Electromagnetic base for magnetic drill press

Patent metadata

Field	Value
Publication number	US-9764438-B2
Application number	US-201514639559-A
Country	US
Kind code	B2
Filing date	Mar 5, 2015
Priority date	Mar 7, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A magnetic base for coupling a drill press to a ferromagnetic workpiece includes a ferromagnetic body having spaced, substantially parallel first and second rails. Each of the first and second rails includes a flat bottom surface engageable with the ferromagnetic workpiece. A coil is positioned between the first and second rails for generating a holding force on the ferromagnetic workpiece. The coil defines a central axis that is parallel with the bottom surface of each of the first and second rails.

First claim

What is claimed is:

1. A magnetic base for coupling a drill press to a ferromagnetic workpiece, the magnetic base comprising:
a ferromagnetic body including spaced, substantially parallel first and second rails, each of the first and second rails having a flat bottom surface engageable with the ferromagnetic workpiece;
a coil positioned between the first and second rails for generating a holding force on the ferromagnetic workpiece; and
a non-ferromagnetic plate extending between the flat bottom surface of each of the first and second rails and the coil, and
wherein the coil defines a central axis parallel with the bottom surface of each of the first and second rails.

2. The magnetic base of claim 1 , wherein the ferromagnetic body includes a rib interconnecting the first rail and the second rail, and wherein the coil surrounds the rib.

3. The magnetic base of claim 2 , wherein the rib is located between the bottom surface and a top surface of each of the first rail and the second rail.

4. The magnetic base of claim 1 , wherein each of the first rail and the second rail includes a chamfer on an interior edge adjacent the bottom surface of each of the first and second rails.

5. The magnetic base of claim 1 , wherein the non-ferromagnetic plate extends between the first rail and the second rail, and wherein the non-ferromagnetic plate is positioned beneath and spaced from the coil.

6. The magnetic base of claim 1 , further comprising:
a first end cap coupled to a front end of the ferromagnetic body; and
a second end cap coupled to a rear end of the ferromagnetic body, wherein the first and second end caps are made from a non-ferromagnetic material, and wherein the first end cap, the second end cap, and the non-ferromagnetic plate at least partially enclose the coil.

7. The magnetic base of claim 1 , further comprising a groove formed in an interior surface of each of the first rail and the second rail, wherein the non-ferromagnetic plate is received within the groove of each of the first rail and the second rail.

8. The magnetic base of claim 1 , wherein a workpiece receiving space is defined between the first rail, the second rail, and the non-ferromagnetic plate.

9. The magnetic base of claim 1 , further comprising a bobbin upon which the coil is supported, wherein the bobbin includes a first portion and a second portion that are interconnected by an overlapping joint.

10. The magnetic base of claim 1 , further comprising a first insulation layer positioned between the first rail and the coil, and a second insulation layer positioned between the second rail and the coil, wherein a width dimension is defined between the first rail and the second rail, and wherein no more than two layers of insulation are located within the width dimension.

11. The magnetic base of claim 1 , further comprising a top cap positioned above the coil and coupled to a top surface of each of the first and second rails, wherein the top cap is made from a non-ferromagnetic material, and wherein the top cap encloses an upper portion of the coil.

12. The magnetic base of claim 1 , wherein the coil is a bipolar electromagnet.

13. The magnetic base of claim 1 , wherein the coil is spaced from the flat bottom surface of each of the first and second rails.

14. The magnetic base of claim 1 , wherein the coil is the only coil coupled to the ferromagnetic body.

15. A magnetic base for coupling a drill press to a ferromagnetic workpiece, the magnetic base comprising:
a ferromagnetic body including spaced, substantially parallel first and second rails, each of the first and second rails having a flat bottom surface engageable with the ferromagnetic workpiece;
a coil positioned between the first and second rails for generating a holding force on the ferromagnetic workpiece; and
a non-ferromagnetic plate extending from an interior surface of the first rail to an interior surface of the second rail,
wherein each of the first and second rails includes a chamfer adjacent the flat bottom surface and on an interior edge of the respective first and second rails.

16. The magnetic base of claim 15 , wherein the chamfer is inclined between 10 degrees and 12 degrees relative to the flat bottom surface.

17. The magnetic base of claim 15 , wherein the non-ferromagnetic plate is positioned between the coil and the chamfer of each of the first and second rails.

18. The magnetic base of claim 15 , wherein a workpiece receiving space is defined between the first rail, the second rail, and the non-ferromagnetic plate.

19. The magnetic base of claim 18 , wherein the first rail and the second rail are configured to support the magnetic base on a round workpiece, and wherein a portion of the round workpiece is received within the workpiece receiving space.

20. The magnetic base of claim 15 , wherein the chamfers of the respective first and second rails are engageable with a round workpiece.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Reichert Timothy R

Classifications

• B23Q3/1543 Primary

  using electromagnets · CPC title

• B25H1/0071

  by magnetic means · CPC title

• H01F7/20

  without armatures (cores H01F3/00; coils H01F5/00 {; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381}) · CPC title

• Y10T408/554

  Magnetic or suction means · CPC title

• B23Q9/0014

  Portable machines provided with or cooperating with guide means supported directly by the workpiece during action · CPC title