WO2023001408A1

WO2023001408A1 - Swithing roller finger follower with transverse latch pin

Info

Publication number: WO2023001408A1
Application number: PCT/EP2022/025342
Authority: WO
Inventors: Kapil MOHADIKAR; Siddesh KAPDI
Original assignee: Eaton Intelligent Power Limited
Priority date: 2021-07-23
Filing date: 2022-07-22
Publication date: 2023-01-26
Also published as: CN117730193A

Abstract

A switching roller finger follower can comprise an outer arm assembly comprising a pivot end comprising a first and a second pass-through. An inner arm assembly can be configured to pivot relative to the outer arm assembly, the inner arm assembly comprising an extension. A latch pin can be mounted through the first and the second pass-through. The latch pin can comprise a first and second lift zone. The latch pin is configured to slide to abut the extension against a first lift zone or to slide to enable lost motion of the extension relative to the latch pin in the second lift zone. The switching roller finger follower is compatible with an actuation assembly. A rotatable arm comprising a first wing can be configured to act on the latch pin of the switching roller finger follower. A side-latching arrangement in a valvetrain can be configured.

Description

SWITHING ROLLER FINGER FOLLOWER WITH TRANSVERSE LATCH PIN

Field

[001] This application provides a side latching arrangement for variable valve lift, such as lost motion, of a switching roller finger follower. An actuation assembly can be devised so that a rotatable arm acts on the latch pin slidable transversely in the pivot end of the switching roller finger follower.

Background

[002] Valvetrains have tight packaging constraints. It is desired to pack the components as efficiently as possible. Prior art configurations place actuation assemblies behind or above switching roller finger followers. And, other side latching arrangements have large footprints or limited lost motion configurations.

SUMMARY

[003] The methods and devices disclosed herein overcome the above disadvantages and improves the art by way of a switching roller finger follower that can comprise an outer arm assembly comprising a valve end and a pivot end, the pivot end comprising a first and a second pass-through. An inner arm assembly can be configured to pivot relative to the outer arm assembly, the inner arm assembly comprising an extension. A latch pin can be mounted through the first and the second pass-through. The latch pin can comprise a first lift zone and a second lift zone. The latch pin is configured to slide to abut the extension against a first lift zone or to slide to enable lost motion of the extension relative to the latch pin in the second lift zone.

[004] The switching roller finger follower is compatible with an actuation assembly. A rotatable arm comprising a first wing can be configured to act on the latch pin of the switching roller finger follower. A side-latching arrangement in a valvetrain can be configured. A second switching roller finger follower can be configured in the valvetrain assembly adjacent the first switching roller finger follower. The actuation assembly can be configured with a second wing configured to act on the latch pin of the second switching roller finger follower. The second wing can be part of the rotatable arm acting on the first switching roller finger follower, or the second wing can be part of a second rotatable arm. [005] Additional objects and advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. The objects and advantages will also be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[006] Figure 1 is a side view of an actuation assembly.

[007] Figures 2 & 3 are views of aspects of a valvetrain with an actuation assembly and switching roller finger followers.

[008] Figures 4 & 5 are views of alternative switching roller finger followers.

[009] Figures 6A-6C are alternative views to explain an unlatched condition of an example switching roller finger follower.

[010] Figures 7A-7C are alternative views to explain a latched condition of an example switching roller finger follower.

[011] Figures 8-11 are views of alternative inner arm assemblies compatible with the switching roller finger followers disclosed herein.

DETAILED DESCRIPTION

[012] Reference will now be made in detail to the examples which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Directional references such as “lefthand” (“LH”) and “righthand” (“RH”) are for ease of reference to the figures. Commercial implementations can comprise other relative implementations such as north-south, mirror-image, etc.

[013] A switching roller finger follower (“SRFF”), 10, ,6, 20 can be configured to provide lost motion for variable valve actuation (“VVL”). A valvetrain 1 can comprise an overhead cam (“OFIC”) system with a camshaft 50 and cam lobes 51 , 52. The working example comprises a single rotatable cam lobe 51 , 52 for each SRFF 10, 20. Flowever, it is possible to have three cam lobes, among options. The working example comprises a first valve lift mode and a lost motion lift mode. Many WL options can be implemented. For example, when the cam lobe 51 , 52 presses on inner roller assembly 300 for the first valve lift mode, a first valve lift can be accomplished. But, the lost motion lift mode can result in zero valve lift or a valve lift that is less than the first valve lift. WL such as cylinder deactivation (“CDA”), engine braking (“EB”), late intake valve closing (“LIVC”), early exhaust valve opening (“EEVO”), among many other options can be implemented. The working example is particularly suited for low lost motion WL, though the lift height can be varied for the valvetrain application.

[014] An actuation assembly 30 can be controlled to switch between the first valve lift mode and the second valve lift mode. The actuation assembly 30 can actuate a side latching latch pin 500 of an SRFF 10, 16, 20. The latch pin 500 can be configured to slide to abut one or more first lift zone 510 against one or more extension 205, 215, 265, 295 on an inner arm assembly 200, 210, 260, 290. Or, the latch pin 500 can slide to abut one or more second lift zone 520 against the one or more extension 205, 215, 265, 295. In the working examples, the first lift zone 510 is a contact surface and the second lift zone 520 is a transverse slot in the latch pin 500. The contact surface can serve as a latching shelf for locking the inner arm assembly 200, 210, 260, 290. The number of first and second lift zones 510, 520 can be varied to correspond with the number of extensions 205, 215, 265, 295 on the inner arm assembly 200, 210, 260, 290. It can be possible to include a second contact surface for the second lift zone 520. By moving the latch pin 500, the corresponding valve lift height can be conveyed by a combination of the cam lobes 51 , 52 pushing on the inner roller assembly 300 and first lift zone 510, or, when the second lift zone 520 aligns with the extension 205, 215, 165, 295, the cam lobes 51, 52 push the inner roller assembly 300 down in lost motion, either partial or full lost motion, and the cam lobes 51, 52 ride on the outer rollers 107, 108. Figure 7B shows the extension 265 swinging in the transvers slot of second lift zone 520. A downward travel limit can be formed via thru-axle 310 being restricted by roller axle 302. Numerous travel limit alternatives exist in the art, such as steps or other engaging surfaces between the inner arm assembly 200 and the outer arm assembly 100. Or, thru-axle 310 can pass through travel bores in the outer arm assembly 100. Also, many aspects are compatible with cantilever post alternatives. So, first and second outer rollers 107, 108 can be integrated onto the thru-axle 310 for travel therewith. Fasteners 313, 314, such as bushings or the like, can secure the first and second outer rollers 107, 108 to the thru-axle 310. Or, first and second outer rollers 107, 108 can be mounted on cantilevered posts of the first and second outer arms 106, 107, among options. Also, one or more of the inner roller assembly 300 and first and second outer rollers 107, 108 can be exchanged for slider pads.

[015] The SRFF side latching concept helps in providing WL solution to customers without much changes in customer’s cylinder head 63. The disclosed valvetrain 1 design helps where rear latching becomes difficult due to packaging constraints in customer’s cylinder head 63. For example, there are situations when a rear latch interferes with the cylinder head 63 or manifold. Should the latch pin stick out the back of the SRFF, it can abut a mounting feature, bracket, or tower of the cylinder head 63. But, when viewing Figures 2 & 3, it can be seen that the latch pin 500 projects into a space between SRFFs 10, 20. Then, actuation assembly 30 can comprise rotatable arms 31 (left hand 311 & right hand 312) that tuck neatly also between adjacent SRFFs.

[016] In the working example disclosed herein, SRFF side latching can be accomplished using an electromechanical actuation system to help in providing WL solutions. Actuation assembly 30 can receive a control signal at an actuator 41 , such as a motor, chain or gear drive mechanism, linkage, or other actuator. A shaft 40 can be placed parallel to the cam shaft 50. Shaft 40 can be stabilized by mounting brackets 39. An orientation arm 37 can be staked or pressed or crimped or otherwise held in place on the shaft 40. Using opposed ends of arm bias 38, such as ends of a coil spring or leaf spring, among options, rotatable arm 31 can be biased relative to the orientation arm 37. Then, when shaft 40 is rotated by actuator 41 , the orientation arm 37 loads the arm bias 38, which in turn loads the rotatable arm 31. Preload strategies can be applied to the latch pin 500 using the arm bias 38 and one or more spring 531 , 532, which can be fastened to latch pin 500 by spring fasteners 533, 534 like bushings, washers, pins, nuts, etc.

[017] Rotatable arm 31 can comprise options like an arm bracket 35 for anchoring the rotatable arm 31 to the shaft 40 or for positioning arm bias 38. Or an arm stabilizer 36 can be included to guide or position the rotatable arm relative to the orientation arm 37. A wing base 32 on the rotatable arm 31 can swing first and second wings 33, 34 between the SRFFs 10, 20. The shape of the first and second wings 33, 34 can determine the slope of actuation of the latch pin 500. Light weighting and balance considerations can alter the shape of the rotatable arm 31.

As a matter of design choice, left-hand and right-hand rotatable arms 31 can be used, or a single rotatable arm 31 can be usable to actuate LH & RH SRFFs 10, 20. One rotatable arm 31 can be used per each latch pin 500, or a rotatable arm 31 can be scaled to actuated adjacent latch pins 500. Due to the “U” shape of the actuating portion of the rotatable arm 31 , the actuating portion, comprised of the first and second wings 33, 34 and wing base 32, fits compactly between the SRFFs and cam lobes 51 , 52. The “U” shape can extend to the anchor portion of the rotatable arm 31 , so that the arm bracket 35, arm stabilizer 36, and intervening body portion 43 fit compactly between the cam lobes 51 , 52. The compact rotatable arm 31 takes advantage of the space between the cam lobed 51 , 52 in lieu of building out into the space above or behind the SRFFS 10, 16, 20. The footprint of the mounting brackets 39 & shaft 40 is also easily accommodated. In the figures, LH & RFI SRFFs 10, 20 can be any one of the disclosed SRFFs, with mirror image layout implemented thereon. The handedness being optional, it is possible to implement only left-hand SRFFs or only right-hand SRFFs with the teachings herein.

[018] Actuation assembly 30 can be substituted for other actuation systems known in the art configurable to actuate the latch pin 500. Also, other cylinder heads 63 and valve configurations can be used with one or a pair of SRFFs. For example, instead of a single valve, a pair of valves and a valve bridge could be used with additional valve guides 61 and valve springs 63. A vertical actuation assembly, such as that disclosed in commonly owned PCT/EP2022/025251 filed May 27, 2022 could be used, as an example. Thus, with the overhead cam rail shown with cam lobes 51 , 52 for actuating the SRFFs 10, 20, the actuation assembly 30 is packaged between the SRFFs 10, 20 and the cam rail to optimize space use. The rearward stackup is minimized.

[019] Figures 2-7C show various aspects of the side latching latch pin 500. The latch pin 500 is configured to slide transverse to the long axis of the SRFF 10, 16, 20. While parallel to the pivot axle 103, the latch pin 500 is transverse to the plane in which the inner arm assembly 200, 210, 260, 290 swings. The slidable latch pin 500 can comprise a latch pin body 501 that can project from one or both sides of the SRFF 10, 16, 20. The position of the latch pin 500 can be biased by one or more set of first spring 531 with first spring fastener 533 or second spring 532 with second spring fastener 534. Latch pin 500 can be biased to place a first lift zone 510 or a second lift zone 520 in a default or nominal position within the SRFF. Additional contact zones can be included for additional lift height and lost motion variations, with corresponding adjustments to the extent of the corresponding first or second wing 33, 34 and actuator control strategy. Pushing or pulling the latch pin 500 to switch among the various lift zones can be accomplished using the first and second springs 531 , 532 and optionally, an actuating first and second wing 33, 34 by a rotatable arm 31 on each side of the SRFF, among options.

[020] Latch pin body 501 can comprise one or more pin slot 503. One or more alignment pin 410 can ride in the one or more pin slot 503. The optional configuration can be used to prevent rotation of the latch pin 500 in the SRFF so that the various one or more first and second lift zones 510, 520 align with the various extensions 205, 215, 2151 , 265, 295, 2951.

[021] An alignment block 400 or alignment plate 410 can be placed between the first and second outer arms 105, 106. The alignment plate 410 can comprise a top plate or shell that can serve as a brace between the first and second outer arms 105, 106. The alignment block 400 can be a drop-in insert. The alignment plate 410 and alignment block 400 can include alignment bores 404 to position an anti rotation pin, also called alignment pin 409. If the latch pin 500 is handed, or if the latch pin 500 comprises two pin slots 503, the alignment plate 410 or alignment block 400 can comprise two alignment bores 404, with one or both being paired with an alignment pin 409 as a design choice.

[022] The alignment plate 410 can be double-punched to form alignment bores 404, or the alignment block 410 can have castings or drillings for two alignment bores 404, so that the same part number can be used for either left-hand or right-hand SRFFs (left and right being relative terminology to the figures and used for convenience of explanation of the concept). The alignment plate 410 seats in the outer arm assembly 100 of the SRFF and holds the anti-rotation pin, also called alignment pin 409, steady when the slidable side latching pin latch pin 500 is actuated. The alignment pin 409 slides in the pin slot 503 and maintains the general orientation of the one or more first and second lift zones 510, 520. Pin slot 503 can be formed parallel to the actuation axis of the latch pin 500. Sliding the latch pin 500 moves one or more of the first and second lift zones 510, 520, either the transverse slot (lost motion slot) or the contact zone (latching shelf), into position relative to the latch arm (inner arm assembly 200, 210, 260, 290). The latch arm (inner arm assembly 200, 210, 260, 290) can have an extension 205, 215, 2151 , 265, 295,

2951 such as a shelf, rim, peg or other protrusion that can either pass through the transverse slot or seat against the contact zone, or that can switch from one contact zone to another, as the design dictates. Contact zone can be a pad, shelf, step, flat or other surface designed to catch the extension 205, 215, 2151 , 265, 295, 2951 of the inner arm assembly 200, 210, 260, 290 for locking it in position. The transverse slot permits the inner arm assembly 200, 210, 260, 290 to swing. The extension 205, 215, 2151, 265, 295, 2951 can swing in the transverse slot to permit lost motion by the inner arm assembly 200, 210, 260, 290. This switch between the transverse slot and the contact zone enables the WL, as does switching among more than one contact zone.

[023] An additional option of the alignment plate 410 and alignment block 400 is the inclusion of an extension slot 407. It can guide or permit pass-through of the one or more extension 205, 215, 2151 , 265, 295, 2951. Or, a travel limit can be formed in the alignment plate 410 or alignment block 400.

[024] Alignment plate 410 can be pressed, squeeze, welded or otherwise held in place between the first and second outer arms 105, 105 in the pivot end. The one or more alignment pin 409 can aid in anchoring the alignment plate 410 within the pivot end 120.

[025] Alignment block 400 can comprise additional optional features, such as a socket 401 for receiving a pivot head of the cylinder head 63. A lash adjuster head can fit in the socket 401. In the case of a hydraulic lash adjuster, the pivot head can comprise an oil port to the socket 401 and can supply oil to oil feed 402. The oil can lubricate the latch pin 500. Additional options can comprise stake bores 408. Stakes 420 can be pressed in stake ports 121 in the first and second outer arms 105, 106 and through the stake bores 408 to stabilize the alignment block in the pivot end 120. While alignment plate 410 can arch around the latch pin 500, the alignment block 400 can comprise a latch bore 403. Latch bore 403 can be a through-hole, groove, or guide in the alignment block 400.

[026] It is possible to press-fit, squeeze, crimp, or weld block edges 405 between the first and second outer arms 105, 106, among options. Or, it is possible to press-fit, crimp, weld or otherwise secure rims, lips, tabs, steps or other features forming block seat 406 against a block pallet 122 formed in between the first and second outer arms 106 in the pivot end 120. A pivot opening 125 can be formed in the block pallet 122 for drop-in of the alignment block 400 or for pass-through of the pivot head.

[027] A travel limit can be had according to art-recognized techniques such as pump down stops, lash pins, bearing axle extension arms, travel guides in the outer arm assembly 100, windows in the outer arm assembly 100, shaft-in-shaft type hollow bearing shafts, among others. One example of a shaft-in-shaft type hollow bearing shaft is shown in Figures 6B & 7B. In Figure 6B, the transverse slot of second lift zone 520 is aligned with extension 265 so that the inner arm assembly 260 pivots on pivot axle 103 and compresses lost motion spring 104 when the cam lobe 51 presses on the inner roller assembly 300. The travel of the roller 301 is limited by the engagement of the thru-axle 310 against the roller axle 302. The inner arm assembly 200 could alternatively or additionally be travel-limited by the valve pallet 102. Figures 6A & 6C show additional aspects for the latch pin 500 of the lost motion travel of the SRFF 16. The stippling in Figure 6C illustrates the second lift zone 520 is aligned for the extension 265 to swing through. Comparing Figures 6A & 7A, the alignment block 400 is installed in Figure 6A, while the alignment block 400 is removed to illustrate additional aspects of the latch pin 500 and block pallet 122 alternatives.

[028] When the cam lobe 51 rotates to a base circle position from a lift lobe, the lost motion spring 104 can bias the inner arm assembly 200 back through the transverse slot of second lift zone 520. A lash limit or travel limit can limit the travel of the extension 265. For example, the thru-axle 310 can abut an opposite side of the roller axle 302, the thru-axle 310 being limited by thru-axle bores in the first and second outer arms 105, 106 among optional travel limits. The lost motion spring 104 can bias the extension 265 to a position slightly above the first lift zone 510 so that the latch pin 500 can slide without drag. Then, the cam lobe 51 , as it rotates, can push the contacting surface 269 of extension 265 against the latching shelf of the first lift zone 510.

[029] In Figure 7B, the contact surface of the first lift zone 510 engages with the extension 265. The stippling in Figure 7C indicates that the first lift zone 510 is aligned with the extension 265. The inner arm assembly 200 is latched against the latch pin 500, and thus is latched against the outer arm assembly 100 for travel therewith. Figures 7A & 7C show additional aspects for the latch pin 500 when it is latched for valve lift travel of the SRFF 16.

[030] Numerous variations can be had in the formation of the SRFFs. Many of the illustrated designs are readily fabricated from stamped sheets for the outer and inner arm assemblies 100, 200, 260, 290. Or, outer arm assembly 100 and inner arm assembly 210 can be formed via casting and grinding, as options. One benefit of the side-latching latch pin 500 is that the outer arm assembly 100 can be formed via stamping of a sheet material of a first hardness. Then, the alignment plate 410 or alignment block 400 can be formed of a different hardness material. Likewise, the inner arm assembly 200, 210, 260, 290 can be a third hardness material, or a hardness of the first or second material. The stakes 420 and even the latch pin 500 can stabilize the pivot end, even in the case of a low hardness material for the outer arm assembly 100.

[031] Numerous variations can exist for pairing one or more latch arm extension 205, 215, 2151, 265, 295, 2951 and the one or more first and second lift zones 510, 520 of the side latching latch pin 500.

[032] In Figure 8, inner arm assembly 200 comprises an angled arm used for the extension 205. A stamped sheet can be folded to provide the angled arm. A stamped sheet can form the first and second inner arms 201 , 202, the connecting body 2021 , and the extension 205. Controlling the angle on the angled arm controls the latching point yielded by contacting surface 209 of extension 205. Bearing axle bore 206 can receive roller axle 302 while pivot axle bore 207 can receive pivot axle 103. Optional peg bore 203 can receive an optional bias peg 204, or peg bore could receive a leg of lost motion spring 104, or a step or folded piece can be formed to anchor lost motion spring 104, among other options.

[033] In Figure 9, inner arm assembly 290 comprises a pair of extensions. A corresponding pair of transverse slots and contact zones can be formed in the latch pin 500 by duplicating the parts so illustrated. In this example, stamped sheets forming first and second inner arms 291 , 292 are pressed to a bushing to form the inner arm assembly 290. The bushing can double as the bearing axle (roller axle 302) for roller 301 to receive the forces from OHC assembly. A stabilizing pin (bias peg 294) can be included, which can also be a spring seat for lost motion spring 104 or bias peg can serve as a travel stop. The stamped sheets can also include pivot axle bores 297 for receiving pivot axle 103 in addition to the bearing axle bores 296 for the bushing. Two extensions 295, 2951 are formed and so formed are two contacting surfaces 299, 2991.

[034] In Figure 10, a stamped sheet inner arm assembly 260 can comprise a kinked extension 265. The kink can be formed by crimping, extrusion, or a second stamping step, among other options. The extension 265 can form a contacting surface 269 extending from a connecting body 2621 between the first and second inner arms 261 , 262. Pivot axle bore 267, peg bore 263, and bearing axle bore 266 can be stamped in the stamped sheet forming the inner arm assembly 260. Bias peg 264 can be inserted in peg bore 263, while pivot axle bore 267 received pivot axle 103, and bearing axle bore 266 received roller axle 302.

[035] If Figure 11 , a casting can be used to form inner arm assembly 210. A pair of extensions 215, 2151 with a pair of contacting surfaces 219, 2191 are correspondingly formed on the first and second inner arms 211, 212. In lieu of a connecting body, an optional number of braces 218 can be formed to connect the first and second inner arms 211, 212. Pivot axle bore 217 can receive pivot axle 103 and bearing axle bore 216 can receive roller axle 302. Peg bore 213, instead of receiving a leg of lost motion spring or instead of receiving a bias peg, could optionally be replaced with a cast projection.

[036] It can be said that a switching roller finger follower 10, 16, 20 can comprise an outer arm assembly 100 comprising a valve end 101 and a pivot end 120. The pivot end 10 can comprise a first pass-through 123 and a second pass through 124. An inner arm assembly 200, 210, 260, 290 can be configured to pivot relative to the outer arm assembly 100. The inner arm assembly 200, 210, 260, 290 can comprise one or more extension 205, 215, 2151 , 265, 295, 2951.

[037] A latch pin 500 can be mounted through the first pass-through 123 and the second pass-through 124. The latch pin 500 can comprise a first lift zone 510 and a second lift zone 520. The latch pin 500 can be configured to slide to abut the one or more extension 205, 215, 2151, 265, 295, 2951 against the first lift zone 510 or to enable lost motion of the extension 205, 215, 2151 , 265, 295, 2951 relative to the latch pin 500 in the second lift zone 520.

[038] Optionally, the first lift zone 510 can comprise a contact surface and the second lift zone 520 can comprises a transverse slot. Duplication of the first and second lift zones 510, 520 can be included. Additional lift zones, such as third lift zones with additional contact surfaces can be included.

[039] Also, the switching roller finger follower can comprise an alignment block 400 or an alignment plate 410 configured in the pivot end 120. An anti-rotation pin (alignment pin 409) can be configured in the alignment block 400 or in the alignment plate 410. The latch pin 500 can comprise a pin slot 503 and the anti rotation pin can be configured to slide in the pin slot 503. When comprising the alignment block 400, the alignment block 400 can comprise a socket 401 configured for receiving a lash adjuster or pivot head.

[040] As an option, the outer arm assembly 100 can comprise a stamped sheet. When the SRFF is comprising the alignment block 400, the alignment block 400 can be affixed to the stamped sheet. Also, when comprising the alignment block 400, the alignment block 400 can comprise a latch bore 403. The latch pin 500 can be configured to affix the alignment block 400 to the pivot end 120 by additionally passing through the latch bore 403. As yet another option, the alignment block 400 can comprise an oil feed 402 configured to lubricate the latch pin 500.

[041] The SRFF can comprise at least one spring, first spring 531 , configured against the pivot end 120 to bias the latch pin 500. As an option, the first spring 531 can be configured against the pivot end 120 to bias the latch pin 500 in a first direction. Then, a second spring 532 can be configured against the pivot end 120 to bias the latch pin 500 in a second direction.

[042] An inner arm assembly 200 for an SRFF can comprise a stamped sheet. One or more extension 205 on the inner arm assembly 200 can comprise a folded portion of the stamped sheet to form an angled arm. Alternatively, an inner arm assembly 210 for an SRFF can comprise a pair of stamped sheets fitted to a bushing, as by pressing first and second inner arms 291 , 292 to a roller axle 302. Alternatively, an inner arm assembly 260 for an SRFF can comprise a single stamped sheet forming a pair of inner arms joined by one or more kink. First and second inner arms 261, 262 can be contiguously and integrally formed with the one or more kink to include the one or more extension 265. Alternatively, an inner arm assembly 210 for an SRFF can comprise a casting. The casting can be formed with a pair of inner arms (first and second inner arms 211, 212) and a pair of extensions 215, 2151. [043] A valvetrain assembly 1 can comprise a first switching roller finger follower 10 and a second switching roller finger follower 20 configured in the valvetrain assembly 1 adjacent the first switching roller finger follower 10.

[044] An actuation assembly 30 can comprise a rotatable arm 31. The rotatable arm 31 can comprise a first wing 33 configured to act on a latch pin 500 of a first switching roller finger follower 10. A second wing 34 can be configured to act on a latch pin 500 of an adjacent second switching roller finger follower 20.

[045] Other implementations will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein.

Claims

WHAT IS CLAIMED IS:

1 ) A switching roller finger follower comprising: an outer arm assembly comprising a valve end and a pivot end, the pivot end comprising a first pass-through and a second pass-through; an inner arm assembly configured to pivot relative to the outer arm assembly, the inner arm assembly comprising an extension; and a latch pin mounted through the first pass-through and the second pass through, the latch pin comprising a first lift zone and a second lift zone, wherein the latch pin is configured to slide to abut the extension against a first lift zone or to enable lost motion of the extension relative to the latch pin in the second lift zone.

2) The switching roller finger follower of claim 1 , wherein the first lift zone comprises a contact surface, and wherein the second lift zone comprises a transverse slot.

3) The switching roller finger follower of claim 2, comprising an alignment block or an alignment plate configured in the pivot end.

4) The switching roller finger follower of claim 3, comprising an anti-rotation pin configured in the alignment block or in the alignment plate, wherein the latch pin comprises a pin slot, and wherein the anti-rotation pin is slidable in the pin slot.

5) The switching roller finger follower of claim 3, wherein, when comprising the alignment block, the alignment block comprises a socket configured for receiving a lash adjuster or pivot head.

6) The switching roller finger follower of claim 3, wherein the outer arm assembly comprises a stamped sheet, and wherein, when comprising the alignment block, the alignment block is affixed to the stamped sheet.

7) The switching roller finger follower of claim 6, wherein, when comprising the alignment block, the alignment block comprises a latch bore, and wherein the latch pin affixes the alignment block to the pivot end by passing through the latch bore.

8) The switching roller finger follower of claim 7, wherein, when comprising the alignment block, the alignment block comprises an oil feed configured to lubricate the latch pin.

9) The switching roller finger follower of any one of claims 1 -8, comprising at least one spring configured against the pivot end to bias the latch pin. 10) The switching roller finger follower of any one of claims 1 -8, comprising a first spring configured against the pivot end to bias the latch pin in a first direction; and comprising a second spring configured against the pivot end to bias the latch pin in a second direction.

11 ) The switching roller finger follower of any one of claims 1 -8, wherein the inner arm assembly comprises a stamped sheet, and wherein the extension comprises a folded portion of the stamped sheet.

12) The switching roller finger follower of any one of claims 1 -8, wherein the inner arm assembly comprises a pair of stamped sheets fitted to a bushing.

13) The switching roller finger follower of any one of claims 1 -8, wherein the inner arm assembly comprises a single stamped sheet forming a pair of inner arms joined by one or more kink.

14) The switching roller finger follower of any one of claims 1 -8, wherein the inner arm assembly comprises a casting, and wherein the casting is formed with a pair of inner arms and a pair of extensions.

15) A valvetrain assembly, comprising: a first switching roller finger follower of any preceding claim; a second switching roller finger follower of any preceding claim configured in the valvetrain assembly adjacent the first switching roller finger follower; and an actuation assembly comprising a rotatable arm, the rotatable arm comprising: a first wing configured to act on the latch pin of the first switching roller finger follower; and a second wing configured to act on the latch pin of the second switching roller finger follower.