CN117916454A

CN117916454A - Roller finger follower with pivot body and outer arm

Info

Publication number: CN117916454A
Application number: CN202280059810.7A
Authority: CN
Inventors: 马修·A·万斯; 西德什·卡普迪; 卡皮尔·莫哈迪卡尔
Original assignee: Eaton Intelligent Power Ltd
Current assignee: Eaton Intelligent Power Ltd
Priority date: 2021-09-03
Filing date: 2022-09-02
Publication date: 2024-04-19
Also published as: WO2023030691A1

Abstract

A switching roller finger follower may include: an outer arm assembly including a valve end and a pivot end; an inner arm assembly configured to pivot relative to the outer arm assembly, the inner arm assembly including a latch; a pivot body mounted to the pivot end of the outer arm assembly, the pivot body including a latch pin aperture and an inner lever aperture; a latch pin mounted in the latch pin aperture, the latch pin including a guide groove and a contact surface, the guide groove including a first lifting region and a second lifting region; and a rod passing through the inner rod hole, the rod configured to be aligned through the guide groove.

Description

Roller finger follower with pivot body and outer arm

Technical Field

The present application relates to a roller finger follower (rolling finger follower, RFF) with variations in the design of the outer arm and pivot body to accommodate alternative assembly methods.

Background

The valve mechanism has severe packaging limitations. It is desirable to package the components as efficiently as possible. The prior art constructions have limited lost motion constructions, large footprints or may also interfere with adjacent components. The prior art constructions also have high costs in terms of the use of materials.

Disclosure of Invention

As disclosed herein, a Roller Finger Follower (RFF) may include a variety of variations of external arms and pivoting bodies designed to accommodate alternative assembly methods. These methods help to avoid interference with adjacent cylinder head components while achieving high lost motion. The disclosed roller finger follower fits compactly on the cylinder head. In addition, cost can be saved by mixing materials. For example, a highly durable material may be used to form a portion of the male pivot body that is the pivot location. The material that facilitates stamping may then be used for the outer arm assembly or the inner arm assembly. The retaining clip can be designed to secure the pivot body regardless of whether the pivot body includes a latch pin or not. The retention clip may also optionally include a guide formation to mate with a pivot location of the associated valve train. In use, the additional features may ensure latch pin alignment. Additional features may ensure connection between the male pivot body and the outer arm assembly.

A switching roller finger follower may include: the latch pin is configured to reciprocate in the latch pin aperture between a latched position in which the lever is configured to enter the first lift region and the latch is configured to engage the contact surface and an unlatched position in which the lever is configured to enter the second lift region and the latch is configured to not engage the contact surface.

A switching roller finger follower may include: the outer arm assembly includes two outer shaft holes, the inner arm assembly includes an inner shaft hole in which the roller shaft is mounted, and the penetrating shaft is disposed inside the roller shaft and penetrates the two outer shaft holes.

A switching roller finger follower may include: the pivot body is configured for assembly into the top of the outer arm assembly in an insertion manner.

A switching roller finger follower may include: the pivot body includes at least one tab, and wherein the outer arm assembly further includes at least one vertical slot for receiving the at least one tab.

A switching roller finger follower may include: the pivot body includes at least one tab, and wherein the outer arm assembly further includes at least one top profile (top draft) integrally formed with the at least one vertical slot, and the vertical slot is configured to receive the at least one tab.

A switching roller finger follower may include: the pivot body is configured for insertion assembly into the rear of the outer arm assembly.

A switching roller finger follower may include: the pivot body includes at least one tab, and wherein the outer arm assembly further includes at least one horizontal slot for receiving the at least one tab.

A switching roller finger follower may include: the outer arm assembly includes at least one top molding, and wherein the pivot body further includes at least one top molding receiver for receiving the at least one top molding.

A switching roller finger follower may include: the pivot body is manufactured by cold forming and the outer arm assembly is manufactured by stamping.

A switching roller finger follower may include: the outer arm assembly includes first and second outer arms, each including an inner surface and an outer surface, wherein each outer surface includes a recess, and wherein each inner surface includes a protrusion.

A switching roller finger follower may include: the inner surface is configured to abut the pivot body.

A switching roller finger follower may include: a retention clip and a recess, wherein the retention clip includes respective retention fingers configured to be disposed in the recess.

A switching roller finger follower may include: a retention clip and at least one tab, wherein the retention clip includes at least one curved arm configured to abut the at least one tab.

A switching roller finger follower may include: a retention clip, wherein the retention clip includes a guide aperture, a retention pawl, and a curved arm.

A roller finger follower may include: an outer arm assembly including a valve end and a pivot end, the pivot end including an outer arm slot and a connecting portion; an inner arm assembly configured to pivot relative to the outer arm assembly; and a pivot body including a pivot body tab disposed in the outer arm slot, the pivot body mounted to the connecting portion.

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.

Drawings

Fig. 1A-1D are views of a roller finger follower.

Fig. 2A-2D are views of alternative roller finger followers.

Fig. 3A-3C are views of an alternative outer arm assembly and latch pin for use with a roller finger follower.

Fig. 4A-4C are views of an alternative outer arm assembly and latch pin for use with a roller finger follower.

Fig. 5 is a view of a portion of an alternative outer arm assembly for use with a roller finger follower.

FIG. 6 is a view of a portion of an alternative outer arm assembly and pivot body for use with a roller finger follower.

Detailed Description

Reference will now be made in detail to examples shown in the accompanying drawings. The directional references are for convenience in referring to the drawings. Commercial implementations may include other related implementations such as north-south, mirror images, etc.

A roller finger follower ("RFF") may form a valve actuation device in a type II end pivot valve train. The roller pad or slider pad may be actuated by an overhead cam actuator with the pivot end pivoting on the cylinder head and the valve end transferring the roller cam lobe actuation (rolling cam lobe actuation) to the valve end. As an option, the type II valvetrain may include a switching feature, such as a switching roller finger follower ("SRFF") 1. The SRFF 1 may be configured to provide lost motion for variable valve actuation (variable valve actuation, "VVA"), including, for example, a first valve lift mode and a lost motion lift mode, and a variety of VVAs may be implemented. The use of one or more SRFFs 1 in the valvetrain may enable advance or retard of valve opening or valve closing, engine braking, cylinder deactivation, internal exhaust gas recirculation, etc.

As shown in fig. 1A-1D, an example of operation of SRFF 1 includes an inner arm assembly 101, an outer arm assembly 102, a pivot body 103, and a latch pin 104, and includes a pivot end 107 and a valve end 108. The construction of SRFF 1 may replace a number of alternatives known in the art while being compatible with the teachings herein. For example, the outer arm assembly 102 may or may not have roller pads or slider pads on the outside. As another example, the valve ends 108, 208 may have inserts instead of valve gaskets. As yet another example, the through shafts 163, 263 may be omitted. The lost motion springs 161, 261 may be configured in another manner.

The inner arm assembly 101 is disposed inside the outer arm assembly 102 and includes an inner pivot shaft aperture 110, an inner shaft aperture 111, an inner roller assembly 112, and a latch 113.

The outer arm assembly 102 may be cold formed or manufactured from a single piece of stamped material and may include a first outer arm 120, a second outer arm 121, and at least one connecting portion 122 linking the first outer arm 120 and the second outer arm 121. The first and second outer arms 120, 121 each include outer pivot axle holes 123, 124, outer axle holes 125, 126, outer rollers 127, 128, optional outer rod holes 129, 130, a block bracket 131, a top molding 133, and outer arm slots 135, 136. At least one connecting portion 122 may form one or more portions of a blockbracket 131 for arranging pivot body 103. The one or more recesses 182 may include a stepped portion that may receive the retaining clip 137. As an option, the retention clip 137 may be disposed in the recess 182 or may be disposed in the outer arm slots 135, 136. Other options for the retention clip may include a flex arm 191 extending from the retention clip 137 into the outer arm slots 135, 136 to press against the pivot body 103. The holding claw 189 may be caught against the recess 182.

Optionally, the outer surfaces 180, 181 of the first and second outer arms 120, 121 may include recesses 182 and mirrored recesses on the second outer arm 121 to help retain other portions of the SRFF 1. For example, the curved arms 191 and the retaining fingers 189 of the retaining clip 137 may be moved back into the SRFF 1 to maintain a small footprint of the retaining clip 137. Conversely and optionally, the inner surfaces 184, 185 of the first and second outer arms 120, 121 may include a protrusion 186 and a mirrored protrusion on the first outer arm 120 to help retain other portions of the SRFF 2. For example, pivot body 103 may be inserted, guided, press fit, or clamped in place by inner surfaces 184, 185.

Pivot body 103 is disposed in pivot end 107 of outer arm assembly 102. Pivot body 103 may optionally be secured by a top molding 133 and a mirrored top molding on second outer arm 121. Pivot body 103 may include one or more of latch pin holes 141, optional inner rod holes 142, sockets 143, top molding receiving portions 144, 145, and block base 148. The connecting portion 122 of the outer arm assembly 102 can form a blockbracket 131 that can surround or be disposed at one or more portions of a blocky base 148 of the pivot body 103. Options for disposing pivot body 103 in pivot end 107 may include press-fit, slip-fit, welding, and the like. Optional protrusions in outer arm assembly 102, such as protrusion 186 and a mirrored protrusion on first outer arm 120, may also optionally help to retain pivot body 103.

Latch pin 104 is disposed within and slides within latch pin aperture 141 of pivot body 103. Optional features of the latch pin 104 include a contact surface 150, a guide groove 151, a biasing retainer 152, and an actuation surface 153. A drain passage 156 through latch pin 104 may optionally be included to transfer lubrication, actuation or other fluid from socket 143 to drain port 149. The biasing retainer 152 secures a biasing mechanism 154 that is nested along the latch pin 104. A biasing mechanism 154 is disposed between the biasing holder 152 and the pivot body 103. While biasing mechanism 154 is shown biasing latch pin 104 to the unlatched position, the opposite bias may be accomplished using alternatives known in the art to bias latch pin 104 to the latched position. Latch pin 104 may be configured to reciprocate in latch pin bore 141 between a latched position in which lever 155 is configured to enter first lift region 193 and latch 113 is configured to engage contact surface 150, and an unlatched position in which lever 155 is configured to enter second lift region 194 and latch 113 is configured to not engage contact surface 150. In the unlocked position, latch 113 may swing past contact surface 150. Or switching between the multiple contact surfaces may be performed using a stepped latch pin as known in the art.

Optional rod 155 passes through optional outer rod holes 129, 130 of outer arm assembly 102, optional inner rod hole 142 of pivot body 103, and guide groove 151 of latch pin 104. An optional lever 155 may optionally be used to further secure pivot body 103 to outer arm assembly 102 and may optionally serve as a travel limiter for latch pin 104 within guide groove 151. However, instead of the optional lever 155 and associated lever holes 129, 130, 142, pivot body 103 may be welded or otherwise coupled to the outer arm assembly 102 in a squeeze-like manner.

The pivot shaft 160 passes through the outer arm assembly 102 via the outer pivot holes 123, 124, through the inner arm assembly 101 via the inner pivot hole 110, and through the lost motion spring 161. The pivot shaft 160 is one example for providing relative movement between the inner arm assembly 101 and the outer arm assembly 102. Other alternatives known in the art may also be compatible with the outer arm assembly, such as a sliding or reciprocating inner arm assembly.

The hollow roller shaft 162 is received by the inner shaft bore 111. The inner rollers may roll on roller shafts 162 with or without needle bearings. The outer axle bores may be similarly shaped as outer axle bores 325, 425 such that the inner roller assembly 112 and outer rollers 127, 128 may be associated with the through axle 163. The penetrating shaft 163 passes through the roller shaft 162, and the roller shaft 162 may form a stroke limiting part of the penetrating shaft 163. The stroke range of the through shaft 163 inside the roller shaft 162 is defined by the gap G1, and serves as a boundary of the lost motion amplitude that can be absorbed by the SRFF 1. There are a number of alternative lost motion configurations in the art and these are compatible with the teachings of the pivoting body and external arm herein.

In one embodiment, SRFF 1 may comprise: an outer arm assembly 101 comprising a valve end 108 and a pivot end 107; an inner arm assembly 101 configured to pivot relative to the outer arm assembly 101, the inner arm assembly 101 including a latch 113; a pivot body 103 mounted to the pivot end 107 of the outer arm assembly 101, the pivot body 103 including a latch pin bore 141 and an inner lever bore 142; a latch pin 104 mounted in the latch pin hole 141, the latch pin 104 including a guide groove 151 and a contact surface 150, the guide groove 151 including a first lift region 193 and a second lift region 194; and a rod 155 passing through the inner rod hole 142, the rod 155 being configured to be aligned through the guide groove 151.

In another embodiment, the latch pin 104 may be configured to reciprocate in the latch pin bore 141 between a latched position in which the lever 155 is configured to enter the first lift region 193 and the latch 113 is configured to engage the contact surface 150, and an unlatched position in which the lever 155 is configured to enter the second lift region 194 and the latch 113 is configured to not engage the contact surface 150.

In another embodiment, the outer arm assembly 102 may include two outer shaft bores 125, 126, the inner arm assembly 101 may include an inner shaft bore 111, the roller shaft 162 is mounted in the inner shaft bore 111, and the through shaft 163 is disposed within the roller shaft 162 and through the two outer shaft bores 125, 126.

As shown in fig. 2A, SRFF 2 includes an inner arm assembly 201, an outer arm assembly 202, a pivot body 203, and a latch pin 204, and includes a pivot end 207 and a valve end 208. Fig. 1A-1D and 3A-5 provide pivoting bodies 103, 303, 403 configured for assembly into the top of outer arm assemblies 102, 302, 402 in a plug-in-assembly (plug-and-play) manner, while fig. 2A-2D and 6 provide pivoting bodies 203, 603 configured for assembly into the rear of outer arm assemblies 202, 602 in a plug-in manner. The switch roller finger follower 2 includes a pivot body 203 that further includes at least one tab (pivot body tabs 246, 247), and the outer arm assembly 202 further includes at least one horizontal slot (outer arm slot 235) for receiving the at least one tab.

In fig. 3C and 4C, the switching roller finger followers 3, 4 are configured for insertion assembly of the pivoting bodies 303, 403 into the top of the outer arm assemblies 302, 402. Pivoting bodies 303, 403 include at least one tab (also referred to as pivoting body tabs 348, 448). The outer arm assemblies 302, 402 include at least one vertical slot (also referred to as outer arm slots 335, 433) for receiving at least one tab. In fig. 4A-4C, the outer arm assembly is configured to include at least one top molding having an integral slot 433 or 434. The vertical slot portion 433 or 434 is configured to receive at least one tab (pivot body tab 447 or 448) and the top molding portion 433 or 434 is configured to mate with the pivot body 403, which further includes at least one top molding receiver 444 for receiving the at least one top molding 433 or 434.

In this working example, the inner arm assembly 201 is disposed within the outer arm assembly 202 and includes an inner pivot shaft bore 210, an inner shaft bore 211, an inner roller assembly 212, and a latch 213.

The outer arm assembly 202 may be cold formed or manufactured from a single piece of stamped material and may include a first outer arm 220, a second outer arm 221, and at least one connecting portion 222 linking the first outer arm 220 and the second outer arm 221. The first and second outer arms 220, 221 each include an outer pivot axle hole 223, 224, an outer axle hole 225, 226, an outer roller 227, 228, an optional outer rod hole 229, 230, a block bracket 231, a top molding 233, 234, and an outer arm slot 235, 236 for receiving an optional retaining clip 237 and pivot body tabs 246, 247.

Alternatively, the outer surfaces 280, 281 of the first and second outer arms 220, 221 may be stamped or otherwise formed to include recesses 282 and mirrored recesses on the outer arms 221 to help retain other portions of the SRFF 2. Similarly and conversely, the inner surfaces 284, 285 of the first and second outer arms 220, 221 may be stamped or otherwise formed to include a protrusion 286 and a mirrored protrusion on the inner surface 285 to help retain other portions of the SRFF 2.

Thus, the outer arm assembly 202 may include first and second outer arms 220, 221, each including an inner surface 284, 285 and an outer surface 280, 281, wherein each outer surface 280, 281 may include a recess 282 and a mirrored recess on the outer surface 281, and each inner surface 284, 285 may include a protrusion 286 and a mirrored protrusion on the inner surface 285.

As shown in fig. 2B, pivot body 203 is disposed in pivot end 207 of outer arm assembly 202 from above, secured by top molding 233, 234, and includes latch pin hole 241, optional inner rod hole 242, socket 243, top molding receiver 244, and mirrored top molding receivers on opposite sides of pivot body 203, pivot body tabs 246, 247, and block base 248. Inner surfaces 284, 285 may be configured to abut pivot body 203. As shown in fig. 3C and 4C, optional protrusions 286 in outer arm assembly 202 and mirrored protrusions on inner surface 285 may also help to retain pivot body 203 within outer arm assembly 202. The connecting portion 222 of the outer arm assembly 202 may form a blockstent 231 that may surround or position one or more portions of a blocky base 248 of the pivot body 203. Optional tab 286 in outer arm assembly 202 and the mirrored tab on inner surface 285 may also help to retain pivot body 203. Note that block-shaped base 248 can optionally be reduced such that pivot body 203 has less footprint than pivot body 103. Reducing the size of pivot body 203 or otherwise reducing the footprint of SRFF enables SRFF 2 to be deployed in a limited area.

The retention clip 237 may include a guide aperture 288, retention fingers 289, 290, and curved arms 291, 292. The retention clip 237 provides a circular guide aperture 288 to guide the spherical end of the hydraulic lash adjuster or other pivoting device into the receptacle 243 of the pivot body 203. The retention clip 237 may be stamped to form retention fingers 289, 290. The retaining pawls 289, 290 may be disposed in the recess 282 and in mirror image recesses on the outer arm 221, while the curved arms 291, 292 may engage with the outer arm slots 235, 236. When the flex arms 291, 292 are applied over the outer arm slots 235, 236, the flex arms 291, 292 can press against the pivot body 203 to bias the pivot body 203 into the position shown in fig. 2D. Although fig. 2B shows the outer arm slots 235, 236 as through-gaps in the first and second outer arms 220, 221, the outer arm slots 235, 236 may also be shown as recesses in the first and second outer arms 220, 221, as seen in fig. 2C.

Alternatively, the retention clip 237 may be configured to include only the retention jaws 289, 290. As described above, the retaining pawls 289, 290 may be configured to be disposed in the recess 282 and in a mirrored recess in the outer arm 221. In another alternative, the retention clip 237 can include at least one curved arm 291 or 292 configured to abut at least one pivot body tab 246 or 247.

The latch pin 204 is disposed within and slides within the latch pin hole 241 of the pivot body 203. Optional features of the latch pin 204 include a contact surface 250, a guide groove 251, a biasing retainer 252, and an actuation surface 253. A drain passage 256 through the latch pin 204 may optionally be included to transfer lubrication, actuation or other fluid from the receptacle 243 to the drain port 249. The biasing retainer 252 secures a biasing mechanism 254 that is nested along the latch pin 204. A biasing mechanism 254 is disposed between the biasing retainer 252 and the pivot body 203. The biasing mechanism 254 is shown biasing the latch pin 204 to the unlatched position, but the opposite bias may be accomplished using alternatives known in the art to bias the latch pin 204 to the latched position. The latch pin 204 may be configured to reciprocate in the latch pin aperture 241 between a latched position in which the lever 255 is configured to enter the first lift region 293 and the latch 213 is configured to engage the contact surface 250, and an unlatched position in which the lever 255 is configured to enter the second lift region 294 and the latch 213 is configured to not engage the contact surface 250. In the unlocked position, the latch 213 may swing past the contact surface 250. Or switching between the multiple contact surfaces may be performed using a stepped latch pin as known in the art.

Optional rod 255 may pass through optional outer rod bores 229, 230 of outer arm assembly 202, optional inner rod bore 242 of pivot body 203, and guide recess 251 of latch pin 204. The top forms 233, 234 can be configured to hold the pivot body 203 against the blockbracket 231 while the optional lever 255 prevents the pivot body 203 from rocking on the blockbracket 231 as the latch pin 204 reciprocates. Furthermore, an optional lever 255 may serve as a travel limiter for the latch pin 204 within the size range of the guide groove 251. However, pivot body 203 may be welded or otherwise coupled to outer arm assembly 202 in a squeeze-like manner, instead of or in addition to optional lever 255 and associated lever apertures 229, 230, 242. As seen in fig. 2C, top molding 233, 234 and top molding receiver 244, as well as mirror image top molding receivers on opposite sides of pivot body 203, may be removed to simplify manufacturing, pivot body 203 may be secured by welding, extrusion coupling, or by interfacing with protrusions 286 and mirror image protrusions on inner surface 285.

The pivot shaft 260 passes through the outer arm assembly 202 via the outer pivot shaft holes 223, 224, through the inner arm assembly 201 via the inner pivot shaft hole 210, and through the lost motion spring 261.

The hollow roller shaft 262 is received by the inner and outer shaft bores 211, 225, 226, the inner roller assembly 212 and the outer rollers 227, 228. The penetrating shaft 263 passes through the roller shaft 262, and the roller shaft 262 may form a stroke limiter of the penetrating shaft 263. When the cam lobe presses against the inner roller assembly 212, the inner arm assembly 201 pivots on the pivot shaft 260 and compresses the lost motion spring 261. The travel of the rollers in the inner roller assembly 202 is limited by the engagement of the through shaft 263 against the roller shaft 262. The range of travel of the through shaft 263 within the roller shaft 262 is defined by the gap G2. Note that the larger diameter of the roller shaft 262 and outer axle bores 225, 226 as compared to the roller shaft 162 and outer axle bores 125, 126 of fig. 1 results in a gap G2 that is larger than gap G1, resulting in a potentially larger amount of lost motion that can be absorbed by the SRFF 2, while the value of G1 or G2 is related to design options to balance lift height.

The actuation assembly 270 may be controlled to switch between a first valve lift mode and a second valve lift mode. The actuation assembly 270 may actuate the latch pin 204 of the SRFF 2 by applying or releasing a force to an actuation surface 253 of the latch pin 204. When the actuation assembly 270 is engaged with the actuation surface 253, the latch pin 204 may be configured to slide along the latch pin aperture 241 and the guide groove 251 to engage the contact surface 250 against the latch 213 on the inner arm assembly 201. When the actuation assembly 270 is disengaged from the actuation surface 253, the biasing mechanism 254 pushes the biasing retainer 252 of the latch pin 204, sliding the latch pin 204 along the longitudinal axis of the latch pin hole 241 and the guide groove 251 such that the contact surface 250 is no longer engaged against the latch 213 on the inner arm assembly 201. As mentioned above, the latch pin 204 may be configured in alternative ways, such as having the actuation assembly 270 push or pull the latch pin 204.

Placing the lever 255 in the guide groove 251 may prevent the latch pin 204 from rotating in the latch pin hole 241. The lever 255 may also function as a travel limiter together with the guide groove 251 in order to achieve a desired VVA. The first lift region 293 may be achieved by having the latch pin 204 in the first position and the second lift region 294 may be achieved by having the latch pin 204 in the second position. By adjusting the latch pin 213, the contact surface 250 and the guide groove 251, the number of lifting areas can be changed corresponding to the additional positions of the latch pin 204. The contact surface 250 may serve as a latch shelf for locking the latch 213 of the inner arm assembly 101. By moving the latch pin 204, the corresponding valve lift height may be transferred by the cam lobe pushing the inner roller assembly 212 downward, and the cam lobe may rest on the outer rollers 127, 128 in either the first lift region 293 where the latch pin 204 is positioned such that the latch 213 engages the contact surface 250 or the second lift position 281 where the latch pin 204 is positioned such that the latch 213 disengages from the contact surface 250.

The inner roller assembly 212 may be engaged by a cam lobe to complete the first valve lift. However, the lost motion lift mode may cause the valve lift to be zero or result in a valve lift that is less than the first valve lift. VVL such as cylinder deactivation ("CDA"), engine braking ("EB"), intake valve closing retard ("LIVC"), exhaust valve opening advance ("EEVO"), etc., may be implemented. The lift height may vary depending on the application of the valve train.

Fig. 2A shows the latch 213 unlocked from the contact surface 250. The stroke limiter may be formed by a through shaft 263 limited by a roller shaft 262. There are a number of alternatives to travel limits in the art, such as steps or other engagement surfaces between the inner arm assembly 201 and the outer arm assembly 202. Or the through shaft 263 may pass through a travel hole in the outer arm assembly 202. Furthermore, there are a number of solutions compatible with the alternatives of cantilever columns. Thus, the first outer roller 227 and the second outer roller 228 may be integrated onto the through shaft 263 so as to travel therewith. Fasteners (such as bushings, etc.) may secure the first and second outer rollers 227, 228 to the through-shaft 263. Or the first and second outer rollers 227, 228 may be mounted on cantilevered posts of the first and second outer arms 220, 221, etc. Further, the inner roller assembly 212 and one or more of the first and second outer rollers 227, 228 may be replaced with a slider pad.

As shown in fig. 2B, SRFF 2 allows for an alternative to assembly of the pivot body from the rear of outer arm assembly 202 (rather than from the top of outer arm assembly 202 in SRFF 1) through outer arm slots 235, 236 and pivot body tabs 246, 247. This rear assembly approach enables the SRFF 2 to be installed into a confined space, which may be detrimental to the use of SRFFs having top-down assembly as shown in SRFF 1. Further, as shown in fig. 2C, the top molding can be omitted in the outer arm and the top molding receiving portion can also be omitted in the pivot body, which saves machining time and cost.

Other variations on the outer arm assembly and latch pin body are possible. As shown in fig. 3A, the SRFF may include an outer arm assembly 302, a pivot body 303, and a latch pin 304. The outer arm assembly 302 may include a first outer arm 320, a second outer arm 321, a connection portion 322, compact top forms 333, 334, outer arm slots 335, 336, an outer pivot shaft hole 323, an outer shaft hole 325, outer lever holes 329, 330, inner surfaces 384, 385 with protrusions 386, outer surfaces 380, 381 with recesses 382, and retention clip receivers 387, 388. Pivot body 303 may include pivot body tabs 347, 348, optional inner rod aperture 342, top molding receiving portions 344, 345 and latch pin aperture 341.

Pivot body 303 may be assembled from the top of outer arm assembly 302, as partially shown in SRFF 3 of fig. 3C, with pivot body tabs 347, 348 mated with outer arm slots 335, 336 of outer arm assembly 302, and compact top forms 333, 334 of the outer arm assembly locked into top form receptacles 344, 345. Shortening the length of compact top forms 333, 334 can provide additional space on pivot body 303 and outer arm assembly 302 for pivot body tabs 347, 348 and outer arm slots 335, 336. Optional rods 355 disposed in outer rod bores 329, 330 and inner rod bore 342 can help secure pivot body 303.

Note that pivot body 303 has less footprint than pivot body 103 shown in fig. 1 and pivot body 203 shown in fig. 2. Reducing the footprint of pivot body 303 in turn reduces the size of the SRFF and enables the SRFF to be used in a limited environmental space where SRFF 1 or SRFF 2 may be too large or unsuitable for other reasons.

Fig. 4A-4C illustrate another variation of an outer arm assembly and pivot body incorporated into SRFF 4, as partially illustrated in fig. 4C. The SRFF may include an outer arm assembly 402, a pivot body 403, and a latch pin 404. The outer arm assembly 402 includes a first outer arm 420, a second outer arm 421, a connecting portion 422, a top molding with integral slots 433, 434, retention clip receivers 435, 436, outer rod bores 429, 430, an outer pivot shaft bore 423, and an outer shaft bore 425.

Pivot body 403 includes a molded portion receiver with integral tabs 447, 448, a latch pin aperture 441, and an optional lever aperture 442. The top molding with integral slots 433, 434 can then be interlocked with the molding receiving portion with integral tabs 447, 448 to secure pivot body 403 to outer arm assembly 402. The rod 455 may be disposed in the inner rod bore 442 and the outer rod bores 429, 430. In addition, pivot body 403 may be manufactured to be laterally symmetrical with respect to axis AA by cold forming, thereby reducing manufacturing time and cost. Furthermore, different manufacturing techniques may be employed, such as manufacturing pivot bodies 303, 403 by cold forming, while manufacturing outer arm assemblies 302, 402 by stamping.

Thus, as a design choice, the various pivoting bodies 103, 203, 303, 403, 603 are insertedly assembled into their respective outer arm assemblies 102, 202, 302, 402, 502, 602, allowing for materials of different combined cost and durability. The retention clips 137, 237 also make the retention clips lightweight and other materials may be selected, such as by providing the guide aperture 288 as an extension of the receptacle 243. Moreover, when the retention clips 137, 237 are used as a biasing or pressure source on the pivoting body, the welding step may optionally be omitted. The retention clips 137, 237 may be used with or without the alternative top molding 334, 433 and top molding receiving portions 344, 444 shown. Thus, the teachings of the various embodiments may be used together.

Fig. 5 and 6 show an alternative to the outer arm assembly and latch pin. Fig. 5 shows a portion of an alternative outer arm for use with an outer arm assembly. The outer arm 520 includes: an outer arm slot 521 for receiving a latch pin assembly from above; an optional outer rod aperture 522 for receiving an optional rod; and an external recess 523. The recess 523 may receive an optional retaining clip. Outer arm slots 521 may provide vertical and lateral support for the pivot body and serve as stop features. Outer arm slot 521 may also prevent the pivot body from rocking as the latch pin reciprocates. The outer arm 520 may be coupled with a mirrored outer arm via a connecting portion to form an outer arm assembly.

Fig. 6 shows an alternative external arm assembly 602 and pivot body 603 in a partial view of RFF 6. RFF 6 may include an outer arm assembly 602 and a pivot body 603.

The outer arm assembly 602 may be a single piece of stamped material and may include a first outer arm 620, a second outer arm 621, and at least one connecting portion 622 linking the first outer arm 620 and the second outer arm 621. The first and second outer arms 620, 621 can each include an outer shaft aperture 626, optional outer lever apertures 629, 630, a recess 632 on an outer surface, a protrusion 633 on an inner surface, and outer arm slots 635, 636 for receiving the retention clip and/or pivot body 603.

Pivot body 603 includes pivot body tabs 640, 641, internal rod holes 642, and sockets similar to sockets 143, 243 discussed above. Pivot body tabs 640, 641 are retained by outer arm slots 635, 636 and optional tab 633 to facilitate placement and positioning of pivot body 630 within outer arm assembly 602. As a compatible option, pivot body tabs 640, 641 may be press fit, or welded into outer arm slots 635, 636, or pivot body tabs 640, 641 may be biased in place as taught above with respect to retention clip 237.

One embodiment of RFF 6 may include: an outer arm assembly 602 including a valve end similar to the valve end discussed above and a pivot end 607 including outer arm slots 635, 636 and a connecting portion 622; an inner arm assembly similar to the inner arm assembly discussed above, configured to pivot relative to the outer arm assembly 602; and pivot body 603, including pivot body tabs 640, 641 disposed in outer arm slots 635, 636, pivot body 603 being mounted to connecting portion 622.

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

Claims

1. A switching roller finger follower comprising:

An outer arm assembly including a valve end and a pivot end;

an inner arm assembly configured to pivot relative to the outer arm assembly, the inner arm assembly including a latch;

A pivot body mounted to the pivot end of the outer arm assembly, the pivot body including a latch pin aperture and an inner lever aperture;

a latch pin mounted in the latch pin aperture, the latch pin including a guide groove and a contact surface, the guide groove including a first lifting region and a second lifting region; and

A rod passing through the inner rod hole, the rod configured to pass through the guide groove in alignment.

2. The switch roller finger follower as defined in claim 1 wherein said latch pin is configured to reciprocate in said latch pin aperture between a latched position in which said lever is configured to enter said first lift region and said latch is configured to engage said contact surface and an unlatched position in which said lever is configured to enter said second lift region and said latch is configured to not engage said contact surface.

3. The switching roller finger follower as defined in claim 1, wherein:

the outer arm assembly includes two outer shaft bores,

The inner arm assembly includes an inner shaft bore,

A roller shaft is installed in the inner shaft hole, and

A through shaft is provided inside the roller shaft, and the through shaft passes through the two outer shaft holes.

4. The switch roller finger follower as defined in claim 1 wherein said pivot body is configured for insertion assembly into a top portion of said outer arm assembly.

5. The switching roller finger follower as defined in claim 4, wherein said pivot body further comprises at least one tab, and wherein said outer arm assembly further comprises at least one vertical slot for receiving said at least one tab.

6. The switch roller finger follower as defined in claim 4 wherein said pivot body further comprises at least one tab and wherein said outer arm assembly further comprises at least one top molding integrally formed with at least one vertical slot and said vertical slot is configured to receive said at least one tab.

7. The switch roller finger follower as defined in claim 1 wherein said pivot body is configured to be insertedly assembled into a rear portion of said outer arm assembly.

8. The switch roller finger follower as defined in claim 7 wherein said pivot body further comprises at least one tab and wherein said outer arm assembly further comprises at least one horizontal slot for receiving said at least one tab.

9. The switch roller finger follower as defined in any one of claims 1-5, 7 and 8 wherein the outer arm assembly further comprises at least one top molding and wherein the pivot body further comprises at least one top molding receiver for receiving the at least one top molding.

10. A switch roller finger follower as defined in any one of the preceding claims wherein the pivot body is manufactured by cold forming and the outer arm assembly is manufactured by stamping.

11. The switching roller finger follower as defined in any one of claims 1-5, 7 and 8, wherein said outer arm assembly comprises first and second outer arms, each comprising an inner surface and an outer surface, wherein each outer surface comprises a recess, and wherein each inner surface comprises a protrusion.

12. The switch roller finger follower as defined in claim 11 wherein each said inner surface is configured to abut said pivot body.

13. The switching roller finger follower as defined in claim 11, further comprising a retaining clip, wherein the retaining clip comprises a respective retaining claw configured to be disposed in each of the recesses.

14. The switch roller finger follower as defined in claim 8, further comprising a retaining clip, wherein the retaining clip comprises at least one curved arm configured to abut the at least one tab.

15. The switching roller finger follower as defined in any one of claims 1-5, 7 and 8, further comprising a retention clip, wherein the retention clip comprises a guide aperture, a retention pawl and a curved arm.

16. A roller finger follower comprising:

an outer arm assembly comprising a valve end and a pivot end, the pivot end comprising an outer arm slot and a connecting portion;

an inner arm assembly configured to pivot relative to the outer arm assembly; and

A pivot body including a pivot body tab disposed in the outer arm slot, the pivot body mounted to the connecting portion.