US2557757A - Nail chuck - Google Patents

Description

Patented June l9, 1951 UNITED STATES NAIL CHUCK Floyd G. Paxton and Albert I. Obermiller, Riverside, Calif.

Application October 22, 1947, Serial No. 781,308

3 Claims. (Cl. 15)

Our invention relates tonailing machines and more particularly to an improved nailing head for use on such machines. The type of machine to which the present invention relates is commonly used for nailing wooden boxes and for nailing lids on boxes. These machines include a frame having a nailing table for supporting the work to be nailed. A group of nailing heads is supported on the frame above the table for driving nails in the work, the heads being adjustable to obtain the desired nail pattern for different sizes and types of boxes.

- A nail-feedingmechanism, common in the art, is provided for stripping the nails and automatically feeding a single nail through a tube to each nailing head at each cycle of operation. The machine brings the work and the nailing heads together and the nails are driven from the nailing heads into the work by nail drivers which are slidable in the heads,the nail drivers being power driven by the machine.

During operation of nailing machines, the nailing heads occasionally jam when bent, malformed, or oversize nails are fed to the nailing head. It is not uncommon to find a number of nails in a single keg which are deformed and cause the nailing head to jam. The conventional heads in present use are designed to yield in the event of a jam to prevent serious damage or breakage of the head. Such heads usually comprise a body formed of two halves. The halves are held in alignment by a pair of studs which are threaded into and extend from one of the halves, the other half of the nailing head body being slidable on the studs. The two halves are yieldably held together by a pair of compression springs, one spring on each stud, the springs being compressed by nuts threaded on the studs.

When the nailing heads of a machine become jammed, the head must be taken apart to clear the trouble. To disassemble the conventional head, the nuts which compress thesprings are removed, many turns of the nuts being required as the studs are of sullicient length to enable compressing and decompressing the springs. After removal of the nuts, the springs are removed and finally the free half of the head. When the jam is cleared, the head is assembled by reversing the steps above described.

The time required to clear the conventional type of nailing head is highly objectionable, particularly when the nailing machine is being used on lidding operations where the boxes are carried from the packing stations to the lidding machine on a conveyor in a continuous line. Some boxes are lidded at an average rate of 1200 boxes. per hour and maximum speeds of as high as; 1800 boxes per hour are obtainable. A delay-at the lidding machine beyond a certainlimit results in congestion of packed boxes along the conveyor which forces the packers to remain idle until the lidding machine is repaired and the congestion cleared.

It is, accordingly, an object of the present invention to provide an improved nailing head which may be disassembled and reassembled in but a fraction of the time required to disassemble. and reassemble the conventional head.

A further object of our invention is to provide a nailing head which can be taken apart and reassembled without the use of wrenches or other tools.

Another object hereof is the provision of a nailing head spring assembly in whichthe springs are retained under compression when the springs are removed from the nailing head thereby relieving the operator of the work required to decompress the springs when disassembling the nailing head and to compress the springs when assembling the head.

Another object of our invention is the provision of a self-locking spring retainer which holds the springs of a nailing head under constant pressure without working loose during vibration and shock of the machine during nail ing operations.

Still another object hereof is the provision of a spring. assembly in which the springs are permanently compressed to the proper degree thereby making it impossible for an inexperienced or careless operator to over or under compress the spring when assembling a nailing head.

A further object .of our invention is to provide a nailing head of reduced thickness thereby permitting the vertical axes of adjacent nailing heads to be brought close together to enable the driving of nails on relatively close center to center distances when desired.

Other advantages and objects will become apparent in the following description in view of the drawings in which: I .7

Fig. 1 is a front elevational view of a preferred form of nailing head of our invention.

Fig. 2 is a side view of the nailing head shown in Fig. 1. a

Fig. 3 Ba vertical sectional view taken-on line 33 of Fig. 2.

Fig. 4 is a horizontal sectional view taken on line 4-4 of Fig. 1.

Fig. 5 is a front view similar to Fig. 1 but showing the first step in disassembly of the nailing head.

Fig. 6 is a perspective view showing the main parts of the nailing head as they appear when disassembled.

Referring specifically to the drawings, a preferred form of nailing head of our invention is indicated generally throughout the several views at I0. The nailing head |D includes a body comprised of two sections, a stationary section l2 and a floating section l3.

The stationary section I2 is shaped at its upper end to provide shoulders l4, as seen in Fig.1, which serve to position the nailing head ID in relation to a pair of bars to which the head His secured by a cap screw Hi. The bars extend horizontally, as seen in Figs. 2 and 6. and are secured to the frame of the nailing machine (not shown) in a well-known manner. In practice, a number of the nailing heads ID are secured to the bars |5 for driving 'a row of 'nails into the work to be nailed. The heads are readily adjustable along thebars |5 to obtain the desired nail spacing.

Secured .to'opposite .sides of the stationary section l2 by means of rivets is azpair of guide bars 21, the latter being .set :in channels 22 milled'on op'positesides .of thexsection 12. 'As seen in :Fig. 2, the outer surfaces of the guide bars 2| are flush with the outer-surfaces of'the stationary section I2. The-free ends of the guide bars 2| are formed to. provide hooks123 'having semi-circular recesses 24 and openings 25. As-seen in Fig. 2, the guide bars 2| are relatively thin for the purpose of reducing the overall'thickness of the nailing head Hi to a minimum. In actual practice, theoverall thickness of the head does .not exceed fiveeighths of an inch although the head is designed to drive nails as large as 'eightpenny. Two or more heads can therefore be positioned to drive nails on as little as five-eigh'ths of an inchcenter to-center spacing.

'The floating fsection H! has channels '28 milled oniopposite :sides thereof as best seen in Fig. 6. The channels 28 slidably receive the guide'bars 2| which properly orient thesections l2 and I3 while permitting horizontal movement of the floating section I3 relative to the stationary section |2.

Formed 'longitu'dinallyialong the adjacent inside 'faces'of the'hody sections |2 and'l3 are naildriver channels 29 and 30 respectively as .shown in FigsI3 and 4. When the sections |2 and 13 are closedinnormal nail-driving relation, the channe'ls .2 9 and-3'0 form alsquarezpassage for slidably receiving anail driver 3|. 'The nail driver '31] is a square 'bar .of hardened 'steel, attached at its upper end to a vertically zmovable nail-driving bar (not shown), aWell-known element in the nailing machine art.

Both of the nailing headzsection's |.2 Iand'i 3 have cavities and 36, respectively, at the lower portions thereof as seeniinFig. 3. The cavities E35 and 36 are shaped to'receive the nail chuck 3'1 comprised of a'pair'of complementary steel-chuck springs 38 mountedon the sections I2 and 13 by means of screws 39. Thesprings '38' are shaped to/receive the point of :a nail 40, as seen in Fig. 3, and also serve to aguide the nail 40 as the latter is driven from the head l0 into the work by the nail driver 3| in a well-known manner. Formed in the floating section |3,-as shown in Fig; 3, is a hole 44 for receiving a nail-feeding' tube 45, the latterbeing secured in the section -I3'by a set screw 46.

Slidable on the .guide'barsa2-l isa' spring pressure unit 50 which includes a frame member 5|, opposite edges of the latter being shaped to slidably receive the guide bars 2| as indicated at 52. Opposite ends of the frame member 5| have holes 53 for receiving rivets 54, the latter being slidable in the holes 53 and having heads 55 and 55 at opposite ends thereof. Mounted on each of the rivets is a compression spring 51 confined longitudinally between the rivet heads 55 and ends of the frame member 5|. The pressure unit 50 is assembled by heading the rivets 54 with the springs 51 under compression. After the pressure unit 50 is assembled, the springs 51 are permanently compressed by an amount suitable for proper-operation of the nailing head I0.

The nailing head In is locked up after assembly by a cam shown best in Fig. 6. The cam 60 is comprised of a cylindrical head 6| having trunnions 62 on opposite ends thereof. The trunnions 62 are on a common axis which is eccentric in relation to the-axis of the head 5|. Extendingfrom the head 6| is a handle 63 provided for manual operation of the cam 60 and also for limiting rotation of the head til. The cam 60 is locked in position by placing the trunnions 62 in the semicircular recesses 24 of the guide 'bars'2| with the cam 60 in the position in which it is shown in Fig. 5. It will be noted'by the dotted lines in Fig. 5 that while in this position, the head 6| of the cam 60 does not contact the frame member 5| of the spring pressure unit 50. As the handle 63 is forced downward to the position shown in Fig. l, the head 6| contacts the frame 5| and presses the springs 51 against the floating section l3 thereby forcing the section |3 .against the stationarysection I2. When the handle 63 stops against the head 56 of the lower rivet 54, the cam :is locked against accidental displacement because the axis of the cylindrical head 6| is well above the axis of the trunnions-62as seen in Fig. 1.

Operation The normal operating positions of the various parts of the nailing head ID are as shown in Figs. 1 to 4, Fig. 3 showing the-proper position of the nail 40 prior to driving. If the head-l0 becomes jammed as a result of a deformed nail, or as -'a result of two nails instead of one being fed tothe head, the floating'section 13 is forced away from the stationary section |2 against the pressure of the springs51. To clear the jam, it isnecess-ar'y to disassamble the head-an'dremove the deformed nail. The first step in disassembling thenailing head I0 is removal-of the cam '60 by lifting the handle63 to the position shown in'Fig.'5 thereby relieving'the cam-60 of the pressure of the springs 51 and permitting removal of the cam "60. The pressure unit 50 and floating section l3 of the nailing head 10 'are withdrawn from the guide bars 2| as shown in Fig.6. After the head'is cleared, reassembly is accomplished in but a few seconds by reversing the-steps followed in disassembly. I

'It is clear that disassembly and assembly of the nailing head |-|l can be accomplished in a minimum of time, without the use oftools,and that upon assembly,-the proper pressure of the springs 51 is automatically accomplished without depending upon the degree of skill and care exercised by the operator.

Although we have limited the present discloswe to but one-form of our invention, it is understood that modifications and changes may be made in the structure without departing from the scope of the following claims.

We claim as our invention:

1. In a nailing head, the combination of: a body divided longitudinally to form two sections, one of said sections being movable toward and away from the other, guide means for maintaining said sections in alignment relative to each other, a spring pressure unit for urging said movable section toward the other, and a cam engageable with said guide means and said spring pressure unit, said cam being manually operable for urging said spring pressure unit into operative position and locking said unit in said position.

2. In a nailing head, the combination of a body divided longitudinally to form a stationary section and a floating section, a nail driver slidable longitudinally between said sections for driving a nail from said head, a pair of guide bars extending from said stationary section, said floating section being slidable on said guide bars toward and away from said stationary section, a pressure unit comprising a frame slidable on said guide bars, a spring secured to said frame, means for retaining said spring in partially compressed condition, and a manually operable cam for removable engagement with the free ends of said guide bars, a lever for manual rotation of said cam, said cam urging said pressure unit against said floating section in response to rotation of said cam.

3. In a nailing head, the combination of: a body divided longitudinally to form a stationary section and a floating section, a nail driver slidable longitudinally between said sections for driving a nail from said head, a pair of guide bars extending from said stationary section, said floating section being slidable on said guide bars toward and away from said stationary section, said guide bars having hooks formed on extremities thereof, a pressure unit comprising a frame slidable on said guide bars, a spring secured to said frame, means for retaining said spring in partially compressed condition, a rotary cam having aligned trunnions on opposite sides thereof, said trunnions being removably engageable with the hooks of said guide bars, means for rotating said cam against the frame of said pressure unit to urge said pressure unit against said floating section to yieldably retain said floating section against said stationary section, and a stop halting rotation of said cam after the high-point of said cam passes the line of contact between said cam and said frame.

FLOYD G. PAXTON. ALBERT I. OBERMILLER.

Name Date Milliken May 14, 1907 Number

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