Latching pin assembly and deactivating rocker arm assembly

Patent metadata

Field	Value
Publication number	US-12378903-B2
Application number	US-202418973939-A
Country	US
Kind code	B2
Filing date	Dec 9, 2024
Priority date	Nov 10, 2020
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A latch assembly can comprise a main latch pin assembly comprising a first diameter on a first main pin face, and a secondary latch piston comprising a second diameter on a secondary piston face. The secondary latch piston can be configured to selectively act on the main latching pin assembly. The main latch pin assembly can be biased to oppose the secondary latch piston. The first diameter can be greater than the second diameter. A rocker arm assembly can comprise the latch assembly. A primary arm can be configured to receive the main latch pin assembly. A secondary arm can be configured to receive the secondary latch piston.

First claim

What is claimed is:

1. A rocker arm assembly comprising:
a primary arm defining a primary pivot knee and a primary rocker shaft bore sized to receive a rocker shaft;
a secondary arm defining a secondary pivot knee and a secondary rocker shaft bore sized to receive the rocker shaft;
a latching assembly movable between
a latched arrangement inhibiting rotation of the secondary arm relative to the primary arm, and
an unlatched arrangement allowing rotation of the secondary arm relative to the primary arm; and

a lost motion spring extending between the primary pivot knee and the secondary pivot knee.

2. The rocker arm assembly of claim 1 , wherein the lost motion spring includes a spring guide and plunger secured between the primary pivot knee and the secondary pivot knee.

3. The rocker arm assembly of claim 1 , wherein the lost motion spring includes a swivel end and a stay end.

4. The rocker arm assembly of claim 1 , wherein the lost motion spring biases the primary pivot knee away from the secondary pivot knee.

5. The rocker arm assembly of claim 1 , wherein the lost motion spring is configured to be compressed when the latching assembly is in the unlatched arrangement.

6. The rocker arm assembly of claim 1 , wherein the primary arm includes a pin bore defining a pin outer diameter,
wherein the secondary arm includes a bore step and a piston bore defining a piston diameter, and
wherein the latching assembly includes
a latch pin sized to be received within the pin bore and including a main pin face defining a first diameter, the first diameter less than the pin outer diameter of the pin bore and greater than the piston diameter of the piston bore, the main pin face selectively engaged with the bore step of the secondary arm, and the latch pin biased toward the secondary arm, and
a latch piston sized to be received within the piston bore and configured to move the latch pin out of engagement with the bore step.

7. The rocker arm assembly of claim 6 , wherein the latching assembly further includes a pin spring engaged with the latch pin and biasing the latch pin into engagement with the latch piston.

8. The rocker arm assembly of claim 7 , wherein the latch pin defines a pin step between the pin outer diameter and the first diameter.

9. The rocker arm assembly of claim 6 , wherein:
the primary arm comprises a primary travel limit,
the secondary arm comprises a secondary travel limit, and
the secondary travel limit contacts the primary travel limit when the latching assembly is in the latched arrangement, but the secondary travel limit is configured to swing away from the primary travel limit when the latching assembly is in the unlatched arrangement.

10. The rocker arm assembly of claim 9 , wherein the lost motion spring biases the primary travel limit toward the secondary travel limit.

11. The rocker arm assembly of claim 6 , wherein the latch pin includes an anti-rotation flat.

12. The rocker arm assembly of claim 6 , further comprising a bearing end on the secondary arm and a valve end on the primary arm.

13. The rocker arm assembly of claim 12 , wherein the bearing end, the valve end, and the latching assembly are positioned relative to the primary rocker shaft bore in a triangular distribution.

14. The rocker arm assembly of claim 6 , wherein the primary arm comprises a lubrication port to the latching assembly.

15. The rocker arm assembly of claim 6 , wherein the secondary arm comprises an actuation port to the latch piston.

16. The rocker arm assembly of claim 15 , wherein the latch piston comprises a cupped cavity configured to receive an actuation fluid.

17. A rocker arm assembly comprising:
a primary arm including a pivot slot, a first pin bore, a second pin bore, and a primary pivot knee, each of the first pin bore and the second pin bore defining a pin outer diameter;
a secondary arm received within the pivot slot of the primary arm and including a secondary pivot knee and a piston bore defining
a piston diameter,
a first bore step, and
a second bore step,
wherein the piston diameter is less than the pin outer diameter, and
wherein the first bore step and the second bore step define a bore step diameter that is greater than the piston diameter and less than the pin outer diameter;

a lost motion spring extending between the primary pivot knee and the secondary pivot knee, the lost motion spring biasing the primary pivot knee away from the secondary pivot knee; and
a latch assembly, comprising:
a first latch pin sized to be received within the first pin bore and including a first main pin body and first main pin face defining a pin latching diameter, the pin latching diameter of the first latch pin selectively engaged with the first bore step of the secondary arm, and the first latch pin biased toward the secondary arm;
a first latch piston sized to be received within the piston bore and configured to move the first latch pin out of engagement with the first bore step;
a second latch pin sized to be received within the second pin bore and including a second main pin body and second main pin face defining the pin latching diameter, the pin latching diameter of the second latch pin selectively engaged with the second bore step of the secondary arm, and the second latch pin biased toward the secondary arm; and
a second latch piston sized to be received within the piston bore and configured to move the second latch pin out of engagement with the second bore step.

18. The rocker arm assembly of claim 17 , wherein the lost motion spring includes a spring guide and plunger secured between the primary pivot knee and the secondary pivot knee.

19. The rocker arm assembly of claim 17 , wherein the lost motion spring includes a swivel end and a stay end.

20. A rocker arm assembly comprising:
a primary arm defining a primary pivot knee, a primary rocker shaft bore sized to receive a rocker shaft, and a valve end;
a secondary arm defining a secondary pivot knee, a secondary rocker shaft bore sized to receive the rocker shaft, and a bearing end;
a latching assembly movable between
a latched arrangement inhibiting rotation of the secondary arm relative to the primary arm, and
an unlatched arrangement allowing rotation of the secondary arm relative to the primary arm; and

a lost motion spring extending between the primary pivot knee and the secondary pivot knee,
wherein the valve end, the bearing end, and the latching assembly are positioned relative to the primary rocker shaft bore in a triangular distribution.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Guaschino Mirko
• Ravoni Marco
• Andrisani Nicola
• Cecchi Michele Angelo
• D'Amore Massimo

Classifications

• F01L2810/02

  Lubrication · CPC title

• F01L2001/467

  Lost motion springs · CPC title

• F01L2001/186

  Split rocking arms, e.g. rocker arms having two articulated parts and means for varying the relative position of these parts or for selectively connecting the parts to move in unison · CPC title

• F01L13/0005 Primary

  Deactivating valves · CPC title

• F01L1/181

  Centre pivot rocking arms · CPC title