Press-fit installation tool with dynamic load assist and method of press-fitting

Patent metadata

Field	Value
Publication number	US-9808921-B2
Application number	US-201414538844-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 12, 2014
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A tool has a biased piston, a plunger, and a base contained in a tool body. The plunger is positioned between the biased piston and the base and in contact with the base. A tool head is fixed to the base and extends outside of the tool body. The tool body is configured to be movable along a longitudinal axis relative to the base and plunger to move the plunger to load the piston when a load is applied to the tool body along a first load path. The tool body, the base, and the biased piston are configured to align the plunger with the longitudinal axis only when the load applied along the first load path is at least a first predetermined load, and thereby release stored energy of the piston as a dynamic load applied to the tool head along a second load path.

First claim

The invention claimed is:

1. A tool comprising:
a tool body having a longitudinal axis;
a biased piston, a plunger, and a base contained in the tool body; wherein the plunger is positioned between the biased piston and the base and in contact with the base;
a tool head fixed to the base and extending outside of the tool body;
wherein the tool body is configured to be movable along the longitudinal axis relative to the base and plunger to move the plunger to load the piston when a load is applied along a first load path that extends through the tool body, the plunger, the base, and the tool head; and
wherein the tool body, the base, and the biased piston are configured to align the plunger with the longitudinal axis only when the load applied along the first load path is at least a first predetermined load, and thereby release stored energy of the piston as a dynamic load applied to the tool head along a second load path that extends through the plunger, the base, and the tool head and avoids the tool body.

2. The tool of claim 1 , wherein the tool body has a first cavity, a second cavity, and a tapered passage connecting the first cavity and the second cavity; wherein the tapered passage is centered along the longitudinal axis; and
wherein the piston, the plunger, and the tapered passage are configured so that a gap is maintained between the piston and the tool body when stored energy of the piston is released, thereby preventing the second load path from passing through the tool body.

3. The tool of claim 2 , wherein the piston has an outer surface with a recess that is substantially aligned with the tapered passage; and
wherein the plunger has a tip configured to be received in the recess when the plunger is aligned with the longitudinal axis.

4. The tool of claim 2 , wherein the base has a first curved surface; wherein the plunger has a contact surface; and
a biasing element in the second cavity biasing the contact surface against the first curved surface.

5. The tool of claim 2 , wherein the biasing element is a tapered spiral spring concentric with the longitudinal axis, and having a first end positioned against the tool body and a second end positioned against the plunger.

6. The tool of claim 2 , further comprising:
a spring positioned in the first cavity and configured to bias the piston toward the tapered passage.

7. The tool of claim 2 , wherein the first cavity is filled with compressible fluid, and further comprising:
a seal retained by the piston between the piston and the tool body.

8. The tool of claim 2 , wherein the tool head is a first tool head configured to be removable from the base; and further comprising:
a second tool head configured to be fixed to the base for press-fitting a second component different than the first component.

9. The tool of claim 8 , further comprising:
a first spring having a first spring stiffness positioned in the first cavity and configured to bias the piston toward the tapered passage when the first tool head is fixed to the base; and
a second spring having a second spring stiffness positioned in the first cavity and configured to bias the piston toward the tapered passage when the second tool head is fixed to the base.

10. A tool for press-fit installation of a component, the tool comprising:
a tool body having a first cavity, a second cavity, and a tapered passage connecting the first cavity and the second cavity; wherein the tapered passage has a longitudinal axis;
a piston housed in the first cavity and biased toward the tapered passage; wherein the piston has an outer surface with a recess that is substantially aligned with the longitudinal axis;
a base positioned in the second cavity and having a first curved surface;
a tool head for press-fitting a component; wherein the tool head is fixed to the base and extends outside of the tool body; wherein the base and the tool body are configured such that the tool body slides relative to the base when force is applied on the tool body toward the tool head;
a plunger positioned in the second cavity;
a biasing element in the second cavity biasing the plunger against the first curved surface of the base and away from the first cavity;
wherein the plunger and the base are configured so that the plunger is in a first position tilted relative to the longitudinal axis in a first state;
wherein the plunger is configured to extend into the first cavity through the tapered passage and load the piston as the plunger is moved toward a position aligned with the longitudinal axis by the tool body at the tapered passage so that the tip of the plunger moves into the recess when the predetermined force is applied on the tool body, thereby releasing the piston and directing a dynamic load of stored energy of the piston through the plunger, the base, and the tool head;
wherein the piston, the plunger, and the tapered passage are configured so that a gap is maintained between the piston and the tool body when the piston is released, thereby preventing the dynamic load from passing through the tool body.

11. The tool of claim 10 , wherein the biasing element is a tapered spiral spring concentric with the longitudinal axis; wherein the tapered spiral spring has a first end positioned against the tool body and a second end positioned against the plunger.

12. The tool of claim 10 , further comprising:
a spring positioned in the first cavity and configured to bias the piston toward the tapered passage.

13. The tool of claim 10 , wherein the first cavity is filled with compressible fluid, and further comprising:
a seal retained by the piston between the piston and the tool body.

14. The tool of claim 10 , wherein the tool head is a first tool head configured to be removable from the base; and further comprising:
a second tool head configured to be fixed to the base for press-fitting a second component different than the first component.

15. The tool of claim 14 , further comprising:
a first spring with a first spring stiffness positioned in the first cavity and configured to bias the piston toward the tapered passage when the first tool head is fixed to the base; and
a second spring with a second spring stiffness positioned in the first cavity and configured to bias the piston toward the tapered passage when the second tool head is fixed to the base.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Christoff Brian D
• Larson Travis S

Classifications

• B25B27/02 Primary

  for connecting objects by press fit or detaching same {(B25D1/16 takes precedence)} · CPC title

• B25B27/026 Primary

  fluid driven · CPC title