US2785716A - Safety guard for rotary power tool - Google Patents

Description

Mardl 1957 J. B. LUTTON 2,785,716

SAFETY GUARD FOR ROTARY POWER TOOL Filed July 6. 1955 FIG 3 14 g i 1: 68 INVENTOR J \\\5! JOSEPH B. LUTTON 22, av g ATTORNEY United States Fatent @fiice Patented Mar. 1 3, 1957 SAFETY GUARD FUR ROTARY POWER TOOL Joseph B. Lutton, Lancaster, Pa., assignor to De Wait Inc., a corporation of Pennsylvania Application July 6, 1955, Serial No. 529,193

4 Claims. (Cl. 144-251) This invention relates to safety guards for power tools, and more particularly to a safety guard for a rotary shaping tool secured to a rotating vertical shaft.

It is the purpose of this invention to provide a simple and readily adjustable means for guarding a rotary cutting tool during the cutting operation to prevent injury to the operator.

Heretofore, to my knowledge, no satisfactory guard has been devised for protecting the operator when a power tool is used for shaping. Various types of tool guards have been devised for use when the power tool has a circular saw mounted thereon but such guards must be removed or moved into inoperative position when a shaping tool is employed or more specifically when the motor or drive shaft are in a vertical position as in the operation of shaping. It is therefore an obiect of my invention to design a simple but eifective guard to prevent inadvertent injury during this type of operation.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of operation may be undersiood by reference to the structure embodying my invention and shown in the accompanying drawings in which I illustrate:

Fig. 1 shows a plan view of the safety guard mounted on the motor housing;

Fig. 2 is a perspective front elevation of the device, and

Fig. 3 is a sectional elevation taken on the line 3-3 of Fig. l.

The motor 16 has a housing 12 having an annular extension 14 in which is formed an annular groove 16. The extended arbor shaft 1'? of the motor ll protrudes through the center of extension 14. Arbor shaft 1? has a shoulder 19 and is threaded at its end to receive nut 20. Collar 18 and a shaping tool 22 are detachably secured to the shaft between shoulder 19 and nut Shaping tool 22 carries the cutting bits 23.

A semi-circular bracket 24 has a flange 2-5 shaped to engage the annular groove 16 as shown in Figs. 1 and 3. Bracket 24 is secured in this position by a threaded stud 26 extending from motor housing 12 through a slot in annular bracket 24. Wing nut 28 draws the bracket 24 tight on stud 26 for tight fitting engagement of the bracket in annular groove 16.

An arcuate skirt-like guard 32 is slidably supported on a pair of upstanding pins 39 secured to bracket 24. Set screws 34 hold guard 32 in adjusted position on the pins 36. As shown, the pins 30 are spaced about 100 degrees from each other to provide adequate support for guard 32.

In operation, the workpiece 36 is supported on the table 38 and the guard 32 is lowered almost to the workpiece as shown in Fig. 3, whereupon the set screws 34 are secured. The height of the pins 30 provides a range of adjustment for various sizes of workpieces 36. The workpiece 36 may then be guided along a conventional fence (not shown) and into engagement with the cutting bits 23 of shaping tool 22.

It will be evident that the operator who is holding the workpiece 36 is positively prevented from inadvertently inserting his fingers into the cutting tool during the shaping operation. A simple adjustment of the guard 32 up and down along the pins 39 accommodates the various sized workpieces 36.

I claim:

1. A safety guard suitable for attachment to a rotary power tool having a motor and protruding arbor shaft positioned above a work supporting table, an arcuate bracket securable to the housing of said motor, upstanding pins on said bracket, an arcuate skirt-shaped guard slidably mounted on said pins, and means to secure said guard against movement along said pins whereby said guard may be adjusted to a position above the workpiece and with said bracket and said workpiece enclosing a cutting tool on said arbor shaft.

2. In combination, a machine having a rotary cutting tool positioned on a vertical axis adapted to engage a workpiece by relative movement between said cutting tool and said workpiece, a horizontal arcuate bracket secured against rotation above said rotary cutting tool and concentric thereto, upstanding pins adjacent the edge of said arcuate bracket, a skirt-like arcuate guard slidably secured on said pins for vertical adjustment, said skirt-like guard having a greater are than the arc of said cutting tool and being positioned concentric thereto on said arcuate bracket, and means to secure said skirtlike guard in adjusted vertical elevation on said upstanding pins whereby said skirt-like guard may be adjusted down to a workpiece to form therewith a guard about said tool.

3. In combination, a machine having a rotating shaft, a stationary housing concentric about a portion of said rotating shaft, a cutting tool on said rotating shaft, said shaft being in substantially vertical position and said cutting tool rotating in a substantially horizontal plane, an arcuate bracket securable to said housing and concentric to said shaft, vertical pins secured to said bracket, an arcuate skirt slidably supported on said pins for vertical adjustment, said arcuate skirt having an arc of greater radius than the radius of said cutting tool, and means to secure said arcuate skirt in an adiusted position slightly above a workpiece, said arcuate skirt said bracket and said workpiece forming a protective guard about the top and side of said cutting tool.

4. A safety device suitable for positioning about a rotating shaft having a cutting tool thereton, said device comprising an arcuate stationary bracket to be positioned concentrically about said shaft in a plane transverse thereto, upstanding pins on said bracket, said pins being substantially parallel to said rotating shaft, and an arcuate skirt-like guard slidably mounted on said pins and having a skirt-like arcuate wall substantially concentric to said shaft, said guard forming with said bracket a protective guard about a portion of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,598,498 Paden Aug. 31, 1926 1,715,292 Hoffman et al May 28, 1929 1,807,561 White May 26, 1931 FOREIGN PATENTS 13,858 Great Britain of 1898 142,431 Germany July 13, 1903 191,600 Great Britain Ian. 18, 1923

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