Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS2422755 A
Publication typeGrant
Publication dateJun 24, 1947
Filing dateApr 27, 1944
Priority dateApr 27, 1944
Publication numberUS 2422755 A, US 2422755A, US-A-2422755, US2422755 A, US2422755A
InventorsStrother John
Original AssigneeStrother John
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety drill
US 2422755 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 24,1947. x J STRQTHER 2,422,755

SAFETY DRILL Filed April 27, 1944 2 Sheets-Sheet l ATTE! RN EYE 111118124, 1947. `J STROTHER v2,422,755

SAFETY DRILL *Filed April 27, 1944 2 Sheets-Sheet 2 Patented June 24, 1947 UNITED STATES PATENT OFFICE l SAFETY DRILL John simmer, Rome, N.l Y.

Application April 27, 1944, `Serial N o. 532,999

2 Claims.

The invention relates to a drill attachment, and more particularly to a safety device for drills.

The primary object of the invention is the provision of a device of this character, wherein the control for a drill can be guarded so as to prevent accidental working thereof, for safety purposes, the device being readily moved to a position for'the free actuation of the control for the automatic driving of the said drill when required.

Another object of the invention is the provision of a device of this character, wherein it is located on the drill in a position for easy manipulation thereof for safety purposes, so that the drill will not prematurely operate, the device being a releasable guard for the control trigger or other control medium for the starting and stopping of such drill.

A further object of the invention is the provision of adevice of this character, wherein the same is adaptable for fluid or electrically driven drills of standard constructions, and when such drill is brought to rest, it cannot be accidentally set in motion, which might result in injury to an operator or damage to a piece of work.

A still further object of the invention is the provision of a device of this character, wherein for the'mounting of the same upon a drill avoids the necessity of any alteration in its standard construction, and is in a convenient position for handy manipulation thereof at all times, so that such drill cannot operate until a selected time by a user thereof.

Since it is possible for a safety device of this character to be moved accidentally to a position which would free the squeeze trigger of a drill, I also provide as one of the improved features of my invention, positive means in the form of a spring for normally holding the safety device in such position that the trigger cannot be cperated, and which necessitates that the safety device be positively and purposely moved to open position against the tension of the spring.

A still further object of the invention is the provision of a device of this character, which. is simple in construction, thoroughly reliable and eflicient in operation, readily and easily operated, possessing few parts, durable, easily installed, and inexpensive to manufacture.

With these and other objects in View, the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings, which disclose the preferred and modified forms of the invention,

2 and pointed out in the claims hereunto appended. In the accompanying drawings:

Figure 1 is a sideelevation of a drill showing the device constructed in accordance with the invention applied and in unlocked position.

Figure 2 is a fragmentary sectional view taken on the line' 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 isa fragmentary sectional view taken on the line 34-3 of Figure 1 looking inthe direction of the arrows.

" Figure 4 is a View similar t'o Figure 1 showing the device in locking position.

Figure 5 is a view similar to Figure 1 showing a modification.

Figure 6is a fragmentary side view 'of a iurther modification. i

Figure 7 isa perspective view of the guard part of the device shown in Figure l.

Figure 8 is an exploded perspective View showing the guides of the'device. 1

Figure 9 is a perspective view of the guard part shown in Figure 5. I v Figure 10 is a side elevation of a drill, partly fragmentary, wherein I have shown another form of'my invention in the nature of a keeper or guard above the squeeze trigger so that it cannot be accidentally depressed. Y y

Similar reference characters indicate corresponding parts throughout the several views in the drawings.

Referring to the drawings, particularly Figures l to 4, 7 and 8, inclusive, A designates generally an electrically driven hand controlled drill of any standard construction, having a push button control medium I0, for a normally open electric switch l I in an electric current supply to an electric motor (not shown) as built within the drill A for driving its rotary bit I2, as usual.

As is ordinary in drills of one standard type, there is provided a squeeze trigger I3, which is pivoted at M to overhang the button control medium l0, so that when the hand grip l5 of the drill is grasped in the hand of an operator the trigger can be nger actuated to depress the button control medium I0 for the closing of the switch Il whereby the electric current will be turned on for the driving of the drill or the setting 'thereof in motion, the switch l l being opened under spring action when pressure is released from the button control medium l0, as is customary.

Arranged at opposite sides of the control medium l0 is a pair of spaced parallel channeled guide rails I6 for a slidable safety cap ll, these constituting the device forming the subject matter of the present invention. This cap II is closed at its top, sides and one end, while the opposite end next to the medium I is open, and extending laterally from the bases of the closed sides of the cap are flanges interfitting the channels in the rails IB, the cap I'I being adapted to be manually shifted for conning Within the same the medium I 0 beneath the `trigger I3, to eliminate the possibility of depressing such medium for the closing of the switch II accidentally. When the cap I 1 is moved clear of the control medium I0, the same can then be actuated by the trigger I3 for the closing of the said switch. j Since it might be possible, under certainir: cumstances, for the safety cap I'I t'obev moved from beneath the squeeze triggerlglrproyide a spring 24 between guide rails I6 and retained in position by a keeper 25, which spring presses upon the cap I1 to hold it normally in locking position beneath Lthe .squeeze.tri'gger.j In practice, the safetycapmust be moved out from 'under the *squeeze` trigger;positively and ,intenitionally against: the action of spring 24.

iI9; so'th`at the trigger; within 1 the same .cannot be accidentally active.V j' Y A spring 24A and a keeper 25A ,is provided to maintain the cap 2| positively in position over the guard I9 so that the trigger cannot be operatedunless the cap Yis intentionally pushed'into the open position against the spring.'A f i 1 -InFigure 6 of thedrawings there is Ashown a further modification ofthe invention, wherein a blockingwedge 22 is sldably tted on the drill A in the path of the trigger 23 and this wedge is movable-under and frornyunder such trigger,V the wenigen when-under. thetrigger-- beingv effec'- f tive for blocking-,operation thereof to avoid depressingthe .control-medium-of the kind hereinoperated 1, iorgeridering the" drill before described, soiitheiisucndrill,Wil1,r10t be andi keeper 2l3yare in Aall re- .-50

spects similar to springs 24 and 24A and keepers 25 and 25A. v

In Figure 10, I have shown another modified form of my invention wherein a guard 2'I having a horizontal position 28 and a vertical support 29 is provided which overhangs the squeeze trigger I3 and prevents pressing of the same. The support 29 is slidable between rails I6 and is urged in its closing or guarding position by spring 24C retained by keeper 25C. v

' What is claimed is:

1. A safety device for an automatically driven drill having a power energy control medium,

comprising a sliding safety cap closed at its top,

sides and one end and laterally extending flanges formed integral with the bases of said closed side, forA blocking the actuation of the said mediuiniand chanelled rails slidably fitting said latrally'extending flanges of said safety cap upon the drill for movements thereof to blocking and non-blocking position. H

A2.1 A safety device for an automatically driven drill having; a power energy control mdium, comprising a sliding safety cap closed at its top, sides and one Yend and laterally extending'flanges formed integral with the basesof said closed side, for blocking ,the actuation of the said medium, and channelledj rails slidably tting said laterally extending flanges of said safety cap upon the drill for movements thereof to blocking and non-blocking positions, the last named means locating the rst'named -means for reach of an operator when hand gripping ,the drill.


matematicasV CITED The following references are ofrecordin ,the file of this patent: Y

Name Date` Number* 955,237 Westcott et al Apr. 19, 1910 1,659,284 Smith Feb. 14, 1928 1,563,250l Capon Nov. v2v4, 1925 21,080,202 Drake May 11, 193'? y V926,027 Smith Junev22, 1909 898,386v Nagle Sept, 8, 1908 1,419,398

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US898386 *Jun 17, 1908Sep 8, 1908Nagle Zane & NagleAngle-cock.
US926027 *Dec 12, 1908Jun 22, 1909William C JordanFire-plug.
US955237 *Jun 10, 1909Apr 19, 1910Henry P WestcottTrigger-guard.
US1419398 *Sep 24, 1921Jun 13, 1922Mell MasonCoupling device for trailers
US1563250 *Jun 24, 1925Nov 24, 1925Capon Frank JTrigger guard
US1659284 *May 16, 1927Feb 14, 1928Smith Lab IncStarter control for automotive vehicles
US2080202 *May 27, 1935May 11, 1937Drake Wilkie MTrigger protector
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2492739 *Feb 18, 1947Dec 27, 1949Electric Railway Equipment ComSafety connection and distribution box
US4683682 *Sep 19, 1986Aug 4, 1987Dresser Industries, Inc.Safety lever for portable power tool
US5161679 *Jun 28, 1991Nov 10, 1992Guardian Electric Manufacturing CompanyElectrical trigger switch with safety features
US5347764 *Mar 2, 1993Sep 20, 1994Indresco Inc.Handle arrangement for air power tool
US5654595 *Dec 29, 1994Aug 5, 1997Ferguson; Thomas R.Electrical current regulating device for a power tool
US7407018 *Feb 18, 2005Aug 5, 2008Honda Motor Co., Ltd.Power working machine
US20050204568 *Feb 18, 2005Sep 22, 2005Honda Motor Co., Ltd.Power working machine
U.S. Classification192/129.00A, 200/334, 408/710
International ClassificationH01H3/20, B23B45/00
Cooperative ClassificationY10S408/71, B23B45/001, H01H3/20
European ClassificationB23B45/00C, H01H3/20