Bridge with pivoting stopper for Anti-bridge dislodgement function for valvetrain application
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-08-13
Smart Images
Figure IB2026051110_13082026_PF_FP_ABST
Abstract
Description
MCC Docket No. 11694-120WO1 BRIDGE WITH PIVOTING STOPPER FOR ANTI-BRIDGE DISLODGEMENT FUNCTION FOR VALVETRAIN APPLICATIONCROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of Indian Patent Application No.202511009794, filed February 6, 2025, the entire contents of which are incorporated herein by reference.BACKGROUND
[0002] In valvetrain systems, a failure mode known as critical shift can occur when a rocker arm and the bridge attached thereto suddenly move towards a cam, which leads to a sudden increase in the distance between the bridge and an engaged valve stem. This sudden movement increases the risk that the valve stem will completely dislodge from the bridge (i.e., bridge dislodgement). The failure can cause complete valvetrain failure or engine stop since the system can no longer translate the cam lift to the valves.
[0003] Therefore, a need exists for an anti-bridge dislodgement device that can secure the bridge to the valve(s) in a valvetrain system.SUMMARY
[0004] According to one implementation a valvetrain assembly including a bridge and a pivoting stopper is disclosed. The bridge includes a first end coupled to a first valve stem and a second end coupled to a second valve stem. The pivoting stopper includes a retainer pin extending through a portion of the bridge. The pivoting stopper is rotatable about the retainer pin. The pivoting stopper further includes a stopper pin extending across a valve stem end of the pivoting stopper. The stopper pin is configured to engage with a groove on the first valve stem. The pivoting stopper further includes a mechanical stop extending across a bridge end of the pivoting stopper, the bridge end being opposite from the valve stem end. The pivoting stopper further includes a spring support pin extending across the pivoting stopper and disposed between the retainer pin and the stopper pin. The pivoting stopper further includes a torsional spring disposed about the retainer pin. The torsional spring includes a bridge arm configured to engage a portion of the bridge. The torsional spring further includes a pin arm configured to engage the spring support pin. A force from the torsional spring is configured to maintain contact between the stopper pin and the groove on the first valve stem.MCC Docket No. 11694-120WO1
[0005] In some implementations, the torsional spring exerts a biasing force on the spring support pin to bias the valve stem end of the pivoting stopper and the stopper pin thereon towards the groove of the first valve stem.
[0006] In some implementations, the valve stem end of the pivoting stopper and the stopper pin thereon are rotatable in a second direction away from the first valve stem during assembly of the valvetrain assembly.
[0007] In some implementations, the mechanical stop prevents rotation of the pivoting stopper in a first direction past an engaged position, wherein the pivoting stopper is in the engaged position when the stopper pin engages the groove of the first valve stem.
[0008] In some implementations, contact between the pivoting stopper and the first valve stem, via the stopper pin, prevents disengagement of the first valve stem from the bridge.
[0009] In some implementations, the pivoting stopper includes a first arm and a second arm extending parallel to the first arm, wherein the first arm is integrally formed with the second arm and the mechanical stop to form a continuous rigid body.
[0010] In some implementations, the stopper pin contacts the first valve stem on an inner side of the first valve stem, the inner side of the first valve stem faces toward the second valve stem.
[0011] In some implementations, the retainer pin extends through a central portion of the bridge.
[0012] In some implementations, the mechanical stop is disposed closer to the second valve stem than the first valve stem.
[0013] In some implementations, the bridge further includes a rocker arm coupler on an upper surface of the bridge that extends between the first and second ends, wherein the mechanical stop abuts a portion of the upper surface of the bridge.
[0014] According to another implementation, a valvetrain assembly is disclosed including a bridge and a pivoting stopper. The bridge includes a first end coupled to a first valve stem and a second end coupled to a second valve stem. The pivoting stopper includes a first arm coupled to and extending parallel to a second arm, The first and second arms are disposed on opposite sides of the bridge. The pivoting stopper further includes a retainer pin extending through a portion ofMCC Docket No. 11694-120WO1 the bridge, the retainer pin extending between the first arm and the second arm of the pivoting stopper. The pivoting stopper is rotatable about the retainer pin. The pivoting stopper further includes a stopper pin extending between the first arm and the second arm across a valve stem end of the pivoting stopper. The stopper pin is configured to engage with a groove on the first valve stem. The pivoting stopper further includes a removable pin extending between the first arm and the second arm across a bridge end of the pivoting stopper, the bridge end being opposite from the valve stem end. The removable pin provides a mechanical stop, wherein the pivoting stopper is configured to maintain contact between the stopper pin and the groove on the first valve stem.
[0015] In some implementations, contact between the pivoting stopper and the first valve stem, via the stopper pin, prevents disengagement of the first valve stem from the bridge.
[0016] In some implementations, the valve stem end of the pivoting stopper, and the stopper pin thereon, are rotatable in a second direction away from the first valve stem during assembly of the valvetrain assembly.
[0017] In some implementations, during assembly, the removable pin is not coupled between the first and second arms until the pivoting stopper is rotated such that the stopper pin engages with the groove of the first valve stem.
[0018] In some implementations, the removable pin prevents rotation of the pivoting stopper in a first direction past an engaged position, wherein the pivoting stopper is in the engaged position when the stopper pin engages the groove of the first valve stem.
[0019] In some implementations, the stopper pin contacts the first valve stem on an outer side of the first valve stem, the outer side of the first valve stem faces away from the second valve stem.
[0020] In some implementations, the portion of the bridge through which the retainer pin extends is disposed adjacent to the first valve stem.
[0021] In some implementations, the bridge further includes a rocker arm coupler on an upper surface of the bridge that extends between the first and second ends of the bridge, wherein the retainer pin abuts a portion of the upper surface of the bridge.
[0022] According to another implementation, a pivoting stopper configured to prevent disengagement of a valve stem from a bridge is disclosed. The pivoting stopper includes a firstMCC Docket No. 11694-120WO1 arm and a second arm coupled to and extending parallel to each other, the first and second arms each having a bridge end and a valve stem end opposite from the bridge end. The pivoting stopper further includes a retainer pin coupled between the first arm and the second arm and configured to extend through a portion of the bridge. The pivoting stopper is rotatable about the retainer pin. The pivoting stopper further includes a stopper pin extending between the valve stem end of the first arm and the valve stem end of the second arm, the stopper pin configured to engage with a groove on the valve stem to prevent disengagement of the pivoting stopper from the bridge during operation. The pivoting stopper further includes a mechanical stop extending between the bridge end of the first arm and the bridge end of the second arm, the mechanical stop configured to prevent rotation of the pivoting stopper beyond an engaged position. The engaged position is when the stopper pin engages the groove of the valve stem.
[0023] In some implementations, the valve stem end of the first and second arms and the stopper pin therebetween are rotatable in a direction away from the valve stem during installation of the pivoting stopper.
[0024] This summary is illustrative only and is not intended to be in any way limiting. Other aspects, features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements.BRIEF DESCRIPTION OF DRAWINGS
[0025] The systems, methods, and devices are explained in even greater detail in the following drawings. The drawings are merely exemplary and certain features may be used singularly or in combination with other features. The drawings are not necessarily drawn to scale.
[0026] FIG. 1 is a side view of a valvetrain assembly including a pivoting stopper in an engaged position, according to one implementation.
[0027] FIG. 2 is a side view of the valvetrain assembly of FIG. 1 with the pivoting stopper in a disengaged position, according to one implementation.
[0028] FIG. 3 is an isometric view of the valvetrain assembly of FIG. 1, according to one implementation.MCC Docket No. 11694-120WO1
[0029] FIG. 4 is a top view of the valvetrain assembly of FIG. 1, according to one implementation.
[0030] FIG. 5 is a bottom view of the valvetrain assembly of FIG. 1, according to one implementation.
[0031] FIG. 6 is a first side view of the valvetrain assembly of FIG. 1, according to one implementation.
[0032] FIG. 7 is a second side view of the valvetrain assembly of FIG. 1, according to one implementation.
[0033] FIG. 8 is a side view of a valvetrain assembly including a pivoting stopper in an engaged position, according to one implementation.
[0034] FIG. 9 is a side view of the valvetrain assembly of FIG. 8 with the pivoting stopper in a disengaged position, according to one implementation.
[0035] FIG. 10 is an isometric view of the valvetrain assembly of FIG. 8, according to one implementation.
[0036] FIG. 11 is a top view of the valvetrain assembly of FIG. 8, according to one implementation.
[0037] FIG. 12 is a bottom view of the valvetrain assembly of FIG. 8, according to one implementation.
[0038] FIG. 13 is a first side view of the valvetrain assembly of FIG. 8, according to one implementation.
[0039] FIG. 14 is a second side view of the valvetrain assembly of FIG. 8, according to one implementation.DETAILED DESCRIPTION
[0040] Following below are more detailed descriptions of concepts related to, and implementations of, methods, apparatuses, and systems for a pivoting stopper couplable to a valveMCC Docket No. 11694-120WO1 bridge. The figures illustrate exemplary implementations in detail and the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. The terminology used herein is for the purpose of description only and should not be regarded as limiting.
[0041] Disclosed herein are systems, methods, and devices for anti-bridge dislodgment in a valvetrain application, including a pivoting stopper couplable to a bridge. The disclosed pivoting stopper is configured to maintain a consistent connection between the bridge and the valve stem(s). The disclosed pivoting stopper is compatible with both traditional valvetrain systems and variable valve actuation systems. Thus, the disclosed pivoting stopper avoids bridge dislodgement, whether the valvetrain is in stabilized motion or is in a switching operation.
[0042] In a variable valvetrain application system, due to a failure mode known as critical shift, an event can occur where the rocker arm along with the bridge suddenly moves towards the cam. The sudden movement of the bridge increases the distance between the bridge and the valve, increasing the risk of the valve stem disconnecting from the bridge. In some cases, the valve stem can completely separate and disengage from the bridge pocket. This phenomenon is called bridge dislodgment, and it causes valvetrain failure or, in most severe cases, engine stop, because the system is not able to translate cam lift to the valves. Many existing anti -bridge dislodgement solutions include external fixtures that are assembled on a portion of the engine to block bridge movement. By contrast, the disclosed pivoting stopper is embedded in the bridge design and is directly assembled with the bridge, eliminating the need for additional external parts and complicated assembly.
[0043] The disclosed system includes a bridge on which is assembled a pivoting stopper. The pivoting stopper is pivotable about a retainer pin mounted on the bridge. The rotation of the pivoting stopper facilitates assembly and / or disassembly from the bridge and valve stems. The anti-bridge dislodgment function is consistently produced through a special seat or groove on the valve stem. For example, the seat or groove may be formed directly on the valve or created by an additional component assembled on the valve. In some implementations, the anti-bridge dislodgement function is carried out by the contact between the valve stem (e.g., a groove or seat thereof) and a stopper pin of the pivoting stopper with respect to the bridge. The stopper pin is attached to a valve end of the pivoting stopper. The stopper pin can be integrated into the pivoting stopper or separately attached. The pivoting stopper is designed to have a hard stop feature (e.g.,MCC Docket No. 11694-120WO1 a mechanical stop) on an end opposite the stopper pin. The hard stop feature abuts and / or engages with the bridge, which allows rotation of the pivoting stopper about the retainer pin only in one direction and blocks rotation in the other direction. In some implementations, constant contact between the valve stem and the stopper pin is provided by, or enhanced by, the mechanical stop.
[0044] In some implementations, constant contact between the valve stem and the stopper pin is provided by a spring component positioned on the bridge. In some implementations, a spring (e.g., a torsion or linear spring) is positioned within the bridge (e.g., under and or partially within a cavity of the bridge). One end of the spring is blocked on the bridge itself, and the other end of the spring is mounted on a spring support pin. The spring support pin is attached to the pivoting stopper between the stopper pin and the retainer pin. The force from the spring maintains a positive contact between the stopper pin and the special seat or groove on the valve stem, which restricts the unintended loss of contact between the valve and the pivoting stopper in the case of critical shift failure.
[0045] In some implementations, the kinematic points on the pivoting stopper can be positioned in different locations relative to the bridge. For example, the hard stop feature can be achieved by a removable pin. During assembly, this pin can be disassembled, and the pivoting stopper can rotate in either direction about the retainer pin to allow assembly of the valve. After assembly of the valve, the removable pin can be re-assembled, which will act as a hard stop to maintain positive contact between the seat or groove on the valve stem and a stopper pin, restricting bridge dislodgement during operation.
[0046] FIGS. 1-7 illustrate a valvetrain assembly 10, according to one implementation. The valvetrain assembly 10 includes a bridge 20, a first valve stem 32, a second valve stem 42, and a pivoting stopper 100. The first and second valve stems 32, 42 are coupled to the bridge 20 to form a portion of a valvetrain system as further described herein.
[0047] The bridge 20 includes a first end 22 and a second end 24 opposite and spaced apart from the first end 22. The bridge 20 includes an upper surface 26 extending between the first end 22 and the second end 24. As shown in FIG. 1, the bridge 20 further includes a rocker arm coupling surface 28 integrally formed with the upper surface 26 of the bridge 20. The rocker arm coupling surface 28 is a machined flat surface configured to provide a sliding contact. The rocker arm coupling surface 28 is configured to couple to or engage with a rocker arm (not shown) or an e-foot coupledMCC Docket No. 11694-120WO1 to the rocker arm (not shown) of a valvetrain system. For example, the rocker arm may transfer motion to the bridge 20 via contact with the rocker arm coupling surface 28. In some implementations, the valvetrain system is a variable valvetrain actuation system wherein the rocker arm provides controllably varied motion transfer to the bridge 20. The bridge 20 further includes a lower surface 16 disposed opposite from the upper surface 26. The lower surface 16 extends between the first end 22 and the second end 24. As shown in FIG. 3, a cavity 18 is defined by the bridge 20. The cavity 18 extends from the lower surface 16 into the body of the bridge 20 towards the upper surface 26.
[0048] The first end 22 of the bridge 20 is coupled to the first valve stem 32 (e.g., the first valve stem 32 may extend into a valve stem pocket defined in the bridge 20). The bridge 20 is configured to transfer motion to a first end of the first valve stem 32, which is coupled to the first end 22 of the bridge 20. As shown in FIG. 4, an opposite end of the first valve stem 32 includes a valve 30, which may be coupled to a valve of a piston cylinder (not shown) such that motion of the first valve stem 32 prevents or allows a flow of fluid through an opening in a piston cylinder.
[0049] The first valve stem 32 includes a plurality of grooves 34 extending circumferentially around the first valve stem 32. The plurality of grooves 34 include an engagement groove or an upper groove 36 disposed closest to the first end 22 of the bridge 20. The plurality of grooves 34 have a contoured cross-sectional shape, as shown in FIG. 1.
[0050] The second end 24 of the bridge 20 is coupled to the second valve stem 42 (e.g., the second valve stem 42 may extend into a valve stem pocket defined in the bridge 20). Specifically, the second valve stem 42 is insertable through a side opening 29 on the second end 24 of the bridge 20. The bridge 20 is configured to transfer motion to a first end of the second valve stem 42 which is coupled to the second end 24 of the bridge 20. As shown in FIG. 4, an opposite end of the second valve stem 42 includes a valve 40, which may be coupled to a valve of a piston cylinder (not shown) such that motion of the second valve stem 42 prevents or allows a flow of fluid through an opening in a piston cylinder.
[0051] The second valve stem 42 includes a plurality of grooves 44 extending circumferentially around the second valve stem 42. The plurality of grooves 44 includes an engagement groove or an upper groove 46 disposed closest to the second end 24 of the bridge 20. The plurality of grooves 44 have a contoured cross-sectional shape, as shown in FIG. 1.MCC Docket No. 11694-120WO1
[0052] In other implementations, any one of the plurality of grooves of any of the valve stems may have a different cross-sectional shape configured to seat a pin, rod, or other rigid element (e.g., a semi-circular shape, a partial-circular shape, a partial-elliptical shape, an angled shape, a triangular shape, or a rectangular shape).
[0053] The pivoting stopper 100 is coupled to the bridge 20. The pivoting stopper 100 includes a first arm 102 coupled to a second arm 104. The first arm 102 and the second arm 104 extend substantially parallel to each other. The first arm 102 is disposed on one side of the bridge 20, and the second arm 104 is disposed on an opposite side of the bridge 20, as shown in FIGS. 3 and 4.
[0054] The first arm 102 and the second arm 104 both extend from a bridge end 106 of the pivoting stopper 100 to a valve stem end 108 of the pivoting stopper 100. The first arm 102 is coupled to the second arm 104 on the bridge end 106 of the pivoting stopper 100. Specifically, the first arm 102 is integrally formed with the second arm 104 by a mechanical stop 110 on the bridge end 106 of the pivoting stopper 100. The mechanical stop 110 extends between the bridge ends 106 of the first arm 102 and the second arm 104 in a direction substantially perpendicular to the first and second arms 102, 104. The mechanical stop 110 on the bridge end 106 of the pivoting stopper 100 extends across a portion of the upper surface 26 of the bridge 20, as shown in FIG. 1 and FIG. 4.
[0055] The pivoting stopper 100 further includes a retainer pin 120 extending through a portion of the bridge 20, as shown in FIG. 1. Specifically, the retainer pin 120 extends through a central portion of the bridge 20. The central portion of the bridge 20 is located substantially halfway between the first valve stem 32 and the second valve stem 42, as shown in FIG. 1. The retainer pin 120 extends from one side of the bridge 20 adjacent to the first arm 102 to the opposite side of the bridge 20 adjacent to the second arm 104. The retainer pin 120 is coupled to the first arm 102 and the second arm 104 (e.g., via an opening defined in the first and second arms 102, 104). The bridge end 106 and the valve stem end 108 of the pivoting stopper 100 are pivotable about the retainer pin 120, as shown in FIGS. 1 and 2.
[0056] The pivoting stopper 100 further includes a stopper pin 130 extending from the first arm 102 to the second arm 104, as shown in FIG. 1. The stopper pin 130 is coupled to the first arm 102 and the second arm 104 (e .g . , via an opening defined in the first and second arms 102, 104) adj acent the valve stem end 108 of the pivoting stopper 100. The stopper pin 130 is spaced apart from theMCC Docket No. 11694-120WO1 retainer pin 120 along an axis of the pivoting stopper 100 that extends between the retainer pin 120 and the valve stem end 108.
[0057] As shown in FIG. 1, the stopper pin 130 is configured to engage with the first valve stem 32. In particular, the stopper pin 130 engages with the upper groove 36 of the plurality of grooves 34 of the first valve stem 32. As shown in FIG. 3, the stopper pin 130 engages with the upper groove 36 on an inner side of the first valve stem 32. The inner side of the first valve stem 32 faces towards the second valve stem 42.
[0058] The stopper pin 130 has a substantially circular cross-sectional shape that fits within the upper groove 36. The upper groove 36 on the first valve stem 32 forms a seat for the stopper pin 130. The upper groove 36 is shaped to facilitate engagement with the stopper pin 130 and maintain contact therebetween. For example, the upper groove 36 includes a sloped lower entry surface along which the stopper pin 130 may slide as the stopper pin 130 engages with the upper groove 36. The upper groove 36 includes a flat upper retention surface substantially perpendicular to the longitudinal axis of the first valve stem 32. Furthermore, the depth of the upper groove 36 may be configured to properly align with and seat the stopper pin 130 within the upper groove 36.
[0059] The pivoting stopper 100 further includes a spring support pin 140 extending from the first arm 102 to the second arm 104. The spring support pin 140 is coupled to the first arm 102 and the second arm 104 (e.g., via an opening defined in the first and second arms 102, 104). The spring support pin 140 is disposed between the retainer pin 120 and the stopper pin 130. As shown in FIG. 3, the spring support pin 140 is spaced apart from both the lower surface 16 of the bridge 20 and each of the valve stems 32, 42.
[0060] The pivoting stopper 100 further includes a torsional spring 150 disposed about the retainer pin 120. As shown in FIG. 3, the retainer pin 120 extends through the central portion of the bridge 20 through the cavity 18. At least a portion of the torsional spring 150 is disposed within the cavity 18 of the bridge 20. The torsional spring 150 is coupled to and / or extends around the retainer pin 120 therein.
[0061] As shown in FIGS. 3 and 5, the torsional spring 150 includes a bridge arm 152 and a pin arm 154. The bridge arm 152 extends out of the cavity 18 towards the second end 24 of the bridge 20. As shown in FIG. 3, the bridge arm 152 is configured to abut and engage with a portion of theMCC Docket No. 11694-120WO1 lower surface 16 of the bridge 20 and / or a portion of the cavity 18. The pin arm 154 of the torsional spring 150 extends out of the cavity 18 towards the first end 22 of the bridge 20. As shown in FIGS. 3 and 5, the pin arm 154 is configured to abut and engage with the spring support pin 140.
[0062] The torsional spring 150 transfers a force between the bridge 20 and the first and second arms 102, 104 of the pivoting stopper 100. In particular, the torsional spring 150 provides a rotational force on the pivoting stopper 100 in a first direction. The first direction is defined as the rotational direction in which the stopper pin 130 is moved towards the first valve stem 32 (i.e., from the position shown in FIG. 2 toward the position shown in FIG. 1).
[0063] In use, the torsional spring 150 is configured to maintain contact between the stopper pin 130 and the upper groove 36 of the first valve stem 32. The torsional spring 150 exerts a biasing force on the spring support pin 140 to bias the valve stem end 108 of the pivoting stopper 100 towards the first valve stem 32. The biasing force of the torsional spring 150 further forces the stopper pin 130 into engagement with the upper groove 36 of the first valve stem 32.
[0064] As shown in FIG. 1, the position of the pivoting stopper 100 in which the stopper pin 130 is biased into engagement with the upper groove 36 of the first valve stem 32 is the “engaged configuration” or the “engaged position.” In the engaged position, the contact between the pivoting stopper 100 and the first valve stem 32 - via the contact between the stopper pin 130 and the upper groove 36 - prevents disengagement of the first valve stem 32 from the bridge 20. The torsional spring 150 provides a constant force on the stopper pin 130 within the upper groove 36 in a direction substantially towards the bridge 20, ensuring engagement therebetween. Therefore, during operation of the valvetrain system (e.g., during a failure mode such as critical shift), the pivoting stopper 100 maintains consistent contact between the bridge 20 and the first and second valve stems 32, 42, preventing bridge dislodgement.
[0065] Furthermore, in the engaged position, the mechanical stop 110 on the bridge end 106 of the pivoting stopper 100 is disposed adjacent to, and may abut, the upper surface 26 of the bridge 20. The mechanical stop 110 prevents the pivoting stopper 100 from rotating about the retainer pin 120 further in the first direction. The pivoting stopper 100 cannot over-rotate in the first direction (e.g., past the point where the stopper pin 130 engages with the first valve stem 32) due to the mechanical stop 110 abutting the upper surface 26 of the bridge 20.MCC Docket No. 11694-120WO1
[0066] During assembly of the valvetrain assembly 10, the pivoting stopper 100 may be rotated in a second direction about the retainer pin 120 that is opposite from the first direction (e.g., opposite the biasing force of the torsional spring 150) by overcoming the biasing force of the torsional spring 150. As shown in FIG. 2, the pivoting stopper 100 may be rotated in the second direction such that the stopper pin 130 is spaced apart from the first valve stem 32 and the mechanical stop 110 is spaced apart from the upper surface 26 of the bridge 20. FIG. 2 shows the pivoting stopper 100 in a “disengaged configuration” or a “disengaged position.”
[0067] A user may rotate the pivoting stopper 100 in the second direction manually or via one or more tools to facilitate installation of the bridge 20 with the pivoting stopper 100 onto the valve stems 32, 42. For example, the pivoting stopper 100 may be rotated to the disengaged position (e.g., from the position shown in FIG. 1 to the position shown in FIG. 2). In the disengaged position, the stopper pin 130 does not interfere with the first valve stem 32 as the first valve stem 32 engages with the first end 22 of the bridge 20. For example, in the disengaged position, the stopper pin 130 does not block a cavity defined on the lower surface 16 on the first end 22 of the bridge 20 that is configured to receive a portion of the first valve stem 32. Once the bridge 20 is coupled to the valve stems 32, 42, the pivoting stopper 100 is rotated in the first direction to the engaged position wherein the stopper pin 130 engages the upper groove 36 of the first valve stem 32, as shown in FIG. 1.
[0068] In other implementations of the valvetrain assembly and the pivoting stopper, the first and second arms may have a different shape and / or geometry. For example, the first arm may be coupled to the second arm via a separable element comprising one or more fasteners. In other implementations, the retainer pin is disposed at a different position on the bridge (e.g., closer to one of the ends). In other implementations, the torsional spring is replaced with a linear spring (e.g., pulling one end of the pivoting stopper towards the engaged position). In other implementations, the spring may be coupled to the bridge outside of the cavity. In other implementations, the connection between the stopper pin and the upper groove may be secured with a clip, snap fit, or other feature ensuring connection of the elements. In other implementations, any of the pins of the pivoting stopper may have a different shape (e.g., a cross-sectional shape other than a circle or including a discontinuity, such an engagement groove).MCC Docket No. 11694-120WO1
[0069] FIGS. 8-14 illustrate a valvetrain assembly 12, according to another implementation. This implementation is similar to the implementation described in relation to FIGS. 1-7 except as described below.
[0070] The bridge 20’ of FIGS. 8-14 does not include a cavity, but the bridge 20’ is otherwise similar to the bridge 20 shown in FIGS. 1-7. The first and second valve stems 32’, 42’ of FIGS. 8-14 include a plurality of grooves 34’, 44’ having a total number of grooves greater than the implementation shown in FIGS. 1-7. Furthermore, as shown in FIG. 10, the plurality of grooves 34’, 44’ in FIGS. 8-14 extend above the point of contact with the pivoting stopper 200 such that an “engagement groove” is provided to engage with the pivoting stopper 200 instead of the “upper groove 36, 46” of FIGS. 1-7. Additionally, the plurality of grooves 34’, 44’ in FIGS. 8-14 may include a slightly different shape than that of FIGS. 1-7.
[0071] The pivoting stopper 200 is coupled to the bridge 20’. The pivoting stopper 200 includes a first arm 202 and a second arm 204. The first arm 202 and the second arm 204 extend substantially parallel to each other. The first arm 202 is disposed on one side of the bridge 20’, and the second arm 204 is disposed on an opposite side of the bridge 20’, as shown in FIG. 10. The first arm 202 and the second arm 204 both extend from a bridge end 206 of the pivoting stopper 200 to a valve stem end 208 of the pivoting stopper 200 opposite from the bridge end 206. The bridge end 206 of the pivoting stopper 200 is disposed closer to the central portion of the bridge 20’ than the valve stem end 208.
[0072] The first arm 202 is coupled to the second arm 204 via one or more pins of the pivoting stopper 200. In particular, the pivoting stopper 200 includes a removable pin 210, a retainer pin 220, and a stopper pin 230. Each of the removable pin 210, the retainer pin 220, and the stopper pin 230 extend between the first arm 202 and the second arm 204. The removable pin 210, the retainer pin 220, and the stopper pin 230 are each coupled to the first arm 202 and the second arm 204 (e.g., via an opening defined in the first and second arms 202, 204).
[0073] The retainer pin 220 extends through a portion of the bridge 20’ (e.g., through an opening defined in the bridge 20’). Specifically, the retainer pin 220 extends through a portion adjacent to the second end 24’ of the bridge 20’ (e.g., near the second valve stem 42’). The retainer pin 220 extends through one side of the bridge 20’ adjacent to the first arm 202 and through the opposite side of the bridge 20’ adjacent to the second arm 204. The retainer pin 220 is coupled to both theMCC Docket No. 11694-120WO1 first arm 202 and the second arm 204 at a central portion of each arm 202, 204 between the bridge end 206 and the valve stem end 208. The pivoting stopper 200 is rotatable about the retainer pin 220, as shown in FIGS. 8 and 9, wherein the bridge end 206 and the valve stem end 208 pivot about the retainer pin 220.
[0074] The stopper pin 230 extends between and is coupled to the first arm 202 and the second arm 204 adjacent the valve stem end 208 of the pivoting stopper 200. The stopper pin 230 is spaced apart from the retainer pin 220 along the pivoting stopper 200 along an axis of the pivoting stopper 200 that extends between the retainer pin 220 and the valve stem end 208. As shown in FIGS. 8 and 10, the stopper pin 230 is configured to engage with the second valve stem 42’. In particular, the stopper pin 230 engages with an engagement groove 48 of the plurality of grooves 44’ of the second valve stem 42’. The stopper pin 230 engages with the engagement groove 48 on an outer side of the second valve stem 42’. The outer side of the second valve stem 42’ faces away from the first valve stem 32.
[0075] The stopper pin 230 has a substantially circular cross-sectional shape that fits within the engagement groove 48. The engagement groove 48 on the second valve stem 42’ forms a seat for the stopper pin 230. The engagement groove 48 is shaped to facilitate engagement with the stopper pin 230 and maintain contact therebetween. For example, the engagement groove 48 includes a sloped entry surface along which the stopper pin 230 may slide as the stopper pin 230 engages with the engagement groove 48. The engagement groove 48 includes a flat upper retention surface substantially perpendicular to the longitudinal axis of the second valve stem 42’ . Furthermore, the depth of the engagement groove 48 may be configured to properly align with and seat the stopper pin 230 within the engagement groove 48.
[0076] The removable pin 210 extends between and is coupled to the first arm 202 and the second arm 204 on the bridge end 206 of the pivoting stopper 200. The removable pin 210 is spaced apart from the retainer pin 220 along an axis of the pivoting stopper 200 that extends between the retainer pin 220 and the bridge end 206 of the pivoting stopper 200. The removable pin 210 provides a mechanical stop for the pivoting stopper 200, similar to the mechanical stop 110 of the pivoting stopper 100.
[0077] During assembly of the pivoting stopper 200, the pivoting stopper 200 without the removable pin 210 is installed onto the bridge 20 via the retainer pin 220. As shown in theMCC Docket No. 11694-120WO1 disengaged position of FIG. 9, the first and second arms 202, 204 are rotated about the retainer pin 220 in a first direction during the assembly process. The first direction is defined as rotation of the pivoting stopper 200 about the retainer pin 220 wherein the stopper pin 230 moves away from the second valve stem 42 (i.e., moving from the position shown in FIG. 8 towards the position shown in FIG. 9).
[0078] To complete the assembly of the pivoting stopper 200, the pivoting stopper 200 is rotated in a second direction opposite from the first direction. As shown in FIG. 8, the removable pin 210 is installed into the openings defined in the first and second arms 202, 204 on the bridge end 206. Once the removable pin 210 is coupled to the first and second arms, 202, 204, the pivoting stopper 200 is in the engaged position, as shown in FIG. 8. In the engaged position, the removable pin 210 prevents rotation of the pivoting stopper 200 in the first direction. Specifically, the removable pin 210 abuts the upper surface 26’ of the bridge 20’ to prevent rotation in the first direction.
[0079] In the engaged position, the stopper pin 230 engages with the engagement groove 48 of the second valve stem 42’. The geometry of the first and second arms 202, 204 ensures that the pivoting stopper 200 locks into the engaged position. Thus, the pivoting stopper 200 provides a constant force to bias the valve stem end 208 and the stopper pin 230 thereon towards the engagement groove 48 of the second valve stem 42’. In the engaged position, contact between the stopper pin 230 and the engagement groove 48 prevents disengagement of the second valve stem 42’ from the bridge 20’. Thus, during the operation of the valvetrain system (e.g., during a failure mode such as critical shift), the pivoting stopper 200 maintains consistent contact between the bridge 20’ and the first and second valve stems 32’, 42’, avoiding bridge dislodgment.
[0080] In other implementations, one or more of the pins of the pivoting stopper have a different cross-sectional shape (e.g., a cross-sectional area other than a circle or including a discontinuity, such as a larger diameter stop feature). In other implementations, the retainer pin may be disposed at a different point along the bridge. In other implementations, a second pivoting stopper may be disposed on the first end of the bridge to engage with the first valve stem. In other implementations, the pivoting stopper may include one or more springs. In other implementations, the first and second arms may be integrally formed with each other on one end.
[0081] For purposes of this description, certain advantages and novel features of the aspects and configurations of this disclosure are described herein. The described methods, systems, andMCC Docket No. 11694-120WO1 apparatus should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed aspects, alone and in various combinations and sub-combinations with one another. The disclosed methods, systems, and apparatus are not limited to any specific aspect, feature, or combination thereof, nor do the disclosed methods, systems, and apparatus require that any one or more specific advantages be present or problems be solved.
[0082] Features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The claimed features extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
[0083] The terms “coupled”, “connected”, and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.
[0084] Certain terminology is used in the following description for convenience only and is not limiting. The words “right”, “left”, “lower”, and “upper” designate direction in the drawings to which reference is made. The words “inner” and “outer” refer to directions toward and away from, respectively, the geometric center of the described feature or device. The words “distal” and “proximal” refer to directions taken in context of the item described and, with regard to the instruments herein described, are typically based on the perspective of the practitioner using such instrument, with “proximal” indicating a position closer to the practitioner and “distal” indicatingMCC Docket No. 11694-120WO1 a position further from the practitioner. The terminology includes the above-listed words, derivatives thereof, and words of similar import.
[0085] Throughout the description and claims of this specification, the word “comprise” and variations of the word, such as “comprising” and “comprises”, means “including but not limited to”, and is not intended to exclude, for example, other additives, components, integers or steps. “Exemplary” means “an example of’ and is not intended to convey an indication of a preferred or ideal aspect. “Such as” is not used in a restrictive sense, but for explanatory purposes.
[0086] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present disclosure.
Claims
MCC Docket No. 11694-120WO1 What is claimed is:
1. A valvetrain assembly comprising:a bridge comprising a first end coupled to a first valve stem and a second end coupled to a second valve stem; anda pivoting stopper comprising:a retainer pin extending through a portion of the bridge, wherein the pivoting stopper is rotatable about the retainer pin;a stopper pin extending across a valve stem end of the pivoting stopper, the stopper pin configured to engage with a groove on the first valve stem;a mechanical stop extending across a bridge end of the pivoting stopper, the bridge end being opposite from the valve stem end;a spring support pin extending across the pivoting stopper and disposed between the retainer pin and the stopper pin; anda torsional spring disposed about the retainer pin, the torsional spring comprising (i) a bridge arm configured to engage a portion of the bridge and (ii) a pin arm configured to engage the spring support pin,wherein a force from the torsional spring is configured to maintain contact between the stopper pin and the groove on the first valve stem.
2. The valvetrain assembly of claim 1, wherein the torsional spring exerts a biasing force on the spring support pin to bias the valve stem end of the pivoting stopper and the stopper pin thereon towards the groove of the first valve stem.
3. The valvetrain assembly of claim 1, wherein the valve stem end of the pivoting stopper and the stopper pin thereon are rotatable in a second direction away from the first valve stem during assembly of the valvetrain assembly.
4. The valvetrain assembly of claim 1, wherein the mechanical stop prevents rotation of the pivoting stopper in a first direction past an engaged position, wherein the pivoting stopper is in the engaged position when the stopper pin engages the groove of the first valve stem.MCC Docket No. 11694-120WO1 5. The valvetrain assembly of claim 1, wherein contact between the pivoting stopper and the first valve stem, via the stopper pin, prevents disengagement of the first valve stem from the bridge.
6. The valvetrain assembly of claim 1, wherein the pivoting stopper comprises a first arm and a second arm extending parallel to the first arm, wherein the first arm is integrally formed with the second arm and the mechanical stop to form a continuous rigid body.
7. The valvetrain assembly of claim 1, wherein the stopper pin contacts the first valve stem on an inner side of the first valve stem, the inner side of the first valve stem faces toward the second valve stem.
8. The valvetrain assembly of claim 1, wherein the retainer pin extends through a central portion of the bridge.
9. The valvetrain assembly of claim 8, wherein the mechanical stop is disposed closer to the second valve stem than the first valve stem.
10. The valvetrain assembly of claim 1, wherein the bridge further comprises a rocker arm coupler on an upper surface of the bridge that extends between the first and second ends, wherein the mechanical stop abuts a portion of the upper surface of the bridge.
11. A valvetrain assembly comprising :a bridge comprising a first end coupled to a first valve stem and a second end coupled to a second valve stem; anda pivoting stopper comprising:a first arm coupled to and extending parallel to a second arm, the first and second arms disposed on opposite sides of the bridge;a retainer pin extending through a portion of the bridge, the retainer pin extending between the first arm and the second arm of the pivoting stopper, wherein the pivoting stopper is rotatable about the retainer pin;MCC Docket No. 11694-120WO1 a stopper pin extending between the first arm and the second arm across a valve stem end of the pivoting stopper, the stopper pin configured to engage with a groove on the first valve stem; anda removable pin extending between the first arm and the second arm across a bridge end of the pivoting stopper, the bridge end being opposite from the valve stem end, wherein the removable pin provides a mechanical stop,wherein the pivoting stopper is configured to maintain contact between the stopper pin and the groove on the first valve stem.
12. The valvetrain assembly of claim 11, wherein contact between the pivoting stopper and the first valve stem, via the stopper pin, prevents disengagement of the first valve stem from the bridge.
13. The valvetrain assembly of claim 11, wherein the valve stem end of the pivoting stopper, and the stopper pin thereon, are rotatable in a second direction away from the first valve stem during assembly of the valvetrain assembly.
14. The valvetrain assembly of claim 13, wherein, during assembly, the removable pin is not coupled between the first and second arms until the pivoting stopper is rotated such that the stopper pin engages with the groove of the first valve stem.
15. The valvetrain assembly of claim 11, wherein the removable pin prevents rotation of the pivoting stopper in a first direction past an engaged position, wherein the pivoting stopper is in the engaged position when the stopper pin engages the groove of the first valve stem.
16. The valvetrain assembly of claim 11, wherein the stopper pin contacts the first valve stem on an outer side of the first valve stem, the outer side of the first valve stem faces away from the second valve stem.
17. The valvetrain assembly of claim 11, wherein the portion of the bridge through which the retainer pin extends is disposed adjacent to the first valve stem.MCC Docket No. 11694-120WO1 18. The valvetrain assembly of claim 11, wherein the bridge further comprises a rocker arm coupler on an upper surface of the bridge that extends between the first and second ends of the bridge, wherein the retainer pin abuts a portion of the upper surface of the bridge.
19. A pivoting stopper configured to prevent disengagement of a valve stem from a bridge, the pivoting stopper comprising:a first arm and a second arm coupled to and extending parallel to each other, the first and second arms each having a bridge end and a valve stem end opposite from the bridge end;a retainer pin coupled between the first arm and the second arm and configured to extend through a portion of the bridge, the pivoting stopper being rotatable about the retainer pin;a stopper pin extending between the valve stem end of the first arm and the valve stem end of the second arm, the stopper pin configured to engage with a groove on the valve stem to prevent disengagement of the pivoting stopper from the bridge during operation; anda mechanical stop extending between the bridge end of the first arm and the bridge end of the second arm, the mechanical stop configured to prevent rotation of the pivoting stopper beyond an engaged position, wherein the engaged position is when the stopper pin engages the groove of the valve stem.
20. The pivoting stopper of claim 19, wherein the valve stem end of the first and second arms and the stopper pin therebetween are rotatable in a direction away from the valve stem during installation of the pivoting stopper.