Present examples relate to a peripheral device which utilizes a gear train, for non-limiting example, a printing peripheral device. More specifically, but without limitation, present examples relate to a mechanism or assembly which protects the gear train during operation.
Examples are described in further detail below, with reference to the drawings, in which:
During the print process, end users sometimes pull on the media as it is indexing out of the peripheral device. When an end user pulls on the media, an external force or torque may be applied to the gear train and motor. Over time, or in severe instances, this external force or torque can result in damage to a gear train which controls indexing of the media through the peripheral. Accordingly, these forces may be transmitted through the gear train to the motor to cause damage to, and have negative impact on the wear life, of either or both of the gear train and motor. The present examples provide a gear assembly which will disengage when such external force or torque is applied so as to limit the transmittal of such through the gear train and to the motor.
Referring now to
Referring now to
The peripheral device 10 also comprises a gear train 24 which may be utilized to move the print media 16 through the housing 12. The print media 16 may move through a media path 18 which is defined by a media input 19 for the print media 16, a media output 20, and a path therebetween. The gear train 24 rotates in response to rotation of the motor 22 to effectuate movement of the print media 16 through the peripheral. As the print media 16 moves through the housing 12 and is indexed by the gear train 24 and the motor 22, the print media 16 is printed upon to form an image, document, or other desirable print output. The print media 16 may be paper stock, photo media, or any of various materials which may be passed through the peripheral to receive ink or laser toner. The motor 22 may be, but is not limited to, in some examples a stepper motor, and may be fixed in relation to a frame (not shown) within the housing 12 by a fixation component, such as a screw which may engage the frame. The motor 22 receives power via a power input (not shown) to drive the gear train 24. The power input may be an electrical power input or a mechanical power input. In some examples, the motor 22 may be an electric A/C or D/C motor.
Near the media output 20, a hand H is shown grasping the media 16 and a force F is applied to the print media 16 to pull such from the peripheral device 10. As depicted, the print media 16 is still engaging the gear train 24 and indirectly the motor 22. The instant examples serve to protect the gear train 24 and the motor 22 from this application of external force.
As previously noted, this may be detrimental to the longevity of gear trains and/or the motors in prior art systems. Accordingly, the present examples open or disengage the gear train 24 in a manner such that external force F applied by the end user, as depicted in
In the side section view, one can glean that when the sheet is pulled by a user, the torque applied to the gear train 24 increases torque direction applied between those gears as opposed when the motor 22 is driving the gear train 24, even when the media is moving in the same direction through the peripheral device 10. When the motor 22 is driving the print media 16 forward along media path 18, the torque applied to the roller gear 52 (
Referring now to
The gear train 24 may comprise a gear couple 50 which may engage one another for rotation in one driving direction but which mechanically disengage from one another when an external force is applied to drive rotation in the opposite direction. As depicted, the gear couple 50 may comprise a roller gear 52 and a second gear 54 that causes the disengagement of the roller gear 52 in one direction. The rubber roller 42 may be connected to one of the first and second gears 52, 54 and in the instant example, is located on the shaft 40 and adjacent to the second gear 54. In other examples, the gear couple 50 may be located at other locations along the gear train 24, and therefore is not limited to positioning at the rubber roller 42. The rubber roller 42 engages the print media 16 (
Further, as will become clear with further reading, the roller gear 52 and the second gear 54 are shown in an exaggerated separated state in
Referring now to
The second gear 54 of the gear couple 50 may be generally circular in cross section and provides the asymmetric teeth 56 on a side surface 58 of the second gear 54 closest to the roller gear 52. The second gear 54 may also be in the form of a collar having a hollow central interior area 55 such that a hub 53 of the roller gear 52 may pass into a hollow area of the second gear 54. As shown in this view, the roller gear 52 and the second gear 54 are coaxial and the roller gear 52 is formed as to allow for lateral movement of the roller gear 52 relative to the shaft 40. The hollow central interior area also allows for close proximity and engagement of the gears 52, 54.
The roller gear 52 may have a plurality of tooth engagement apertures 60 wherein the asymmetric teeth 56 may be positioned. The teeth 56 are positioned in the tooth engagement apertures 60 for engagement by the teeth 56 when the roller gear 52 and the second gear 54 are engaged. When the two gears 52, 54 open or disconnect, the teeth 56 are no longer positioned in the tooth engagement apertures 60.
The view also depicts the engagement of the teeth 56 with the apertures to drive rotation of the second gear 54, shaft 40 and rubber roller 42. The arrangement of the teeth 56 and tooth engagement apertures 60 provides that the first presented surface 57 of the asymmetric teeth 56 drives rotation of the second gear 54. With rotation of gear 52 in a second direction, the second surface 59 of the asymmetric teeth 56 is presented to an edge of the tooth engagement aperture 60, which causes lateral movement of the gear 52 along the shaft 40. The second surface 59 may be angled, tapered, rounded or any of various shapes which cause a lateral force upon engagement by the roller gear 52.
The roller gear 52 may also comprise a plurality of teeth 66 extending about the circumferential surface 68 of the roller gear 52. The teeth 66 allow for engagement with the remainder of the gear train 28 (
Adjacent to the roller gear 52 is a bias element 70 which may in some examples be in the form of a pressure spring. The bias element 70 forces the roller gear 52 into engagement with the second gear 54 when the teeth 66 are aligned with the tooth engagement apertures 60. The bias element 70 is also elastic which allows for the roller gear 52 to move toward the bias element 70 but force the roller gear 52 back toward its engaged position with the second gear 54. In a normal operating condition, the bias element 70 applies a pressure to the roller gear 52 and forces it toward the second gear 54. In some examples, the bias element 70 may be a compressed spring which pushes the roller gear 52 toward the second gear 54. In other examples, the bias element 70 may be a stretched or tensioned spring placed at the second gear 54 to pull the roller gear 52 toward the second gear 54. In some examples, the direction of bias force and the spring movement will be depend on which gear of a gear couple is moving away from the other. Further, other structures beyond springs may be utilized to bias the roller and gears 52, 54 into engagement when the teeth 66 and the tooth engagement apertures 60 are indexed appropriately.
A retaining clip, or other retention mechanism 72 is shown adjacent to the spring 70. The retention mechanism 72 may engage the shaft 40 to retain the spring 70 and the roller gear 52 on the shaft 40 inhibiting lateral movement beyond a certain preselected allowance or amount of lateral movement. In the instant examples a keyway 74 is provided on the shaft 40 at which location the retention mechanism 72 may be disposed and allows for stationary location of the retention mechanism 72 against which the pressure spring 70 may be biased. In other examples, the keyway 74 may take the form of a hole extending through the shaft 40 and a clip which extends into the hole. In stiff further examples the retaining mechanism may be adhered, formed integrally or otherwise fixed on the shaft 40 to function as a retaining structure.
Referring now to
With reference now to
While the foregoing is directed to the various examples described, other and further examples may be devised without departing from the basic scope of the claims that follow. For example, the present examples contemplate that any of the features shown in any of the examples described herein, or incorporated by reference herein, may be incorporated with any of the features shown in any of the other examples described herein, or incorporated by reference herein, and still fall within the scope of the present claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2019/050259 | 9/9/2019 | WO | 00 |