US2727235A - Nail driver - Google Patents

Description

Dec. 20, 1955 J. G. CAMERON NAIL DRIVER Filed May 14, 1952 INVIENTDK JOHN GKIFFIIWS c/wawu United States Patent This invention relates to improvements in nail drivers.

It is known to provide manually or mechanically operated nail drivers, such a device commonly including a tubular casing the lower end of which is adapted to be placed on timber to be nailed, and a plunger slidable in the casing, the plunger being weighted usually by a heavy handle at its upper end in the case of manually operable apparatus, the lower end of the'plunger being provided with a co-axial striker. Nails fed into the easing, either individually or by means of a magazine, pass gravitationally to the lower part of the casing, and are driven into the timber when the connected plunger and striker are brought forcibly down so that the striker hits the nail head.

It has been found that nail drivers of this character have the disadvantage that after being used for some time, the end of the striker which impinges on the nail heads quickly becomes burred over, and consequently it is liable to jam in the part of the casing in which it is mounted, making the nail driver useless until repaired.

My present invention has been devised to overcome the said present disadvantages, and it has for its principal object the provision of a nail'driver the striker of which is so made and arranged that its end which drives 'nails is not liable to become burred over, at least until it has been in use for a very long time.

Another object of the invention is to provide a nail driver the striker of which is of the improved character stated and which may be easily replaced whenever required.

Further objects of the invention are to provide a nail driver the striker of which is of the improved character set out, and which is simple and economical to manufacture, efficient in operation, and sturdy and durable in use.

According to my invention, I provide a nail driver which includes a weighted plunger reciprocally slidable in a plunger guide, preferably of tubular form and terminating at its lower end in a tubular nail guide, which may be positioned on the material to be nailed, a striker being connected to the plunger so that, when the plunger is raised, the striker is lifted from the nail guide to enable a nail to. be fed thereinto from a communicating nail passage, and when the plunger is forcibly depressed, the striker is caused to drive the nail through its guide into the material on which the device has been-placed, a resilient butfer being interposed between the weighted plunger and the striker such that the striker is maintained in extended position in relation to the plunger until the striker is brought to bear on the head of a nail in the striker guide. The striker, then, remains momentarily at rest on the nail until, after the buffer has been compressed longitudinally by the still descending plunger, the force of the plunger is transmitted to the striker which is caused to drive the nail.

I have found that, whereas a striker fixedly connected to the plunger becomes burred after a short period of use, the interposition of a resilient buffer betweenthe 1 2,727,235 Patented Dec. 20, 1955 plunger and striker ensures that the end of the striker contacting the nail head does not become burred, at least until the device has been used for a very considerable period. In the preferred form of the invention, the butter consists of a plug of rubber or like resilient material capable of being distorted, but more or less incompressible, enclosed in a cavity such that its lateral expansion, and therefore its longitudinal compression, is

limited; and in this form of the invention, the striker is found to'have a 'very considerable life, not being liable to burr at either end at least until the device has been used for a very long period.

I prefer that the nail passage be such that an operator may feed nails thereto at a convenient height while standing, the nails being carried gravitationally through the passage to the nail guide; and for ease of operation of the device, I prefer to provide a foot holder at the lower end of the nail driver which can be fastened to one foot of the operator to facilitate the correct positioning of the device on a floor, for example.

Inorder that my invention may be readily understood and put into practical effect, I now refer to the accompanying drawings, wherein:

Figure 1 is a side elevational view of a nail driver according to the invention;

Figure 2 is a broken away sectional view of the nail driver; and 1 Figure 3 is a broken away sectional view of a nail driver according to a modification of the invention.

The nail driver includes a casing 10 consisting of a length of metal tube. Screw-threadedly engaged in the lower end portion of the casing 10 is a metal nail guide member -11, which is of substantially cylindrical shape with an integral peripheral flange 12, the upper part of the nail guide member above the flange being threaded for engagement in the casing, the said flange 12 hearing against the bottom of the casing 10. An axial boring 13, the greater part of which is slightly greater in diameter than the heads of nails to be driven, is formed through the nail guide 11, the upper end portion of the said axial bore being flared at 14 to form a lead-in to the remainder of the bore.

Engaged on the nail guide 11 is a foot holder 15, which includes a strap 16 apertured at one end to fit closely about the nail guide below its flange 12; a metal sleeve 17 fitted closely but rotatably on the nail guide and acting to retain the strap 16 in place; an angle bracket 18 secured to or formed integrally with the sleeve 17 and extending from the lower part thereof; a foot bracket 19 secured by rivets 20 to the said angle bracket; and a foot 21 riveted or otherwise secured to the foot bracket at one end, and having secured to its other end a buckle 22 adapted to engage the strap 16 in desired adjustment. The foot holder 15 is retained in place by means of a knurled nut 23 threadedly engaged on the lower end portion of the nail guide 11. The lower part of the bore of the nut 23 is enlarged and plain to form an annular recess 24, which houses portion of an annular resilient pad 25 of rubber, for example, which is fitted closely on the lower end of the nail guide, and extends downwardly for some distance below the said nail guide.

There is fitted slidably within the casing 10 a plunger 26, consisting of a metal rod, the upper end portion of which 'is reduced in diameter, screw-threaded and engaged the adjustment nut in desired adjusted position.

A nail passage 31 is formed longitudinally in the side of the plunger 26 from the bottom of the threaded upper portion to the bottom of the plunger. A key 32 secured to and extending inwardly from the upperend portiontof xthe casing 10 engages in the said nail passage to preuentthe plunger 26 from being rotated in relation ito the said casing.

A longitudinal slot-like feedopeningfiS isforme inrthe upper ;part of the-casing 10, some distance below .the key 32, and in register witht the nail passage 31. A mailchute 34 is secured to the casing 10, leading to the said feed.

opening, and it has secured in its .upper'enda metal gauge ring 35,:the bore of which is aboutequalto the bore 13 of the .nail guide 11, so that anormalnail to :hGtdIi QI -Wm pass freely therethrough into the chute .34 and through-the feedopening 33 into .the.nail passage 31; but a .nail'the head of which is oversize or badly deformed will not be vablezto-pass throughthesaid gauge ring.

The lower-endof the plunger 26 is axially bored at 36.

Referring now to Figure 2, there is provided ta striker 37, the lower part of which is of-such:diametertbat-it-will fit fairly closely but slidably in the boring 1343f zthe nail guide, the striker having an enlarged diameter .hea 3. which is adapted to engage slidably in the bore Of the plunger. There is fitted closely into the upper part of .the said bore of the plunger a resilient-cylindrical ;plug ,39 madegfor: preference, of rubber, the head -38- of th e'striker 37 then being fitted into the said bore. ;An annularrecess 40 is formed .about the strikerrhead, and a;.,gr ub screw 41 engaged in a tapped radial aperture in the loweqpartof the plunger .26 engages in the said recess, as is tclearly shown-in the drawing.

.In. using the nail driver, if it is desired-topuneh .as Well as drivethenails, the adjustment nut.29 is ,so positioned that when it. rests upon the topof the casing-10,1116 bottom of the striker 37 extends for some distanee-below-ghe level of the bottom of the annular pad 25,1the:adjnstment;nut being retained in such positionby the lock nut 30. A foot, usually-the right foot, .is en eed. ;by lhfiiflflt'ihQldfiBrthe footrresting on the .foot :strapfil andioot-bracketrlflaan the :straps 16 .and'21 being ifirmly buckled-over the foot. The casing 10 is turned so that nails may conveniently be-fed by one hand, usually the left hand,-through: the gauge ring 35. ofrthe chute -34,-and the handleib'kiagrasped by the other hand. The engaged foot is usedetozpflsition the resilient annular pad 25 overthe position where ta, nail isto-be driven,-and a nail is; fed, point-first, fllrohgh:.the said gauge ring, falling gravitationally throughlhewhute 34, the-feed opening 33, and the nailrpassagegi'ahsandathe handle 27 israised to lift the plungers26 and the associated striker 37 .so that the said striker is-brought elear 10f the nail guide 11, enabling the nail.to fall through the boring 13 of the nail guide so that its-point rests :on theztimbenw be nailed. The handle 27 with associated :phmger, are then brought forcibly down, and consequently the Striker 37 is dropped onto the nail head and comestorest'mementarily. The plunger, continuing its downward stroke, causes the resilient plug 39 to be brought downonto the head 38 of the striker 37. The plug can yield slightly but,

being substantially incompressible, it follows :that :the

force of the descending plunger 26 is then transmittedato the striker 37 which drives the nail homeandipunehes: it below the surface of the timber. A Mentor-example, may be nailed in place in this fashion and sincere foot, positioning the tool, leaves a hand free:for:-'fceding1nails to the device, the driving and punching of onenail .after another may be carried out very rapidly. It will-be-fouud, moreover, that the striker is not liable .to-bewmdburred over at its lower end which drives the. nails,;-,at least'fo'r a very considerable time; and the upper end of the: striker, which is struck by the resilient pad 39,,-is-als0-not -1iable to become burred. I

I now refer toFigure 3, which shows-a modified 'form of the invention, in which the striker 42 is; for thegreater part of its length, of such diameter that it-willfitslidably in the axial boring 13 of the nail guide 11; but near to the top has an integral coaxial head 43, the lower part of which fits slidably in the bore 36 of the plunger 26, the upper part being of somewhat reduced diameter. The striker head 43 is restrained from leaving the plunger by means of a washer 44 secured to the bottom of the plunger 26 by screws 45,the central aperture of the washer being such that the ,lower part of the striker passes freely therethrough, but of less diameter than that of the 'lower part ot' the striker head 43. The washer 44 is notched at one side,,as indicated at 4,6, the notch registering with the nail passage 31 in the plunger. The striker head 43 ,is of less length than the axial bore 36 in the lower part of the plunger; and the said head is normally maintained in lowermost position in the said bore by means of a helical compression spring 47, its upper end bearing against the top of the said bore, its lower end bearingon the peripheral shoulder formed at the change of diameter of the striker head.

{litreail driver according to this modification of the invention-is usedin the same .manner as before described. When the handle 27 is being forcibly brought down to drive and punch .a nail, indicated at 48, the striker 42 ijsretained in .extended position by the spring 47 until zthe striker contacts -.the head of the nail 48. Thereupon the striker comes momentarily to rest, until the further :downward movementof the plunger 36, compressing the ,spring 47,-,eauses the plunger to strike the top of the striker head 4-3-so that the nail 48 is driven and punched. iltwill-ibe found that the lower end of the striker 42 will not become burred over for avery considerable period.

-,I-n. e ither;modil icati on otthe invention, the striker and the nail guide :may be interchangeable with others of ,difierentdiameter and bore respectively, to suit different sizes of -nails appropriateadjustment being made also lo the adjustment; nut 29. -I may prefer to make the gauge ring 135 --rem o vable and interchangeable with others of 'rlitterem o eshat l ela rn i l. ,A nail driveninclnding a. plunger guide; a plunger ,-r 'eio .e allyr is ab i th pl nge guide; a nail guide pogmeeted tothe plunger guide and adapted to be positioned adjacent to the material to be nailed; a striker reciprocally slidable through-the guide and connected to theplppgena stop limiting the sliding movement of the striker relativeto'the plunger; a nail passage adapted to conduct a nail gravitationally into the nail guide when the ,striker is at least partly withdrawn therefrom; and a resilient distortable buffer between the striker and the ,plungenadapted to maintain the striker in extended relationship to.the-plun ger until on a working stroke of the plunger the striker is brought momentarily at rest on the head ofthe naiLin-the nail guide, further movement of the plunger-causing the striker to drive the nail.

2. -A nail driverincluding a plunger guide; a plunger .reciprocally :slidable in the plunger guide; a nail guide connected-t0 the plunger guide and adapted to be positioned adjacent tothe material to be nailed; a striker reeiprocallyslidable,through the nail guide and connected to the;plunger;arstop limiting the sliding movement of the strikerzrelativeto the plunger; a nail passage adapted .tO Conducha naihgravitationally into the nail guide when t.he striker-,is atleast partly withdrawn therefrom; and a vbuffer of. a-resilient distortahle but nearly incompressible material interposed between the striker and the plunger and contained .in arecess adapted to permit a limited lateral expansion of the buffer.

53. Aflnail guide.includinga tubular plunger guide; a tubular nailguide: secured co-axially to the lower end of the plunger guidepaplungerreciprocally slidable in the plungenguide; said plunger having a longitudinal hole in its lower end; a resilient buffer formed of distortable but -nearly incompressible material in. the innermost part of:saidhtztlepa striker reciprocally slidable through the nail -guidei its-upper-end-being housed inthe said hole; a stop limiting the sliding movement of the striker in the said hole away from the bufier; and a nail passage adapted to conduct a nail gravitationally from a position near to the top of the plunger guide into the nail guide when the striker has been at least partly withdrawn therefrom.

4. A nail driver including a plunger guide; a plunger reciprocally slidable in the plunger guide; a nail guide connected to the plunger guide and adapted to be positioned adjacent to the material to be nailed; a striker reciprocally slidable through the nail guide and connected to the plunger; a stop limiting the sliding movement of the striker to the plunger; a nail passage adapted to conduct a nail gravitationally into the nail guide when the striker is at least partly withdrawn therefrom; and a spring disposed between and in engagement with the striker and plunger for yieldably urging the striker in extended relationship to the plunger.

5. A nail guide including a tubular plunger guide; a tubular nail guide secured co-axially to the lower end of the plunger guide; a plunger reciprocally slidable in the plunger guide, said plunger having a hole; a boring in said tubular nail guide; a striker reciprocally slidable through the nail guide, its upper end being housed and longitudinally movable in the said hole; means for retaining the upper end of the striker in the said hole with limited longitudinal movement relative to the plunger; a spring in the hole engageable with the plunger and striker to urge the striker to extended position relative to the plunger; and a nail passage adapted to conduct a nail gravitationally from a position near to the top of the plunger guide into the nail guide when the striker has been at least partly withdrawn therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 620,426 Danzer Feb. 28, 1899 1,222,129 Palkowski Apr. 10, 1917 1,262,486 Hansen Apr. 9, 1918 1,409,419 Signell Mar. 14, 1922 2,587,944 Williams Mar. 4, 1952 FOREIGN PATENTS 140,641 Austria Feb. 11, 1935 588,189 Great Britain May 16, 1947

Images