US2188929A - Drilling deep holes in wood - Google Patents

Description

Feb. 6, 1940. J. W.STOILLE 2,188,929

DRILLING DEEP HOLES IN WOOD Filed June 20, 1936 4 Sheets-Sheet 1 INVENTOR John W. Stolle BYn Feb. 6, 1940. J. w. STOLLE DRILLING DEEP HOLES IN WOOD 4 Sheets-Sheet 2 Filed June 20, 1936 Feb. 6, 1940.

Filed June 20, 1936 4 Sheets-Sheet 3 Troy/1 Feb. 6, 1940. J. w, ST LLE DRILLING DEEP HOLES IN WOOD Filed June 20, 1956 4 Sheets-Sheet 4 INVENTOR John W Sta! [6 BY 9 I ATTQRKJEY Patented Feb. 6, 1940 PATENT OFFICE DRILLING DEEP HOLES IN WOOD John William Stolle, Danbury, C'onn., assignor to Charles W. Stevens, Danbury, Conn.

Application June 20, 193 Serial No. 86,244

7 Claims This invention relates to the woodworking art, and particularly to the formation of holes in textile spools and bobbin blanks and the like, and

A particularly to the drilling of straight deep holes having sections of different diameter in elongated blanks by the use of relatively slender and flexible drills.

In the drilling of these blanks according to conventional practice there is a very substantial 10 Waste and loss of material due, among other things, to the long slender drill or boring tool being deflected from its rectilinear path by the grain of the wood which is not always parallel to the hole to be driven. This difficulty may be largely obviated by the use of the invention of my Patent No. 1,513,350, issued October 28, 1924, which comprises the use of a drill having a special cutting and shaving edge and a stream of liquid, such as water or oil, to wash out the chips which are formed during the drilling operation, and to moisten and soften the wood to be bored. While the liquid step is satisfactory in some branches of the wood boring art, such as the boring of hook handles, whifiletrees, wood machine rolls,

etc., I have found that in the drilling of textile spools and bobbin blanks that the oil or soap water employed has a deleterious effect upon the Wood.

One object of the invention,therefore, is the provision of means for utilizing compressed air andthe like to blow out the chips and cuttings during the boring operation, together with the provision of a special drill which, in addition to the patented features of my Patent 1,513,350, embodies features particularly adapted to the use of compressed air and capable of forming a,

hole in a manner which is self directing and guiding along a straight rectilinear path, notwithstanding the non-parallelism of the Wood grains.

40 A further object of the invention is the formation of a hole havingseotions of different diameter through a wooden blank, as for example a blank having an elongated hole of three different cross-sections, by first, and in one operation, drilling a hole equal to the desired diameter of the middle section of the blank and then in another single operation continuing the hole at a smaller diameter through to the end and reaming out the other end and by the use of a drill which does not rub against the walls of the intermediate hole previously formed.

A further object of the invention is a drill of the above indicated character which leaves an uncut core of wood in the center of the blank surrounded "by a cylindrical guiding groove for assuring the straight rectilinear progress of the drill through the blank, notwithstanding the fibrous character of the wood. I

A further object of the invention isa novel and I, improved form of machine for drilling and bor- 5'. ing wooden blanks of the above indicated character.

For a better understanding of the invention, reference may be had to the accompanying drawh ings forming a part of this application wherein: 10

Figs. 1 to 5' inclusive are .diagrammaticviews illustrating steps in the drilling of a blank ac cording to the invention; V

Fig. 3a is an enlarged sectional view showing the cylindrical centralguiding core and the sur- 15 rounding cylindrical guiding groove formed at the bottom of the, bore. U

Fig. 6 is a plan view substantially enlarged of the end of the drill; f

Fig. 7 is an end view thereof; 1 20 Fig. 8 is a side view of the machine;

Fig. 9 is a plan View of the machine;

Fig. 10 is a side view showing a step in th operation of the machine;

Fig. 11 is a sectional viewalong the line il ll 25 n of Fig. 8-; and i Fig. 12 is a detail view of certain parts of the machine.

Referring to Figs. 1,to 5, I have indicated at l a textile bobbin blank or the like to be drilled 30 and at 2 a drill according to thevpresent invention for drilling and forming a hole 3 of the desired diameter in the middle section of the blank.- This drill 2 forms the bore 3 to the point 3-where it is desired to discontinue the bore of that sec- 35 tion.

At 4 I have shown a drill which continues the bore throughout the blank to form a bored section 5 at one end and simultaneouslytherewith to ream out a section 6 of a still larger bore at 40 the other end; the completed drilling operation being indicated in the blank of Fig. 5. The multiple section bore 3, 5 and 6 of the'blank is formed in two operations; the drill 2 forming the bore indicated in Figs. 2 and 3 and the drill 4 forming the bore} and 6 of Fig. 5. Fig. 4 shows the second drilling operation. The shank I of the drill- 4 is of smaller diameter than the intermediate bore 3 of'the'blank. r

I have found that by drilling the hole inthe ,0 I

two operations by thetwo drills 2 and 4,that the a tendency of the drill to be deflected from a reeftilinear path during the relative longitudinal and rotational movements of the blank and the drill is substantially reduced. I believe this due to reduction in vibrations of the long slender drill which are present when a single drill is utilized for drilling simultaneously both larger and smaller bore sections, namely, when the drill is engaging the wood at two or more Widely separated points longitudinally of the blank. According to one aspect of the invention the drill 2 is utilized for forming the intermediate bore 3, While the drill 4 is utilized for forming the end bores 5 and 6. The reaming part 8 of the drill 4 for forming the enlarged bore end 6 does not come into operation until the bore 5 is on its way to coinpletion and, accordingly, the drilling operation of the two ends of the blank at this stage does not produce the same tendency to deflection as when the two operations occur at points closer to the middle section. By having the shank Iv of a smaller diameter than the bore 3 the rubbing of the shank against the walls of the 'bore'3 is prevented, thus removing any danger of vibration from the tip 9 of the drill, while it completes the bore 5.

For disposing of the chips and cuttings as the drill progresses, I supply fluid gaseous pressure, such as air, through the passages I0, Ifl' formed longitudinally of the drills. This passage or channel I0 (18') passes down through the tip 9 of the drill and the compressed air or other gaseous fluid blows the chips and cuttings backwardly along the drill, namely, along the groove II which is formed in the side of the drill.

' As afurther means forobviating deflection of the long slender drill from a straight rectilinear path, notwithstanding the departure from parallelism of the Wood grain, I have provided a drill tip 9 formed generally as indicated in Figsrl to 4, and as more specifically'illustrated in Figs. 6 and '7. This improvement consists of forming theltip '9 of the drill so that it will' form in advance of the bores 3 and 5 an annular groove I5 which approaches the cylindrical form with an uncut core I6 surrounded by the annular groove l5 and disposed in the axes of the bores. For this purpose 'I have provided the, tip 9 of the drill with a relatively short pilot cutting section I! eccentric to or'oflfset from the axis I 8 of the drill and bores. This pilot section I'll is of lesser diameter than: the main body tip 9 and forms the groove i5 and the core I6 in advance of and in alinement with the bores 3 and 5. The pilot section is formed on, the advancing edge II {of the drill, that is, relatively'to the blank I and it may be milled or ground at I9 to form the cutting edge 20. The drill is provided with a cutting and reaming side edge 2| (preferably formed by milling or grinding, as indicated at H) of my patent above referred to. Thus, two reaming edges 20, 2| and three'boringedges ll, I1 and 22 are provided, the edges I1, ll of the pilot section forming a salient. The groove II in the side of the drill should be deep enough to accommodate the uncut core I 6 which isformed on the axis I8 of the blank and drill. Thismay be effected by having the, sides of the groove II meet at a point far enough beyond the axis I8 to clear the core being formed; or, as is shown in Figs. 6 and 7, the drill may be provided with a central circular groove 25 to accommodate the core with the sides of the longitudinal groove ll discontinued at the groove.

.The dimensions of the groove I5 and the uncut core I6 may be varied to suit particular requirements, but generally the core should be of sulficient diameter and stifiness correlated with the depth of the groove I5 to aid in keeping the drill concentric with the'axis of the relatively rotating 2,188,929 I e I drill and wooden blank. I'have found in prac tice that a core one-fourth the diameter of the bore, namely, with the core I6 one-fourth the diameter of the bore 3, is efiective, with the depth of groove indicated in the drawings in guiding and causing the drill tip 9 to follow a straightrectilinear path, notwithstanding the direction of the Wooden fibres and the slenderness and flex'i-y' bility of the drills. The uncut core I6 is illus-" trated'as of compartively short but substantial depth.

The drill itself is of very small diameter and in operation the outer free end of the core is. 1

gradually and progressively broken or twisted off,

due to its small diameter.

In Figs. 8 to 11 I have shown somewhat diagrammatically a machine for drilling and boring, blanks in accordance with my invention, this machine embodying novel and improved mecha-I nisms'for drilling deep, straight holes in Wooden blanks for formingtextile spools and bobbins and the like. The machine comprises a bed plate 30,

having mounted thereon at one end ahead stock flexible pipe or hos'eAEl leading through suitable fittings M to passages formed in the chucks or sockets 36, 31 which receive the drills,,the air pressure being supplied to the passages II! of the drills. The'carriage 35 is reciprocated along the guideway 33 by means of a mechanism including a pivot le'ver'44 pivoted to the'bed at 44', the carriage and the lev'erbeingoperatively con.- nected together by a link 45 which is pivot-ally attached at 46 to the carriage and to the lever at v 41. The lever 44 is provided with a number of openings 48 to provide for the adjustable attachment of the end 4'! of the'link 45 to the pivoted lever 44. The lever '44 is oscillated about the pivot point .44 by means of a crank shaft 49. suit,-

ably journaled in the tail stock 32 and having a crank 50 which operatively engages thelever 44. The driving connection between the crank 52] and the oscillating lever 44 consists of a sliding bearing block 5I which'is pivotally fastened to' the crank 50 and this block 5i is guided by and slides back and forth in an elongated slot 52 formed longitudinally of the lever 44. The pivot point 44' of the lever is below the axis of the shaft 49, and at the position of the drill carriage indicated in Fig. 8, namely, at the end of the return stroke of the drills, the pivoted lever 44 is to the left of the axis of the shank 49 and the bearing block 5I is disposed about midway the ends of the slot 52. Therefore, with the shaft 49 turning clockwise (Fig. 8) a relatively slow forward movement of the drill carriage 3515 pro-;

duced and a relatively fast return movement is obtained, because in the former the-operative connection between the crank and the lever 44 nearer the outer end of the slot; 52 and-in the latter it is nearer the inner end thereof. 6 The drive for the shaft 49 is diagrammatically illusnism 54 and a drive shaft 55. l

705 trated, comprising the gear reduction meehaf Inthe particular embodiment shown therelas v tive longitudinal movement between-the drills and the blanks is produced by moving "the drills 2,188,929 longitudinally by means of the reciprocating drill cluding the axis of the drill. For this purpose the head stock 3| is provided with a pair of spindles 6I and 62 which are driven in anysuitable man ner,;as for example by the belting indicated, and which are suitably journaled in the head stock 3|, these spindles carrying at their inner ends adjacent the magazine 60 gripping chucks 6| and 62. The chucks 6| and 62' are in line with the drills 2 and 4 and the arrangement is such that when the blanks disposed in the magazine 60 are pressed against these chucks the blanks are caused to rotate at a high speed. The chucks BI and 62' are provided with recesses 64 and teeth 65 which function to bite into the end of v the wooden blank to be bored when the blanks are pressed thereagainst. The blanks are brought into driving relation with the chucks 6| and 62' by means of a pair of reciprocating work support units 66 and 61 which are reciprocated back and forth along the guide rods 33 and 34, each work support being mounted on an outer rod 33 and the adjacent rod 34. Each of these work supports. is provided with a bearing 66 and 61' in alinement with the drills and the'chucks BI and 62. In

these bearings are disposed guide bushings or sleeves 68 through which pass the drills to and fro-in their reciprocating'movements. On the end of each sleeve 68 there is journaled a chuck 69 having a conical recess 10. These journaled chucks 69 engage the blanks I when the work supports are moved forwardly to press the blanks against the driving chucks 6| and 62'.

i The work supports 66 and 61 are independently biased in a direction to engage the blanks. and force them against the driving'chucks. In the particular embodiment shown, this biasing operation is obtained by means of Weights I2 fastened by chains 13 fastened over pulleys I4 and attached to the work supports. The chucks of the work supports are automatically withdrawn from engagement with the blanks against the weights 12 by means of pull rods 15, which are fastened at one end to the drill carriage 35 and at the other end pass through openings formed in the work support uprights l6; and these pull rods 15 are provided with heads 15 which engage the uprights 16, when the drill carriage 35 nears its outermost position, to withdraw the work supports'and their chucks from engagement with the" blanks. i .1

The magazine 60 consists of an intermittently rotatable frame journaled upon a shaft 80, the latter being carried in any suitable manner, as for example by the head stock 3|, and this shaft 88 isin the horizontal plane of the drillsand the chucks; The magazine frame consists of a sleeve journaled upon the shaft 89 and carrying end discs lilv and 82. These discs carry near their peripheries eight cylindrical receivers .83, these cylindrical receivers and carriers being intermittently alineable with the chucks and being shorter than the blanks in order that the chucks may engage the projecting ends of the blanks for rotating them. This magazine 60 is intermittently rotated one-eighth of a revolution at each complete reciprocation of the drill carriage 35.

tively in engagement with the ratchet teeth 85,'

there being altogether eight ratchet teeth and this pawl 86 moving the magazine 60 through oneeighth of a revolution at each reciprocation.

The pawl 86 is carried by one arm 81 of a bellcrank lever pivoted at 89-upona bracket 90 carried by the machine bed. The other end 88 of the bell-crank lever is engaged and operated by an upright 16 which carries a finger 9| for that purpose, the finger 9l engaging the outer end of the lever 88 when the work support is actuated to the left (Fig. 8), which causes the upward movement of the pawl 86 and the movement of the magazine through one-eighth of a revolution. Upon movement of thework support to the right the bellcrank lever 81, 88 operates by gravity to cause the pawl 86 to engage the next lower tooth for the next intermittent operation. Any suitable means may be provided for preventing the overtravel of the magazine 60, namely, beyond. the positionto which it is actuated by the pawl 86. For this purpose I have shown a belt or rope friction means 93 disposed in agroove on the hub 8 i of I the end plate 8|, one end of this belt or rope being attached to the frame and the other end having a suitable weight. attached thereto; This operates as a friction brake to prevent overtravel of the magazine.

A hopper95 is shown for containing the charge of blanks I for drilling, the lower part of this hopper consisting of a receptacle 96 which holds a blank in alinement with the uppermost cylindrical receiver 83 of the magazine 60. The lowermost blank in the hopper .95 is automatically fed to the uppermostreceiver 83 by means of a push rod 91 mounted in alinement with the receptacle 96 and the receptacle 83 and adjustably carried-at one end by a bracket 98 carriedfrom the drill carriage 35. The receptacle 96 being open at both ends the push rod 91 in each forward movement of the drill carriage 35 pushes the lowermost blank out of-the receptacle 96 and into the uppermost receptacle 83' of the magazine. The blank which is being pushedinto the cylindrical receptacle 83 automatically pushes out a drilled blank therein onto a trough I00. Cam or lining members llll are mounted adjacent one end of the periphery of the magazine to engage the blanks disposed in the cylindrical carriers 83' to adjust the blanks automatically to a position wherein their ends will not foul the chucks.

I As indicated above, eachdrill is supported by a butt or socket 4| to which the compressed air fitting 4| is attached, the set-screws 38 permitting the removal and replacement of drills. I prefer to make the drill tip 9 separate from the shank to avoid the necessity of drilling the relatively small air hole ID the entire length of the drill. a The tip may be brazed or welded to the shank. When the overall 'length of the shank carriage 35 the push rod 91 pushes a blank from the hopper 95 into the uppermost cylindrical receptacle 83. At the first backward movement of the drill carriage 35 the magazine 69 is rotated one-eighth of a revolution and on the next forward stroke another blank is fed into the magadoes not exceed [2 inches I prefer to make the forward movement of the drill carriage 35 'results both in the supply of another blank to the intermittently'rotated magazine 68 and on for- Ward movement of the drill 2 to drill the middle section bore :3. Before the drillreaches the blank 1:9 the pull rod l5'which is carried by the drill carriage .35 releases the work supports 66 which then moves forward under the infiuence' of the weights #2 to engage and line up the blanks disposed in the receptacles 83 in line therewith. The forward movement of the work support 66 also presses the blank against its corresponding driving chuck 6!, 62, whereupon the blank is rotated at .a rapid speed while the drill 2 advances to form the bore. .At'each reciprocation thereafter of the drill carriage '35 a blank'is supplied tothe magazine 60, the bore '3 is formed in a blankand the magazine fit is advanced one-eighth of a revolution. When the blank formed with the bore .3 reaches the three-fourths position the drill 4 comes into operationto form the bores 5 and 6.

This operation continues as long as the hopper 95 and the magazine 60 contain blanks to be drilled.

The flexing of; the long slender drills is pre- 38 vented according to the method of drilling above set forth. 'In the first drilling operation, which is performed by the drill .2, only the bore part 3 is formed, namely, a bore of one cross section throughout and the'boring is effected only at 'one point throughout the length of the drill, namely, at the tip 9.' Accordingly, the flexing of common practice, which I believe to be due in part to drilling two .or more different sections simultaneously, is thereby prevented or minimized. Moreover, by forming the annular groove I5 slightly in advance of the bore 3 and the uncut core l5 and groove form a guide and directing means for the drill tip tending to keep it in a 7 straight rectilinear line, namely; along the axis of the blank and'notwithstanding the particular fibrous character of the wood being worked upon.

When the drill 4 isxintroduced into the bore 3 to form the smaller section bore 5, the guiding groove l5 and the uncut core I6 function to aline and center this drill not only at the beginning of the operation but throughout the formation of the bore 5'. The. compressed air supply through the flexible pipes .45 continuously blows out the chips andcuttings and clears the end of the bore for fresh cutting operations.

I claim:

1. The method of drilling holes of relatively small diameter through elongated wooden blanks which consists informing a bore of the desired diameter therein with no'uncut core portion extending therethrough and simultaneously with the formation of thebore forming an annular cylindrical-like groove a short uncutcor-e I in the center thereof in advance of the bore throughout the drilling operation-for 'guiding thef;

drill in the rectilineardireotioni I 2. The method of forming a bore having sec-- tionsof different'diam'eters inelongated wooden blanks which consists in drilling onebore section part Way through the blank and form-ing 'a cen f 1 tral guiding core at the bottom thereof in-oneQ single operation and continuing the bore into -a bore of smaller diameter by means of a drill whose shank and'tip are ofsmaller diameter", than that-of the first bored sectionwith said core guiding and positioning the drill of smaller di v ameter. l l

3. The method of forming a bore having sec.

7 tions of different diameters in elongated wooden blanks which consists in drilling one bore section a part way through the blank in one single operaer diameter by means of a drill whose shank and I tip are of smaller diameter than that of the first bored section and simultaneously reamingo'ut'.

the end of the first bore formed to form a 'bore of larger cross section than either of theother bores.

"4.. The method as set forth in claim 3 comprising thestep of forming at the bottom of the first bore section part a centrally disposed coreand annular groove for guiding the second drill.

5. The method of drilling holes .of relatively small diameter through elongated wooden blanks which consists in forming a bore of the 'desired diameter therein with no uncut core portion extendingtherethrough and simultaneously with the formation of the-bore, reaming the [side thereof and forming and-maintaining in advance of the'bore throughout the drilling operation a centralguiding core of short but substam tial depth-extending into the chip channel for. guiding the drill in the rectilinear direction. v

6. ,The method of drilling holes of relatively small diameter through elongated woodenblanks which consists'in forming a bore of the desired diameter therein with no uncut core portion exe tending therethrough and simultaneously with throughoutthe drilling operation for guiding the drill in the rectilinearldirection. v

7; The method of forming a bore having sectionsof differentdiameters in elongated wooden blanks which consists in drilling one bore section part way through the blank and forming at the bottom thereof a centrally disposed core and. :an-

nulargroove therearoundand continuing the bore into a bore .of smaller diameter by means of a drill whose :tip .isof smaller diameter than that of the 'firsthbore section with said coreguiding and positioning the drill of smaller diameter.

' j JOI-IN'W. STOLLE.

tion and continuing the bore into a bore of small- 3

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