. Each side wall 304 is substantially rectangular in shape. This means that the coordinates. { x, y) of the apex A correspond substantially to the coordinates of the apex G. There is a similar situation with respect to the apex of BH, the pair of apices Cl, the pair of apices DJ, the pair of apices EK and the pair of Apices FL. Each of the apexes ABCDEF and the apices GH IJKL forms an irregular hexagon. The irregular hexagon is formed to a shape similar to that of an isosceles triangle with bulging sides. To complicate this: • The apex A is equidistant from the apex B and the apex F. • The apex B is equidistant from the apex A and the apex C. • The apex C is equidistant from the apex B and the apex D. • The apex D is equidistant from apex C and apex E. · Apex E is equidistant from apex D and apex F.

• The apex F is equidistant from the apex A and the apex E. • The apexes ACE are equidistant from each other. • The BDF apices are equidistant from each other. • The apex G is equidistant from the apex H and the apex L. · The apex H is equidistant from the apex G and from the apex I. • The apex I is equidistant from the apex H and the apex J. • The apex J is equidistant from the apex I and from the apex K. • The apex K is equidistant from the apex J and from the apex L. • The apex L is equidistant from the apex G and the apex K. · The GIK apices are equidistant from each other; and • The HJL apices are equidistant from each other. Each apex is rounded to smooth the sharp edges in the irregular hexagon. As mentioned before, the side walls 304 have a substantially rectangular shape. Each side wall has a curved portion 306 and a straight portion 308. The curved portion 306 of each side wall 304 is adjacent to the respective portion of the irregular hexagon ABCDEF to which it is connected. The straight portion 308 of each side wall is adjacent to the respective portion of the irregular hexagon GHIJKL to which it is connected. In that way, the size of the irregular hexagon ABCDEF is greater than the size of the irregular hexagon GHIJKL. According to a ninth embodiment of the invention, in which the same numbers refer to the same parts, there is a guide force member 400. The driving force member 400 is identical to the driving force member 300, except that the edges 304 are curved, and that each apex is rounded in the xy plane. Figure 7 shows the preferred implementation of this embodiment of the invention. As shown, there is a minimum curve profile 402, and a maximum curve profile 404, for each apex; although only one is shown for clarity). The maximum curve profile 404 represents the curve of the side wall 304 at the point of the rounded apex which has the maximum distance from the center point of the projection 300, when determined in the xy plane. The minimum curve profile 402 represents the curve of the side wall 304 at the two points of the rounded apex having the minimum distance from the center point of the projection 300, when determined in the xy plane. In Figure 7, as shown, the distance (oi) between a point of the side wall 304 and the center point of the projection 300, when determined within the xy plane, can be determined by means of the following formulas: curve minimum d = 0.0341 z2 + 0.0361 z + 4.0812 (mm) Maximum curve profile d = 0.0406z2 + 0.0589z + 4.1093 (mm). It should be appreciated that the above equations of curve minimum profile 402 and maximum curve profile 404 have been determined with reference to a particular opening having a crooked depression configuration of a substantially similar size. However, the invention can be used with any particular aperture configuration, and not just one having a twisted depression configuration. For example, as far as the applicant can determine, to adjust a wide variety of aperture configurations, including non-twisted configurations, the gradient of the curve minimum profile 402 and the maximum curve profile 404 may vary from zero to 0.2z + r; where r is the approximate minimum radius of the tapered surface profile of the projection 12. Additionally, the general angle T, as shown in Figure 8, and taken from the point of the driving force member closest to the photosensitive drum, in the longitudinal direction, up to the point of the driving force member farthest from the photosensitive drum, in the longitudinal direction, taken with reference to a right angle parallel with. the longitudinal direction of the photosensitive drum can vary from 5o to 25 °. The invention will now be described in use with respect to a processing cartridge 500, according to the seventh embodiment of the invention. The processing cartridge 500 includes a drum hub 300, according to the sixth embodiment of the invention. However, the drum hub 300 includes the driving force member 400 of the ninth embodiment of the invention. The configuration is shown appropriately in Figures 9 and 10. The processing cartridge 500 is adapted to be received within an image processing apparatus (not shown). The image processing apparatus has a driving force member 502 positioned therein, adapted to receive the driving force member 400 when the processing cartridge 500 is received within the image processing apparatus. The driving force member 502 of the image processing apparatus is shown in Figure 11. The driving force member 502 of the image processing apparatus is a depression 504, integrally formed within a transmission shaft 506 of the image processing apparatus. The depression 504 is a polygonal shape twisted in the direction of rotation R of the transmission shaft 506. The depression 504 has a cross section, in the xy plane of a substantially equilateral triangle. The degree of torsion in the depression 504 shown is approximately 7.5 ° for 1 mm axial length of the depression 504.

The relationship between the depression 504 and the driving force member 400 can be shown by the rule < d0 < d2; where dO is the diameter of a circumscribed circle of the triangular prism of the driving force member 400; d 1 is the diameter of the inscribed circle of the triangle of the depression 5o4, and d2 is the diameter of the circumscribed circle of the triangle of the depression 504. When the processing cartridge 500 is received within the image processing apparatus, the transmission arrow 506 moves from a retracted position to a coupled position by means of the requesting force that is applied to it by a weak spring. In the coupled position, the driving force member 502 engages the driving force member 400. The coupling process and the subsequent transfer of the steering force of rotation will now be described in detail. Figure 12 shows a schematic view of the driving force member 400, when it is received within the driving force member 502. The twisted configuration of the depression 504 is represented by the first equilateral triangle 508 and the second equilateral triangle 51 0. The first equilateral triangle 508 represents the cross section profile of the depression 504, as taken in the xy plane, in the opening that opens The second equilateral triangle 51 0 represents the cross section profile of the depression 504, when taken in the xy plane, at the bottom of the opening. As illustrated in Figure 1 3, the shape of the member 400 of driving force is such that it is substantially equal to the "free space" area 512, represented by the intersection of the first equilateral triangle 508 and the second equilateral triangle 51 0. Thus, the driving force member 400 is capable of to be fully received within depression 504.

In addition, due to the curved profile of each sidewall 304, in the embodiment shown, when directional rotation force is applied to the driving force member 400, by the driving force member 502, the driving force member 400 moves to a second directional force member. position, which is shown in figure 12. In this second position, the twisted configuration of the depression 504 prevents the driving force member 400 from moving along the z axis, and thus from the depression 504. While also in this second position, the side walls 304 of the driving force member 400 are regularly brought into contact with the interior surfaces of the depression 504. In doing so, the center of the transmission force member 400 is aligned with the center of depression 504, as part of the rotation process. This provides the additional advantage of precision in the rotation due to the minimization of the irregularity of rotation of the coupling transmission, due to the variation of load, and also the minimization of the changes in the points of contact. Once a regular contact has been made, the directional rotation force applied to the driving force member 500 can be efficiently transported to the driving force member 400. The same resilient driving force member 400 may also be received within a driving force member (not shown) of substantially similar size, having a non-twisted polygonal depression. In this configuration, once the resilient driving force member 400 is received within the non-twisted depression, the rotational driving force application causes the apices to contact the corners of the depression. The degree of contact is determined by the profile of the non-twisted polygonal depression, with respect to the profile of the driving force member 400. The directional rotation force applied to the driving force member is then transported to the driving force member 400. As is clear from the foregoing description, the described driving force members are easy to manufacture and do not require high precision tooling equipment to do so. further, the configuration of the driving force members described are such that any failure of the component is unlikely to result in breakage along its entire length. Therefore, the driving force member will still be able to facilitate the transfer of the steering rotation force, even in the case of breakage. Since this will also likely result in fewer components failing, the damage potentially caused to the other components near the driving force member is also likely to be minimized. Whoever is a person skilled in the art will appreciate that the invention described in the foregoing is not limited to the modality described. In particular, the following modifications and improvements can be made, without departing from the scope of the present invention: · the profile of the projections can be such that instead of being tapered along its entire length, the profile can be tapered to along one or more portions of it. • The driving force member 10 may include an electrically conductive portion, or may be formed entirely of electrically conductive material. This allows the driving force member to ground the electrical components to which it is connected. For example, the circular opening provided in the center of the projection 300 may be made of electrically conductive material, and may be adapted to receive an electrically conductive portion of the other driving force member, to which it is then attached. The side walls and edges between the apices defining the upper face 18 can be bevelled. This helps to avoid wobbling and vibration in the projection 12. The depression may have another configuration different from that described above. For example, the depression may be rectangular or may have any other shape, or the depression may have a cross-sectional profile equal to an isosceles triangle. Alternatively, the guide force member 10 of a relatively soft substance can be manufactured. This reduces the potential for damage to other components near the coupling of the driving force members, which is reduced in the unlikely event of failure. The guide force member can be adapted to be coupled with a guide force member in the form of a bent depression, where the degree of torsion is 1 or 15 ° for 1 mm axial length of the depression. The driving force member may be configured as a regular hexagon. The driving force member can be used to rotate a component of the processing cartridge other than the photosensitive drum; for example, the driving force member may be used to rotate a developing roller and / or a stirrer contained within the toner container. It should be further appreciated, by those who have experience in the field, that the aspects described in a modality, where they are not mutually exclusive or alternative, can be combined with aspects described in other described modalities, to create additional modalities that remain within the scope of the present invention.

Claims (10)

1 .- Member of leadership strength that has an external profile adapted to be coupled with another member of force. guideline, substantially of similar size, having a twisted or uncrossed depression, such that, when coupled in that manner, rotational driving force can be transferred from one driving force member to the other; the outer profile having at least one tapered portion.

2. Member of driving force according to claim 1, wherein, when coupled, the directing force of rotation facilitates self-centering of the driving force member within the other driving force member.

3. Member of driving force according to claim 1 or claim 2, having an external profile adapted to mate with another member of driving force, of substantially similar size, having a non-twisted depression or a crooked depression, with a degree of torsion on the scale of 1 or 15 ° per mm of the axial length of the depression.

4. A steering force member according to any of the preceding claims, wherein the external profile of the driving force member is defined by a projection; the projection having a base, side walls and a triangular upper surface; the upper surface being parallel to one floor of the depression of the other member of driving force, when the guide force members are engaged.

5. A guide force member according to claim 4, wherein the top surface has a shape substantially equal to an equilateral triangle.

6. A guide force member according to any of claims 1 to 3, wherein the external profile of the driving force member is defined by a projection; the projection having a base, side walls and a hexagonal top surface; the top surface being substantially parallel to a floor of the depression of the other directional force member when the directional force members are engaged.

7. - A directional force member according to claim 6, wherein the top surface is substantially equal to an irregular hexagon.

8. - A directional force member according to any of claims 4 to 7, wherein at least one tapered portion is defined by the outer profiles of the side walls.

9. A guide force member according to any of claims 4 to 8, further including a short cylindrical base; the short cylindrical base being connected to the projection on the base, and having a diameter greater than the maximum width of the upper surface.

10. A driving force member according to any of claims 4 to 8, further including an axial rod comprising a support member and an arrow; the axial stem being connected to the guard at the base, and where the size of the base is greater than the size of the support member, which is greater than the size of the arrow. 1 - A driving force member according to any of claims 4 to 10, wherein the distance between each side wall and the axis of rotation of the driving force member increases along a predetermined length of the axis of rotation, as it extends away from the base; and the predetermined length is correlated with a segment of the at least one tapered portion. 2. A steering force member according to claim 11, wherein the distance between each side wall and the axis of rotation of the driving force member increases according to a non-linear equation. 3. A power steering member according to claim 1 or claim 12, wherein the gradient of the profile of the side wall, with respect to the axis of rotation of the driving force member (z) is between 0 and 0.2z + r; where r is the approximate minimum radius of the upper surface. 14. - A driving force member according to claim 1, wherein the distance (d) between each portion of the side wall and the axis of rotation of the driving force member (z) is within the range indicated by The equations: . d = 0.0341? 2 + 0.0361 z + 4.0812; d =? .0406? 2 + 0.05892 + 4.1 093. 1 5.- A power steering member according to any of claims 4 to 10, wherein the distance between each side wall and the axis of rotation of the member force of direction decreases along a predetermined length of the axis of rotation, as it extends away from the base; and the predetermined length is correlated with at least one segment of the at least one tapered portion. 1 6. A steering force member according to claim 1, wherein the distance between each side wall and the axis of rotation of the driving force member decreases according to a non-linear equation. 17. - A driving force member according to any of claims 1 to 16, wherein the angle of a line taken between the connection point of the side wall with the base, and the connection point of the wall lateral with the upper surface, with respect to the axis of rotation, varies from 5o to 25 °. 18. - A guide force member according to any of claims 4 to 17, wherein the joints between the side walls are beveled. 19. - A guide force member according to any of claims 4 to 18, wherein the joints between the side walls and the top surface are bevelled. 20. - A driving force member according to any of claims 10 to 19, depending on claim 10, wherein the dividing line produced during the manufacture of the driving force member is parallel to the upper surface. twenty-one . - A guide force member according to any of claims 4 to 20, wherein the apices of the upper surface are rounded. 22. - A driving force member according to any of the preceding claims, which includes a conductive portion of electricity. 23. A photosensitive drum including a driving force member according to any of claims 1 to 22; the axis of rotation of the driving force member being concentric with the axis of rotation of the photosensitive drum. 24. A drum hub that includes a guide force member according to any of claims 1 to 22; the drum hub being adapted to be coupled with a photosensitive drum, so that the axis of rotation of the driving force member of the drum hub is concentric with the axis of rotation of the photosensitive drum. 25. - A processing cartridge including a photosensitive drum according to claim 23, or a drum hub in accordance with claim 24. 26. - A developer cartridge including a developer roller having a guideline force member fixed to the; the axis of rotation of the driving force member being concentric with the axis of rotation of the developing roller. 27. - A member of driving force, substantially as described herein with reference to the drawings, except Figures 1 a and 1 1 b.