US1967282A - Nailing machine - Google Patents

Description

LQRZSE S. E. BOYNTON NAILING MACHINE Juy 249 M934.,

Filed June 20, 1930 2 Sheets-Sheet NAILING MACHINE Filed June 2o. 195o 2 sheets-sheet 2 MAMA/TUR 5"., E, @o YN TUN mm A T TURA/EY Patented July 24, 1934 mimic mom Stanley E. Boynton, Elizabeth, N. J., assigner to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 20, 1930, Serial No. 462,501

Claims. (Cl. 146.1)

This invention relates to nailing machines and more particularly to nailing machines of the portable type used in light construction.

An object of the invention is to provide an apparatus which will be rapid and efiicientin action, operative with al minimum of shock and wear of the elements involved, and with a minimum of strain on the operator.

The invention contemplates the provision, in

1o a portable device for driving nails or other holding elements, of a toggle operated by a pneumatically driven plunger, which advances a rod for driving a nail from an indexed magazine with a single squeeze stroke into the workpositioned against an anvil carried by the device. The air pressure for the plunger, and the magazine indexing mechanism, are controlled from a common lever, and the piston of the plunger is driven by a transfer of the compressed air from one side to the other thereof, the return movement being air cushioned to prevent shock.

A better understanding of the invention will be had from the following detailed description, read in connection with the accompanying drawings forming a part thereof, in which Fig. 1 is a fragmentary sectional view partly in elevation, of an apparatus showing the position of the parts with the control lever in its first position; y

Fig. 2 is a similar View, but showing the position of theparts when the control lever is in its second position, and g Fig. 3 is a fragmentary elevation taken on the line 3-3 of Fig. 2.

35 Referring to the drawings wherein similar parts are indicated by identical reference numerals throughout the several views, a portable pneumatic toggle hammer, generally denoted by the numeral 10, for driving nails, screws, dowels, etc., 4is provided with a casing or body 11 surmounted by a head 12 suitably bolted thereto. A cylinder 14"surmounts the head and is threaded thereto to form an ,airtight joint and is in tum provided with a cylinder head 15 which is threaded to the cylinder in an airtight manner. A piston rod 18 is shown (Fig. 1) in its uppermost positionl or that assumed preparatory to a driving stroke. The head is centrally apertured to receive the piston rod 18, the rod being centrally 5o located therein by means of a gland nut 19. A

top air pipe 20 is provided for furnishing the driving compression and is operatively connected with the cylinder head by means of a screw bushing 22. Secured by any suitable bolt 103 to the casing 11 at one side thereof and spaced therefrom so as to comprise a handle for holding and manipulating the machine is a valve casing or body 23, and longitudinally disposed therein a cylindrical valve bushing 24. A dowel 26 is suitably positioned between the body and the so bushing to prevent rotation of the latter. A valve spring plunger 27, having a valve spring 28, extends upwardly into the bushing from the lower end thereof and is provided with a head 30 against which the spring is seated. The valve 55 spring plunger is slidably mounted in a valve nut 31 which is threaded into the body serving to maintain the bushing 24 in proper position, and which is centrally apertured to receive a. gland nut 32, in which the valve spring plunger rides. A valve plunger 34is slidablyA mounted in the upper part of the bushing, resting upon the spring plunger head 30, and projects upwardly from the bushing a short distance to engage a cam surface 35 of a control lever 36. 'I'he control lever is pivoted in the body 23 upon a pin 38 and is provided with a projecting corner 39 which engages with the body when the lever is in its first position (Fig. 1) to maintain engagement between the cam surface 35 and the upper end of the plunger 34.

The valve body is provided at the bottom thereof with an outwardly projecting tubular member 40 which it will be understood is engaged by an airline (not shown) of any suitable type for connecting the machine to a source of compressed air. The casing 23 is provided interiorly thereof with an aperture 42 connecting with the tubular member 40 and this aperture is connected by a passage 43 with the air pipe 20. Extending from the passage43 through the casing or body to the outside or other surrounding atmosphere is an exhaust passage 44. An apertured regulatingv screw 45 is fitted into the outlet of the exhaust passage 44 for diminishing the rate of passage of air therethrough. Another exhaust passage 46 connecting the interior of the cylinder 14 with the aperture 42 extends through the head 12, body 11 and valve casing 23, and an exhaust passage 47 is provided in the body of the valve casing for affording communication from the interior of the cylinder to the surrounding atmosphere. The valve plunger 34 is provided with four peripheral grooves 48, 48 which are spaced thereon in such a manner as to permit control of the flow of air therein in a manner to be hereinafter made clear. A bell crank lever 50 having a fixed toggle pin 51 is pivotally secured at one end by a pin 52 to the lower extremity of the piston rod 18. A link 53, pivotally connected to the other end of the toggle 110 arm by a pin 54, is pivotally connected to the upper end of a nail rod by means of a clevis and pin mechanism 56. Bolted or otherwise suitably secured to the body 11 is a guide plate 58 having a guideway 59 for insuring that the movement of the nail rod shall always be parallel with the movement of the piston rod 18.

Suitably secured to the body 11 in such a manner as to permit its ready removal therefrom is a block 60 having a downwardly projecting arm4 62 and an anvil 63 thereon. The anvil 63 is designed to engage any article of work 64 and hold the work and the hammer in proper respective positions to permit a nail 66 to be driven into the work at any desired angle. Although the anvil shown is provided with an angular recess to receive the work, it will be understood that any desired configuration may be employed in connection with the hammer that the type of work being nailed may call for. It is also a simple matter, if desired, to cause the arm 62 to be extensible in order to permit it to accommodate work of varying sizes.

When the lever 36 is depressed by the operator it moves from the first position shown in Fig. 1 to the second position shown in Fig. 2 and in so doing opens the following air circuit to drive the hammer: From the tubular projection 40 through the aperture 42, bushing 24, the lowest groove 48, passage 43 and top air pipe 20 into the upper portion of the cylinder 14. Exhausting of the cylinder below the piston 16 occurs through the passage 46, bushing 24, second groove 48 and exhaust passage 47, and permits the descent of the piston 16, rod 18 and bell crank 50. When fully developed the latter movement causes the link 53 to assume a practically vertical position (Fig. 2) thus straining the toggle to push the nail rod downwardly, the clevis pin 56 being guided in the way 59. The effect of this operation is to cause the nail to be squeezed into the work at first rapidly, and, as it assumes its nal driven position, more slowly but with the necessary increased power. When the nail has been finally driven, as may be readily determined by inspection, the operator releases the lever 36, causing the spring 28 to become operative to thrust the spring plunger 27 upwardly. This in turn thrusts the valve plunger 34 upwardly through the bushing, the upward end of the valve plunger 34 maintaining contact with the cam surface 35 of the lever, with the result that the entire movement of the valve elements ceases when the corner 39 comes to rest upon the body 11.

The upward movement of the valve plunger 34 causes the air circuit described above to be abrogated, the passages 43 and 47 being blocked by the valve plunger, which in its upward movement carries the second and lowest grooves 48 out of alignment with the passages in question. A new circuit, however, for the compressed air is established and proceeds from the tubular projection 40, through aperture 42, valve bushing 24, third groove 48 to the passage 46, thus causing the air pressure to be effective upon the lower surface of the piston 16 to cause its upward movement in the cylinder. The air is exhausted during this movement from the upper portion of the cylinder through the pipe 20, bushing 24, the uppermost of the grooves 48, and the exhaust passage 44. 1t will be noted that the aperture in the screw 45 is much smaller than the exhaust passage 47 or the passages 46 and 43 and is so formed to insure that the piston 16 on its return stroke shall be driven upwardly against a cushion of air which, though yielding due to leakage through the screw 45, will yet be sufficient to prevent the piston reaching the top of its stroke with a perceptible impact. It will thus be seen that both the driving and return movements taking place in the hammer are caused without any perceptible shock such as would tend to fatigue the operator, or wear upon the machine.

The machine is provided with a magazine for holding a supply of nails which consists of a circular member or turret 67 having a central tubular portion 68 which is rotatably mounted upon a turret holding stud 70 secured in the block 60, by means of a nut or other readily detachable holding means 71. The turret is provided with a peripheral wall 72 having a number of notches 74 formed therein to correspond with the number of nails to be carried by the magazine. The turret may be provided with any desired number of such notches, the number being determined by the number of nails which it is desired that the magazine hold, one convenient form adapted to carry 24 of the nails 66 being illustrated. At the base of each notch a hole 75 is formed in the wall for accommodating a nail, the diameter of the hole being suiiicient to permit the head of the nail to pass longitudinally therethrough without friction.

To prevent dislocation of the nails when the magazine or the machine is tilted to properly address the work during normal operation, the magazine is provided at each notch with an upper nail holding jaw 76 and a lower nail holding jaw 78, which are pivotally mounted upon hinge rings 79 and 80 respectively, secured to the turret. A hinge ring holding plate 82 having a central aperture adapted to t upon the central tubular portion 68 is superposed upon the lower side of the turret for holding the lower ring in position, and a leaf spring 83 suitably secured to the jaws is provided at each of the nail holding jaws in order to hold them resiliently in a normal closed position, in which position the shank of the nail is engaged between the upper and lower jaws respectively, and prevented from falling. By this construction not only is a dislocation of the nails prevented when, during the course of rotation of the turret they become inverted and tend to fall out head first, but is also of great utility in insuring that the nails shall be held in alignment with the nail rod 55 in whatever position the operator may find it necessary to tilt the machine in order to properly address the work.

The peripheral wall 72 is provided with a gear ring 84 having a plurality of suitably spaced teeth 86 upon the inner edge thereof. 'Ihe nail rod guide plate 58 is provided with a projection 88 extending beyond the body 11 and upon which is mounted, by means of a pivot pin 90, a lever 91 for locking the turret against accidental rotation and to insure that a nail being driven shall be properly aligned axially with the nail rod 55. Suitably seated upon the exterior of the body is a coil spring 92, which engages the upper end of the turret locking lever to normally urge it outwardly, and cause the lower portion thereof to be retracted. 'Ihe lock lever 91 is provided at the lower portion thereof, and upon its inner edge with a shoulder 94 which, upon the downward stroke of the nail rod, is engaged by the clevis 56 in cam manner. The lower portion of the lever 91 is thereby rotated outwardly against the tension of the spring 92 from the position shown in Fig. 1 to that shown in Fig. 2 wherein it engages an appropriate notch 74 to lock the turret against rotation.

A mechanism for indexing the magazine in lill@ lll@ cludes a bushing 96 suitably secured in an aperture 97 longitudinally disposed in the block 60, and a shaft 98 rotatably journalled therein, having secured upon that end adjacent the turret a gear 100 whichmeshes with the internal teeth 86 of the gear ring 84. A ratchet assembly, including a ratchet wheel 101, is mounted at the opposite end of the shaft 98 upon a bracket 102, which is secured to the body of the machine in any suitable manner. A ratchet pawl arm 104 is pivotally mounted upon the bracket by a pin 105 and carries a pawl 106 pivotally secured to the arm by a pivot pin 108, the pointed end of the' pawl resting upon the periphery of the ratchet wheel 101. A trip shelf or arm '109 is secured upon the side of the ratchet pawl arm and extends beneaththe valve spring plunger 27. In order to maintain the trip arm in position against the end of the valve spring plunger when the latter is in its uppermost position a spring- 110 is provided connecting the pivot pin 108 with the bolt 103.

During the driving of a nail and while the lever 36 is in the position shown in Fig. 2, the turret lock'lever projects outwardly engaging in the notch Ar14 to maintain the turret in a rigid position. The spring plunger 27 assumes its lowermost position causing the trip arm to tilt downwardly moving the ratchet pawl arm in a counterclockwise direction and causing the pawl 106 to be carried along the periphery of the ratchet wheel over one of its teeth. Upon the driving of a nail however, and upon return of the lever 36 to the position shown in Fig. 1, the valve spring plunger moves upwardly and the trip arm under tension of the spring 110 follows, rotating the ratchet pawl arm 104 in a clockwise direction, whereupon the pawl catches upon the ratchet wheel tooth and moving with the pawl arm rotates the ratchet wheel in a clockwise direction. 'I'he shaft 98 is thereby rotated causing the gear 100 to index the turret by means of the ring gear 84 through one position to present the next nail for driving. The turret is then locked in such position by the lever 91 upon the next downward movement of the clevis 56.

The magazine described is of such a type that it may be readily illled either manually, or at any conventional nailing machine by simply passing the holes '15 in succession to the delivery point of the loading nailing machine. The nails will be deposited through the holes 'l5 and pressed downwardly between the nail holding jaws 'I6 and 78 which, being spring pressed, will engage the shank of the nail and hold it in position as described above for driving. In practice, a number of loaded magazines are kept at hand in'order that the operator of the toggle nailing machine may quickly and easily replenish the supply Vtherefor by unscrewing and removing the nut '11, drawing the empty magazine from the stud 70, placing a ,loaded magazine thereon and replacing and tightening the nut 11.

The anvil 63 is placed a sumcient distance from the lower edge of the magazine to insure that there will be sumcient clearance between the surface of the work and the jaws '16 and 78, to permit their expansion when a nail is being forced into the work.

Although the invention as herein illustrated and described is particularly well adapted for use in connection with the driving of holding members such as nails, dowels, screws, etc., it

should be understood that the novel features thereof are capable of other applications and should be limited only by the scope of the appended claims.

What is claimed is:

1. In a mechanism for driving holding elements, a `body having a projecting member, a

vmagazine rotatably mounted thereon with its axis oblique with respect to the axis of the body for supplying elements to be driven, cooperating jaws on the magazine for holding an element, and pneumatically operated toggle means actuating in parallel planes for releasing the jaws and driving the elements.

2. In a portable nail driving mechanism, a body having a projecting member, a magazine rotatably mounted thereon for supplying nails to be driven, cooperating jaws on the magazine for holding a nail, an anvil secured to the body for supporting the work to be nailed, and a handle secured to the body to permit positioning of themachine to secure proper address between the work and the nail holding jaws.

3. In a nailing machine, a cylinder, a piston reciprocally mounted therein, a plural ty of iiuid passages connecting with the cylinder upon either sideof the piston, a valve body, an exhaust passage therein communicating with the cylinder on one side of the piston, a smaller exhaust passage therein communicating with the cyl nder on the other side of the piston, and an auxiliary valve mounted in the smaller exhaust passage wall to provide an air cushion in the cylinder to obviate shock.

4. In a nailing mechanism, a valve body thereon, a cylinder on the body, a magazine, means for supporting an article to be nailed, a piston in the cylinder, toggle means actuated by one vstroke thereof for squeezing a nail from the magazine into the article, and means operative during the return stroke of the piston to provide an air cushion in the cylinder to obviate shock.

5. In a nailing machine, a valve body thereon, a turret having a ring gear, a gear meshing with the ring gear, a ratchet for rotating the gear, and a spring plunger in the valve body for operating the ratchet to index the turret.

6. In a portable nailing machine, a body, a valve body spaced therefrom to provide a handle for moving the machine to a plurality of positions, a rotatable nail supply magazine on the body, and resilient means on the magazine for preventing dislocation of the nails during movement of the machine androtation ofthe magazine.

STANLEY E. BOYNTON.

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