US2925160A - Drilling machine - Google Patents

Description

Feb. 16, 1960 F. H. MUELLER 2,925,160

DRILLING MACHINE Filed July 22, 1958 2 Sheets-Sheet 1 INVENTOR FRANK H MUELLER ATTORNEYS F. H. MUELLER 2,925,160

DRILLING MACHINE Feb. 16, 1960 Filed July 22, 1958 2 Sheets-Sheet 2 INVENTOR FkA/VK MUELLER ATTORNEYS United States Patent DRILLING MACHINE Frank H. Mueller, Decatur, 111., assignor to Mueller Co., Decatur, 111., a corporation of Illinois Application July 22,1958, Serial No. 750,130 8 Claims. (Cl. 192-93 This inveniton relates to machines for drilling or tap anism can be operated by hand, but the machine also is provided with an automatic drive for the feed mechanism to advance the boring bar, as it rotates, at a rate The automatic appropriate for a cutting operation. drive includes a clutch mechanism which, upon its disengagement, permits hand advance, or retraction, of the boring bar at a rapid rate by the rotation of a crank handle. The machine also includes a preset feed mec hanism which is settable to permit the boring bar toad: vance, under automatic feed, through a predetermined distance, starting from any selected axial position of the boring bar, and then automatically operates to disengage the clutch mechanism in the automatic drive so that advance of the boring bar will automatically cease.

The clutch mechanism in the aforementioned automatic drive is engageable and disengageable by the axial shifting of a countershaft, and the preset feed mechanism includes a cam arrangement operable to automatically shift the shaft to disengage the clutch mechanism. In actual practice, it has been found that under certain vibratory conditions the cam and cam follower of the aforementioned cam arrangement tend to pound against each other and thereby slowly but surely effect shifting of the countershaft, in a direction to disengage the aforementioned clutch mechanism Consequently,.

it is an object of this invention ,to provide an improved arrangement for yieldably maintaining the cam and cam operated by the preset feed mechanism. j j It also has been found in actual practice that when the eountershaft is in its clutch-disengaged position, upon occasion the aforedescribed camming mechanism will assume a dead center position that will hang up and prevent axial shifting movement of the countershaft to its clutch-engaged position. Accordingly, it is another object .of this invention to provide an improved arrangement wherein means are provided for preventing the cam parts from assuming the aforedescribed dead centerf position.

become apparentjfro m the following description and accompanying drawings in which:

Figure l is a fragmentary longitudinal sectional view of a drilling machine embodying this invention.

Figure 2 is an enlarged fragmentary view of a portion of Figure 1, but showing the countershaft' in its clutch-disengaged position.

Figure- 3 is an enlarged sectional view, taken. substantially on line3-5 of Figure g .Other objects and advantages of the invention will Figure 4 is an enlarged fragmentary view of the countershaft shown in Figure 1.

Figure 5 is a sectional view taken on line 5-5 of Figure 4. t

Figure 6 is a fragmentary plan view of the counter shaft shown in Figure 4.

Figure 7 is a sectional view taken on line 77 of Figure 6.

Referring now to Figure l of the drawings, there is shown a drilling machine having a barrel 10 provided at one end thereof with a plate-like eccentric circumfer= ential flange 12, which, in conjunction with a bowl-like top cap 14 bolted thereto, constitutes a gear housing 16. At its other end (not shown) the barrel 10 has secured thereto a driving gear housing (not shown) adapted to be detachably secured to one end of a valve (not shown) through which the boring bar 18 of the follower out of engagement until the same are positively machine is adapted to extend for main cutting or drilling operations, all as described more in detail in the aforementioned patent.

Journalled in a bushing 29 in the barrel It is the corresponding end of a drive tube 22 which projects into the housing 16 and has a pair of gears secured thereon by a key 28. The other end (not shown) of the tube 22 projects into and is driven from within the aforementioned driving gear housing. Received in the drive tube 22 is the hollow boring bar 18, the upper portion of which has a close sliding fit in the drive tube and is splined thereto for rotation thereby an axial movement relative thereto, preferably by a pair of keys (not shown) secured to thebar and slidable in diametrically opposite interior longitudinal grooves or keyways (not shown) extending the length of the drive tube. The upper in- I terior portion 'of the boring bar 18 is enlarged to .pro-

vide'a shoulder 30 which supports an inwardly overhanging abutment ring 32 against which is seated a coaxial feed nut 34. The nut 34 is fixed against rotation relative to the bar 13 by keys 36, and fixed against axial movement relative to the bar by a retaining ring 38 threaded into the upper end of the boring bar and locked in place by set screws 40 hearing against the upper end of the nut.

A hollow feed screw 42 is engaged withinthe nut 34 and depends coaxially within the boring bar 18. The upper end of the screw 42 has an enlarged, unthreaded extension 44 which extends through the upper gear hous- '-ing 16 and projects through and is journalled in a-sleeve bearing 46 supported by the top cap 14. The projecting outer end of the screwextension 44 terminates in a squared or otherwise non-circularly formed outer end 48 for detachable engagement within the complementary "socket of a crank handle 50, only a portion of which is the machine for advancing the boring bar 18 on relain tive rotation between the nut and screw.

spaced parallel relation to the feed screw 42. end the countershaft 54 projects out of the housing 16 and has an operating knob 60 pinned thereto. Mounted An axially-shiftable countershaft 54 is journalled in a cap bearing 56 mounted in theflange 12 and in a sleeve bearing 58 mounted in the cap 14, in laterally- At one on the countershaft 54 is a gear 62 that isselectively connectable and disconnectable with the countershaft for -rotation therewith or relative thereto by means, of a dive-key type of clutch mechanism. This clutch mechanism includes a spring key 64 received with sliding clearance in a longitudinally-extending slot 66 in the countershaft 54. The base or foot portion 68 0f the key is secured in the slot by a transverse'pin 70,'while Q Patented Feb. 16, 1960 the' head'72 -of the key is urgedby itsspring shank'74 to project out of the slot 66 for engagement within a longitpdinalgroove 76 in the interior ofthe hub of the gear 62. The key 64- is engaged and disengaged with the gear 62 by axial movement of the countershaft 54; which may be shifted manuallybythe knob '60. Thus, when the countershaft 54 is in the axial position shown in Figure 1, the key 64 projects into the groove 76 in the gear 62 so as to lock the latter to the countershaftfor rotation therewith. When the countershaft' 54 is shifted to the left, however, an angular face on the key 64 bears against the edge of an aperture in a bushing 80 on the shaft '54 and cams the key head 72 back into the slot 66 and out of engagement with the gear 62 so that the latter can rotate relative to the countershaft.

Also mounted on the countershaft 54, by a key 82, isa'gear 84. The gears 24 and 62. are in constant mesh while the gears 52 and 84 are in constant mesh. Consequently, when the clutch mechanism is engaged, the gears 24 and 62, the countershaft 54, and the gears 82 and 52 form a-power train that constitutes an automatic drive for the feed mechanism. The ratios of the gears in the automatic drive are such that whenthe clutch mechanism is engaged, rotation of the drive tube 22 drives the feed screw 42 at a slightly greater rate of rotation than the feed nut 34 to thereby advance the boring bar 18 atan appropriate rate for cutting a main.'

When the aforedescribed clutch mechanism isdisengaged, manual rotation of the'feed screw 42, by the crankhandle 50, when the drive'tube 22 and the nut 34 are at rest, rotates the feed screw 42 at a rate fast enough to rather rapidly thread'the nut therealongfor a fast advance or retraction of the boring bar 18. V

' The machine also embodies a preset feed mechanism 3 which canbe adjustedso that when the machineis in automatic feed and. the boring bar 18 advances a predeternnned'drstance'from any'axial position ofLsuch bar,

I the automatic drive will be disengaged and stop further advance of the boring bar. For this purpose, thepreset feed mechanism includes means for shifting lthe countershaft 54 from its automatic feed to its hand feed pos1t1on,"i.e., from its clutch-engaged to its clutch-disengaged position. This shifting means includes awcam sleeve86, shown formed in two parts welded together for manufacturing convenience, which. is journa-lled ,on the-countershaft' 54. One end .of the sleeve 86 is. formed with what may be. termed a counterbore that forms a shoulder 88 provided withdiametrically opposite, Alshaped cam grooves '90 Within which ride the opposite ends of a pin or cam. follower $2, extending diametrilatter position of the countershaft 54, the projecting ends-J ofvthe v.Cal1'h -P:i1l 192/6183? theqshoulderjfis in the cam sleeve 56 so that the countershaft can rotatefreely relativeto the camsleeve and; enable operation ofitheunanua1 feed.

The ,countershaft 54 is yieldablyaretained .in :its..-auto matic feed position by ,agdetent 94' slidable in .a radial interior. blind :socket 96 in .the camsleevezsti and urged inwardly by a spring 98 interposed between. the ;,;detent and the .base of the socket, It will .be noted that the sleeve.;86 isprovided with ,a radial bore-1th). alignedwith the socket 96- so .thatthe spring {98 .and detentfi iscan be passed. ,through the bore 1 1th it andsnto-the socket in assembling the detent elements with the'camsleeve. The

detent. 94, has n va-purigled mose,;,engagea;ble-:vtitl1in cone. or

'theother-of a pair of diametrically opposite circular re cesses 102 in the countershaft-54.

When the detent 94 is engaged with one of the recesses 102 in the countershaft 54, not only is the latter yieldably retained in its automatic feed position, but also the projecting ends of the pin are yieldably maintained out of engagement with the sidesof the cam grooves 90, as shown in Figure 1. Consequently, when the cam sleeve 86 is rotating with the shaft 54, no camming action between the pin 92 and the sides of thecam grooves 90 can occur because of hammering action therebetween occasioned by vibratory conditions, becauseof the outof-engagement relationship between these parts yieldably maintained by the detent 94 and one'of its corresponding recesses 102 in the countershaft 54.

The mechanism for arresting rotation of the cam sleeve 86 constitutes'a part of the aforementionedpreset feed mechanism that is'driven by the gear 26 and which is settable by a rotatable and axially shiftablej shaft 104 one end of which projects out of the housing 16 and hasa knurled operating knob 106 secured thereon. The details of the preset feed mechanism are described in the aforementioned patent and form no part automatically movable by operation of the preset feed mechanism to the left from the position shown in Figure 1; -A counterbore at one end'of the aperture in the army 108 isprovided with a radial stop lug 110 (Fig.3)

engageable witha radial lug 112 on and adjacent one end of the cam sleeve 86, when the arm 108 is shifted previously described, such arrestment will automatically shift the countershaft 54 from automatic to hand feed T position.

ca'lly through the countershaft 54,.when the latter is.

-The circumferential extent of the cam grooves 901 prefer'ably is such that the shoulder 88 on the cam sleeve 86 is in-the form of diametrically opposite narrow edges, as shown in Figure 3. Even so, when the countershaft "54 is in its hand feed position, if the projecting ends of the pin 92 in the countershaft are substantially in anguwill prevent such shifting fromtaking place. In other words,-the countershaft 54 and the cam sleeve 86 may assume .a'relative'angular position that maybe termed dead center and which will prevent the. aforementioned manual shifting. This invention includes means for me I venting the'occurrence ofsuch a dead center relative angular position.

For this purpose, the countershaft 54is provided'with a. circumferential groove 114, spaced axially from the detent-recesses 102,"in a position tobe yieldably engaged by the detent 94 when the countershaft is inits hand feed position to yieldably retain the countershaft in such position. On diametrically opposite sides of the countershaft 54, the groove 114 is provided with a pair of bott. tom-=fiats- 1'16 extending tangentially of the countershaft and having diverging side walls 118. These fiats"116 are spaced angularly with respect to the pin 92, as shown best "in Figure 3. -In;actual practice, a" diameter passing perpendicular to the-flats 116--is spaced angularly about 33 degrees away from a diametric plane through the .tion, the detent 94 will engage-at an acute angle with one-or atheother of the flats '116 .and' exert a camming action effective to cause relative rotation-between "the cam sleeve and the countershaft suflicient to move the pin 92 and the cam sleeve 86 out of their dead center relative angular position, as shown in Figures 2 and 3. As a result the countershaft 54 can always be shifted by hand.

It thus will be seen that the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing specific embodiment has been shown and described only for the purpose of illustrating the principles of this invention and is subject to extensive change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

I claim:

1. Shiftable apparatus comprising: a shaft member; a sleeve member on and rotatable with said shaft member, a first of said members being shiftable axially by hand between first and second positions and a second of said members being fixed against axial movement with said first member; means defining a cam surface on one of said members inclined to their axes; a radial cam follower on the other of said members effective in one of said positions of said first member to engage said surface and shift said first member automatically to the other of said positions on relative rotation between said members in at least one direction; and detent means interengaged between said members in said one position of said first member to yieldably restrain shifting of the latter to said other position and also to yieldably restrain said relative rotation and yieldably maintain said follower and said surface out of engagement with each other.

2. The structure defined in claim 1 in which the detent means includes means defining a circular recess in one of the members and a detent element on the other of said members having a roundednose receivable in said recess.

3. The structure defined in claim 1 in which there are two diametrically disposed cam surfaces, two diametrically disposed cam followers cooperative with said surfaces, and the detent means includes means defining two diametrically disposed circular recesses in one of the members and at least one detent element on the other of said members having a rounded nose receivable in either of said recesses.

4. Mechanism for operating a clutch comprising: a clutch-operating shaft shiftable axially by hand between clutch-engaged and clutch-disengaged positions; a sleeve on and rotatable with said shaft but fixed against axial movement therewith, said sleeve having in an end edge thereof a pair of diametrically-disposed notches, each having side wall camming surfaces that converge longitudinally inwardly of said edge; a pair of diametricallydisposed cam follower projections on said shaft receivable in said notches without engagement with said surfaces in one of said shaft positions, said projections being effective to engage a corresponding pair of said camming surfaces and shift said shaft automatically from its said one position to the other on the arrestment of rotation of said sleeve with said shaft; means defining a pair of diametrically-disposed circular detent recesses in said shaft; and a spring-pressed radial detent element on said sleeve having a rounded nose yieldably receivable in one of said recesses in said one shaft position to yieldably restrain shifting of said shaft to said other position and also to yieldably maintain said projections out of engagement with said camming surfaces during rotation of said sleeve with said shaft.

5. Shiftable apparatus comprising: a shaft member; a sleeve member on and rotatable with said shaft member, a first of said members being shiftable axially by hand between first and second positions and a second of said members being fixed against axial movement with said first member; means defining a cam surface on one of said members inclined to their axes; a radial cam follower on the other of said members effective in one of said positions of said first member to engage said surface and shift said first member automatically to the other of said positions on relative rotation between said members in at least one direction, said inclined cam surface at one end thereof merging into a surface portion which, if engaged by said follower on initial movement of said first member to shift from said other to said one position, causes said follower to hang up and prevent completion of said shifting movement; and separate cam surface and yieldable follower means on said members interengaged in said other position for yieldably urging said members into a relative angular position wherein said radial cam follower is out of longitudinal alignment with said surface portion, whereby said first member can be shifted by hand from said other position to said one position without hanging up.

6. The structure defined in claim 5 in which the separate cam surface and yieldable follower means includes means defining an elongated transverse surface portion on one of the members substantially non-convex in section takentransversely of said members, and a yieldable radial detent element on the other of said members engageable with said surface portion.

7. The structure defined in claim 6 including means defining a circular detent recess in the one member engageable by the detent element in the one position to yieldably restrain shifting of the first member to the other position and also to yieldably restrain said relative rotation and yieldably maintain the radial follower and the inclined cam surface out of engagement with each other.

8. The structure defined in claim 6 including a circumferential groove in the one member engageable by the detent element in the other position to yieldably restrain shifting of the first member to the one position, and wherein the transverse surface portion defines a portion of said groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,381,990 Hanson June 21, 1921 1,900,312 Storm et al. Mar. 7, 1933 FOREIGN PATENTS 484,761 Italy Sept. 18, 1953

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