US3595460A - Washer feeder for nail driver - Google Patents

Abstract

An automatic mechanism for feeding washers to a nail driver so that each nail will be driven through a washer, through the work and anchored.

Description

United States Patent Inventor Roy S. Pitkin 2735 N.E. 18th Ave., Portland, Oreg. 97212 Applo No. 768,046

Filed Oct. 16, 1968 Patented July 27, 1971 WASHER FEEDER FOR NAIL DRIVER 11 Claims, 13 Drawing Figs.

us.c1 227/48, 227/99,227 112,227/13o 1111. c1. 112111/02 FieldofSearch 227/s,1s, 18,99,100,104,105,106,112,130,39,40,41, 43,4s,49,so

References Cited UNITED STATESPATENTS 5/1959 Young 227/130X 4/1961 Moberg 227/112 UX 3/1965 Kremi11er.. 227/130X 2/1966 Crooks 227/130 Primary Examiner-Granville Y. Custer, Jr. Attorney-Rummier and Snow ABSTRACT: An automatic mechanism for feeding washers to a nail driver so that each nail will be driven through a washer, through the work and anchored.

PATENTEDJULZHHZI 3595460SHEET 2 OF 4 WASHER FEEDER FOR NAIL DRIVER BACKGROUND AND FIELD OF INVENTION Highly effective pneumatically operated'fastener driving machines are available, the fasteners usually being in the form of staples. It is often desirable, however, in applying sheet-type built-up roofing, composition shingles, plastic films or tarpaulins and other such materials to employ washers with the fasteners in order to provide a large bearing surface which will hold the material more securely. Much of the advantage of a rapidly operating fastener driving machine is lost if the washers have to be placed manually. A need exists for a machine which will drive nails with washers with the same speed and convenience that is possible with staples.

SUMMARY ofINVENTION The present feeder is arranged to feed washers one after another to thedriving position of a pneumatically operated nailing machine. The feeder is pneumatically operated from certain air passages in the nailing machine for automatic synchronization with the nailing machine whereby a washer is placed in position to receive a nail in each driving stroke of the driver blade of the machine. The washers are fed separately from the nails to eliminate any preliminary step of assembling the washers on the nails, and held in operative position by magnets or by air pressure.

BRIEF DESCRIPTION of DRAWINGS FIG. 1 is a perspective view of the mailing machine embodying the features of the invention;

FIG. 2 is a perspective view of a nail and washer as driven by the machine, apart from the work;

FIG. 3 is an enlarged sectional view taken on the line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken on the line 5-5 in FIG. 3;

FIG. 6 is a sectional view taken on the line 6-6 in FIG. 3;

FIG. 7 is a view similar to FIG. 5 showing a modification;

FIG. 8 is a sectional view taken on the line 8-8 in FIG. 7;

FIG. 9 is a view similar to FIG. 5 showing another modification;

FIG. 10 is a view of the machine shown in FIG. I with parts broken away, showing the trigger in actuated position; and

FIG. 11 is a fragmentary view similar to FIG. 10 showing the trigger in released position;

FIG. 12 is plan view of upper side of the soleplate;

FIG. 13 is a sectional view taken on line 13-13 of FIG. 12 with parts broken away for clarity.

DESCRIPTION OF PREFERRED EMBODIMENTS In order to illustrate the application of the invention, a particular form of nail driver will first be described, but it is to be understood that the invention may be applied with equal facility to other nail drivers which are of generally similar form of construction. As shown in FIGS. 1 and 10, the present nail driver comprises abase magazine 10 having a hollow handle 11 equipped with anair inlet connection 12 for a compressed air hose (not shown). The magazine is equipped with a conventional spring feed device (not shown) to feed adhered sticks" of nails N into driving position under ahead portion 13 of the machine.

Integral withhead portion 13 is avertical driver cylinder 15 having an upperlarge diameter portion 16 and a lower small diameter portion 17. A spool-shaped piston 20 is mounted for reciprocation in the cylinder, the piston having alarge head 21 in thelarge cylinder portion 16 and asmaller head 22 in the smaller cylinder portion 17. Connected to the lower end ofpiston 20 is a driver blade 19 for driving the nails N.

The hollow handle 11 contains anair reservoir chamber 23 and anotherchamber 24 of the reservoir is contained inhead 13. These two reservoir chambers are parts of acommon reservoir and are in constant communication with each other as well as with an air supply thru'connection 12. A' series of ports 25 communicate through the cylinder wall fromchamber 24 into the space between the upper andlower piston heads 21 and 22. By reason of the slightly larger diameter ofupper piston 21, the reservoir pressure thereby produces a constant upward bias on the piston, tending to retract and/or maintain blade 19 in its upper position.

The cylinder has a free upper edge 26 which is exposed around its entire periphery to the air pressure in areservoir chamber 24. Mounted for reciprocation immediately above the edge 26 is apoppet valve 27 having aresilient sealingring 28 arranged to engage said edge 26 of the cylinder end.Poppet valve 27 is incorporated in a piston 30 which is free to reciprocate in a short cylinder bore 31, the valve and piston being biased downward by a compression spring 32. The upper side of the piston is formed as ahead stem 33 having aresilient seal ring 34 for sliding engagement in abore 35. The piston contains anaxial passage 36 which registers with an opening 37 in acushion seat 38 in the upper end ofbore 35. Registering with said bore and passage is apassage 39 communicating with a tappedopening 40 in the top of the head. A radial exhaust port 41 communicates withbore 35 just below thecushion seat 38.

The upper end of cylinder 31 has aport 45 which communicates with two different passages. One is apassage 46 extending to a tappedopening 47 in the top of the head and the other is apassage 48 communicating with atrigger valve assembly 50 in the handle. This assembly is made as a cylindrical unit which is mounted in'an interior web orboss portion 51 of the handle extending through thereservoir chamber 23. Valveunit 50 andweb 51 do not obstruct communication between the tworeservoir chambers 23 and 24. The valve assembly contains aspool valve element 52 which is normally biased downward by aspring 53 and air pressure through aport 54, as shown in FIG. 11, to connectpassage 48 with reservoir pressure. When thetrigger 55 is raised (see FIG. 11), the valve spool is lifted to connectpassage 48 with adischarge passage 56 asshown in FIG. 10.

When thetrigger 55 is released as shown in FIG. 11, reservoir air pressure is transmitted throughport 54 andpassage 48 to the top of cylinder 31 to act on a large area of piston 30 and hold. the poppet valve 27' closed against the top end 26 ofcylinder 15. Reservoir pressure also exists around the upper end of the cylinder inreservoir chamber 24 and acts on a small area of piston 30. Piston 20 is normally held in its uppermost position by the action of reservoir pressure in the space between the upper andlower piston heads 21 and 22 as previously mentioned, i.e. being permitted to move upward becauseexhaust passage 36 is in communication with passage 41 to permit the air pressure to escape, since valve 30 is in closed" position (down).

When thetrigger 55 is raised as shown in FIG. 10,passage 48 is switched fromsupply port 54 toexhaust passage 56, allowing the air pressure above piston 30 to exhaust to atmosphere. The reservoir air pressure inannular chamber 24 around thecylinder 15 is effective on the under side of piston 30 to raise the piston and compress spring 32. This opens the upper end ofcylinder 15 to reservoir pressure above thepiston head 21, driving thepiston 20 and driver blade 19 downward in a nail driving stroke. The upper end ofstem 33 of piston 30 is then seated and sealed againstcushion member 38 closing the'exhaust port 41 and allowing reservoir air'to also flow upwardly throughpassages 36 and 39 for operating the washer feeder as will presently be explained.

When the trigger is released, as in FIG. 11, air pressure is restored topassage 48 and the top of cylinder 31 to return thepoppet valve 27 into sealing engagement with the upper end ofcylinder 15. At the same time, the air pressure admitted through ports 25 incylinder 15 raises thepiston 20 in a return stroke, the air from the upper end ofcylinder 15 being exhausted to atmosphere through passage 36' and exhaust port 41.

Thus, thepassages 39 and 46 are alternately connected with 40 and 47 provide pipe connections to reciprocate a piston in g the washer feeding mechanism synchronously with the operation of the nail driver as will now be described. Except for thepassages 39 and 46 the tappedopenings 40 and 47, the structure and operation thus far described are conventional.

The present washer feeder may be used with nail driving machines adapted to drive any conventional type of nail, such as round head or T-head, but in the illustrated embodiments, the nails N are of special L-shape having an angular head portion extending laterally in one direction from the shank. Such nails are conveniently and economically formed by cutting a stick of U-shaped staples in half through the middle of the crown. Each staple thereby forms two nails, the head of each nail being half the crown portion of the original staple. When one of these nails is driven through the aperture in a washer W, the head or half crown portion overlies the washer as shown in FIG. 2. With only slight modification of the machine, such nails are readily fed through the magazine of a conventional staple driving machine whereby it becomes a nail driving machine. Although it is not necessary to use apertured washers it would be preferable. The nails will drive through unapertured discs if desired.

The washer feeding mechanism is mounted on abase plat 60 as shown in FIGS. 1 and 3. While such base plate may be incorporated as an integral part of the main casting of the nail driving machine, it is herein illustrated in the form of an attachment. Thus, the conventional guard plate of the nail driving machine is removed andbase plate 60 is attached to the under side ofbase magazine 10 byscrews 6!, two of which appear in FIG. 5.Base plate 60 is hollowed out to provide cavities for the operating mechanism and the underside is enclosed by a shoe orsoleplate 62 secured byscrews 63. These two plates are separated by a flatmarginal spacer plate 64 which is slightly thicker than the washer W for purposes which will presently appear. Preferably, the soleplate is tapered in thickness so that its bottom surface slopes upward at a small angle in longitudinal and lateral directions away from the nailing point as shown.

Base plate 60 extends laterally to one side ofbase magazine 10 to provide room for acylinder block 65 and inclinedwasher feed tube 66 as shown in FIG. 1. The lower end offeed tube 66 is located alongside nail driver blade 19. The lowermost washer infeed tube 66 is held down flat againstsoleplate 62 by one ormore magnets 67 as shown in FIG. 3. This places the bottom washer in the plane ofspacer plate 64 which is cut away in this region. The feeder mechanism shown in FIGS. 3, 5 and 6 is adapted for use with washers of magnetic material.

Spacer plate 64 has aU-shaped cutout 70 providing a washer pocket facing toward the lowermost washer in thefeed tube 66 and providing guide and positioning walls so that when the lowermost washer is shifted from its feed tube position at W in FIG. 5 by means to be described, the wall ofcutout 70 will stop the lateral movement of the washer and position it accurately at W with its aperture in alignment with the shank of the next nail to be driven by driver blade 19. This location of the nail shank and washer aperture is indicated at N in FIG. 5.

The nail is driven through avertical slot 71 in anail guide 72 which projects through acircular opening 75 inbase plate 60.Opening 75 is smaller than a washer. Underneath the washer W in nailing position, thesoleplate 62 is provided with acircular opening 73 slightly larger than the washer to permit the washer to move through the soleplate against the nailing surface when the nail is driven. In this embodiment the washers are prevented from dropping through theopening 73 prematurely by a pair ofmagnets 74 which are contained in recesses inbase plate 60 and have flat under surfaces flush with the underside of said base plate. See also FIG. 10. Thus, the bottom washer infeed tube 66 is first engaged on its under side by themagnets 67 and then as this washer is moved over theopening 73 to W, position, it is engaged on its upper side by themagnets 74, this lateral sliding movement of the washer being in a passage in the plane ofspacer plate 64 betweenbase plate 60 andsoleplate 62.

There also appears in the views in FIGS. 5 and 6 asafety plunger 77 which is arranged to prevent actuation of thepoppet valve 27 until the plunger is depressed upwardly to the level ofsoleplate 62 so that the nail driving mechanism cannot be operated until the machine is applied in driving position to a working surface.Plunger rod 77 is arranged to liftexhaust valve 78 in FIG. 10 andopen exhaust passage 56 to atmosphere. It should be apparent that the plunger could be set in a position level with thesoleplate 66 if this safety feature is not needed.

In order to feed washers when the nail driver is held in different positions, thefeed tube 66 is preferably provided with acap 80 equipped with acompression spring 81 and afollower 82 to press the stack of washers toward themagnets 67.

FIGS. 7 and 9 show two different modifications for holding washers of nonmagnetic material such as plastic. As shown in FIGS. 7 and 8, such washers may be gripped by their edges between a pair ofspring fingers 108 which are pivotally mounted onpins 109 inbase plate 60 and urged together by aspring 110. These fingers have slopinggripping surfaces 115 which converge downwardly as shown in FIG. 8 to retain the washer. When the nail is driven, the fingers yield outwardly to release the washer throughopening 73.

The modification shown in FIG. 9 more nearly resembles FIG. 5,suction apertures 100 inbase plate 60 being substituted for theupper magnets 74. This arrangement is suitable for use where there is a convenient source of air suction available. When the nail is driven, the washer is pulled away from the suction apertures on the top side of the washer, allowing the washer to pass downwardly throughsoleplate opening 73.

The washer lateral feeding mechanism is the same for all embodiments as shown in FIGS. 3 and 5. The washer is shifted laterally from a position W at the lower end oftube 66 to a position W, overlyingopening 73 by adelivery arm 86 which is pivotally mounted at 87 on thebase plate 60. The main portion ofarm 86 is of slightly less thickness than a washer and moves in the plane ofspacer plate 64 which is cut away to provide space for the arm. This arm has a rear end with an upward facing slot 88 (see FIG. 3) to receive a dependingdrive pin 89 in apiston 90. This piston is mounted for reciprocation in abore 91 incylinder block 65. The retract stroke of the piston is cushioned by arubber bumper ring 92 and the feed stroke is cushioned by arubber bumper ring 93 which seats against anadjustable plug 94 to accurately control the length of the feed stroke ofdelivery arm 86.

The feed stroke is produced by air received through anair pipe 95 connected with theopening 47 in FIG. 10 and the retract stroke is produced by air received through apipe 96 from thecenter opening 40. The cylinder bore 91 may also be provided with a port 97a short distance from the port forsupply pipe 96. When thus provided,port 97 is connected with apipe 98 leading to anopening 99 in the washer feed chamber as shown in FIG. 5. Then eachtime delivery arm 86 retracts, a momentary putf of air is delivered to opening 99 into the washer feed chamber to prevent the entrance of dirt and dust from the impact of the nail during its driving stroke.

When the driving mechanism is in normal rest position as shown in FIG. I], there is a washer in driving position at W, anddelivery arm 86 is held advanced in its solid line position in FIG. 5 by air pressure inpassage 48 andpipe 95 to hold the washer firmly inpocket 70. Then whentrigger 55 is actuated to its FIG. 10 position,pipe 95 is exhausted to atmosphere throughpassages 48 and 56 and air pressure is applied topipe 96 throughpassages 36 and 39, retracting piston anddelivery arm 86 as shown in dotted lines in FIG. 5. I employ a base check valve 122 in fitting 129 to slow down the feed stroke, at which time thearm 86 will snap back quickly. In retracted position,delivery arm 86 clears the stack of washers infeed tube 66 allowing the stack to move down and place the next bottom washer in position to be engaged by the delivery arm. During retraction of thedelivery arm 86, the downward movement ofdriver piston 20 drives the nail through the aperture in the washer, removing the washer from the machine and applying it to the working surface under the head of the nail.

Whentrigger 55 is released causingdriver piston 20 to retract upwardly, air pressure is supplied throughpassage 48 andpipe 95 to simultaneously drivepiston 90 anddelivery arm 86 for sliding another bottom washer to W, position inpocket 70. Exhaust air from cylinder bore 91 is discharged throughpipe 96 and port 41 in FIG. 11.

When nonmagnetic washers are to be used, i.e., plastic, aluminum, etc., I have adopted a substitute therefor, namely, air pressure. In FIGS. 12 and 13 [show a modified form of my invention wherein soleplate is provided with avertical passageway 123 extending from and communicating with the interior ofbore 91 between thebumper 92 and left-hand head ofpiston 90 as shown in FIG. 13. Thepassageway 123 communicates withpassageways 124 and itsbranches 125, 126, and 127. Each of the terminal ends of branches I25, 126 and 127 are curved, as at 128, outwardly and upwardly therefromterminating in anaperture 130 directed towards the washer W-l as shown in FIG. 13.

Thus compressed air flowing throughconduit 95 through fitting 129 into thebore 91 thru the passageways 123-127 inclusive and outwardly thru theapertures 130 will be directed to the bottom of the washer W retaining the washer in place subject to the nail and driver blade forcing it out of position to the work.

Thus all of the magnets required in the principle embodiment may be eliminated and ordinary blocks substituted therefore.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. In a nailing machine having a reciprocating nail driver, a reservoir for holding a supply .of washers on one side of the nail driver and in cooperative relation thereto, reciprocating means for feeding by a forward stroke thereof a washer from said supply to nailing position directly below the nail drive, means for holding said washer in said nailing position until said driver is operated, means for retracting said feed means in preparation for feeding another washer when said driver is operated, and control means having a first position for actuating the driving stroke of said nail driver and the retracting stroke of said feeding means and a second position for actuating the retracting stroke of said nail driver and the feeding stroke of said feeding means.

2. In a nailing machine having a reciprocating nail driver arranged to drive a nail, means to actuate said driver in a driving stroke, and means to retract said driver; means for holding a supply of washers on one side of said driver, reciprocating means for feeding a washer from said supply to nailing position directly below said driver, means to retract said feed means upon actuation of said driver and feeding a washer after actuation of said driver, means for holding a washer in said nailing position until said driver is actuated in a driving stroke, and control means having two positions, said driver-actuating means and said feed-means retracting means being responsive to one and said driver-retracting means and said feeding means to the other of said positions.

3. in a nailing machine having a nail driver arranged to drive a nail, a washer feed tube on one side of said driver, a soleplate having an opening positioned below and in axial alignment with said driver, a semicircular washer pocket above said.

opening on one side thereof, a reciprocating arm for sliding a washer from said feed tube into said pocket after operation of another washer and for operatin said driver, and second means for retracting said driver an moving said arm In its forward feeding stroke.

4. In a nailing machine having a nail driver arranged to drive a nail, a washer feed tube on one side of a soleplate having an opening positioned below and in axial alignment with said driver, a washer pocket above said opening' on one side thereof, a reciprocating washer feeder, first means for actuating said feeder in a feed stroke to slide a washer from said feed tube into nailing position in said pocket and for retracting said driver, and second means for actuating said feeder in a retract stroke and said driver in its operating stroke.

5. The device ofclaim 4 wherein means are provided to retain the washer in said pocket until rejected during a driver stroke.

6. In a pneumatic nailing machine having a driver, a driver cylinder, an air supply reservoir, an inlet valve between said reservoir and cylinder, a double acting piston for operating said inlet valve, and a trigger valve for connecting one side of said piston to pressure and exhaust for opening and closing said inlet valve; a washer feed tube on one side of said driver, a soleplate having an opening in nailing position for passing a washer through the soleplate when said driver is operated, a washer pocket above said opening on one side thereof, a washer feed piston in a double-acting cylinder, an air conduit connecting one end of said feed cylinder with said driver cylinder and reservoir when said inlet valve is opened by operation of said trigger valve whereby when said driver is operated, said feed piston is in a retract stroke and an air conduit connecting the opposite end of said feed cylinder with said reservoir when said trigger valve is released, to operate said feed piston in a feed stroke for sliding a washer from said feed tube into nailing position in said pocket.

7. In a pneumatic nail-driving machine having a driver and valve-controlled air supply and exhaust passages, means for holding a supply of washers, pneumatic means for feeding one washer at a time from said supply to nailing position beneath said driver after operation of said driver, fluid pressure connections between said feed means and said passages for operating said feed means, a soleplate having an opening in said'nailing position for passing a washer through the soleplate with a nail when said driver is operated, and means independent of said feeding means for holding a washer in said nailing position above the bottom of said soleplate and over said opening until said driver is operated.

8. In a mailing machine having a nail driver arranged to drive a nail, means for holding a supply of washers on said one side of said driver, means for feeding one washer at a time from said supply to mailing position beneath said driver on said one side of the work piece, a soleplate on said machine having an opening positioned directly below and in axial alignment with said driver for passing a washer through the soleplate with a nail when said driver is operated, and means for holding a washer in said nailing position above the bottom of said soleplate and over said opening until said driver is operated.

Claims (11)

1. In a nailing machine having a reciprocating nail driver, a reservoir for holding a supply of washers on one side of the nail driver and in cooperative relation thereto, reciprocating means for feeding by a forward stroke thereof a washer from said supply to nailing position directly below the nail drive, means for holding said washer in said nailing position until said driver is operated, means for retracting said feed means in preparation for feeding another washer when said driver is operated, and contrOl means having a first position for actuating the driving stroke of said nail driver and the retracting stroke of said feeding means and a second position for actuating the retracting stroke of said nail driver and the feeding stroke of said feeding means.

2. In a nailing machine having a reciprocating nail driver arranged to drive a nail, means to actuate said driver in a driving stroke, and means to retract said driver; means for holding a supply of washers on one side of said driver, reciprocating means for feeding a washer from said supply to nailing position directly below said driver, means to retract said feed means upon actuation of said driver and feeding a washer after actuation of said driver, means for holding a washer in said nailing position until said driver is actuated in a driving stroke, and control means having two positions, said driver-actuating means and said feed-means retracting means being responsive to one and said driver-retracting means and said feeding means to the other of said positions.

3. In a nailing machine having a nail driver arranged to drive a nail, a washer feed tube on one side of said driver, a soleplate having an opening positioned below and in axial alignment with said driver, a semicircular washer pocket above said opening on one side thereof, a reciprocating arm for sliding a washer from said feed tube into said pocket after operation of said driver, means for holding said washer in said pocket, first means for retracting said arm in preparation for feeding another washer and for operating said driver, and second means for retracting said driver and moving said arm in its forward feeding stroke.

4. In a nailing machine having a nail driver arranged to drive a nail, a washer feed tube on one side of a soleplate having an opening positioned below and in axial alignment with said driver, a washer pocket above said opening on one side thereof, a reciprocating washer feeder, first means for actuating said feeder in a feed stroke to slide a washer from said feed tube into nailing position in said pocket and for retracting said driver, and second means for actuating said feeder in a retract stroke and said driver in its operating stroke.

5. The device of claim 4 wherein means are provided to retain the washer in said pocket until rejected during a driver stroke.

6. In a pneumatic nailing machine having a driver, a driver cylinder, an air supply reservoir, an inlet valve between said reservoir and cylinder, a double acting piston for operating said inlet valve, and a trigger valve for connecting one side of said piston to pressure and exhaust for opening and closing said inlet valve; a washer feed tube on one side of said driver, a soleplate having an opening in nailing position for passing a washer through the soleplate when said driver is operated, a washer pocket above said opening on one side thereof, a washer feed piston in a double-acting cylinder, an air conduit connecting one end of said feed cylinder with said driver cylinder and reservoir when said inlet valve is opened by operation of said trigger valve whereby when said driver is operated, said feed piston is in a retract stroke and an air conduit connecting the opposite end of said feed cylinder with said reservoir when said trigger valve is released, to operate said feed piston in a feed stroke for sliding a washer from said feed tube into nailing position in said pocket.

7. In a pneumatic nail-driving machine having a driver and valve-controlled air supply and exhaust passages, means for holding a supply of washers, pneumatic means for feeding one washer at a time from said supply to nailing position beneath said driver after operation of said driver, fluid pressure connections between said feed means and said passages for operating said feed means, a soleplate having an opening in said nailing position for passing a washer through the soleplate with a nail when said driver is operated, and means independent of said feeding means for holding a waSher in said nailing position above the bottom of said soleplate and over said opening until said driver is operated.

8. In a mailing machine having a nail driver arranged to drive a nail, means for holding a supply of washers on said one side of said driver, means for feeding one washer at a time from said supply to mailing position beneath said driver on said one side of the work piece, a soleplate on said machine having an opening positioned directly below and in axial alignment with said driver for passing a washer through the soleplate with a nail when said driver is operated, and means for holding a washer in said nailing position above the bottom of said soleplate and over said opening until said driver is operated.

9. A machine as defined in claim 8, wherein said holding means comprises magnets positioned above said opening engageable with the upper side of a washer adjacent the perimeter thereof in said nailing position.

10. A machine as defined in claim 8, wherein said holding means comprising a pair of constrictive spring arms arranged to clamp a washer by its opposite edges in said nailing position.

11. A machine as defined by claim 7 wherein said washer holding means comprises subjecting jets of air against the bottom of said washer.

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