Hydraulic tool having ram piston with integrated overload assembly

Patent metadata

Field	Value
Publication number	US-11999042-B2
Application number	US-202017051396-A
Country	US
Kind code	B2
Filing date	Aug 28, 2020
Priority date	Aug 29, 2019
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

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. A ram assembly for a hydraulic tool, the ram assembly comprising:
a ram piston having a ram cavity at an end of the ram piston, the ram piston receiving a hydraulic pressure reaction force; and
an overload assembly disposed in the ram cavity, the overload assembly including:
a burst disc positioned at a first end of the ram cavity;
a lock nut positioned at a second end of the ram cavity, the second end opposite the first end, the lock nut receiving a supporting force;
the hydraulic pressure reaction force and the supporting force acting in the same direction; and
a spacer positioned between the burst disc and the lock nut, the spacer transferring the supporting force applied from the lock nut to the burst disc.

2. The ram assembly of claim 1 , wherein the first end comprises a mounting surface, and the burst disc is mounted to the mounting surface so that a peripheral flange of the burst disc is substantially flat against the mounting surface.

3. The ram 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.

4. The ram 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 in contact with the convex radial surface and having substantially matching contours.

5. The ram assembly of claim 1 , wherein the spacer includes a conical surface and the lock nut includes a convex radial surface,
the conical surface in contact with the convex radial surface.

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

7. The ram assembly of claim 1 , wherein the overload assembly further comprises a ball positioned between the lock nut and the spacer,
the ball configured to transfer loads from the lock nut to the spacer, and
the lock nut and the spacer each include a recess contoured to substantially match a contour of the ball.

8. The ram assembly of claim 1 , wherein a spring surrounds an outer surface of the ram piston.

9. A hydraulic tool comprising:
a manifold that defines a ram chamber having a fluid inlet to receive a pressurized hydraulic fluid;
a ram assembly having a ram piston disposed within at least a portion of the ram chamber;
a burst disc having a peripheral flange;
a spacer in contact with the burst disc at the peripheral flange; and
a lock nut configured to receive a first hydraulic pressure reaction force acting in a first direction and a second supporting force acting in the first direction;
the spacer positioned between the burst disc and the lock nut to transfer the supporting force applied from the lock nut to the burst disc.

10. The hydraulic tool of claim 9 , wherein the first hydraulic pressure reaction force results from the pressurized hydraulic fluid pushing on the ram piston during operation of the hydraulic tool, and the second supporting force is applied on the lock nut and transferred to the burst disc.

11. The hydraulic tool of claim 9 , further comprising:
a hydraulic fluid passage circuit for hydraulically driving the hydraulic tool,
the fluid inlet in fluid communication with the hydraulic fluid passage circuit.

12. The hydraulic tool of claim 9 , wherein the ram piston includes a ram cavity at an end of the ram piston, the ram cavity positioned at a back portion of the ram chamber proximate to the fluid inlet.

13. The hydraulic tool of claim 12 , wherein the first hydraulic pressure reaction force and the second supporting force seal the burst disc against the ram cavity.

14. The hydraulic tool of claim 9 further comprising a cutting head.

15. The hydraulic tool of claim 12 , wherein the lock nut is threaded to the ram cavity.

16. A hydraulic tool comprising:
a manifold that defines a ram chamber having a fluid inlet to receive a pressurized hydraulic fluid;
a ram assembly having a ram piston disposed within at least a portion of the ram chamber;
a burst disc having a peripheral flange;
a spacer in contact with the burst disc at the peripheral flange;
a lock nut to receive a first hydraulic pressure reaction force acting in a first direction and a second supporting force acting in the first direction; and
a ball positioned between the lock nut and the spacer.

17. The hydraulic tool of claim 16 , wherein the first hydraulic pressure reaction force results from the pressurized hydraulic fluid pushing on the ram piston during operation of the hydraulic tool, and the second supporting force applied on the lock nut and transferred to the burst disc.

18. The hydraulic tool of claim 16 , further comprising:
a hydraulic fluid passage circuit for hydraulically driving the hydraulic tool,
the fluid inlet in fluid communication with the hydraulic fluid passage circuit.

19. The hydraulic tool of claim 16 , wherein the ram piston includes a ram cavity at an end of the ram piston, the ram cavity positioned at a back portion of the ram chamber proximate to the fluid inlet.

20. The hydraulic tool of claim 19 , wherein the first hydraulic pressure reaction force and the second supporting force seal the burst disc against the ram cavity.

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