US2538895A - Nail driving device - Google Patents

Description

2 Sheets-Sheet 1 P. H. BRENNAN NAIL DRIVING DEVICE INVENTOR.

Jan. 23, 1951 Filed Feb. 15, 1949 Jan. 23, 1 951 P. H. BRENNAN NAIL DRIVING DEVICE 2 Sheets-Sheet 2 Filed Feb. 15, 1949 INVENTOR. ZZ /1 61 fire/7,741

Patented Jan. 23, [951 I .i

UNITED STATES PATENT Patrick H. Brennan, Detroit, Mich. 7 Application February 15, 1949," ser al No. 741543 employed with a' minimum of skill and efiort on the-part of the operator, which may 'bequickly and easily loaded without jamming, and whichis positive in its action without reliance upon gravity feed. 7 7

Another object is to provide a durable, compact, lightweight and highly efiicient nail driving tool of the above class which may be safely used by an inexperienced operator without danger of injury to himself or others or to the work. Still other objects of the present. invention are to provide such a tool having a simple highly eflicient guard means adapted to prevent accidental discharge of a nail from the tool during operation and thereby to protect the operator and fellow workers from.. the possibility of injury which might otherwise result from uncontrolled nails flyingthrough space under the impact of the driving hammer; and to provide such a tool having a simple protective movement limit: i'ng means which permits a nail to be driven the full length thereof by the tool and thereafter.

automatica ly prevents needless or undesirable countersinking of the nail beyond a predetermined extent regardless of the length of the nail.

Other objects are to provide such a nail driving tool which is readily adaptable for use with nails of various lengths within a given range; to provide a hand loaded nail driving tool having improved means to facilitate loading or feed-.

ing of nails to the tool; and to provide such a tool which readily receives the nail to be driven and positive y holds the latter in operative position, permitting use of the tool at any con venient angle. I

Another object of this invention is to provide a tool embodying a nail driving plunger which may be readily adapted for actuation by con-v ventional types of hand operated power hammers,v

as for example pneumatic hammers of the type commonly employed for riveting operations.

, Other objects of 'thisyinvention will anpearin the. following description and; appended. claims; reference bei'ng" had to the' eeconfniiairiyingdraw 7 Claims. (01.1-46.1)

ings forming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views. I

The; above and otherobjects are accomplished in a preferred embodiment of the'present in vention comprising a vibratory nail driving member preferably adaptedfor power actuation by a? power driven: pneumatic hammer or other ham; mer means suitably powered for exampleby el'ec-' tric or hydraulic'meansewhereby arapid vibratory nail Crivingmotion of smallamplitude is im parted to the nail driving member. -A-nailholding headhaving a longitudinal nail receiving chafnbe'r therein is slidably mounted on the vibratory nail driving member in such a manner that the latter may be moved forward into the chamber to displace a" nail therein; whereby the nail is forceably driven from the hea'd through afora Td OpeninQ of the hamber. 4 H Manual loading of a nail substantially lengthwise into the nailreceivi'ng chamber is permitted By a naiij receiving" slot within the side'w'allof the" head and o ening longitudinally into; the

chamber A fee troug extending longitudi nally withinthe upper surface of the nail holdhead" converges to tl'i "ail" receiving slot to faci itate loading of a na l thereinto. Thus a nailplaced withirilthe' span of the trough is readily guided along the converging sidewalls thereof to he nail rec "vi ngj slot and into the aforementioned chamber.

mentioned feed trough at the rearwardextremity thereof. togreceive the enlarged head of the nail.

and guide the latter to a desiredioperative position within" the nail receiving chamber. In order to permit positivemanual control over .the nail during the loadingooperation central por- .of theopposingfl sidewalls oflthefe'ed trough are deepened to: provide rounded finger receivingngrooves haying, the lower portions thereof opening immediately above the nail receiving chamhern; o'llhushthe operator, while holding a nail. between-hisflthumb. andforefinger for example, -may vplace the-riailwith-in-the confines of the feed trough with the nail head within. the deepened. lnailnheadt receiving portion thereof.

The operator v may thenfollow the vnail downward withhis fingers along-the converging; sides of 'sh ndrcs ti e y force the. nail i t J 'i i h m er'e zfine fin e t e onith 1 "upper portion-of the-nail.

Per lol eiii Q fii eii' nli a 1b: a o o ham s with .res e ttq e v ra mem ifec l t tedj r ee ender or n i head i ece v n tr u h olo eie tiaihe ide .Oi.,. he a ore,

Suitable nail retaining means are provided within the nail receiving chamber for yieldingly and frictionally engaging the nail so as to hold the same positively in central alignment in an operative position within the chamber. Accidental displacement of the nail within the chamber or its accidental dropping through the discharge opening of the chamber is thus prevented regardless of the angle at which the tool may be held.

Details of a preferred construction of a nail driving tool embodying the present invention are illustrated by way of example in the following drawings wherein:

Fig. 1 is a fragmentary view partially in longitudinal mid-section and partially in elevation, showing the nail driving tool in operative position for driving a nail into a workpiece.

Fig. 2 is a fragmentary enlarged plan view the tool and workpiece of Fig. 1, showing the tool in the operative position upon completion of a nail driving operation.

Fig. 3 is a transverse section taken in the direction of the arrows substantially along the line 3-4 of Fig. 2.

Fig. 4 is a transverse section taken in the direction of the arrows substantially along the line 4-4 of Fig. 2.

Fig. 5 is a transverse section taken in the direction of the arrows substantially along the line 5 5 of Fig. 2.

Fig'. 6 is a transverse section t ken in'the direction of the arrows substantially along the line 66ofFig.2.

Fig.'7'is a longitudinal section taken in the direction of the arrows substantially along the line 1-1 of Fig. 4.

Before explaining the present invention in detail it is to be understood that the invention is not limited in its application to the details of construction and arrangement of arts illustrated in the accompanying drawings, since the invention is capable of ot er embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

The present invention is descri ed by way of example in connection with a nail driving tool which is readily adaptable. for-use with a conventional type of pneumatic hammer, indicated by the numeral 10, Figs. land 2. In this instance the tool comprises a generally cylindrical nail holding head, indicated by the numeral.l2,. slid-1 ably mounted on a vibratory nail driving s aft !4 for movement longitudinally thereof. In Fig. l a nail. I6 is shownheld by the head I2 in.an. operativeposition preparatory to ,be driven into a workpiecel8. 1 a

Although a preferred application of thepresent invention is illustrated herein in connection with a pneumatic type of hand .operatedpower actuatedghammer, it is to, be understood that the tude to the hammer member 24. The hammer in is manually supported by a handle 26 and is provided with connection and trigger means, not shown, whereby air pressure may be suitably supplied through flexible conduits and. controlled for selective actuation of the vibratory hammer 24. The forward end of the housing 20 is reduced in diameter to a projecting nose 2! and is provided with a cylindrical shaft holding bore 28 adapted to receive and support the butt portion 39 of the vibratory shaft I4, which is of suitable diameter to effect a snug sliding fit within the bore 28. Integral with the shaft I 4 at the forward end of the butt 30 is an annular movement limiting flange 32 suitably located with respect to the dimensions of the hammer I!) so as to abut the nose 2'! thereof when the butt 3B is inserted into the bore 28 in abutting relation with the face of the hammer 24.

In the present instance, the forward body portion of the housing 20 is exteriorly screw threaded at 34 to receive a comparatively heavy coil spring 35 dimensioned to be screwed tightly on the threaded portion 34. The forward coils of the spring 35 are of successively decreasing diameter and converge around the reduced nose 2! and flange 32, Fig. l, with at least one coil 35a wrapping around the shaft l4 forward of the flange 32 in a manner for resiliently urging the latter i hammer ID.

The head !2 may be constructed of any suitable material, preferably a lightweight aluminum or magnesium alloy, and is formed with a generally central bore or nail receiving chamber 35 extending longitudinally therethrough in diameter for conveniently receiving the largest nail head for which the tool is adapted. A rearward extension 38 of the head l2 of reduced exterior diameter is provided with a continuation oft'ne bore or chamber 35 and is adapted to receive the forward end of the shaft [4 on which the head I2 is firmly and securely supported. In this connection, the diameter of the shaft 54 is selected to permit a snug freely sliding fit within the cham-,

'; ber 36.

present invention is not dependent upon such 5 The limit of relative sliding movement between thehead l2 and shaft [4 is determined by paired diametrically opposed guide slots 40 extending longitudinally of the shaft I4, Figs. 1 and 6, with-' in which ride a pair. of movement limiting guide lugs 42 projecting into the bore or chamber 38 from paired essentially semi-annularretaining plates 44 suitably secured. to the extremity of the extension 38 by a plurality of Allen-type screws 46,. 'Iihe outerperipheries of the retaining plates 44 conform substantially to the re duced diameter of the extension 38, whereas their inner peripheries preferably conform to the diameter of the chamber 35 to comprise substantially a rearward continuation thereof.

In assembly of the tool the forward'end of the shaft i4 is inserted intothe bore 35 of the extension'38 until'the forward extremities "of the paired grooves lil pass the assembled posi tions of the lugs 4'2. Thereafter the retaining plates 44 are assembled with their projecting lugs 42 within the grooves 48 and are secured to the extension 38 by the screws 45 to limit the forward movement of the' he ad 12 relative tdthe shaft 14 and thereby .to prey ent' accidental "sep aration of these membersv fin o'perationi of a sesses 5 too]? It "is also"to-beobserved-that the 'engage-F ment between the lugs 42' antl groovles 4'0 prevents: relative rotation between the shaft Ml and head l2. Thus thelatter is readily held 'in 'ian up rightoperative"position during? operation: of the; toolas described hereinafter. q The body of the head I2 for'wardof the extension 38" is preferably of suffieient diameterand length to: accommodate two longitudinally 'spaced'sets of spring pressed nail retaining and centering-"balls 18; Figs; 1 and 3'. Each set com-r prises three balls-48 spaced circumierentially around thechambe'r 36,-: whereby the six balls 48 efigagea nail"withiri the" chamber 36 at three substantially equi-angularly spaced points at. e'a'jch of two locations spaced 1on'gitudinall-y of Accordingly- 'theballs 48 are disposed aianced forces on the nail{ for frio-' liy liolding'the' sameposinveiy' against acnuentar displacement an diin central: longitudinal align-merit: within the chamber 35 regardless theangle at which the tool or head {2 may-be held The balls lfi'of each set are contained Withih thre'e Suitab1y-spaced radial Wei-1S 50' Communicaung -betv'veen the chamber 35 and the ex-' te'rior ofithe head 62 The outer'opening of each-well Eli-is adapted toreceive its retaining can 4'8 andi's preferahlysrew threaded at 52 to receive a-retaining s'c'rew-or plug 54. The base ofeaoh weir 50 is provided with an inner opening of' manerdiameter than the ball communi' c'ati'rigwitli -the'cham-ber- 36 and comprises an aiinular seat 56 forthe ball Q8; whereby-the latter is retained within its well 50 but-permitted tdpiject partially-into "the-chamber 35. Each ban 4's is resiliently urged into its seat'ed'positibn projected into the chamber 36 by'a"coi1 spring 58 under compression between the'screw 54 and ball 58.

As indicated in 'Fig; 3, the eq'ui-angular spacing of-"the balls 48 is not critical to the efficientop erati'on of the present invention -and -may' be suitably varied to meet particular construction requirements of the tool. In" such situations as in-the'present instance, the tensions'in-the spring 58 are" ad-justed with" respect to the circumferentia-l locations-of the ba1ls4'3 so that the forces exerted thereby on a centrally aligned nail will bsubstantially ba-lancedi Preferably; the two-upper balls reef each set are disposed to project into the chamber 3 6 at equal lateral angles of attack from opposite sides and somewhat above the longitudinal center line thereof,-- Fig; 3', so as to exert equal" down-ward forces on opposite sides of a" nail Within the chamber 352 The lower ball- 48" of each set'is disposed to project into the chamber 3% from below the'm'id-line thereof to equalize the'verti'oal forces exertedon the nail bylthe' twoupper balls 48. The two upper balls 48 are also preferably disposed so as to meet the cylindrical sides of a nail within thecham-ber 33 at points above the center line of the nail: Thus immediately upon passage of a nail below the slot 6% and into the chamber 36, the nail will besnapped into the aforesaid central longitudinal alignment by theaction of the spring pressed-balls 481 I I Loading-or feeding of-a-nail l-6 into'the chamber- 36 is-= readily [permitted through a nail, receiving slot 6 Figs. 1 through which 1 extends longitudinally of the chamber 36 and opens to the exterior of the head I2 through the upper sidewall thereof. The slot 60 terminates rearwardly at email-head receiving enlargement 62, of sub stant-ial-ly'thediameterofthe' chamber '36-, Figs,-

of the shaft I4. Thus when a nail I16 is inserted into: the chamber 36 in the manner described hereinafter, with its head 64 passing through the slot: portion 62, the nail It: will 'lie' within the chamber 36 substantially asshown in Fig: 1'.:

In this'po'sition the shaft M will be at the rear ward limit of movement relative to the head-I2 permitted by the studs 42 within the-g'rooves'flflx The nail head 64'wi11 thus be adjacent: the shaft extremity 66 in position to be driven forward through the chamber 36 upon forward relative movement of the shaft M: By virtue of the con:-- caveextremity of the; shaft I4, the head 64 Will be continually'centered within the chamber--36 during a nail' driving operation. Thus the dangerous tendency to cook a'nail out of longi=-- tudinal alignment within the chamber 36, where by the nail may be accidentally shot through the slots 60, 82 by the impact of a nail driving. operation, is minimized. This safeguard is especially important with the use of so called headless or finishing nails which would other; wise be particularly subject to accidentaldis charge'from the slots 6i], 62 in operation of the tool.

The nail receiving slot 69 extends forward from the slot 62 sufficientl-y to'permit substan: tially lengthwise passage into the chamber 36, of a nail of'average length-which; the tool is intended to handle The forward end of the slot 69 terminates at a forward annular guard portion 68 of the head 12' comprising an annular sidewall enclosure'for the forward end:- of the chamber 36. The forward' tip-or nose I!) of the guard 68 is flattened'or blunted to permit pressure against a workpiece is without the danger of damaging the latter by being embedded therein under the impact of a nail driving operation. As" will be apparent hereinafter, the annular guard portion 68 serves as an eflicient safety measure to prevent the accidental discharge of a nail through the slot 60 'during the initial impact of'a hammering or nail driving operation, particularly before the point of thenailis secure 1y embedded within the work I8. h r

An important-feature of the present invention is the means whereby rapid" manual loading of the'chamber 36 with a-nail-tobe driven is readily accomplished. To" this end the upper portion of the'head I2 is provided with a longitudinally extending groove or trough 12 of V-shaped crosssection which converges at its base to the nail receiving slot 69. Thenail may be placed by the operator anywhere on the upper portionfof the head IZ within the span ofthe trough- 12 and substantially longitudinally thereof. trough 12 will then guide the nail into the slot 60 Without undue effort or skill on the part of the operator. A slightly deeper nail head receivingportion 14 of the trough 12 is provided at the rearward extremity of the latter, Figs. and. 5', directly overthe enlarged nailhead receiving opening 62. U V

Asindicated in Fig. 5, the depth-of the trough portion M with respectato the trough is selected to accommodate nailheads of the largest diameter which may be'conveniently retained Within the chamber; 36. Accordingly when a nail is placed with its body within the trough i2 and ,its enlarged 'head,within the trough 14;, the nail is readily-guided toward thenail' receiving --sl0 ts- 60; 62 by the converging walls of the respective troughs I2, 14.

In order to simplify further the loading of the chamber 36 and to permit positive control of the nail by the operator during the loading opera tion, rounded central finger grooves IS are provided within the opposed sidewalls of the trough 12. In the present instance the grooves 16 are formed by a substantially spherical cut into the upper surface of the head I2 and sidewalls of the trough I2, Figs 1, 2, 4 and 7, with the lowest points of the spherical cut meeting the base of the sidewalls of the slot 63 at the opening of the latter into the chamber 36, Fig. 4. Accordingly as a nail held within the fingers of the operator is fed into the chamber 35, the fingers are readily guided by the rounded finger grooves is directly to the upper opening of the chamber 35 at the lowermost region of the paired converging grooves 76. by finger pressure below the level of the base of the slot 63 whereat the two upper balls til of each set will engage the cylindrical sides of the nail above the center line thereof and exert a downward force thereon to force the nail into the centered operative position within the charm ber 36.

In operation of the tool, the assembled head I2 and shaft I4 are connected with the hammer I as shown in Fig. 1. inserted into the retaining bore 28 therefor in abutting engagement with the vibratory power operated hammer member 24 and with the movement limiting flange 32 seated firmly against the nose 2?; whereat it is resiliently held in the seated position by the coil spring 35, 35a screwed on the threaded housing portion 34. The head I2 is then slid forward along the shaft I4 to the nail loading position at the forward limit of movement permitted by the studs 42 riding within the slots 49, Fig. 1. At this position, the concave centering extremity 66 of the shaft I4 will lie immediately to the rear of the nail head receiving slot 62.

While holding a nail between his fingers, as for example between his thumb and index finger, the operator then readily places the nail within the span of the V-troughs I2, I4 with the body of the nail within the trough l2 and the head of the nail within the trough I4, and slides the nailby a guided downward movement along the converging sides of the troughs 12, I4 to the upper openings of the slots 60, 62. In substantially the same motion, while the head of the nail is confined by the sidewalls of the nail head holding trough I4, the operator slides his fingers along the length of the nail without releasing his grip' thereon to the paired rounded finger grooves I6 which guide the fingers to a point at the lowermost portion of the grooves I6 immediately above the lower opening of the slot Bil into the chamber 36. The nail is accordingly moved downward through the slots 60, 62 to a position of alignment for reception by the chamber 36. Upon continued pressure on the nail from above by the thumb or forefinger, the nail is readily forced below the slots 69, 62 whereat the sides of the nail are engaged by the paired sets of spring pressed upper balls 48 and snapped into central position within the chamber 36, I

' If a nail such as the nail I6 is employed which is longer than the length of the slots 60, 62, the nail is preferably inserted angularly downward into the slot 60 with the nail point foremost until'the latter projectsthrough the annular guard The nail may then be forced The shaft butt 3?} is 6 erator then actuates the hammer III in accordance with conventional practice to effect a power driven high frequency vibratory motion of small amplitude to the hammer member 24. The repeated impacts of the vibratory hammer member 24 are imparted to the head of the nail through, the vibratory shaft I4, driving the nail intothe work l8. In this connection, the rounded concave forward extremity 66 of the shaft serves to center the nail head and is particularly useful where headless or small headed finishing nails are employed. Thus the nail is driven longitudinally of the shaft I4 directly into the work I8. The danger of imparting a glancing or an-,

gula impact to the nail head which might causethe nail to fly from the head I2 through the slot 60 is minimized. Likewise, particularly in the situation where the length of the nail is shorter than the length of the slot 60, the annular nose guard 68 around the forward extremity of the chamber 36 retains the nail against accidental discharge through the slot 60, particularly during the initial stages of the nail driving operation before the point of the nail is secured within the work I8. 1

As the nail is driven into the work I8, the vibratory shaft I4 gradually moves forward withinthe chamber 36, driving the nail through the annular nose 68 or discharge end of the chamber-36 until the guide lugs 42 riding within the slots 40 engage the shaft I4 at the rearward extremity of the slots 40 and prevent further relative forward movement of the shaft I4 with respect to the head I2.

The length of the slots 40 is preferably determined so that the forward extremity 66 of the shaft I4 will just reach or slightly clear the forward discharge end 68 of the chamber 36 at the same time the lugs 42 reach the ends of the slots 40, Fig. 2. The nail will be driven its full length into the work IB, whereupon continued forward movement of the shaft I4 is stopped and injury to the work I8 by undesirable countersinking is avoided regardless whether the vibratory driving power is immediately discontinued or not. Likewise injury to the work I8 by the head I2 is also avoided by the blunted nose ID of the latter which preferably provides sufiicient area to abut the work I8 without being driven into the same by the ordinary vibratoryimpacts of the ham mer member 24.

Obviously, the length of the slots 40 may be predetermined to limit the countersinking of the nail to any desired extent or to prevent any appreciable countersinking. By removing the re-' taining plates 44 from the head I2 and the coil spring from the hammer I0, the shaft I4 may be readily removed and replaced by a similar shaftJMi having guide grooves 40 of a-'different length where'it is desired to change the'extent of countersinking permitted by the tool.'

I claim:

1. In a nail driving tool, a nail holding head having a longitudinal nail receiving chamber therein, said head having a longitudinal na'ilfeed ing slot in the sidewall thereof communication with said chamber to permit substantially lengthwise passage of a nail into said chamber and also having a nail discharge opening in an end thereof, a vibratory nail driving member movable within said chamber to drive a nail therein through said discharge opening, and means to facilitate manual feeding of a nail substantially lengthwise into said chamber through said nail feeding slot and including a trough in the sidewall of said head extending longitudinally of said chamber and converging to said nail feeding slot.

2. In a nail driving tool, a nail holding head having a longitudinal nail receiving chamber therein, said head having a longitudinal nail feeding slot in the sidewall thereof in communication with said chamber to permit substantially lengthwise passage of a nail into said chamber and also having a nail discharge opening in an end thereof, a vibratory nail driving member movable within said chamber to drive a nail therein through said discharge opening, means to facilitate manual feeding of a nail substantially lengthwise into said chamber through said nail feeding slot and including a trough in the sidewall of said head extending longitudinally of said chamber and converging to said nail feeding slot, and means to facilitate manual insertion of a nail through said nail feeding slot and including finger recesses in opposed sidewalls of said trough.

3. In a nail driving tool, a nail holding head having a longitudinal nail receiving chamber therein, said head having a longitudinal nail feeding slot in the sidewall thereof in communication with said chamber to permit substantially lengthwise passage of a nail into said chamber and also having a nail discharge opening in an end thereof, a vibratory nail driving member movable within said chamber to drive a nail therein through said discharge opening, means to facilitate manual feeding of a nail substantially lengthwise into said chamber through said nail feeding slot and including a trough in the sidewall of said head extending longitudinally of said chamber and converging to said nail feeding slot, and means to guide a nail into operative driving position within said chamber with the head of the nail adjacent said driving member and including a transverse nail-head guide slot in the sidewall of said trough and leading to said feeding slot.

4. In a nail driving tool, a nail holding head having a longitudinal nail receiving chamber therein, said head having a longitudinal nail feeding slot in the sidewall thereof in communication with said chamber to permit substantially lengthwise passage of a nail into said chamber and also having a nail discharge opening in an end thereof, a vibratory nail driving member movable within said chamber to drive a nail therein through said discharge opening, means to facilitate manual feeding of a nail substantially lengthwise into said chamber through said nail feeding slot and including a trough in the sidewall of said head extending longitudinally of said chamber and converging to said nail feeding slot, means to facilitate manual insertion of a nail through said nail feeding slot and including finger recesses in opposed sidewalls of said trough, and means to guide a nail into operative driving position within said chamber with the head of the nail adjacent said driving member and including a transverse nail-head guide slot in the sidewall of said trough and leading to said feeding slot.

5. In a nail driving tool, a nail hOlding head having a nail receiving chamber therein communicating with a discharge opening, said head also having a nail feed trough communicating inwardly with said chamber and diverging outwardly to facilitate feeding a nail into said. chamher, and a nail driving member movable within said chamber to drive a nail therefrom through said discharge opening.

6. In a nail driving tool, a nail holding head having a nail receiving chamber therein communicating with a discharge opening, said head also having a nail feed trough communicating inwardly with said chamber and diverging outwardl to guide a nail into said chamber, said trough having finger recesses in opposed sidewalls thereof to facilitate manual insertion of a nail thereinto, and a nail driving member movable within said chamber to drive the nail therefrom through said discharge opening.

7. In a nail driving tool, a nail holding head having a nail receiving chamber therein communicating with a discharge opening, said head also having a nail feed trough communicating inwardly with said chamber and diverging outwardly to guide a nail into said chamber, said trough having a nail-head guide slot in the sidewall thereof leading to said chamber for guiding the head of the nail to a predetermined position within the chamber, and a nail driving member movable within said chamber to drive the nail therefrom through said discharge opening.

PATRICK H. BRENNAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,539,473 Ellwood May 26, 1925 1,604,675 Bernard Oct. 26, 1926 2,009,580 Govanus July 30, 1935 2,078,012 Newell Apr. 20, 1937

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