BACKGROUND

[0001] Braking devices are devices for slowing or decreasing motion. For instance, braking devices are used in vehicles (e.g., automobiles, bicycles, motorcycles, etc.) to slow movement of the vehicles. Braking devices may absorb or transfer energy (e.g., kinetic energy) from momentum. Examples of braking devices include drum brakes, cable brakes, and hydraulic brakes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Figure 1 is a perspective diagram of an example of a brake mechanism;

[0003] Figure 2 is a diagram illustrating another example of a brake mechanism;

[0004] Figure 3 is a diagram illustrating an example of a torque regulator; and

[0005] Figure 4 is a perspective diagram illustrating an example of a pick drive mechanism in accordance with some of the examples described herein.

DETAILED DESCRIPTION

[0006] In some cases, mechanical devices and/or mechanisms may cause sounds and/or noise during operation. For instance, as components interoperate, physical contact between components, impacts, vibrations, etc., may cause sounds and/or noise. [0007] Some examples of the mechanisms described herein include brake mechanisms. A brake mechanism is a mechanism that reduces, slows, dampens, and/or resists motion. For instance, a brake mechanism may be utilized to dampen the velocity of a cam wheel. A cam wheel is a wheel (e.g., a round structure, a structure to rotate, etc.) that includes a cam. A cam is a structure with an irregular or asymmetric form. For instance, a cam may have a varying radius over a rotational range. Some examples of brake mechanisms may be utilized to reduce the magnitudes of vibrational and/or acoustic events during operation. Some examples may enable steadier servo control of an actuation cycle.

[0008] Some examples of the brake mechanisms described herein may be included in a pick drive mechanism. A pick drive mechanism is a mechanism to pick up, grasp, and/or move an item. For instance, a pick drive mechanism may be utilized to pick up media (e.g., paper, cardstock, envelopes, photos, etc.) for intake into a device (e.g., printer, copier, scanner, etc.). In some examples, a pick drive mechanism may include a media pressure plate, restraint mechanism, and/or separation mechanism.

[0009] In some examples, a brake mechanism may include a loaded caliper and/or brake pad. For instance, a brake mechanism may use a loaded caliper and brake pad (e.g., fixed friction pad) to slow a wheel, thus counteracting the accelerations caused during pick engagement motion by forces from a spring or springs of a pressure plate, restraint mechanism, and/or separation mechanism. In some examples, the caliper may include a friction-enhancing surface (e.g., elastomer).

[0010] Throughout the drawings, identical reference numbers may or may not designate similar or identical elements. Similar numbers may or may not indicate similar elements. When an element is referred to without a reference number, this may refer to the element generally, with or without limitation to any particular drawing or figure. The drawings are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples in accordance with the description. However, the description is not limited to the examples provided in the drawings.

[0011] Figure 1 is a perspective diagram of an example of a brake mechanism 100. The brake mechanism 100 includes a cam wheel 102. The cam wheel 102 may rotate around a rotational axis 106. For instance, the cam wheel 102 may be rotationally driven around a rotational axis 106. In some examples, the cam wheel 102 includes and/or is attached to an axle and/or gear used to drive the cam wheel 102.

[0012] The cam wheel 102 includes a cam 120. The cam 120 includes a varying radius with respect to the rotational axis 106. For instance, the cam 120 may vary radially in a direction as the cam wheel 102 rotates.

[0013] The cam wheel 102 includes a protruding fin 104. A fin is a structure having two sides or more than two sides. The fin 104 protrudes in a perpendicular direction from the rotational axis 106 of the cam wheel 102. In some examples, the fin 104 may protrude over an angular range (e.g., 5°, 8°, 10.5°, 15°, 30°, 90°, 122°, 180°, 270°, 340°, etc.) of the cam wheel 102. For instance, the fin 104 may protrude over a partial angular range or full angular range of the cam wheel 102. In some examples, the fin may be positioned at an angle (e.g., may pass over an angle) for a portion of a rotation cycle and/or for a time that is a subset of a cycle time.

[0014] The brake mechanism 100 includes a brake pad 108. A brake pad is a frictional structure. In some examples, a brake pad may be a structure to exert a frictional force. For instance, the brake pad 108 may exert a frictional force on the fin 104 when in contact with the fin 104.

[0015] The brake mechanism 100 includes a caliper 110. A caliper is a structure or device to exert a pressing force. For example, the caliper 110 may be situated opposite from the brake pad 108 (e.g., opposite in terms of sides of the cam wheel 102 and/or fin 104, on opposite or different surfaces of the cam wheel 102 and/or fin 104 when in contact with the fin 104, including directionally different sides, and/or disposed to impart a pinching or squeezing force across another structure). The caliper 110 may exert pressure 112 across the fin 104 against the brake pad 108 for a portion of cam wheel 102 rotation. For instance, when the fin 104 is in contact with the caliper 110 and the brake pad 108, the caliper 110 may exert pressure 112 across the fin 104 against the brake pad 108. The caliper 110 may not exert pressure on the cam wheel 102 (e.g., fin 104) for a portion of cam wheel 102 rotation. For instance, the caliper 110 may not exert pressure on the cam wheel 102 for a portion of cam wheel 102 rotation where the fin 104 is not engaged (e.g., not in contact) with the caliper 110 and/or brake pad 108.

[0016] In some examples, the caliper 110 may exert pressure 112 across the fin 104 against the brake pad 108 for a portion of cam wheel 102 rotation to produce a braking torque 114 counter to a torque 116 exerted by a lever 118 in contact with the cam 120 of the cam wheel 102. For instance, a lever 118 may exert a force on the cam 120 that may produce a torque 116. In some examples, the lever 118 may be loaded with a spring, counterweight, and/or another mechanism, etc., to exert the force on the cam 120. The torque 116 may be in a same direction as a rotational direction and/or as a driving torque of the cam wheel 102. In some examples, the torque 116 may tend to overdrive the cam wheel 102 for an angular portion of (or all of) the rotation of the cam wheel 102. For instance, the lever 118 may tend to impart the torque 116 (e.g., an increased torque) on the cam wheel 102 as the radial length of the cam 120 is reduced in a direction where the lever 118 is in contact with the cam 120. The braking torque 114 may partially or completely counteract (e.g., resist, dampen, etc.) the torque 116 when the fin 104 is in contact with the caliper 110 and/or brake pad 108. For instance, the braking torque 114 may reduce and/or avoid overdriving of the cam wheel 102 due to the force exerted by the lever 118.

[0017] Figure 2 is a diagram illustrating another example of a brake mechanism 200. The brake mechanism 200 described in relation to Figure 2 may be an example of the brake mechanism 100 described in relation to Figure 1 . For instance, Figure 2 illustrates examples of a cam wheel 202 that includes a cam 220, a fin 204 (that rotates around a rotating axis 206), a brake pad 208, a caliper 210, and a lever 218. The cam 220, brake pad 208, caliper 210, and/or lever 218 may be made from similar or different materials. For instance, the cam 220, brake pad 208, caliper 210, and/or lever 218 may be made from a polymer or polymers (e.g., plastic(s), nylon, thermoplastics, etc.), a metal or metals, and/or another material or materials.

[0018] In some examples, the brake pad 208 includes a contact surface 222. The contact surface 222 is a surface of the brake pad 208 that contacts the fin 204. For instance, the contact surface 222 may contact the fin 204 for a portion of cam wheel 202 rotation. In some examples, the contact surface 222 may include an elastomer on the contact surface 222. For instance, the contact surface 222 may be made from an elastomer and/or may be coated with an elastomer (e.g., an elastomer pad may be affixed to the contact surface 222). An elastomer may increase friction between the fin 204 and the brake pad 208. Examples of elastomer include natural rubber and synthetic rubber (e.g., nitrile rubber, neoprene, etc.). In some examples, the contact surface 222 of the brake pad 208 may not include an elastomer. For instance, the contact surface 222 of the brake pad 208 may be bare nylon in some examples.

[0019] In some examples, the brake pad 208 may include a sloped surface or ramped surface. For instance, the brake pad 208 may include a sloped surface from a leading contact edge of the brake pad 208. The sloped surface may be sloped at an oblique angle relative to a rotational direction of the cam wheel 202. The sloped surface of the brake pad 208 may help to ease the fin 204 into contact with the brake pad 208 (e.g., to avoid catching and/or to gradually increase friction). In some examples, the brake pad 208 may include a sloped surface from a following contact edge (e.g., back or releasing edge) of the brake pad 208. The sloped surface may be sloped at an oblique angle relative to a rotational direction of the cam wheel 202. The sloped surface from the following contact edge of the brake pad 208 may help to transition the fin 204 out of contact from the brake pad 208.

[0020] In some examples, the caliper 210 includes a contact surface 224. The contact surface 224 is a surface of the caliper 210 that contacts the fin 204. For instance, the contact surface 224 may contact the fin 204 for a portion of cam wheel 202 rotation. In some examples, the contact surface 224 may include an elastomer on the contact surface 224. For instance, the contact surface 224 may be made from an elastomer and/or may be coated with an elastomer (e.g., an elastomer pad may be affixed to the contact surface 224). An elastomer may increase friction between the fin 204 and the caliper 210. In some examples, including an elastomer on the caliper 210 may enhance performance uniformity over time and/or may compensate for elastomer wear. Due to the relation of the friction force direction and caliper 210 rotational axis 228 (e.g., hinge axis) in some examples, the self-engagement of the elastomer- on-caliper may enhance braking forces. In some examples, the contact surface 224 of the caliper 210 may not include an elastomer. For instance, the contact surface 224 of the caliper 210 may be bare nylon in some examples.

[0021] In some examples, the caliper 210 may include a sloped surface or ramped surface. For instance, the caliper 210 may include a sloped surface from a leading contact edge of the caliper 210. The sloped surface may be sloped at an oblique angle relative to a rotational direction of the cam wheel 202. The sloped surface of the caliper 210 may help to ease the fin 204 into contact with the caliper 210 (e.g., to avoid catching and/or to gradually increase friction). In some examples, the caliper 210 may include a sloped surface from a following contact edge (e.g., back or releasing edge) of the caliper 210. The sloped surface may be sloped at an oblique angle relative to a rotational direction of the cam wheel 202. The sloped surface from the following contact edge of the caliper 210 may help to transition the fin 204 out of contact from the caliper 210.

[0022] In some examples, the fin 204 may include a wedged surface, sloped surface, or ramped surface. For instance, the fin 204 may include a wedged surface from a rotational leading edge of the fin 204. The wedged surface may be wedged at an oblique angle or oblique angles relative to a rotational direction of the cam wheel 202. The wedged surface of the fin 204 may help to ease the fin 204 into contact with the brake pad 208 and/or caliper 210. In some examples, the fin 204 may include a wedged surface, sloped surface, or ramped surface from a following contact edge (e.g., back or releasing edge) of the fin 204. The wedged surface may be wedged at an oblique angle relative to a rotational direction of the cam wheel 202. The wedged surface from the following contact edge of the fin 204 may help to transition the fin 204 out of contact from the brake pad 208 and/or caliper 210.

[0023] In some examples, the fin 204 may include an elastomer on the fin 204 (e.g., on a contact surface of the fin 204). For instance, a contact surface of the fin 204 may be made from an elastomer and/or may be coated with an elastomer (e.g., an elastomer pad may be affixed to the fin 204). In some examples, the elastomer may be included on a surface or surfaces (e.g., side or sides, one side, two sides, etc.) of the fin 204.

[0024] In some examples, the brake mechanism 200 may include a spring 226. For instance, the brake mechanism 200 may include a spring 226 to exert a force on the caliper 210. For example, the spring 226 may exert a force on the caliper 210 towards the brake pad 208 and/or across the fin 204. In some examples, the spring 226 may load the caliper 210 and/or may cause the caliper 210 to exert pressure across the fin 204 against the brake pad 208 for a portion of cam wheel 202 rotation. Accordingly, the caliper 210 and/or the brake pad 208 may produce a braking torque counter to a torque exerted by the lever 218 in contact with the cam 220 of the cam wheel 202.

[0025] In some examples, a caliper may be a rotational caliper. For instance, the caliper 210 is a rotational caliper. As illustrated in Figure 2, the caliper 210 may be disposed to rotate around a caliper rotational axis 228. For example, the caliper 210 may include a rotational structure (e.g., eye, pivot, hinge, etc.) that allows the caliper 210 to rotate around the caliper rotational axis 228. For instance, as the fin 204 moves into contact between the caliper 210 and the brake pad 208, the motion of the fin 204 may rotationally displace the caliper 210 and/or the caliper 210 may rotate away from the fin 204 around the caliper rotational axis 228. In some example, as the fin 204 moves out of contact from the caliper 210 and/or the brake pad 208, the caliper 210 may rotate towards the brake pad 208.

[0026] In some examples, a translational caliper may be utilized. A translational caliper may be a caliper that is constrained to move along an axis (e.g., line) of motion. For instance, instead of the rotational caliper 210, a caliper may be utilized that is constrained to move along an axis towards and/or away from the brake pad 208. In some examples, a translational caliper may be constrained to move along an axis by a rail, slide, and/or tunnel structure along the axis. For instance, a spring may load a translational caliper to exert a force across (e.g., against) the fin 204 and/or against the brake pad 208. For instance, as the fin 204 moves into contact between the translational caliper and the brake pad 208, the motion of the fin 204 may translationally displace the translational caliper and/or the translational caliper may move (e.g., slide) away from the fin 204 along the translational axis. In some example, as the fin 204 moves out of contact from the translational caliper and/or the brake pad 208, the translational caliper may move (e.g., slide) towards the brake pad 208.

[0027] In some examples, the caliper 210 is disposed in contact with the brake pad 208 when not in contact with the fin 204. For instance, when the fin 204 is not between the caliper 210 and the brake pad 208, the caliper 210 may be positioned in contact with (e.g., against) the brake pad 208.

[0028] In some examples, the caliper 210 is distanced from the brake pad 208 when not in contact with the fin 204. For instance, when the fin 204 is not between the caliper 210 and the brake pad 208, the caliper 210 may not be in contact with the brake pad 208 when the caliper 210 is not in contact with the fin 204. For instance, a space or gap may exist between the caliper 210 and the brake pad 208 when the fin 204 is not between the caliper 210 and the brake pad 208. In some examples, the brake mechanism 200 may include an interfering feature (e.g., keeper, post, spacer, etc.). The caliper 210 may rest against the interfering feature when the fin 204 is not between the caliper 210 and the brake pad 208. For instance, a spacer (that is thinner than the fin 204, for instance) may be situated between the brake pad 208 and the caliper 210. In some examples, a keeper (e.g., hook) feature may be disposed to hold the caliper 210 out of contact with the brake pad 208 when the fin 204 is not between the caliper 210 and the brake pad 208.

[0029] In some examples, the brake mechanism 200 may be included in a pick drive mechanism of a printing device. For instance, a pick drive mechanism may include a pressure plate 230, a pressure plate spring 232, a loadstop arm 236, and/or a separator arm 234. A portion of the pick drive mechanism is shown in Figure 2.

[0030] In some examples, the cam wheel 202 may include a gear 238. The gear 238 may have an omitted portion for lost motion. In some examples, the cam wheel 202 includes two cams (e.g., cam 220 and a second cam that is not shown in Figure 2). For example, the cam 220 may control the position of the pressure plate 230 through the lever 218. The second cam may control the position of a loadstop and/or separator lever(s). The loadstop and/or separator lever(s) may control the position of the loadstop arm 236 and/or the position of the separator arm 234.

[0031] In some examples, the lever 218 may be loaded against the cam 220 by a spring force. For instance, the pressure plate spring 232 may pull the pressure plate 230 against the lever 218, which may exert a force on the cam 220. In some examples, a spring may be directly linked to the lever 218 (instead of or in addition to the pressure plate spring 232 linked to the pressure plate 230, for instance). In some examples, the loadstop and/or separator lever(s) may be loaded against the second cam by respective spring forces. At an engagement stage, a motor gear train of the pick drive mechanism may drive the cam wheel 202, which may release the pressure plate 230, may release a separation pad, and/or may retract loadstop gathering paddles. The spring load(s) transmitted to the cam(s) may create leverage torques on the cam wheel 202. Without the braking mechanism, the torques may drive a cam wheel ahead of a motor controller, which may result in loss of control and impulses that create noise and/or vibration.

[0032] In some examples, the spring-loaded caliper 210 may pinch the fin 204 (e.g., rotor segment) on the cam wheel 202, creating a friction force that opposes the leverage torques. The braking mechanism 200 may enable a motor controller to retain control and/or may reduce and/or eliminate noise and/or vibration.

[0033] Figure 3 is a diagram illustrating an example of a torque regulator 340. The torque regulator 340 described in relation to Figure 3 may be an example of the brake mechanism 100 described in relation to Figure 1 and/or of the brake mechanism 200 described in relation to Figure 2.

[0034] The torque regulator 340 may include a wheel 342. The wheel 342 may be an example of the cam wheel(s) 102, 202 described in relation to Figure 1 and/or Figure 2. The wheel 342 may include a gear 344, a cam 346, and an extended fin 348. The wheel 342 may include a gear 344, a cam 346, and/or the extended fin 348 may be examples of corresponding component(s) described in relation to Figure 1 and/or Figure 2 in some examples.

[0035] A gear torque 350 may be imparted to the wheel 342 from the gear 344. For instance, the gear torque 350 may cause the wheel 342 to rotate in a clockwise direction in the view of Figure 3. In some examples, the fin 348 may include a wedged surface 386 from a rotational leading edge of the fin 348. For example, the wedged surface may gradually expand the thickness of the fin 348 when proceeding in the rotational direction of the wheel 342. In some examples, the fin 348 may include a second wedged surface 384 from a rotational following edge of the fin 348. For example, the second wedged surface may gradually decrease the thickness of the fin 348 when proceeding in the rotational direction of the wheel 342. The brake pad 376 and/or caliper 378 may include sloped surfaces in some examples as described herein.

[0036] In some examples, the cam 346 may be in slidable contact with a lever 352. The lever 352 may exert a lever force 354 on the wheel 342. For example, the lever 352 may exert the lever force 354 on the wheel 342 based on a spring force 356. For instance, a spring may be linked to a pressure plate 358 (e.g., a pressure plate for media) and may impart the spring force 356 on the pressure plate 358 (in an upward direction, for instance). The spring force 356 may cause the pressure plate 358 to press on the lever 352, which may produce the lever force 354 on the cam 346 of the wheel 342.

[0037] In some examples, the wheel 342 may include a second cam 360. A second lever 362 (e.g., a loadstop and/or separation lever) may be in slidable contact with the second cam 360. The second lever 362 may exert a second lever force 364 on the wheel 342. For example, a loadstop arm 366 may be loaded with a spring or springs. The loadstop arm 366 may exert a loadstop arm force 368 on the second lever 362. In some examples, a separator arm 370 may be loaded with a spring or springs. The separator arm 370 may exert a separator arm force 372 on the second lever 362. The loadstop arm force 368 and/or the separator arm force 372 may cause the second lever 362 to exert the second lever force 364 on the wheel 342. The lever force 354 and/or the second lever force 364 may add torque to the wheel 342. For instance, the lever force 354 and/or the second lever force 364 may add torque to the gear torque 350 (in the direction of the gear torque 350, for example).

[0038] The torque regulator 340 may include a compression mechanism 374. The compression mechanism 374 may include a brake pad 376 and a caliper 378. The brake pad 376 may be an example of the brake pad(s) 108, 208 described in relation to Figure 1 and/or Figure 2. The caliper 378 may be an example of the caliper(s) 110, 210 described in relation to Figure 1 and/or Figure 2. The compression mechanism 374 may contact the fin 348 to regulate wheel 342 torque during a partial rotation of the wheel 342. For instance, the fin 348 may pass through the compression mechanism 374 during a portion (e.g., 45°) of a full rotation (360°) of the wheel 342. In some examples, the partial rotation may occur during a transition from an extended position to a retracted position of the lever 352. For instance, the cam 346 may include a transition portion 380 where a distance between the lever 352 and a center of wheel 342 is reduced during rotation of the wheel 342. During the transition portion 380, the cam 346 may allow the lever 352 to retract. When the lever 352 is extended, the pressure plate 358 may be restrained or held down. When the lever 352 retracts, the pressure plate 358 may be raised to allow media (e.g., a sheet of paper) to be picked. The partial rotation in which the fin 348 is engaged with the compression mechanism 374 may occur during all or part of the transition corresponding to the transition portion 380. The contact between the compression mechanism 374 and the fin 348 may cause friction (e.g., friction between the fin 348 and the brake pad 376 and/or caliper 378). The friction may produce a braking torque 382 on the wheel 342. The braking torque 382 may reduce and/or counteract the additional torque(s) exerted on the wheel 342 due to the lever force 354 and/or the second lever force 364. [0039] Figure 4 is a perspective diagram illustrating an example of a pick drive mechanism 488 in accordance with some of the examples described herein. In some examples, the pick drive mechanism 488 may be included in a printer or printing device. An element or elements of the pick drive mechanism 488 may be an example or examples of a corresponding element or elements described in relation to Figure 1 , Figure 2, and/or Figure 3.

[0040] In the example of Figure 4, the pick drive mechanism 488 includes a pressure plate 490. For instance, media (e.g., paper, cardstock, etc.) may rest on the pressure plate 490 when a printer is loaded with media.

[0041] The pick drive mechanism 488 includes a pressure plate spring 492. The pressure plate spring 492 is linked to the pressure plate 490. The pick drive mechanism 488 includes a lever 495 in contact with the pressure plate 490. The pressure plate spring 492 exerts a force on the lever 495 through the pressure plate 490. For example, one end of the pressure plate spring 492 may be linked to the pressure plate 490 and another end of the pressure plate spring 492 may be linked to a structure (e.g., rod, keeper, etc.) under tension. Accordingly, the pressure plate spring 492 may exert an upward force on the pressure plate 490, which may exert an upward force on the lever 495.

[0042] The pick drive mechanism 488 includes a cam wheel 494. The cam wheel 494 includes a cam 496 and a fin 498. The cam 496 is in slidable contact with the lever 495. The lever exerts an overdrive torque on the cam wheel 494. For example, the overdrive torque is a torque in the same direction as a driving torque.

[0043] The pick drive mechanism 488 includes a brake pad 401 . The pick drive mechanism 488 includes a caliper 403. The fin 498 may include a wedged surface from a rotational leading edge of the fin. The caliper 403 may include a sloped surface from a leading contact edge of the caliper 403. The brake pad 401 and the caliper 403 may contact the fin 498 to resist the overdrive torque.

[0044] The pick drive mechanism 488 may include an encoded direct current (DC) motor 411. The pick drive mechanism 488 may include a motor bracket assembly 413. The motor bracket assembly 413 may include gears (e.g., a pinion gear, reduction gears and/or idler gears). The gears may be utilized to drive the cam wheel 494.

[0045] The pick drive mechanism 488 may include a transmission 405. The transmission 405 may include one-way clutches (e.g., three one-way clutches) and a coaxial lost-motion gear and shaft pair 415. The pick drive mechanism 488 includes two tires 407 (e.g., elastomer tires). One of the tires 407 may be utilized for media picking, and one of the tires 407 may be utilized for separation.

[0046] In some examples, the cam wheel 494 includes the cam 496, a second cam, and a gear with an omitted portion for lost motion. The cam 496 on the cam wheel 494 may control the position of the pressure plate 490 through the lever 495.

[0047] In some examples, the pick drive mechanism 488 may include a separator arm and a loadstop arm. For instance, the loadstop arm may drive a gathering paddle 409 or paddles. In some examples, the cam wheel 494 includes a second cam and the pick drive mechanism 488 includes a second lever. The second cam may position the second lever, which may retract and the loadstop arm that restrains (e.g., loadstops) media (e.g., media in an input tray and/or on the pressure plate 490). In some examples, the second lever may be utilized to return excess pages remaining on a separation pad or pads (e.g., performs gathering or returns excess pages into the input tray). In some examples, the pick drive mechanism 488 may include a third lever that is controlled by the second lever. The third lever may extend the separation pad(s) (e.g., elastomer separation pads) to restrain excess sheets during picking.

[0048] Some examples of the brake mechanisms described herein may reduce noise and/or vibration through compact and/or relatively low-cost mechanisms. Some examples of the techniques described herein may enable a range of braking torques, which may allow tailoring for various operating situations (e.g., a large capacity main input tray versus a split main/photo tray, which may utilize different spring forces). Some examples of the brake mechanisms described herein may introduce drag for a portion of motion (e.g., cycle). Some examples of the brake mechanisms described herein may avoid or reduce overall drag of a drive mechanism (e.g., pick drive mechanism 488), which may allow use of a relatively smaller motor. Some examples of the brake mechanisms described herein may enable maintaining servo control of a cam wheel against overdriving forces.

[0049] As used herein, the term “and/or” may mean an item or items. For example, the phrase “A, B, and/or C” may mean any of: A (without B and C), B (without A and C), C (without A and B), A and B (but not C), B and C (but not A), A and C (but not B), or all of A, B, and C.

[0050] While various examples are described herein, the disclosure is not limited to the examples. Variations of the examples described herein may be within the scope of the disclosure. For example, aspects or elements of the examples described herein may be omitted or combined.