Roller clutch

Abstract

A locking clutch has an inner race rotatable relative to an outer race. One of the races is cylindrical and rotates adjacent to a race having valleys. Each valley is connected to an inclined surface. Rollers are located adjacent to the valleys. A cage having a plurality of fingers is selectively restrained relative to the valleys to set the initial position of the rollers. The cage is selectively restrained to determine the direction of roller wedging to determine the direction that the drive rollers contact both races to lock the races relative to each other. Rotation of the inner race relative to the outer race in the opposite direction is the free rotation direction. The locking clutch is designed to simultaneously engage all of its rollers to evenly distribute force between them.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 252,680 (filed October 6, 2021), the disclosure of which is incorporated herein by reference. Background Technology

[0003] A roller clutch is a device that transmits torque in one direction and moves freely in the opposite direction. A roller clutch operates by wedging one or more rollers between two surfaces to prevent relative movement of the two surfaces in one direction (the locking direction), thereby providing torque to be applied in the locking direction.

[0004] U.S. Patents 9,902,049, 9,958,019, and 11,110,570 illustrate examples of roller clutches used in conjunction with hand tools. Each of these patents discloses a roller clutch for use with a ratchet wrench or tool. The roller clutches disclosed in these patents allow a user to selectively determine and change the locking direction to apply force to a bolt, nut, or other object, while allowing the wrench to rotate in the opposite direction without applying force to the bolt, nut, or other object.

[0005] For roller clutches to be useful in hand tools, they must be able to apply a large amount of torque in the locking direction without slippage. Spherical rollers, such as ball bearings, can be used in roller clutches, but cylindrical rollers are preferred because the load applied to them can be distributed along their length when they wedged between two surfaces. A significant challenge in maximizing the torque that a roller clutch can transmit in the locking direction is achieving simultaneous engagement of all rollers as they are wedged in. Past efforts to achieve simultaneous engagement have involved very tight tolerances on the surfaces and on the rollers themselves. Simultaneous engagement of the rollers requires all rollers to be nearly identical, and these rollers must also be coupled to near-perfect surfaces. In practice, this is nearly impossible to achieve, and even if near-perfect tolerances were achieved, it would only be done at an unreasonable cost. Tiny differences between perfectly sized rollers and perfectly mating surfaces mean that only some rollers engage, or they engage unevenly. Thus, only partial or uneven engagement of the usable rollers limits the amount of torque that can be transmitted in the locking direction. There remains an unmet need for a roller clutch whose rollers can engage simultaneously and can be manufactured at a reasonable cost. Summary of the Invention

[0006] The present invention is a locking clutch having an inner race rotatable relative to an outer race. One of the races has a cylindrical surface adjacent the other race. The other race has a plurality of valleys positioned opposite the cylindrical race. Each valley is connected to a corresponding ramped surface adjacent each valley. A plurality of rollers are positioned between the races and adjacent the valleys. A cage having a plurality of fingers is constrained relative to the valleys such that the fingers hold the rollers in a first position relative to the valleys. Rotation of the inner race relative to the outer race in one direction causes the rollers to roll along the ramped surfaces away from the corresponding valleys. This movement of the rollers away from the valleys drives the rollers into contact with both races and positions the rollers in a second position, i.e., a wedged position. This direction of rotation is a wedging direction that causes locking of the races relative to each other. Rotation of the inner race relative to the outer race in a direction opposite the wedging direction tends to push the rollers toward their first position and is a free rotation direction.

[0007] In another aspect of the invention, the cage can be displaceable such that the first position of the rollers can be on the ramped surfaces across the valleys. The side of the valley from which the rollers start determines the wedging direction due to the positioning of the rollers via the fingers of the cage.

[0008] In another aspect of the invention, the spring of the biasing spring can have a pre-installed position and then bend in a plastic and elastic deformation in order to bias the rollers more evenly into the wedged position relative to the races. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a perspective view of a wrench including a roller clutch according to one embodiment of the invention.

[0010] Figure 2 is Figure 1 is an exploded perspective view of the wrench shown in

[0011] Figure 3 is Figure 1 is a perspective view of one end of the wrench shown in

[0012] Figure 4 is Figure 1 is a perspective view of a spindle that is a component of the roller clutch of the wrench shown in

[0013] Figure 5 is Figure 1 is a perspective view of a roller that is a component of the roller clutch of the wrench shown in

[0014] Figure 6 is Figure 1Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench.

[0015] Figure 7 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 3 Figure 8 is a detailed view of the area labeled 7 in Figure 7.

[0016] Figure 8 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench.

[0017] Figure 9 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 8 Figure 9 is a front perspective view of the wrench shown in Figure 8.

[0018] Figure 10 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 8 Figure 10 is a rear perspective view of the wrench shown in Figure 8.

[0019] Figure 11 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 8 Figure 11 is an exploded perspective view of the wrench shown in Figure 8 including Figure 8 Figure 12 is an exploded perspective view of the roller clutch of the wrench shown in Figure 8.

[0020] Figure 12 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 8 Figure 13 is a perspective view of a mandrel shown in Figure 12 as a component of a roller clutch of a wrench.

[0021] Figure 13 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 8 Figure 14 is a perspective view of a biasing member shown in Figure 12 as a component of a roller clutch of a wrench.

[0022] Figure 14 Figure 15 is a front perspective view of the wrench shown in Figure 11 mounted in a wrench. Figure 8 Figure 16 is an elevational view of the roller clutch of the wrench shown in Figure 15.

[0023] Figure 15 Figure 17 is a partial elevational view of the roller clutch of the wrench shown in Figure 15. Figure 8

[0024] Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 16 Figure 18 is a rear perspective view of the wrench shown in Figure 11.

[0025] Figure 17 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 16 Figure 19 is an exploded perspective view of the wrench shown in Figure 11 including Figure 20 is an exploded perspective view of the roller clutch of the wrench shown in Figure 11.

[0026] Figure 18 Figure 16 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 16 Figure 21 is a front perspective view of the wrench shown in Figure 19 mounted in a wrench.

[0027] Figure 19 Figure 7 is a perspective view of a biasing member shown in Figure 6 as a component of a roller clutch of a wrench. Figure 16is a perspective view of a switch as a component of a wrench shown in

[0028] Figure 20 is Figure 16 is an exploded perspective view of a roller and cage as components of a roller clutch of a wrench shown in

[0029] Figure 21 is a roller clutch of a wrench shown in Figure 16 is a front view of a roller clutch of a wrench shown in

[0030] Figure 22 is a roller clutch of a wrench shown in Figure 16 is a partial front view of a roller clutch of a wrench shown in

[0031] Figure 23 is a partial front view showing the relationship between a switch portion and a cage portion (both are components of a wrench shown in Figure 16

[0032] Figure 24 is a partial front view of a roller clutch of a wrench shown in Figure 16

[0033] Figure 25 is a perspective view of a switch and a cage as components of a wrench and a roller clutch according to another embodiment of the invention.

[0034] Figure 26 is a perspective view of a portion of a cage as a component of a roller clutch according to another embodiment of the invention.

[0035] Figure 27 is an exploded perspective view of a cage as a component of a roller clutch according to another embodiment of the invention.

[0036] Figure 28 is a perspective view of a cage shown in Figure 27 DETAILED DESCRIPTION

[0037] Figure 1 A roller clutch of the invention is shown in use in a ratchet wrench 10. The wrench has a handle 20 having a distal end 21 connected to a head 23. The head 23 contains a roller clutch 24. In Figure 2 The components of the roller clutch 24 and how the roller clutch 24 is assembled into the head 23 of the wrench 10 are shown in (exploded view).

[0038] ​​​The head 23 has a chamber 32 with a cylindrical seat 34 defining the outer boundary of the chamber 32 within the head 23. The cylindrical seat 34 terminates on one side by a base lug 36, which serves as a constraint feature for components mounted within the chamber 32 of the head 23. A washer 38 is placed on the base lug 36 to facilitate rotation of a component mounted above the washer 38. The washer 38 may be a high-density, low-friction plastic or metal component. A mandrel 44 is rotatably mounted above the washer 38 within the chamber 32. The mandrel 44 has a central opening 45, such as... Figures 1-7 As shown, the central opening 45 is designed for use with a dodecagonal wrench to engage fasteners. However, it is conceivable that the central opening 45 of the mandrel 44 could be of other shapes designed to engage other fasteners. The mandrel 44 has a second seat 48 with a series of radially outwardly projecting protrusions 50. The second seat 48 has a series of valleys 52 that are radially closest to the central axis 54 about which the mandrel 44 rotates within the cylindrical seat 34. The valleys 52 on the second seat 48 are adjacent to inclined surfaces 56 that extend continuously from the valleys 52 on the second seat 48 and terminate at an outer diameter surface 58, which is the radially outermost portion of each protrusion 50. These inclined surfaces 56 are concave because they face the cylindrical seat 34. The valleys 52 and the inclined surfaces 56 form a continuous surface. Each convex corner 50 has a back surface 62 facing the adjacent concave valley 52. ​​When the mandrel 44 is assembled within the head 23, the second seat ring 48 is positioned adjacent to and within the cylindrical seat ring 34. Figure 3 As shown, in the assembled state, the concave valley 52 is the part of the second seat ring 48 that is furthest from the cylindrical seat ring 34. The inclined surface 56 adjacent to the concave valley 52 gradually slopes in the direction closer to the cylindrical seat ring 34.

[0039] Each lobe 50 of the mandrel 44 is designed to have a roller 66 adjacent thereto. Although the rollers 66 are shown as cylindrical elements, the rollers 66 can have other shapes, such as they are elliptical in cross-section. Each roller 66 is adjacent to a corresponding valley 52. The rollers 66 are held captive between the cylindrical races 34, the corresponding ramped surfaces 56, the valleys 52, and the corresponding back surfaces 62. These adjacently positioned surfaces form a cavity 68 that captures each roller 66 between the races 34, 48. These rollers can be moved from a first position that positions the rollers 66 relatively close to their corresponding valleys 52 to a second position in which each roller is positioned further from its corresponding valley than in the first position. This movement is in a smooth, controlled manner. The movement from the first position to the second position can be imperceptibly small. In other words, the movement from the first position to the second position is associated with movement of each roller 66 along its adjacent ramped surface 56 away from its corresponding adjacent valley. The second position is limited by the rollers 66 impinging on the ramped surfaces 56 and the cylindrical races 34.

[0040] The springs 70 bias each roller toward the second position and along the inclined surface 56. Each spring 70 has a cantilevered biasing member 72 having a distal end 74 opposite a proximal end 76. The proximal end 76 is attached to a mounting portion 78 which is a tubular portion having a slit 73. The mounting portion 78 is compressible such that the sides of the slit 73 can be compressed toward one another. The mounting portion 78 of the spring 70 is compressed into a notch 80 on the back surface 62 of the lobe 50. Because these mounting portions 78 are resilient, they press outward on the notch 80 into which they are inserted and thereby hold the position of each spring 70 in its corresponding notch 80. Once the spring 70 is compressed into its corresponding notch 80, the distal end 74 of the cantilevered biasing member 72 extends away from the back surface 62 a pre-installation distance which corresponds to when the mandrel 44 is not accommodated by the cylindrical race 34 in the head 23. The mandrel 44 is placed into the cylindrical race 34 and the rollers 66 are placed adjacent the cantilevered biasing members 72. The mandrel 44 and rollers 66 are held within the cylindrical race 34 by another washer 38 and a retaining ring 77 mounted in a groove 75. Insertion of the rollers 66 into their corresponding cavities 68 against the corresponding springs 70 plastically deforms each cantilevered biasing member 72 to an installed position which positions the distal end 74 of each cantilevered biasing member 72 closer to the second race 48 on the mandrel. More precisely, these cantilevered biasing members 72 are closer to the back surface 62 which is part of the second race 48. It should be noted that the distal end 74 is where the biasing member 72 contacts its corresponding roller 66 and depending on the shape of the biasing member 72 there can be portions of the biasing member 72 which extend beyond the distal end 74. An example of this is if the end of the biasing member 72 is slightly curved away from the roller 66 to avoid having a sharp edge which contacts the roller 66. The plastic deformation during the movement of the cantilevered biasing member 72 from its pre-installation position to its installed position also occurs with some elastic deformation. The amount of plastic deformation of each spring 70 to its installed position corresponds to the conditions within each corresponding cavity 68 in which each spring 70 resides, providing each spring 70 with nearly uniform preloading to bias its corresponding roller 66 into the races 34, 48. Once the plastic deformation required to move the cantilevered biasing member 72 of each spring 70 from its pre-installation position to its installed position has occurred, the force exerted by each spring 70 to bias each corresponding roller 66 will depend on the Young's modulus of the material from which the spring 70 is made. Once the plastic deformation has occurred, the stress strain curve of the spring 70 will have shifted such that the starting point of further bending of the cantilevered biasing member 72 from its installed position toward the back surface 62 of the second race 48 will be in the elastic range. The starting point of the bending will be just where the distal end 74 contacts its corresponding roller 66.In this manner, the point of origin of the elastic bending within each spring 70 will be tailored to the specific conditions in each cavity 68, which are defined by the diameter of each particular roller 66, the corresponding inclined surface 56, the position of the spring 70 on the corresponding back surface 62, and the cylindrical race 34. Therefore, any deviation of the tolerances of these parameters can be compensated by the plastic deformation of the spring 70 from the pre-installed position to the installed position. This will make the pressure on each roller 66 almost uniform and facilitate that all rollers 66 engage almost simultaneously when moving towards their second position.

[0041] The movement of the rollers 66 into the second position is facilitated by the rotation of the mandrel 44 relative to the cylindrical race 34 in the head 23. Eventually, this movement drives the rollers 66 to their second position. When the mandrel 44 is rotated in a particular direction relative to the cylindrical race 34, this will cause the rollers 66 to wedge against their corresponding adjacent inclined surfaces 56 and the cylindrical race 34. This wedging contact will effectively lock the mandrel 44 relative to the head 23 and allow the application of torque through the central opening 45 of the mandrel 44. These inclined surfaces 56 are concave and this maximizes the contact area that the rollers 66 have with the second race 48 because they are wedged between these inclined surfaces 56 of the second race 48 and the cylindrical race 34. As an example of the wedging action, the rotation of the mandrel 44 relative to the cylindrical race 34 and the head 23 in the clockwise direction as shown in Figures 1 to 7 This relative movement that causes the wedging of the rollers 66 is also achieved by rotating the handle 20 and the head 23 counterclockwise relative to the mandrel 44. The relative movement of the mandrel 44 relative to the head 23, as described for causing the wedging of the rollers 66, is the wedging rotation direction. The rotation of the handle 20 of the wrench 10 in the wedging direction makes the present invention particularly useful. Figure 3The practicality of the configuration described herein is achieved through the near-instantaneous locking of the spindle 44 relative to the head 23. In a typical ratchet wrench or standard ratchet, there is a hysteresis when the user rotates the handle 20 of such a device and when the spindle 44 locks in a particular direction, thus torque can be applied to the fastener. This means that the handle 20 can move a considerable distance in an arc around the spindle 44 before actually applying torque to the fastener. This movement before torque is applied to the fastener can be considered a dead travel, as it is a wasted movement that does not accomplish the task of applying torque. The near-instantaneous locking of the spindle 44 in the wedging direction is partially achieved because each roller 66 is biased by the spring 70 toward its second position, such that each roller 66 simultaneously contacts its corresponding inclined surface 56 and the cylindrical seat 34. Rotating the handle 20 in the wedging direction causes each roller 66 to move away from its groove 52 along its inclined surface 56, as the cylindrical raceway 34, biased by the spring 70, further pulls the roller 66, already in contact with the cylindrical raceway 34, into the raceway 34. As described above, the spring 70 provides a uniform bias on the roller 66, independent of tolerance variations. Therefore, the rollers 66 simultaneously engage to lock the spindle 44 relative to the head 23 in the wedging direction. This provides an immediate application of torque through the spindle 44 as the handle 20 is rotated in the wedging direction. As described above, the uniform bias of the spring 70 distributes the wedging force evenly among the multiple rollers 66. This uniform distribution of the wedging force prevents disproportionate forces on any one roller 66 that could engage in front of other rollers 66 due to minute tolerance variations. Such premature engagement of any one roller 66 could lead to brinelling of the contact surfaces due to plastic deformation and could potentially cause the roller 66 to permanently lock. Because all rollers 66 engage almost simultaneously, a significant amount of torque can be applied to the handle 20 before any rollers 66 undergo plastic deformation or cause indentation of the races 34, 48. The simultaneous engagement of the rollers 66 in this invention also minimizes dead travel due to deformation of the rollers 66 or the surfaces they contact, as the uniform load distributed across the rollers 66 minimizes any deformation of the mating surfaces under torque. Rotating the handle 20 and head 23 in the direction opposite to the wedging direction corresponds to the free rotation direction. Figures 1 to 7The free rotation direction corresponds to the head 23 and cylindrical race 34 rotating clockwise relative to the mandrel 44 as shown. Movement in the free rotation direction tends to drag the rollers 66 toward their first position, thereby bringing the rollers 66 relatively closer to their corresponding valleys 52. Although this movement toward the first position can be very small, the rollers will tend to drag very slightly on the cylindrical race 34, which encourages the rollers 66 to move closer to the valleys to facilitate free rotation opposite the wedging direction of rotation. Because the rollers 66 have an even distribution of force between the rollers 66, no indentation will occur between the rollers 66 or the races 34, 48. The rollers 66 immediately release when the cylindrical race 34 rotates in the free rotation direction because no indentation occurs. If Figures 1 to 7 A user of the wrench 10 shown can wish to reverse the direction in which torque can be applied to a fastener, and the wrench 10 can be flipped to achieve the reversal of the wedging direction of the locking mandrel 44.

[0042] It should also be noted that the above-described components of the wrench 10 described above can have the ramped surfaces 56 located within the head 23, and the cylindrical race 34 can be located on the mandrel 44. This configuration is the reverse of the configuration shown, but the same wedging action results from the relative movement of the mandrel 44 relative to the head 23. Figures 8 to 15

[0043] Although the above-described wrench 10 does not have a mechanism that allows for the purposeful change of the wedging direction and the free rotation direction, it can be done. Figure 11 Such a roller clutch 130 that allows for the change of the wedging direction is shown. The ratchet wrench 100 has a handle 108 attached to a head 112. The handle 108 has a distal end 118 opposite the end of the handle 108 that is attached to the head 112.

[0044] The head 112 contains a roller clutch 130 housed therein. Figure 14 ​An exploded view of the roller clutch 130 is shown in FIG. 1. The interior of the head 112 has a cavity 134 defined by a cylindrical race 138 that defines the outer boundary of the cavity 134. The cylindrical race 138 has a groove 140 for receiving a snap ring 142 that serves as a restraining feature for components mounted within the cavity 134 of the head 112. A base plate 146 rests on the snap ring 142 and supports a spindle 150 that rotates within the cylindrical race 138. The spindle 150 has a square driver 153 that extends through the base plate 146. The square driver 153 is a post that extends from the spindle 150. It is contemplated that the square driver 153 can have other shapes to transmit torque. The spindle 150 has a second race 154 opposite the square driver 153, and the second race 154 has a series of lobes 156. The lobes 156 are separated by valleys 160 that are closest to a central axis 164 about which the spindle 150 rotates within the cylindrical race 138. Each lobe 156 has a sloped surface 168 that continues from the valley 160 adjacent the particular lobe 156 to an outer diameter surface 172 that is the radially outermost portion of each lobe 156. Each valley 160 has a pair of sloped surfaces 168 that span each valley 160 and lead to two lobes 156 that are spaced apart from each valley 160. These sloped surfaces 168 are concave when facing the cylindrical race 138. When the spindle 150 is assembled within the head 112, the second race 154 on the spindle 150 is adjacent to and within the cylindrical race 138. In the assembled state, the valleys 160 are the portions of the second race 154 that are relatively farthest from the cylindrical race 138. The sloped surfaces 168 that span the valleys 160 are gradually sloped in a direction closer to the cylindrical race 138. These sloped surfaces 168 are concave when facing the cylindrical race 138.

[0045] When the mandrel 150 is in its installed position within the cylindrical race 154, each valley 160 of the mandrel 150 has a roller 152 adjacent thereto. As previously mentioned, the rollers 152 are cylindrical, but this is not necessarily the only cross-sectional shape that can be used. The rollers 152 remain captured between the cylindrical race 138 and the corresponding valley 160. The rollers 152 are movable from a first position, in which each roller 152 is positioned relatively close to its corresponding valley 160, and a wedged position or second position, in which the rollers 152 have moved far enough along the inclined surface 168 to contact the inclined surface 168 and the cylindrical race 138. Movement of the rollers 152 along the inclined surface 168 away from their corresponding valleys 160 is achieved by rotating the head 112 and the cylindrical race 138 relative to the mandrel 150 in a wedging direction. This wedging direction is established by the displacement mechanism, which positions the rollers 152 on one side of their valleys 160, so that the rollers 152 can only roll along the inclined surface 168 on one side of the valley 160.

[0046] The shift mechanism includes a cage 180 having fingers 184 extending from a base 186. Each finger 184 has a distal end 188 opposite the base 186. The distal end 188 includes a slot 190 extending toward the base 186. The center of the cage 180 includes a hole 195 extending through the base 186. A boss 194 extends upward from the base 186 and the hole 195 extends through the boss 194 and into a slot 198. The switch 200 has a shaft 204 extending through the hole 195 in the boss 194 and allows the switch 200 to rotate about the shaft 204 when the switch 200 is installed into the hole 195. The shaft 204 has a triangular boss 208 at its end for moving a pawl slide 210 within the slot 198. The pawl slide 210 has teeth 217 on opposite ends that selectively lock the cage 180 in different positions relative to the mandrel 150. The details of how the pawl slide 210 selectively locks the cage 180 relative to the mandrel 150 are not thoroughly described herein but are known in the art. More specifically, U.S. Patent 9,958,019 discloses the details of how the pawl slide 210 locks the cage 180 relative to the mandrel 150. Rotating the switch 200 causes the cage 180 and its fingers 184 to shift relative to the valley 160. Once the switch 200 has shifted the cage 180 to the desired position, the cage 180 and fingers 184 rotate with the mandrel. In other words, once the switch has positioned the cage 180 in the desired position, the fingers 184 remain fixed relative to the valley 160. Other mechanisms besides the use of the pawl slide 210 described above can be used to accomplish the same purpose of keeping the fingers 184 fixed relative to the valley 160 during rotation of the mandrel 150. Such mechanisms for locking the cage 180 and fingers 184 can include spring balls and pawls, or other locking features, to keep the fingers 184 in position relative to the valley. Any locking mechanism used for this purpose should have the desired feature of not releasing the fingers 184 during rotation of the mandrel 150. It can be appreciated from the above description that if the locking mechanism allowed the cage 180 to randomly move during use, the direction of rotation of the mandrel 150 that is locked by the wedging action would change during use. This unpredictable behavior would greatly reduce the utility of the ratchet wrench 100.

[0047] A spring 218 is located within the slot 190 of the finger 184. Each spring 218 has a first cantilevered end 222 and a second cantilevered end 224 connected by a bridge 228. The spring 218 is generally U-shaped. The bridge 228 of the spring 218 is slidably retained within the slot 190 of the finger 184 and is laterally displaceable within the slot 190 relative to the finger 184, which directs the movement of the spring 218.

[0048] Figure 15 An example is shown of how the cage 180 is indexed to position the fingers 184 relative to the valleys 160 on the second race 154 of the mandrel 150. For clarity, the valleys 160 are shown as thin areas of the portion of the second race 154 furthest from the cylindrical race 138. Each valley is defined by adjacent ramped surfaces 168 that converge to form the portion furthest from the cylindrical race 138. Lines 232 represent the specific location of the valleys 160. These lines 232 radiate from a central axis 234 of the mandrel 150 about which the mandrel 150 rotates. Each finger 184 positions each roller 152 to a contact point 240 that is indexed to a location on a particular side of the valley 160. Figure 14 The contact point 240 shown in is the starting point or first position of the contact of each roller 152 with the adjacent ramped surface 168 to a location indexed to one side of the corresponding valley 160. The contact point 240 is actually a line of contact that extends along the length of each roller 152 for its entire contact along the ramped surface 168 of the mandrel 150. When the position of the fingers 184 is locked to the mandrel 154, this means that the roller 152 cannot roll back toward the nearest valley 160 and absolutely cannot roll further than the nearest valley 160 to ride on the ramped surface 168 on the opposite side of the nearest valley 160 from where it is located. As shown in Figure 14 This means that the roller 152 can only roll along the right-hand side valley 160. This starting position (or interchangeably first position) sets the wedging direction that locks the mandrel 150 within the cylindrical race 138 through the wedging action of the roller 152 between the ramped surface 168 and the cylindrical race 138. In Figure 14 the case shown, rotating the head 112 by turning the handle 108 in the clockwise direction is the wedging direction that will cause the roller 152 to wedge between the ramped surface and the cylindrical race 138, thereby applying torque to the mandrel 150 that is connected to the socket or other attachment to apply torque to the fastener connected to the mandrel 150. As shown in Figure 14 the counterclockwise rotation of the handle will release the roller 152 from its wedged engagement and allow the mandrel 150 to rotate freely. The switch 200 can be used to selectively lock the cage 180 so that the fingers 184 position the starting or first position of the roller 152 to the other ramped surface 168 on the opposite side of the Figure 14 shown in. Thus, the wedging direction of the mandrel 150 will be opposite to that shown in Figure 15 .

[0049] Ideally, the rollers 152 would engage simultaneously in the wedging direction with perfect synchronicity. Simultaneous engagement requires the spindle 150 to have a precisely uniform inclined surface 168, where identical rollers 152 are displaced by perfectly uniform fingers 184, each positioned at exactly the same distance from its corresponding concave groove 160. However, perfect manufacturing is unrealistic, and attempting to achieve overly tight tolerances would result in a mechanism that is prohibitively expensive to manufacture. Therefore, a load balancing mechanism is employed to facilitate near-simultaneous engagement of the rollers 152 against the two races 138, 154 within practical manufacturing tolerances. The load balancing mechanism also achieves near-uniform load distribution on the rollers 152 as they wed in along the wedging direction via the movement of the races 138, 154. Simultaneous engagement minimizes dead travel in the wedging direction, ensuring that torque is applied as soon as the handle 108 rotates in the wedging direction.

[0050] The load balancing mechanism includes the aforementioned springs 218, which balance the load and facilitate the simultaneous engagement of the rollers 152. Figure 15 This illustrates how the load balancing mechanism works. Under actual manufacturing tolerances, the roller 152 may not simultaneously wedge or engage between the inclined surface 168 and the cylindrical raceway 138. Figure 15 The diagram shows some rollers 152 marked with the letter O that are not engaged, while the other engaged rollers 152 are marked with X. Figure 14 The wedge direction in Figure 15 The wedging direction is the same. Thus, the clockwise rotation of the cylindrical race 138 relative to the inclined surface 168 will cause the roller 152 to engage in a wedging relationship between the cylindrical race 138 and the inclined surface 168. When a particular roller 152 (such as...) Figure 15 When the rollers marked X enter the wedged engagement slightly before the other rollers marked O, the engaged roller 152 (marked X) will press against the first cantilever end 222 of the spring 218 that contacts the particular engaged roller (marked X) 152. Figure 15 As shown, this will cause spring 218 to shift within its slot 190, where finger 184 holds spring 218. When bridging member 228 shifts and force is applied between the first cantilever end 222 and the second cantilever end 224, this shift of spring 218 will push the incompletely engaged adjacent roller 152 (marked O) into wedge contact. In this way, if some roller 152 (such as roller marked X) enters wedge engagement slightly before roller 152 marked O, spring 218 will cause roller 152 marked O to catch up and enter wedge engagement almost simultaneously. Thus, even with slightly different wedge engagement rates between rollers 152 due to tolerances, spring 218 will still provide almost simultaneous wedge engagement of rollers 152 as spindles 150 and 112 rotate in the wedge direction.Figures 16-25 As shown, when the handle 108 is used to rotate the cylindrical race 138 in the head 112 in a counterclockwise direction, the rollers 152 will be released from the wedging engagement. In addition, the energy stored in the spring 218 will be released so that the rollers 152 will be able to freely rotate when the handle 108 is rotated in the free rotation direction. As can be appreciated from the above description, positioning the fingers 184 on opposite sides of the valleys 160 using the switch 200 will change the wedging and free rotation directions, as well as reverse the interaction of the spring 218 with the rollers 152. Thus, in either direction (the wedging direction) selected to deliver torque, nearly simultaneous engagement of the rollers 152 and nearly simultaneous release of the rollers 152 in the free rotation direction will be achieved. Thus, the switch 200 and the fingers 184 function as components of a shift mechanism for selecting the wedging direction, and the spring 218 within the fingers 184 functions as a load balancing mechanism.

[0051] While the spring 218 can function as a load balancing mechanism, load balancing can be achieved as shown in FIGS. 6A and 6B. As shown in the exploded view of FIG. 6A, a roller clutch 290 includes a cage 296 that functions as a load balancing mechanism to facilitate simultaneous engagement of rollers 300 held within the cage 296. The cage 296 also acts as a shift mechanism as will be described below. The cage 296 has a base 310 with a plurality of fingers 314 extending away from the base 310. The fingers 314 have proximal ends 318 attached to the base 310 and distal ends 320 spaced apart from the base 310 in a cantilevered fashion. The cage 296 is designed to assemble with a head 328 of a ratchet wrench 332. A handle 334 is connected to the head 328. Figure 18 Figure 18 As shown in the exploded view of FIG. 6A, a roller clutch 290 includes a cage 296 that functions as a load balancing mechanism to facilitate simultaneous engagement of rollers 300 held within the cage 296. The cage 296 also acts as a shift mechanism as will be described below. The cage 296 has a base 310 with a plurality of fingers 314 extending away from the base 310. The fingers 314 have proximal ends 318 attached to the base 310 and distal ends 320 spaced apart from the base 310 in a cantilevered fashion. The cage 296 is designed to assemble with a head 328 of a ratchet wrench 332. A handle 334 is connected to the head 328.

[0052] The mandrel 340 includes a cylindrical race 344 and a square driver 348 extending opposite the cylindrical race 344. The cylindrical race 344 is an outer surface on a mandrel body 346. The mandrel body 346 includes a bore 350 for receiving a spring 354 that can press against a catch ball 358 for retaining a socket on the square driver 348. The mandrel 340 is retained in the head 328 on one side by a front cover 349 and a snap ring 351 and on the other side by a rear cover 353.

[0053] ​The head 328 of the ratchet wrench 332 has a second race 366 having a plurality of valleys 370 separated by ridges 374. The valleys 370 are regions of the second race 366 that are radially farthest from the cylindrical race 344 when the cylindrical race 344 is assembled within the second race 366 such that the second race 366 surrounds the cylindrical race 344. Each valley 370 is a region flanked on both sides by an adjacent ramped surface 376. As noted above, the ramped surfaces 376 can be concave when facing the cylindrical race 344. When the cylindrical race 344 is within the second race 366, the rollers 300 are held between the cylindrical race 344 and the ramped surfaces 376. The ramped surfaces 376 are angled toward the cylindrical race 344 such that movement of the rollers 300 along the ramped surfaces 376 away from the valleys 370 in either direction positions them closer to the cylindrical race 344 until each roller 300 eventually contacts both the ramped surface 376 and the cylindrical race 344. The rollers 300 can move from a first position in which each roller 300 is positioned relatively close to its corresponding valley 370 and a wedged position or second position in which the rollers 300 have moved far enough along their ramped surfaces 376 to contact both the ramped surfaces 376 and the cylindrical race 344. Movement of the rollers 300 away from their corresponding valleys 370 along the ramped surfaces is accomplished by rotating the second race 366 relative to the arbor 340 in a wedging direction. The wedging direction is established by purposefully positioning the rollers 300 by shifting the cage 296. The wedging direction is set by positioning the rollers 300 on one side of their corresponding valleys 370 such that the rollers 300 can only roll along the ramped surfaces 376 on one side of the valleys 370.

[0054] The cage 296 functions as part of the entire shifting mechanism, which includes a switch 390 that pivots about a screw 394 extending through the head 328, as Figure 23The screw 394 is threaded into the hole 396 in the pivot post 400 so that the switch 390 can pivot about an axis 406 that passes through the center of the pivot post 400 and the screw 394. The switch 390 has a displacement post 408 that extends down into the head 328 so that it can displace the cage 296. The switch 390 has a detent ball 410 that is urged by a spring 419 into a detent pocket 418 in the switch 390 to selectively lock its position. The displacement post 408 extends into a displacement slot 428 in the base 310 of the cage 296. Pivoting of the switch 390 causes the fingers 314 of the cage 296 to be selectively restricted relative to the valleys 370 on the selected side of the valleys 370. The fingers 314 are restricted relative to the valleys 370 within limits defined by the displacement slot 428 in the base 310. Because the displacement post 408 is selectively fixed relative to the second race 366 by the interaction of the detent ball 410 with the switch 390, the sides 434 of the displacement slot 428 allow the cage 296 and its fingers 314 to be rotationally displaced within limits defined by the distance that the sides 434 of the displacement slot 428 contact the displacement post, which is represented as W in Figure 11 FIG. 19. It is contemplated that the displacement post 408 can be fixed relative to the second race 366 and its valleys 370 so that the displacement post 408 is immovable. A fixed displacement post can be desirable when a single wedging direction is needed for torque transmission.

[0055] In general, it should be noted that the cage 296 is restricted relative to a race having valleys, in this case, the valleys are just the second race 366, which is an outer race around the inner cylindrical race 344 on the mandrel 340, and then used with the cage 296. It is contemplated that the cylindrical race 344 can be reversed so that it is an inner race on the head 328 and the valleys can be on the mandrel 340. Figures 21 to 24 This configuration is shown in FIG. 18, however, the cage 180 is slightly different than the cage 296.

[0056] Pivoting the switch causes the displacement post to bear against one of the sides 434 of the displacement slot 428. With the displacement post 408 bearing against one of the sides 434 of the displacement slot 428, the cage 296 can be further rotated in the direction that the displacement post 408 pushes the cage 296. Figure 21 This relationship is explained as to how it works and the importance of how this action allows the cage 296 in combination with the switch 390 to be both a displacement mechanism that determines the wedging direction and a load balancing mechanism is shown. Figure 21A retainer 296 is shown positioned such that rotation of the head 328 and second race 366 will wedge the rollers 300 into the ramped surface 376 on the left side of the valley 370, as Figure 22 shown. Thus, the wedging direction for applying torque is completed by rotating the handle 334 in the clockwise direction, and the free rotation direction is the counterclockwise direction. Figure 21 A zoomed in view of the rollers 300 interacting as Figure 23 shown, and the positioning of the fingers 314 in this state. Figure 24 A displacement post 408 is shown bearing on the left side 434 of the displacement slot 428. This position, as described above, displaces the rollers 300 to set the wedging direction, but will allow the retainer 296 and its fingers 314 to rotate counterclockwise until the displacement post 408 contacts the right side 434 of the displacement slot 428.

[0057] The load balancing function of the retainer 296 is best shown in Figure 23 Some of the rollers, marked X, are fully engaged between the cylindrical race 344 and the ramped surface 376 of the second race to transmit torque due to the wedging action from rotating the ramped surface 376 in the clockwise wedging direction set by the retainer 296 and the switch 390. When the rollers 300 marked X engage before the rollers 300 marked O, the rollers 300 marked X will push their adjacent fingers 314 to the left in the counterclockwise direction to push the rollers 300 marked O and thereby cause the rollers 300 marked O to engage. Movement of the retainer 296 and fingers 314 in the counterclockwise direction is possible because there is space within the displacement slot 428 such that it can move from the displacement post 408 towards the right side 434 of the displacement slot 428. As Figure 23 shown, the retainer 296 can move counterclockwise away from the displacement post 408 when the displacement post 408 contacts the starting side 434' of the displacement slot 428. This movement is one way the retainer 296 can facilitate load balancing between the rollers 300. Another way the retainer 296 can balance the load and facilitate simultaneous engagement of all rollers 300 is through the flexing of the fingers 314. If a finger 314 contacts a roller 300 that engages before another finger, the first engaging roller 300 can cause the finger 314 to flex near its proximal end 318 and cause the distal end 320 to enhance movement to impact the adjacent roller 300 through cantilever action. Thus, the retainer 296 can facilitate simultaneous engagement of all rollers 300 through both displacement of the entire retainer 296 and flexing of individual fingers 314. In this way, the retainer 296 can accommodate significant tolerance variations between adjacent rollers 300 and non-adjacent rollers 300 through both flexing and displacement.

[0058] The dimensions of the components that interact with the retainer 296 are selected with specific relationships in order to achieve the desired results during use. When the switch 390 is rotated into one of its detent positions by moving the switch left or right, the shift post 408 will contact the outer side 434 of the shift slot 428. The initial contact of the shift post 408 after moving the switch into one of its detent positions is the start side 434’ of the shift slot 428, and can be either the left or right side 434. Figure 24 The start side 434’ is shown. When the switch is in one of its selectively locked detent positions, there is a desired minimum distance W between the shift post 408 of the switch 390 and the opposite side 434 of the shift slot 428 with which the shift post 408 is in contact. This distance W is selected to take into account Figure 23 The load balancing and simultaneous engagement of the retainer 296 in the shift slot 428, the distance W is selected so that the shift slot 428 is wide enough so that the retainer 296 can rotate sufficiently to cause all of the rollers 300 to wedge into contact before the retainer 296 stops on the shift post 408 by bringing the opposite side 434 into contact with the start side 434’. For example, in the embodiment shown in FIG. 6, the distance W is 0.35Tc. Figure 18 In the embodiment shown in FIG. 6, the start side 434’ is the left side 434. The minimum distance W must allow for the necessary rotation of the retainer 296, and is determined as follows:

[0059] W = 0.35Tc

[0060] where Tc is the desired circumferential travel of the retainer 296, which is calculated as follows:

[0061] Tc = (0 / 360) x C

[0062] where 0 is the desired relative angular rotation between the mandrel 340 and the head 328, and where C is the circumference of a circle that passes through the centers of the rollers 300 centered on the center of the mandrel 250. 0 is determined by (a) determining the difference between the angular rotation of the free end of the handle 334 at a specified torque (e.g., 100% of the torque for a given wrench size as determined by the American National Standards Institute (“ANSI”) minus the rotation of the square driver 348 at that torque) and (b) subtracting the contribution to the angular rotation of the free end of the handle 334 (including any contribution due to flexing or bending of the handle 334) from the angular rotation. For example, using the ANSI standard for a 3 / 8 inch wrench, the difference between the rotation of the free end of the handle 334 and the square driver 348 is 14.5 degrees, and the contribution to the angular rotation due to the rotation of the free end of the handle 334 (including any contribution due to flexing or bending of the handle 334) is 6.5 degrees. This results in 0 = 8 degrees.

[0063] C can be calculated as follows:

[0064] C = Pi (SD + RD), where SD is the mandrel 340 diameter at the cylindrical race 344, and RD is the roller 300 diameter.

[0065] The desired range for G (the spacing of the finger 314 from the roller 300) is:

[0066] 0.05 (RD) < G < 0.2 (Tc)

[0067] Applying these equations to a 3 / 8" ratchet wrench 332 (for example) with the following component dimensions:

[0068] Θ = 8 degrees

[0069] SD = 0.0984 inches

[0070] RD = 0.0984 inches

[0071] C = 3.162 inches

[0072] Tc = 0.070 inches

[0073] 0.0049 inches < G < 0.014 inches

[0074] W = 0.0245 inches minimum

[0075] As mentioned above, the shifting mechanism using the switch 390 and the shift bar 408 can be accomplished by other similar mechanisms. For example, the shift post 408 on the switch 390 as shown in FIG. 6 interacts with a shift slot 428 as shown in FIG. 7 by engaging in the shift slot. The shift post 408 enters the shift slot 428 by entering the base 310 of the cage 296 perpendicular to the bottom of the base 310 opposite the finger. It is also contemplated that the shift post can enter the shift slot 428 laterally. This would be perpendicular to how the shift post 408 enters the shift slot 428 as shown in FIG. 8. Other mechanisms besides those described above that perform the same function can be utilized to shift the cage 296, i.e., to shift the cage 296 to a particular side of the valley 370 so that the direction of wedging can be selected, but still allow some constrained movement of the cage 296. Figure 23 Figure 23 Figure 27

[0076] ​​​The cage 296 shown above is not the only type of cage that can be used with the present application. Cage 480 is a different kind of cage that can be used in place of cage 296. Cage 480 includes a base 488 having fingers 494 connected thereto. The base 488 has U-shaped members 492 that span between the fingers 494 to connect the fingers 494. Each member 492 has a bend region 498. The rollers 300 can be mounted between the fingers 494 of the cage 480 in the same manner as described above for the cage 296. The cage 480 is displaced in the same manner as the cage 296. The cage 480 provides an opportunity for additional bending of the members 492 between the fingers 494 that exceeds the degree of rigidity of the base 310 of the cage 296. This additional flexibility within the cage 480 allows adjacent rollers 300 to push against adjacent rollers 300 to a greater degree than in the cage 296. In addition, the cage 480 is not as dependent on cantilever action as described in the cage 296. In this manner, the load balancing effect of having relative movement between the fingers 494 can be enhanced by selecting the properties of the members 492 to provide the desired amount of relative movement between the fingers 494.

[0077] Figure 28 and Figure 27 Another example of a cage 510 is shown in FIG. 54. The cage 510 is very similar to the cage 296, however, the cage 510 has a first base 520 and a second base 524. The first base 520 and the second base 524 are spanned by a plurality of fingers 528 that hold the rollers 300 therebetween. As shown in FIG. 55, each of the fingers 528 can have a tang 538 that extends into a notch 540. The cage 510 is useful for a more flexible material that would have too much cantilever effect as described in the cage 296. Figure 28 and ​

[0078] In general, the present application will allow load balancing between the rollers 66, 152, 300, 300 so that they are equally supported on their corresponding races 34, 48; 138, 154; 344, 366 and simultaneously wedge into locking engagement. When using the cages 180, 296, 480, 510, the cages of the present application function to displace the rollers 152, 300, 300 so that they wedge onto the particular inclined surface 168, 376 on the desired side of the corresponding valley 160, 370 to set the wedge direction and thereby select the locking direction and the free spinning direction. The cages 108, 296, 480, 510 not only have a displacement function, but also an additional and separate load balancing function. This load balancing function facilitates simultaneous engagement of all of the rollers 152, 300, 300 so that the forces exerted on all of the rollers 152, 300, 300 are nearly the same.​

[0079] The cage 180 is selectively fixed relative to its second race 154 to provide a shift function. The springs 218 act as displaceable portions that hold their fingers 184. In this way, the springs 218 acting as the movable portions of the fingers 184 allow for controlled and differential movement of the rollers 152 after the cage 180 is selectively locked to facilitate load balancing.

[0080] The cages 296, 480, and 510 facilitate load balancing in two ways. The first way is that the entire cage 296, 480, and 510 moves in a constrained manner relative to the shift post 408 that constrains these cages 296, 480, and 510 relative to their corresponding second races 154, 366. This allows for some movement to transfer load from rollers 152, 300, 300 that were earlier wedged in engagement to rollers 152, 300, 300 that are not yet engaged. The cages 296 and 480 also allow for relative movement of the fingers 314, 494 relative to the cage 296, 480 as a whole. As noted above, the fingers 314, 494 can move in a flexural manner via their cantilevered nature, or in the case of the cage 480, the fingers can have some relative movement due to flexing of the U-shaped member 492. Thus, the cages 296, 480 can facilitate load balancing via movement of the entire cage 296, 480 or relative movement of the fingers 314, 494 within the cage 296, 480.

[0081] The present invention is not limited to the above disclosure, but can be modified within the scope of the following claims.

Claims

1. A locking clutch comprising: an inner race rotatable within and relative to an outer race; one of the races having a cylindrical surface adjacent the other of the races; the other of the races having a plurality of valleys thereon positioned relatively distal from the one race and each connected to a plurality of corresponding ramped surfaces adjacent each of the valleys such that the ramped surfaces straddle the valleys; a plurality of rollers located between the races and adjacent the valleys; a displacement mechanism comprising a cage having a plurality of fingers selectively restrained relative to the other race in first and second positions such that the plurality of fingers are selectively restrained relative to the valleys, the cage being selectively restrained with a switch selectively locked in first and second positions corresponding to the first and second positions of the cage; the switch comprising a displacement post within a displacement slot in the cage, the displacement slot being larger than the displacement post, the displacement slot having sides and the switch positioned in the first or second position positions the displacement post against a starting sidewall of the displacement slot and differential movement of the rollers allows the cage to rotate such that the displacement post does not contact the starting sidewall and the cage can rotate until the displacement post contacts the sidewall opposite the starting sidewall, the fingers displacing the rollers to a first position spaced from the valleys, the inner race rotating relative to the outer race in a wedging direction, rotation in the wedging direction causing the rollers to roll in a direction away from the corresponding valleys and along the ramped surfaces to drive the rollers into contact with both races to position the rollers in a second position; and the inner race rotating relative to the outer race in a free rotation direction opposite the wedging direction to tend to urge the rollers toward the first position; the wedging direction and the free rotation direction being changeable by moving the cage to either of its first or second positions; a portion of the cage is movable from its first or second position in response to differential movement of the rollers to their second position.

2. The locking clutch of claim 1, wherein, the fingers each comprise a displaceable member movable relative to the finger in response to differential movement of the rollers straddling the finger.

3. The locking clutch of claim 2, wherein, the displaceable member is a spring deflectable in response to the differential movement of the rollers straddling the finger.

4. The locking clutch of claim 2, wherein, the displaceable member is a spring having a bridge held within the finger and a cantilever portion extending from the bridge to contact the rollers straddling the finger.

5. The locking clutch of claim 1, wherein, The fingers have proximal ends connected to a base and distal ends cantilevered from the base, the displacement slots are in the base, and the fingers are bendable relative to the base.

6. The locking clutch of claim 1, wherein, The fingers of the cage are connected by bendable members that allow differential motion of the fingers relative to the cage.

7. A locking clutch comprising: an inner race rotatable within and relative to an outer race; one of the races has a cylindrical surface adjacent the other of the races; the other of the races has a plurality of valleys thereon positioned relatively distal from the one race and each connected to a corresponding inclined surface adjacent each of the valleys; a plurality of rollers between the races and adjacent the valleys; a cage having a plurality of fingers constrained relative to the other race so that the fingers are constrained relative to the valleys, the fingers retaining the rollers in a first position relative to the valleys, rotation of the inner race relative to the outer race in a wedging direction causes the rollers to roll in a direction distal from the corresponding valleys and along the inclined surfaces to drive the rollers into contact with both races, positioning the rollers in a second position; and rotation of the inner race relative to the outer race in a free rotation direction opposite the wedging direction tending to urge the rollers toward the first position; a portion of the cage is movable relative to other portions of the cage in response to differential motion of adjacently positioned rollers, the portion of the cage movable relative to other portions of the cage to allow the adjacently positioned rollers to influence motion of each other.

8. The locking clutch of claim 7, the fingers each including a displaceable member movable relative to the finger in response to differential motion of the rollers across the finger.

9. The locking clutch of claim 8, wherein, The displaceable member is a spring deflectable in response to differential motion of the rollers across the finger.

10. The locking clutch of claim 8, wherein, The displaceable member is a spring having a bridge retained within the finger and a cantilevered portion extending from the bridge to contact the rollers across the finger.

11. The locking clutch of claim 7, wherein, The cage is constrained in displacement slots in the cage by displacement posts fixed relative to the other race, the displacement slots being larger than the displacement posts.

12. The locking clutch of claim 11, wherein, The fingers have proximal ends connected to a base and distal ends cantilevered from the base, the displacement slots are in the base, and the fingers are bendable relative to the base.

13. The locking clutch of claim 11, wherein, The fingers of the cage are connected by bendable members that allow differential motion of the fingers relative to the cage.

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