CA2313898A1 - Dove tail angle degree finder - Google Patents

Abstract

This invention, called a Dove Tail Angle Degree Finder, is a mechanical measuring device. It is a router application accessory enabling the operator to find the specific degree of the cutting angle of dovetail router bits.
Distinct dovetail applications require specific degrees. The degree of the cutting angle is usual not marked on the router bit's shaft. A custom ground or resharpened bit also has a specific cutting angle.
This invention is very handy in a shop with an inventory of many different dovetail bits.
Bits can be specified in a frustration less, fast and accurate way.

Description

Background of the Invention To find the proper angle bit and to be sure it is of the exact required angle was a bit guess work, frustrating and timely. To grind a specific bit In order to match the angle of an existing work piece was equally time consuming. This phenomena led me to the idea of this invention.
Description of the Preferred Embodiments The following detailed description illustrates embodiments of the invention by way of example and not by way of limitation.
This description will clearly enable one to make, use and install this invention.
This Invention is implemented by the use of a sliding bar with two jaws, similar in appearance to that of a vernier caliber. One jaw is secured to the sliding bar and the other jaw moves along said sliding bar.
The secured jaw's inner-side is furnished with a plate which increases its surface area.
The sliding jaw's inner-side is designed to be slanted by approximately 35 degrees. The purpose of this pattern is to allow only the bottom tip of the movable jaw's inner-side to come in contact with the secured jaw's inner-side when closed. A hole has to be furnished near the bottom tip of the sliding jaw. A clock-like hand is to be installed via a spring loaded pin to said hole.
This spring loaded pin contains a coil spring which brings the hand back to it's standard zero degree position. A stopper is to be incorporated for the hand to rest at the zero degree position.
A scale with one degree increments is marked on the sliding bar. The scale Is located opposite to the sliding jaw's hand installation. When an ob-ject is placed between the jaws, the hand moves to indicate the proper de-gree reading.
An optional tension-spring may be used to pull the sliding jaw assem-bly to the closed position.
Remarks: The angle degree specification on dovetail bits refer to the rela-tionship between shaft and one cutting edge of the router bit. This has to be taken into account when calculating the scale increments. Since the hand shows the total V-shope of the dovetail bit, which is double the bit measure-ment, the increments on the device are half degrees in order to display stan-dard bit measurements.
The sliding bar can be made of any material, and in any shape.
The jaws functions can also be reversed. All these changes or modifica-tlons do not have any merit on the distinctiveness of this invention being a dove tall angle degree finder.
The operation of this device is best performed by using two hands, un-less this device is made or fastened to be stationary.
To insert the bit the jaws must be pulled apart. If not installed with the optional closing spring the jaw must be closed manually.
The device works as follows:

The dovetail bit is placed with the cutting edge firmly against the flat plate surface off the fixed jaw. Make sure that the bit shaft is all the way outside of this jaw. The closed sliding jaw forces the hand to move which compensates for the bit angle. The measurements of the dovetail bit are ob-tained from the degree scale reading. Other objects of non parollel shafts can of course also be measured.

Claims (9)

1: A Device enabling one to find and measure the degree of dovetail router bits and other non parallel objects.

2: A stationary jaw affixed to .alpha.. sliding bar

3: The stationary jaw as defined in claim 2 is to be furnished with a plate at it's inner side whereby creating a large surface area for the router bit to rest against.

4: A specially shaped movable jaw which is riding on the sliding bar as defined in claim 2.

5: A hole through the bottom-tip is to be furnished to the specially shaped movable jaw as defined in claim 4 to hold the pin and coil spring for the clocklike hand.

6: A clocklike hand is to be installed v1a a coil spring to said hole as defined in claim 5.

7: A stopper has to be furnished on the movable jaw in order for the spring loaded clock like hand to rest in it's zero degree reading position.

8: A scale with increments of dovetail-bit degree measurements is to be incorporated and located at the prober distance for the tip of the clocklike hand as defined in claim 6 to show the readings.

9: A tension spring is to pull the movable jaw toward .alpha. closed position.