Clockspring for rotatable shaft

Abstract

Described herein is a positioning spring configured to rotatably engage a rotatable shaft. The rotatable shaft is configured to rotate relative to the positioning spring. The positioning spring includes a first compliance lobe positioned at a first radial position. The first compliance lobe is configured to engage one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft in one or more angular positions. The first compliance lobe is configured to flex when engaging the rotatable shaft at a surface location where the first compliance lobe does not contact the detent surface.

Description

[Background technology]

[0001] Rotatable shafts are widely used in modern machinery and manufacturing, such as those used in locking pins, turntables, drive shafts, and the like. In certain applications, precise angular positioning of a rotatable shaft is desirable to properly lock and / or angularly position the rotatable shaft at a predetermined angular position. Accordingly, various methods and devices have been developed for angularly positioning a rotatable shaft and the mechanism attached to the rotatable shaft at a desired angular position. For example, spring-loaded slidable pins that engage with notches in a rotating mechanism attached to the rotatable shaft have been developed for position tracking, angular locking, and stable positioning of the rotatable shaft. However, current devices for locking a rotatable shaft at a desired position require bulky mechanisms with large footprints and multiple components, making them impractical for use in the small, confined spaces where rotatable shafts are frequently used. Therefore, the development of simple, compact positioning springs and mechanisms to facilitate precise angular positioning of rotatable shafts within confined spaces is an ongoing endeavor.

[0002] The features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the features of the invention. [Brief explanation of the drawings]

[0003] [Figure 1a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 1b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 2a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 2b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 3a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 3b]FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 4a] 1 illustrates a front view of a rotatable shaft that can be disposed within a positioning spring according to an example of the present disclosure. [Figure 4b] 1 illustrates a cross-sectional view of a rotatable shaft that can be disposed within a positioning spring according to an example of the present disclosure. [Figure 5] 4b in various angular positions within the positioning spring of FIGS. 1a and 1b; [Figure 6] FIG. 1 illustrates a top view of a single lobe positioning spring according to an example of the present disclosure. [Figure 7a] 1A-1C show cross-sectional views of various rotatable shafts according to examples of the present disclosure. [Figure 7b] 1A-1C show cross-sectional views of various rotatable shafts according to examples of the present disclosure. [Figure 7c] 1A-1C show cross-sectional views of various rotatable shafts according to examples of the present disclosure. [Figure 7d] 1A-1C show cross-sectional views of various rotatable shafts according to examples of the present disclosure. [Figure 8a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 8b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 9a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 9b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 10a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 10b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 11a] 1 illustrates an isometric view of a positioning spring according to an example of the present disclosure. [Figure 11b] FIG. 10 illustrates a top view of a positioning spring according to an example of the present disclosure. [Figure 12a]1A-1C illustrate various exploded views of an exemplary positioning system, each including a rotatable shaft and at least one positioning spring, according to examples of the present disclosure. [Figure 12b] 1A-1C illustrate various exploded views of an exemplary positioning system, each including a rotatable shaft and at least one positioning spring, according to examples of the present disclosure. [Figure 12c] 1A-1C illustrate various exploded views of an exemplary positioning system, each including a rotatable shaft and at least one positioning spring, according to examples of the present disclosure. [Figure 13a] 12b and 12c show cross-sectional views of the rotatable shaft of FIG. [Figure 13b] 12b and 12c show cross-sectional views of a rotatable shaft with the positioning spring of FIG. 12b and FIG. 12c engaged therewith. [Figure 14a] 1 illustrates an isometric view of an exemplary locking pin including a positioning system according to an example of the present disclosure. [Figure 14b] 1 illustrates a cross-sectional side view of an exemplary locking pin including a positioning system according to an example of the present disclosure. [Figure 15a] 1 illustrates an exploded isometric view of an exemplary turntable including a positioning system according to an example of the present disclosure. [Figure 15b] 1 illustrates an exploded side view of an exemplary turntable including a positioning system according to an example of the present disclosure. [Figure 15c] 1 illustrates an isometric view of an exemplary turntable including a positioning system according to an example of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0004] Reference will now be made to exemplary embodiments and specific language will be used herein to describe the same, but it will be understood that no limitation on the scope of the invention is thereby intended.

[0005] As used herein, the term "substantially" refers to the complete or nearly complete extent or degree of an action, feature, characteristic, state, structure, item, or result. For example, a "substantially" enclosed object means that the object is either completely enclosed or nearly completely enclosed. The precise tolerance for deviation from absolute completeness may vary depending on the specific situation. However, generally speaking, approximation to completeness will result in the same overall result as if absolute and total completeness were achieved. The use of "substantially" equally applies when used in a negative sense to refer to the complete or nearly complete absence of an action, feature, characteristic, state, structure, item, or result.

[0006] As used herein, "adjacent" refers to the proximity of two structures or elements. In particular, elements identified as "adjacent" may either abut or be connected. Such elements may not necessarily touch each other, but may be near or in close proximity to each other. The exact degree of proximity may depend on the particular context.

[0007] An initial summary of the inventive concepts is provided below, followed by a more detailed description of specific embodiments. This initial summary is intended to aid the reader in understanding the embodiments more quickly, but is not intended to identify key or essential features of the embodiments, nor is it intended to limit the scope of the claimed subject matter.

[0008] Disclosed herein is a positioning spring configured to rotatably engage a rotatable shaft configured to rotate relative to the positioning spring. The positioning spring has a first axial length measured from a central axis. Corner The rotatable shaft may include a first compliance lobe positioned at a first detent position, the first compliance lobe engaging one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft, and the first compliance lobe engaging one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft, CornerThe first compliance lobe may be configured to bias the rotatable shaft at a predetermined clocked position. The first compliance lobe may be configured to flex (i.e., flex from a state of least or minimum flexion with the compliance lobe engaging a detent surface at a position where the rotatable shaft is at the clocked angular position) when the rotatable shaft rotates away from one or more clocked angular positions. In effect, a force may be applied to the rotatable shaft to cause the rotatable shaft to rotate. This force may be sufficient to overcome the bias applied by the first compliance lobe, thus flexing the first compliance lobe depending on the degree of rotation of the rotatable shaft. The first compliance lobe may flex the greatest amount when the first compliance lobe engages the outer surface of the rotatable shaft, in other words, a surface portion of the rotatable shaft that does not contact a detent surface. While the biasing and flexing functions just described relate to the first compliance lobe, these same functions are applicable to any of the compliance lobes described herein.

[0009] Disclosed herein is a positioning system for a rotatable shaft. The system can include a rotatable shaft having one or more detent surfaces formed thereon. The system can further include a positioning spring configured to rotatably engage the rotatable shaft. The rotatable shaft can be configured to rotate relative to the positioning spring. The positioning spring can include a first CornerThe positioning spring may include a compliance lobe positioned at a clocked angular position. The compliance lobe may be configured to engage one or more detent surfaces on the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at its respective clocked angular position. The first compliance lobe may be configured to flex, such that as the rotatable shaft rotates relative to the positioning spring, it transitions between a maximum flexed state and a minimum or least flexed state, engaging the compliance lobe with at least one detent surface and the outer surface of the rotatable shaft. Indeed, as the rotatable shaft rotates relative to the positioning spring, the compliance lobe may contact the outer surface of the rotatable shaft (which is in the maximum flexed state), and further rotation of the rotatable shaft causes the compliance lobe to contact and engage with the detent surface and slide along the detent surface (where the compliance lobe begins to transition from the maximum flexed state to the minimum or least flexed state). Further rotation of the rotatable shaft causes the rotatable shaft to rotate to the clocked angular position and the compliance lobe to enter the minimum or least flexed state. Further rotation of the rotatable shaft relative to the positioning spring can cause the rotatable shaft to move out of the clocked angular position and the tracking lobe can continue to slide along the detent surface until it again contacts the outer surface of the rotatable shaft or another detent surface. As can be seen, as the rotatable shaft rotates, the positioning spring moves in a different direction (or, in other words, in a different direction) depending on the interactive engagement position of the tracking lobe and the rotatable shaft. angle The positioning spring flexes and relaxes between a maximum flexed state and a minimum or maximum flexed state (depending on the position and the contact surface of the detent surface of the compliant lobe and the outer surface of the rotatable shaft). Note that the compliant lobe may be configured to include a preload when in the minimum or minimum flexed state. The positioning spring may be configured to include a preload when in a different angle The second tracking lobe may have multiple tracking lobes at different positions, which may function in the same or similar manner as the first tracking lobe.

[0010] Disclosed herein is a method for configuring a positioning spring configured to rotatably engage a rotatable shaft configured to rotate relative to the positioning spring. The method includes: Corner The method may include configuring the positioning spring to include a first compliance lobe positioned at a respective clocked angular position. The first compliance lobe may be configured to engage one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the respective clocked angular position. The first compliance lobe may be configured to curve when the rotatable shaft rotates out of the one or more clocked angular positions. The method may further include configuring the positioning spring to include a first compliance lobe positioned at a respective clocked angular position relative to a central axis of the positioning spring. Place The method can further include configuring the positioning spring to have a plurality of compliance lobes, each compliance lobe functioning in the same or similar manner as the first compliance lobe.

[0011] To further illustrate the present technology, examples are now provided with reference to the drawings. Referring to FIGS. 1a and 1b, a positioning spring 100 according to one example of the present disclosure is shown. FIG. 1a shows an isometric view of the positioning spring 100, comprising an elongated bendable member 102 having a desired width that can be bent into the shape of the positioning spring 100. The elongated bendable member 102 can be made from any elongated piece of material suitable for making elastic spring members as taught herein. The elongated bendable member 102 is shown having a long, flat shape. However, this is in no way intended to be limiting, and any shape of elongated material can be used, such as a cylindrical wire, a flat strip of material, etc.

[0012] The positioning spring 100 can be made of any material that imparts compliance characteristics to the positioning spring 100, such as spring steel, plastic, common 3D printing materials, etc. Compliance characteristics in the context of the positioning spring 100 means that the positioning spring 100 is sized, configured, and made of a material such that when a force is applied to the positioning spring 100 to bend it from its original shape, the positioning spring 100 will resiliently return to its original shape (as shown in FIGS. 1a and 1b) upon release of the force from the spring.

[0013] 1b shows a top view of positioning spring 100. Positioning spring 100 can include multiple compliant lobes, including first compliant lobe 104a, second compliant lobe 104b, third compliant lobe 104c, and fourth compliant lobe 104d, each configured to elastically deform (i.e., bend) under a load applied from a rotatable shaft operable with positioning spring 100. Compliance lobes 104a, 104b, 104c, and 104d each rotate at different angles around or relative to a center C of positioning spring 100 (i.e., a central axis C extending into the page in the view shown in FIG. 1b). Corner As shown, the compliant lobes 104a, 104b, 104c, and 104d of the positioning spring 100 are aligned relative to one another. angle The positioning spring 100 is offset 90 degrees in the clockwise direction. Thus, the positioning spring 100 allows the rotatable shaft to be positioned within and engage with the positioning spring 100. Furthermore, the positioning spring 100 allows the rotatable shaft to be biased to four different clockwise positions, each spaced 90 degrees apart. If the rotatable shaft is, for example, angular positionWhen positioning spring 100 includes multiple detent surfaces, such as those positioned at or spaced 45 degrees apart from one another as measured from the central axis of the rotatable shaft, numerous additional clocked angular positions of the rotatable shaft relative to positioning spring 100 are achievable. Thus, the number of angular clocked positions for positioning spring 100 achievable by the rotatable shaft can be determined by the number and configuration of tracking lobes on positioning spring 100, the number and configuration of detent surfaces on the rotatable shaft, or both. Positioning spring 100 can further define a central cavity 112 configured to accommodate at least a portion of the rotatable shaft.

[0014] As discussed herein, a "clocked angular position" refers to a position of the rotatable shaft where the positioning spring is in its least or smallest flexed state (i.e., most relaxed state) and interacts with and engages the rotatable shaft. When the rotatable shaft is in the clocked angular position, the positioning spring resists rotation of the rotatable shaft and biases the rotatable shaft to this position. Note that when the rotatable shaft is in the clocked angular position, the positioning spring may be preloaded when engaging the rotatable shaft. The degree of preload may be equivalent to the least or smallest relaxed state of the positioning spring when engaging the rotatable shaft.

[0015] 1b, the elongated bendable member 102 can be bent into a identified shape such that a first end 106 of the elongated bendable member 102 and a second end 108 of the elongated bendable member 102 are disconnected from one another (i.e., open ended) and a gap 110 is formed therebetween. The gap 110 is added to the positioning spring 100 to facilitate bending, expansion, and / or relaxation or retraction of the positioning spring 100 during rotation of a rotatable shaft positioned within a central cavity 112 of the positioning spring 100. angleThus, positioning spring 100 can be configured such that each compliant lobe 104a, 104b, 104c, and 104d can flex, the entire positioning spring 100 can flex (as gap 110 widens), or a combination thereof.

[0016] 2a and 2b, a positioning spring 200 according to one example of the present disclosure is shown. Figure 2a shows an isometric view of the positioning spring 200, which includes an elongated bendable member 202 bent into the shape of the positioning spring 200. The elongated bendable member 202 can be made from any elongated piece of material suitable for making a resilient spring member as taught herein, as described with respect to the positioning spring 100.

[0017] 2b shows a top view of positioning spring 200. Positioning spring 200 may include multiple compliant lobes, including first compliant lobe 204a, second compliant lobe 204b, and third compliant lobe 204c, each configured to resiliently deform (i.e., bend) under a load applied from a rotatable shaft that may operate with positioning spring 200. Compliance lobes 204a, 204b, and 204c rotate at different angles about center C of positioning spring 200 (e.g., a central axis extending into and out of the page as shown in the drawings). Corner As shown, the compliance lobes 204a, 204b, 204c of the positioning spring 200 are offset 120 degrees from one another. Thus, the positioning spring 200 allows the rotatable shaft to be positioned within and engaged with the positioning spring 200. Furthermore, the positioning spring biases any given detent surface formed on the rotatable shaft at three different clock angle positions, each spaced 120 degrees apart. When the rotatable shaft is, for example, angular positionWhen positioning spring 200 includes multiple detent surfaces, such as those positioned at 45 degrees apart or spaced 45 degrees apart from one another as measured from the central axis of the rotatable shaft, numerous clocked angular positions of the rotatable shaft relative to positioning spring 200 are achievable. Thus, the number of angular clocked positions for positioning spring 200 achievable by the rotatable shaft can be determined by both the configuration of positioning spring 200 and the configuration of the detent surfaces on the rotatable shaft. Positioning spring 200 can further define a central cavity 212 configured to accommodate at least a portion of the rotatable shaft.

[0018] 2b, the elongated bendable member 202 can be bent into a identified shape such that the first end 206 of the elongated bendable member 202 and the second end 208 of the elongated bendable member 202 are disconnected, i.e., leaving a gap 210 formed therebetween open. The gap 210 can expand or contract under a directional force applied to the positioning spring 200 to facilitate bending and / or expansion of the positioning spring 200 during rotation of a rotatable shaft positioned within a central cavity 212 of the positioning spring 200. Thus, the positioning spring 200 can be configured such that each compliant lobe 204a, 204b, and 204c can bend, the entire positioning spring 100 can bend (as the gap 110 widens), or a combination thereof.

[0019] 3a and 3b, an example of a positioning spring 300 according to the present disclosure is shown. Figure 3a shows an isometric view of positioning spring 300 including an elongated bendable member 302 bent into the shape of positioning spring 300. Elongated bendable member 302 can be made from any elongated piece of material suitable for making resilient spring members as taught herein, similar to that described with respect to positioning spring 100 and positioning spring 200.

[0020] 3b shows a top view of positioning spring 300. Positioning spring 300 may include multiple compliant lobes, including first and second compliant lobes 304a and 304b, each configured to resiliently deform (i.e., bend) under a load applied from a rotatable shaft that may operate with positioning spring 300. Compliance lobes 304a and 304b rotate at different angles about a center C of positioning spring 300 (i.e., a central axis extending into the page as shown in the drawings). Corner As shown, the compliance lobes 304a and 304b of the positioning spring 300 are offset 180 degrees from one another. Thus, the positioning spring 300 allows the rotatable shaft to be positioned within and engaged with the positioning spring 300. Furthermore, the positioning spring 300 biases any given detent surface formed on the rotatable shaft at two different clock angle positions, each spaced 180 degrees apart. When the rotatable shaft is, for example, angular position When positioning spring 300 includes multiple detent surfaces, such as those positioned at 45 degrees apart or spaced 45 degrees apart from one another as measured from the central axis of the rotatable shaft, numerous clocked angular positions of the rotatable shaft relative to positioning spring 300 are achievable. Thus, the number of angular clocked positions for positioning spring 300 achievable by the rotatable shaft can be determined by both the configuration of the tracking lobes on positioning spring 300 and the configuration of the detent surfaces on the rotatable shaft. Positioning spring 300 can further define a central cavity 312 configured to accommodate at least a portion of the rotatable shaft.

[0021] 3b, the elongated bendable member 302 can be bent into a shape such that the first end 306 of the elongated bendable member 302 and the second end 308 of the elongated bendable member 302 are disconnected, i.e., leaving a gap 310 formed therebetween open. The gap 310 can expand or contract under a directional force applied to the positioning spring 300 to facilitate bending and / or expansion of the positioning spring 300 during rotation of a rotatable shaft positioned within the central cavity 312 of the positioning spring 300. Thus, the positioning spring 300 can be configured such that each compliant lobe 304a and 304b can bend, the entire positioning spring 100 can bend (as the gap 110 widens), or a combination thereof.

[0022] FIG. 4a shows a front view of a rotatable shaft 402 that can be used with any of the positioning springs discussed herein, the rotatable shaft being formed and configured according to one example of the present disclosure. FIG. 4b shows a cross-sectional view of the rotatable shaft 402 taken along line AA in FIG. 4a. As shown in FIGS. 4a-4b, the rotatable shaft 402 can include a cylindrical portion 404 having a substantially circular cross-section and a cylindrical outer surface 406. Additionally, the rotatable shaft 402 can include a detent portion 408 including one or more detent surfaces. In this example, the rotatable shaft 402 includes four detent surfaces: a first detent surface 410a, a second detent surface 410b, a third detent surface 410c, and a fourth detent surface 410d. The detent surfaces 410a, 410b, 410c, and 410d can be substantially flat surfaces formed within the cylindrical rotatable shaft 402. However, this is not intended to be limiting. The detent surfaces may be formed as pockets, indentations, protrusions, or any other suitable shape for receiving and engaging one or more portions of a positioning spring. Detent portion 408 and detent surfaces 410a, 410b, 410c, and 410d may be configured with a height that is greater than the height of a positioning spring that is intended to be operable with the rotatable shaft.

[0023] The function of the positioning spring will be described herein with reference to FIG. 5 , using the positioning spring 100 of FIGS. 1 a and 1 b and the rotatable shaft 402 of FIGS. 4 a and 4 b as an example. FIG. 5 illustrates the rotatable shaft 402 at a series of angular positions reached during rotation of the rotatable shaft 402, according to one example of the present disclosure. As shown in FIG. 5 , the positioning spring 100 can be positioned to surround and rotatably engage a detent portion 408 of the rotatable shaft 402, allowing the rotatable shaft 402 and the positioning spring 100 to rotate toward one another. The positioning spring 100 can be compliant and can include one or more compliant lobes (see, e.g., compliant lobes 104 a, 104 b, 104 c, and 104 d) configured to engage detent surfaces 410 a, 410 b, 410 c, and 410 d in response to rotation of the rotatable shaft 402 relative to the positioning spring 100. In other words, detent surfaces 410 a , 410 b , 410 c , and 410 d can be configured to receive and engage any one of compliant lobes 104 a , 104 b , 104 c , and 104 d of positioning spring 100 .

[0024] 5 illustrates the rotation of the rotatable shaft 402 within the positioning spring 100, with the rotatable shaft 402 rotating relative to the positioning spring 100. In angular position P1, indicator line A (used to clarify the location of detent surface 410a) shows that the rotatable shaft 402 is oriented relative to the positioning spring 100 with the tracking lobe 104a engaging the detent surface 410a. As shown, the distance or radius from the center of the rotatable shaft 402 to the midpoint of each of the detent surfaces 410a, 410b, 410c, and 410d is less than the distance or radius from the center of the rotatable shaft 402 to any point on the detent surfaces 410a, 410b, 410c, and 410d that is away from the midpoint, which in turn is less than the distance or radius from the center of the rotatable shaft 402 to a point on the outer cylindrical surface 406 of the rotatable shaft 402. At position P1, the compliance of positioning spring 100 causes compliance lobes 104a, 104b, 104c, and 104d to apply a force to detent surfaces 410a, 410b, 410c, and 410d. Due to the engagement of compliance lobes 104a, 104b, 104c, and 104d with detent surfaces 410a, 410b, 410c, and 410d, rotation of rotatable shaft 402 is resisted by positioning spring 100, and rotatable shaft 402 is biased by positioning spring 100 to be held in first clock angle position P1, with indicator line A shown upward in FIG. 5. At this clock angle position (and any clock angle position), compliance lobes 104a, 104b, 104c, and 104d are in a minimal or least flexed state. Additionally, compliant lobes 104a, 104b, 104c, and 104d can be configured (e.g., curved in this example) to provide what is essentially line contact with detent surfaces 410a, 410b, 410c, and 410d, such that rotation of rotatable shaft 802 causes compliant lobes 104a, 104b, 104c, and 104d to slide along detent surfaces 410a, 410b, 410c, and 410d, bending outward to accommodate such rotation of rotatable shaft 402.

[0025] When a torque or rotational force sufficient to induce rotation in the rotatable shaft 402 within the positioning spring 100 and overcome the bias exerted by the tracking lobes 104a, 104b, 104c, and 104d is applied, the tracking lobes 104a, 104b, 104c, and 104d will slide along the detent surfaces 410a, 410b, 410c, and 410d, respectively, and will flex (e.g., outward) to accommodate the increasing distance from the center of the rotatable shaft to the boundary point of the tracking lobes 104a, 104b, 104c, and 104d on the rotatable shaft 402. This distance is greatest when the tracking lobes are not in contact with the detent surfaces but instead are in contact with the outer surface 406 of the rotatable shaft 402 (see, e.g., angular position P2 (not the clock angular position)). Thus, as discussed above, this distance is smallest when the compliance lobes are in contact with the detent surfaces at their midpoints (see, e.g., clock angular position P1). At intermediate position P2, compliance lobes 104a, 104b, 104c, and 104d are not in contact with detent surfaces 410a, 410b, 410c, and 410d, but instead are in contact with outer cylindrical surface 406 of rotatable shaft 402, and are therefore in a state of maximum flexion.

[0026] Clock angle position P3 indicates that rotation of rotatable shaft 402 occurs such that compliant lobes 104a, 104b, 104c, and 104d of positioning spring 100 spring back to their original, unflexed positions (i.e., their least or minimum flexed states) and engage and clamp detent surfaces 410a, 410b, 410c, and 410d. Detent surface 410a receives and engages compliant lobe 104b, detent surface 410b receives and engages compliant lobe 104c, detent surface 410c receives and engages compliant lobe 104d, and detent surface 410d receives and engages compliant lobe 104a. In other words, compliant lobe 104b engages detent surface 410a. This engagement between the compliant lobes and detent surfaces holds rotatable shaft 402 at a new clocked angular position P3 where detent surface 410a engages compliant lobe 104b. The compliance of positioning spring 100 holds compliant lobes 104a, 104b, 104c, and 104d against their respective detent surfaces, resisting rotation of rotatable shaft 402 and biasing rotatable shaft 402 toward clocked angular position P3.

[0027] The illustrated positioning spring 100 and rotatable shaft 402 allow the rotatable shaft 402 to be biased at four different clock angle positions, each 90 degrees apart. However, this is not intended to be limiting. As taught herein, the positioning spring can have any number of compliant lobes to engage any number of detent surfaces on the rotatable shaft. For example, FIG. 6 illustrates a top view of a positioning spring 600 according to one example of the present disclosure. The positioning spring 600 includes a single compliant lobe 602 located on a lobe portion 604 of the positioning spring 600. The remaining portion 606 of the positioning spring 600 can be circular in cross-sectional shape. However, this is not intended to be limiting.

[0028] The positioning springs described herein can be used with a number of different rotatable shafts of different configurations, such as those having different numbers of detent surfaces. The number of detent surfaces can be determined based on the desired number of clocked angular positions to bias the rotatable shaft. As discussed, the number and location of detent surfaces on a given rotatable shaft determine the number and spacing of the clocked angular positions of the rotatable shaft. In one aspect, the number of detent surfaces on a given rotatable shaft can be the sole determinant of the number of available clocked angular positions of a given rotatable shaft (e.g., a positioning spring with only one detent surface operable with a rotatable shaft having multiple detent surfaces). In another aspect, both the configuration of the rotatable shaft and the configuration of the positioning spring operable with the given rotatable shaft can determine the number of available clocked angular positions of a given rotatable shaft (e.g., a rotatable shaft with multiple detent surfaces operable with a positioning spring with multiple detent surfaces). It should be noted that this concept of configuring the positioning spring, or configuring the rotatable shaft, or configuring both, to achieve a desired number of clocked angular positions of the rotatable shaft relative to the positioning spring will be clear to one skilled in the art.

[0029] Referring to Figures 7a, 7b, 7c, and 7d, various rotatable shafts according to different examples of the present disclosure are shown. Figure 7a shows a rotatable shaft 700A having three detent surfaces 702 arranged in a substantially triangular pattern 120 degrees apart. Figure 7b shows a rotatable shaft 700B having two detent surfaces 704 arranged 180 degrees apart. Figure 7c shows a rotatable shaft 700C having three detent surfaces 706, where one or more detent surfaces 706 are unevenly spaced from one or more other detent surfaces 706. Figure 7d shows a rotatable shaft 700D having five detent surfaces 702 arranged in a substantially pentagonal pattern. Although not explicitly shown, many other configurations are possible. The number of detent surfaces on a rotatable shaft is not intended to be limiting in any way. The rotatable shaft may have a uniform detent surface 706. angle Position, uneven angle The camshaft may be designed to have any number of detent surfaces spaced at different positions, or any combination thereof.

[0030] It will be appreciated that a particular positioning spring can be configured to engage multiple different rotatable shafts, and a particular rotatable shaft can be used with multiple different positioning springs, depending on the angular spacing between the compliance lobes on the positioning spring and the detent surfaces on the rotatable shaft. For example, positioning spring 200 of FIG. 2b and positioning spring 600 of FIG. 6 can both be used with rotatable shaft 700A, with either configuration resulting in the rotatable shaft having three clocked angular positions of rotatable shaft 700A approximately 120 degrees apart. Furthermore, positioning spring 300 can be used with both rotatable shaft 402 of FIG. 4b (resulting in clocked angular positions of rotatable shaft 402 being 90 degrees apart) and rotatable shaft 700B of FIG. 7b (resulting in clocked angular positions of rotatable shaft 700B being 180 degrees apart). Positioning spring 600 can be used with any of the rotatable shafts described herein. The single compliant lobe 602 is configured to engage each detent surface of the rotating shaft in a sequence such that as the rotating shaft rotates relative to the positioning spring 600, the clock angle position of the rotating shaft that engages the positioning spring 600 coincides with the position of the detent surface on the rotating shaft.

[0031] Additionally, those skilled in the art will appreciate that the positioning springs and rotatable shafts can be designed relative to one another to bias the rotatable shaft to any desired configuration of clock angular positions. Indeed, a given positioning spring can have a number of compliant lobes equal to the number of detent surfaces on the corresponding rotatable shaft, or a given positioning spring can have a number of compliant lobes different from the number of detent surfaces on the corresponding rotatable shaft. Furthermore, the compliant lobes and detent surfaces can be positioned at any angle around the positioning spring and rotatable shaft, respectively. degree The detent surfaces of the rotatable shaft may be equal or unequal. sharp corners degrees to each other angleThe positioning spring compliance lobes can be offset in either direction, equal or unequal. sharp corners degrees to each other angle It can be offset in the direction.

[0032] Modifications can be made to any of the examples described herein. For example, positioning springs 100, 200, and 300 are shown as discontinuous, with unconnected ends defining gaps 110, 210, and 310 formed in at least a portion of the positioning spring. Positioning springs 100, 200, and 300 can be bent into the desired shape from a single, elongated piece of material. However, continuous examples are also possible. For example, a continuous or closed positioning spring 800 is shown in FIGS. 8a and 8b according to one example of the present disclosure. Any of the positioning springs described herein can be made either continuous (i.e., no open ends, no gaps) or discontinuous (i.e., first and second ends are unconnected, defining a gap therebetween). Continuous positioning spring examples can be machined from a single piece of material or can be made by bending one or more elongated pieces of material and joining the ends to form the continuous positioning spring by a manufacturing process such as welding or by adhesive. Additionally, as shown in positioning spring 900 of FIGS. 9a and 9b, relief cuts or gaps 902 can be formed in the compliant lobes to facilitate bending of the positioning spring under lower loads than a similar positioning spring without such relief cuts or gaps 902.

[0033] Additional examples of positioning springs configured in accordance with embodiments of the present disclosure are described with reference to FIGS. 10a-11b. While the previously described positioning springs are constructed of a single-piece design or configuration, FIGS. 10a and 10b illustrate a multi-piece positioning spring assembly. The positioning spring 1000 shown in FIGS. 10a and 10b can include a tubular outer housing or collar 1002 and one or more flexures 1004 carried by an inner surface 1006 of the tubular outer housing 1002. Each of the one or more flexures 1004 provides and defines a compliance lobe similar to that described in the previous examples. The flexures 1004 can be carried within the tubular outer housing 1002, which applies a load to bend the flexures 1004. The flexures 1004 can then be inserted within the tubular outer housing 1002 and, once in position within the tubular outer housing 1002, partially expanded to a bent position that maintains the flexures at the desired location within the tubular outer housing 1002. The flexure can be maintained in a desired position within the tubular outer housing 1002 in many different ways. In one example, the flexure 1004 can fit within a slot formed in the inner surface of the tubular outer housing 1002. In another example, the flexure 1004 can be glued, welded, or otherwise secured within the tubular outer housing 1002. The method of securing the flexure within the tubular outer housing is not intended to be limiting in any way.

[0034] 11a-11b illustrate a positioning spring 1100 according to one example of the present disclosure. The positioning spring 1110 can include a tubular outer housing or collar 1102 having an inner surface 1106. A flexure 1104 can be retained within the tubular outer housing 1102.

[0035] In the positioning spring 1000 of FIGS. 10a and 10b, the bends 1004 are oriented perpendicular to the longitudinal axis of the tubular outer housing 1002, from a first end contacting the tubular outer housing 1002 to a second end contacting the tubular outer housing 1002. In the positioning spring 1100 of FIGS. 11a and 11b, the bends 1104 are oriented parallel to the longitudinal axis of the tubular outer housing 1102, from a first end contacting the tubular outer housing 1102 to a second end contacting the tubular outer housing 1102. Positioning springs similar to 1000 and 1100 can have any number of compliant lobes / bends and can be manufactured in a similar configuration to any other positioning spring described herein. Additionally, the bends 1004 and 1104 interface with detent surfaces on the rotatable shaft in a similar or identical manner as described herein with respect to other examples.

[0036] The positioning system can include any of the positioning springs described herein (see, e.g., positioning springs 100, 200, 300, 600, 800, 900, 1000, 1100, 1202, 1204, 1212, 1214, 1222, 1224) and any of the rotatable shafts described herein (see, e.g., rotatable shafts 402, 700A, 700B, 700C, 700D, 1206, 1216, 1226), the rotatable shaft having one or more detent surfaces for receiving the tracking lobes of the interconnected positioning springs. Additionally, the positioning systems described herein can include multiple positioning springs operable with a rotatable shaft having multiple detent portions, each detent portion including one or more detent surfaces.

[0037] 12a-12c illustrate positioning systems 1200, 1210, and 1220, respectively, according to examples of the present disclosure. Positioning systems 1200, 1210, and 1220 may include multiple positioning springs arranged axially spaced from one another (e.g., adjacent to one another or stacked) on a single rotatable shaft. FIG. 12a illustrates positioning system 1200, which may include first and second positioning springs 1202 and 1204 configured to rotatably engage a rotatable shaft 1206, each of which may be configured as positioning spring 100 of FIGS. 1a and 1b. The rotatable shaft 1206 can include a first detent portion 1207 configured to receive the first positioning spring 1202 and a second detent portion 1208 configured to receive the second positioning spring 1204, axially spaced from the first detent portion 1207 (e.g., adjacent to one another). Each of the first detent portion 1207 and the second detent portion 1208 can include one or more detent surfaces 1209 configured to receive and engage compliance lobes of the corresponding positioning springs 1202 and 1204 (or any others taught herein). The detent surfaces of the first detent portion 1207 can be spaced apart from the detent surfaces of the second detent portion 1208 relative to the central axis of the rotatable shaft 1206. ,corner are offset in degrees (i.e., angle In the positioning system 1200, the compliance lobe of the second positioning spring 1204 is aligned (with respect to the common central axis of the positioning springs 1202 and 1204) from the compliance lobe of the first positioning spring 1202. corner The first positioning spring 1202 and the second positioning spring 1204 are offset axially from one another on the rotatable shaft 1206, and the positioning springs 1201 and 1204 are not aligned with each other relative to a common central axis of the positioning springs 1202 and 1204. Te-kakuoffset in degrees or not aligned with each other.

[0038] 12b shows a positioning system 1210 including a first positioning spring 1212 and a second positioning spring 1214 configured to engage a rotatable shaft 1216, each configured as the positioning spring 100 of FIGS. 1a and 1b. The rotatable shaft 1216 can include an elongated detent portion 1218 configured to receive the first positioning spring 1212 and the second positioning spring 1214 (i.e., the detent portion 1218 has at least the same height as the first positioning spring 1214 and the second positioning spring 1216 stacked on top of each other). The detent portion 1218 can include a plurality of detent surfaces 1219 configured to receive compliance lobes of the corresponding positioning springs 1212 and 1214. In the positioning system 1210, the compliance lobes of the second positioning spring 1214 and the first positioning spring 1212 are substantially aligned with each other when the first positioning spring 1202 and the second positioning spring 1204 are stacked on the rotatable shaft 1206, i.e., the positioning springs 1212 and 1214 and their compliance lobes are substantially aligned with each other.

[0039] By using multiple positioning springs, the positioning system can be configured with different spring forces acting on the rotatable shaft. By using two identical springs, it is possible to generate twice the spring force on the rotatable shaft. Thus, the rotatable shaft can be rotated in a clockwise direction. cornerThe positioning springs may be more firmly biased to a clockwise position, requiring more force to rotate within the positioning springs. Additionally, the positioning springs may be made of different materials with different spring constants, degrees of compliance, and may have different dimensions and thicknesses. These differences can be exploited to create various degrees of desired spring force on the rotatable shaft. While positioning systems 1200, 1210, and 1220 use multiple identical positioning springs, it will be apparent to those skilled in the art that the positioning springs may be different from one another and may have the same or different numbers of compliance lobes. Axially spaced detent portions (each having one or more detent faces) on the rotatable shaft may be adjacent to one another (i.e., stacked), and they may also position various clockwise angular positions of the rotatable shaft at desired angles and spacings. angle The detent portions may also be formed with the same or different numbers of detent surfaces to position them in different directions. Furthermore, multiple detent portions (each having one or more detent surfaces) on a single rotatable shaft need not be adjacent to one another. Indeed, multiple detent portions on a rotatable shaft may be positioned at spaced axial positions along the rotatable shaft, each configured to receive and engage a positioning spring.

[0040] It should be noted that the positioning system may include multiple detent portions on the rotatable shaft with a single positioning spring operable with either or both of the multiple detent portions. In this example, a first detent portion may include a different number and / or location of detent surfaces than a second detent portion, with the single positioning spring operable with either the first or second detent portion to achieve different clocked angular positions of the rotatable shaft.

[0041] 12c illustrates a positioning system 1220 that may include a first positioning spring 1222 and a second positioning spring 1224, and a rotatable shaft 1226 that includes a detent portion 1228, where each of the first positioning spring 1222 and the second positioning spring 1224 is configured as the positioning spring 100 of FIGS. 1a and 1b. As illustrated, the positioning springs 1222 and 1224 are configured such that each of the compliance lobes of the positioning spring 1222 is aligned with the two adjacent compliance lobes of the positioning spring 1224. angle Between positions angle The positions do not need to be aligned with each other to be positioned.

[0042] FIG. 13a shows a cross-sectional view of the rotatable shaft 1226 through the detent portion 1228 of FIG. 12c. As shown, the rotatable shaft 1226 may include eight detent surfaces 1230. FIG. 13b shows the first positioning spring 1222 and the second positioning spring 1224 engaged with the detent surfaces 1230 of the rotatable shaft 1226. As shown, the compliance lobes 1222a, 1222b, 1222c, and 1222d of the first positioning spring 1222 and the compliance lobes 1224a, 1224b, 1224c, and 1224d of the second positioning spring 1224 can engage all of the detent surfaces 1230 of the multiple detent surfaces of the rotatable shaft 1226 in response to rotation of the rotatable shaft 1226 relative to the first positioning spring 1222 and the second positioning spring 1224. With this configuration, the rotatable shaft 1226 has eight clocked angular positions that are equally spaced apart from one another. As shown, each of the eight clocked angular position configurations of the rotatable shaft 1226 is achieved by using multiple positioning springs, each with four compliant lobes.

[0043] The positioning system described herein can be used in a number of different applications. For example, FIGS. 14a and 14b show an exemplary retaining pin 1400 incorporating a positioning system according to one example of the present disclosure. The retaining pin 1400 can include a handle 1402 and an outer housing 1404. The handle 1402 can rotate a rotatable shaft 1406 disposed within the housing 1404. The rotatable shaft 1406 can be a rotatable shaft according to one example of the present disclosure. The rotatable shaft 1406 can engage a positioning spring 1408 described herein to provide a clocked angular position for the rotatable shaft 1406 and the locking pin 1400.

[0044] In another example, a turntable can utilize a positioning system as described herein. FIGS. 15a-15c illustrate a turntable 1500 that can include a table 1502 including a rotatable shaft 1504 engaged with a positioning spring 1506. The rotatable shaft 1504 and positioning spring 1506 can be any configuration of rotatable shaft and / or positioning spring as described herein or recognized by one of ordinary skill in the art within the spirit of the present disclosure. The rotatable shaft 1504 can be rotatably engaged with a roller bearing 1508 and a base 1510 to form a complete turntable 1500 having multiple clocked angular positions of the rotatable shaft 1504 and table 1502 defined by the interface between the rotatable shaft 1504 and the positioning spring 1506, as taught herein. Of course, these exemplary applications are not intended to be limiting in any way. Indeed, one of ordinary skill in the art will recognize a variety of different applications in which one or more of the positioning systems described herein can be implemented.

[0045] A method of configuring a positioning spring configured to rotatably engage a rotatable shaft operable to rotate relative to the positioning spring includes: angleThe method may include configuring the positioning spring to include one or more compliance lobes positioned at the one or more clocked angular positions. The one or more compliance lobes may be configured to engage one or more detent surfaces on the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at one or more clocked angular positions. The one or more compliance lobes may be configured to curve upon rotation of the rotatable shaft out of one or more clocked angular positions. Configuring the positioning spring in this manner may include configuring any of the positioning springs described herein (e.g., positioning springs 100, 200, 300, 600, 800, 900, 1000, 1100, 1202, 1204, 1212, 1214, 1222, 1224), or any other configuration apparent to one of ordinary skill in the art with an understanding of the scope of this disclosure. Additionally, the rotatable shaft operable with the positioning spring may be configured as any of the rotatable shafts described herein (see, e.g., rotatable shafts 402, 700A, 700B, 700C, 700D, 1206, 1216, 1226) or any other configuration apparent to those skilled in the art with an understanding of the scope of this disclosure.

[0046] Reference has been made to the examples illustrated in the drawings, and specific language has been used herein to describe these. It should be understood, however, that no limitation of the scope of the technology is intended thereby. Modifications and further variations of the features illustrated herein, as well as additional uses of the examples illustrated herein, should be considered within the scope of the description.

[0047] Although the present disclosure may not explicitly disclose that some embodiments or features described herein may be combined with other embodiments or features described herein, the present disclosure should be read to describe any such combinations feasible by one of ordinary skill in the art. The use of "or" in this disclosure should be understood to mean a non-exclusive or, i.e., "and / or," unless otherwise stated herein.

[0048] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the foregoing description, numerous specific details, such as example configurations, are provided to provide a thorough understanding of examples of the described technology. However, it will be understood that the technology may be practiced without one or more of the specific details, or with other methods, components, devices, etc. In other instances, well-known structures or operations have not been shown or described in detail to avoid obscuring aspects of the technology.

[0049] Although the subject matter has been described in language specific to structural features and / or operations, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the particular features and operations described. Rather, the specific features and operations described above are disclosed as example forms of implementing the claims. Numerous modifications and alternative arrangements may be made without departing from the spirit and scope of the described technology.

Claims

1. A rotatable shaft having a detent portion including one or more detent surfaces; a positioning spring configured to rotatably engage the rotatable shaft configured to rotate relative to the positioning spring, a first tracking lobe positioned at a first angular position; the first compliance lobe is configured to engage the one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at one or more clocked angular positions; the first compliance lobe is configured to flex when the rotatable shaft rotates away from the one or more clocked angular positions. the positioning spring; the one or more detent surfaces of the rotatable shaft are located within an outer surface of the rotatable shaft in an axial view of the rotatable shaft, and the first compliance lobe engages the one or more detent surfaces within the outer surface of the rotatable shaft in an axial view of the rotatable shaft at the one or more clock angular positions. Positioning system for rotatable shafts.

2. a second tracking lobe angularly offset from the first tracking lobe at a second angular position; the second compliance lobe is configured to engage the one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the one or more clocked angular positions; The positioning system of claim 1 , wherein the second compliance lobe is configured to flex when the rotatable shaft rotates away from the one or more clocked angular positions.

3. a third tracking lobe angularly offset from the first and second tracking lobes at a third angular position; the third compliance lobe is configured to engage the one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the one or more clocked angular positions; The positioning system of claim 2 , wherein the third tracking lobe is configured to deflect rotations of the rotatable shaft away from the one or more clocked angular positions.

4. The positioning system of claim 3 , wherein the first, second, and third tracking lobes are angularly offset from one another by equal angles.

5. 4. The positioning system of claim 3, wherein one or more of the first, second, or third compliant lobes are angularly offset from one another at unequal angular positions around the elongated bendable member.

6. a fourth tracking lobe angularly offset from the first, second, and third tracking lobes at a fourth angular position; the fourth compliance lobe is configured to engage the one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the one or more clocked angular positions; The positioning system of claim 3 , wherein the fourth compliance lobe is configured to flex when the rotatable shaft rotates away from the one or more clocked angular positions.

7. The positioning system of claim 1 , further comprising an elongated bendable member shaped to form the first compliance lobe.

8. The positioning system of claim 7 , wherein the elongated bendable member is continuous.

9. The positioning system of claim 7 , wherein the elongated bendable member is discontinuous and includes first and second ends that are disconnected from one another and define a gap therebetween.

10. a tubular outer housing; The positioning system of claim 1 , further comprising a first bend carried by an inner surface of the tubular outer housing, the first bend defining the first compliance lobe.

11. a second bend carried by the inner surface of the tubular outer housing; 11. The positioning system of claim 10, wherein the second flexure defines a second compliance lobe angularly offset from the first compliance lobe at a second angular position, the second compliance lobe configured to engage one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the one or more clocked angular positions, and wherein the second compliance lobe is configured to flex upon engagement with the rotatable shaft at a surface location out of contact with the detent surfaces.

12. The positioning system of claim 1 , wherein the first compliance lobe is preloaded when it engages the one or more detent surfaces at the one or more clock angular positions.

13. the rotatable shaft includes a second detent portion including one or more detent surfaces, the positioning spring includes a first positioning spring, and the positioning system further includes a second positioning spring including one or more compliance lobes; the one or more compliance lobes of the second positioning spring are configured to engage the one or more detent surfaces of the second detent portion of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at the one or more clocked angular positions; 2. The positioning system of claim 1, wherein the one or more compliant lobes of the second positioning spring are configured to flex when the rotatable shaft rotates out of the one or more clocked angular positions.

14. The positioning system of claim 13 , wherein the first positioning spring and the second positioning spring have the same number of compliant lobes.

15. The positioning system of claim 13 , wherein the first positioning spring and the second positioning spring have different numbers of compliant lobes.

16. 14. The positioning system of claim 13, wherein the first positioning spring and the second positioning spring are axially offset from one another on the rotatable shaft, and the one or more compliance lobes of the first positioning spring are not angularly aligned with the one or more compliance lobes of the second positioning spring.

17. 14. The positioning system of claim 13, wherein the first positioning spring and the second positioning spring are axially offset from one another on the rotatable shaft, and the one or more compliance lobes of the first positioning spring are angularly aligned with the one or more compliance lobes of the second positioning spring.

18. 2. The positioning system of claim 1, wherein the one or more detent surfaces of the detent portion of the rotatable shaft are disposed at a first axial position, the rotatable shaft includes a second detent portion including one or more detent surfaces disposed at a second axial position, and the positioning spring is operable with at least one of the first or second detent portions.

19. 20. The positioning system of claim 18, wherein the one or more detent surfaces of the detent portion at the first axial position are angularly offset from the one or more detent surfaces of the second detent portion at the second axial position.

20. A method of constructing a positioning system for a rotatable shaft having a rotatable shaft having a detent portion including one or more detent surfaces, and a positioning spring configured to rotatably engage the rotatable shaft operable to rotate relative to the positioning spring, comprising: configuring the positioning spring to include one or more compliant lobes positioned at respective angular positions; the one or more compliance lobes are configured to engage one or more detent surfaces of the rotatable shaft to resist rotation of the rotatable shaft and bias the rotatable shaft at one or more clocked angular positions; the one or more compliant lobes are configured to flex when the rotatable shaft rotates away from the one or more clocked angular positions; the one or more detent surfaces of the rotatable shaft are located within an outer surface of the rotatable shaft in an axial view of the rotatable shaft, and the one or more tracking lobes engage the one or more detent surfaces within the outer surface of the rotatable shaft in an axial view of the rotatable shaft at the one or more clock angle positions.

Images