Hydraulic tool having ram piston with integrated overload assembly

Patent metadata

Field	Value
Publication number	US-12397407-B2
Application number	US-202418670408-A
Country	US
Kind code	B2
Filing date	May 21, 2024
Priority date	Aug 29, 2019
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

Embodiments of the invention provide a ram assembly for a hydraulic tool. The ram assembly includes a ram piston having a ram cavity. The ram piston receives a hydraulic pressure reaction force. The ram assembly further includes an overload assembly disposed in the ram cavity or in a cavity defined by a manifold. The overload assembly includes a burst disc positioned at a first end of the ram cavity or manifold, a lock nut positioned at a second end of the ram cavity or manifold, and a spacer positioned between the burst disc and the lock nut. The spacer transfers a supporting force applied to the lock nut to the burst disc. The hydraulic pressure reaction force and the supporting force both act in the same direction, and thus, are additive forces acting on the burst disk.

First claim

The invention claimed is:

1. An overload assembly for use in a ram cavity of a ram piston of a hydraulic tool, the ram cavity including a first end and a second end opposite the first end, the overload assembly comprising:
a burst disc positioned at the first end of the ram cavity;
a lock nut positioned at the second end of the ram cavity, the lock nut receiving from the ram piston a hydraulic pressure reaction force acting in a first direction, the lock nut receiving a supporting force acting in the first direction; and
a spacer positioned between the burst disc and the lock nut.

2. The overload assembly of claim 1 , wherein the spacer transfers the supporting force applied from the lock nut to the burst disc.

3. The overload assembly of claim 1 , and further comprising a ball positioned between the lock nut and the spacer.

4. The overload assembly of claim 1 , wherein the burst disc includes a radially extending peripheral flange that contacts a mounting surface of the first end.

5. The overload assembly of claim 1 , wherein the lock nut is threaded to the second end of the ram cavity and the supporting force is generated by torqueing the lock nut.

6. The overload assembly of claim 1 , wherein the spacer includes a concave radial surface and the lock nut includes a convex radial surface,
the concave radial surface being in contact with the convex radial surface and having matching contours.

7. The overload assembly of claim 1 , and further comprising a lock cap to lock the overload assembly in a manifold.

8. The overload assembly of claim 1 , wherein the spacer supplies a leak path when the burst disc is ruptured.

9. A hydraulic tool comprising:
a manifold including a ram chamber that receives a pressurized hydraulic fluid;
a ram assembly having a ram piston, the ram piston receiving a hydraulic pressure reaction force, the ram piston including a ram cavity within at least a portion of the ram chamber, the ram cavity including a mounting surface;
a burst disc sealed against the mounting surface;
a lock nut that receives the hydraulic pressure reaction force and a supporting force acting in a same direction as the hydraulic pressure reaction force; and
a spacer positioned between the burst disc and the lock nut to transfer the supporting force from the lock nut to the burst disc.

10. The hydraulic tool of claim 9 , wherein the hydraulic pressure reaction force results from the pressurized hydraulic fluid pushing on the ram piston during operation of the hydraulic tool.

11. The hydraulic tool of claim 9 , and further comprising a hydraulic fluid passage circuit to hydraulically drive the hydraulic tool; and a fluid inlet in fluid communication with the hydraulic fluid passage circuit.

12. The hydraulic tool of claim 9 , wherein a spring surrounds an outer surface of the ram piston.

13. The hydraulic tool of claim 9 , wherein the lock nut and the spacer have radially-contoured surfaces to self-align during operation.

14. The hydraulic tool of claim 9 , wherein the lock nut is threaded to the ram cavity.

15. A ram assembly for a hydraulic tool, the ram assembly comprising:
a ram piston that receives a hydraulic pressure reaction force, the ram piston having a ram cavity; and
an overload assembly in the ram cavity, the overload assembly including:
a burst disc;
a lock nut that receives a supporting force, the hydraulic pressure reaction force and the supporting force acting in a same direction; and
a spacer positioned between the burst disc and the lock nut.

16. The ram assembly of claim 15 , wherein the spacer transfers the supporting force from the lock nut to the burst disc.

17. The ram assembly of claim 15 , wherein the burst disc includes a peripheral flange that seals the burst disc against the ram cavity.

18. The ram assembly of claim 15 , wherein the spacer includes a concave radial surface and the lock nut includes a convex radial surface.

19. The ram assembly of claim 15 , wherein the overload assembly is housed within the ram piston.

20. The ram assembly of claim 15 , and further comprising a spring that surrounds an outer surface of the ram piston.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Ballard James G
• Myrhum Jr James O

Classifications

• B23D17/06 Primary

  actuated by fluid or gas pressure · CPC title

• F16K17/162

  of the non reverse-buckling-type (F16K17/1633 takes precedence) · CPC title

• F16K17/16

  with fracturing diaphragm {; Rupture discs} · CPC title

• B25F5/00

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• F16K17/383

  the valve comprising fusible, softening or meltable elements, e.g. used as link, blocking element, seal, closure plug (F16K17/386 takes precedence) · CPC title