CA1128784A - Generating head - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Particularly compact generating head structure including a housing having an axis of rotation and adapted to be directly secured to a rotating spindle for rotation about the axis of rotation thereof, slides secured to an end face of the housing for movement transversely of the axis of rotation of the housing, an actuating member posi-tioned within the housing for movement axially thereof having external helical cam teeth thereon, an axially fixed cam member positioned between the housing and actuating member for rotation relative thereto having internal helical cam teeth engaged with the helical cam teeth on the actuat-ing member whereby on axial movement of the actuating member relative to the housing the cam member is rotated angularly with respect thereto, and slot and pin mechanisms operable between the slides and cam member for moving the slides transversely of the axis of rotation of the housing on rotation of the cam member, which generating head extends a minimum distance beyond the mounting face of the spindle.
One end of the actuating member may extend through the end face of the housing so that a boring tool may be secured to the end of the actuating member whereby simul-taneous boring and facing operations may be accomplished with the generating head. The slides are spring biased in one direction in all positions thereof by means of a helical spring operable between a bolt in the slides and a pin in the housing to compensate for centrifugal force, backlash and generating head wear.

Structure is provided for lubrication of the generating head under predetermined pressure with the generating head rotating. Passages are provided in the generating head for passing coolant to a workpiece through the head.

Description

S P E C.I F I C A T I O ~
The inv0ntion relates to generating heads and refers more specifically to a generating head having a minimum axial dimension beyond the mounting surface thereof and which is capable in one embodiment of simultaneous boring and facing operations. The generating head includes slides movable transversely thereof which are biased in one direction in all positions thereof and structure for lubricating the generating head and/or passing coolant therethrough during rotation thereof.
In the past, generating heads have been unnecessarily extended from the spindles to which they are attached, thus causing undue lateral stresses on the spindle bearings and within the generating head structure itself. Further, gener-ating heads of the past have often includad particularly complicated structure for effecting transverse movement of a cutting tool relative to the axis of rotation of the generating head, which has increased the cost of such ge.nerating heads and lowered their efficiencyr Similarly, where simultaneous boring and facing have been accomplished in the past with generating heads, the structure for effecting such combined operations has sometimes :
been built into or heen formed by a part of the associated spindles and usually has been complicated and expensi~e and sometimes ineficient.
Prior generating heads have also often incorporated considerable backlash in the structure included therein for moving cutting tools transversely thereof which has prevented ~l--~lZB7t34 effective precision control of start and stop positions. More important, such bac~lash has often resulted in chatter o~ the cutting tools, shortening the life of the tools and cutting mechanism and often providing an undesirable finish on a machined workpiece. Prior generating heads have sel~om in-cluded wear compensation structure therein. Also with such prior structures, an inconsistency in the finish of the work has also occurred during the transition which occurs when the center of gravity of tha slide combined with any objects fastened to it crosses over the balance center of the gener-ating head assemblyO
Further, in the past, lubrication of generating heads usually has not been possible during operation of the heads, and lubrication in the past has been a manual operation. Cool-ant has usually not been supplied to a workpiece through priorgenerating heads.
Therefore, in accordance with the present invention, there is provided a generating head constructed and arranged to extend axially outwardly of an end o a spindle to which it is connected for rotation a minimum distance whereby wear of the generating head due to transverse forces on cutting tools carried thereby and wear on the spindle structure will be mi~imized. Such a generating head is constructed in accordance with the invention by maans o~ a housing having transversely movable slides secured thereon, an actuating member having exterior helical cam teeth thereon which is held against rota~ -tion relative to the housing but permitted axial movement relative thereto, a cam member having helical internal cam

-2-~ f~ 78~1 teeth thereon engaged with the cam teeth on the actuaking member fixed against axial movement but permitted angular movement relative to the housing, whereby the cam member is rotated on axial movement o~ the actuating member, and pin and slot structure operable between the slid~s and cam member for moving the slides transversely on the bod~ mem-ber on rotation of the gear member.
Simultaneous boring and facing with the generating head is accomplished in accordance with the invention by extending the actuating member beyond the front face of the - generating head and securing a boring tool on the actuating member.
Backlash is removed from the slides by biasing the slides in one direction in all positions of movement thereof.
Thus, wear of the head structure is compensated for and the effect of a relatively changing center of gravity of the generating head as a whole and the slide structure is mini-mized. Biasing the slides is accomplished by a pin secured to the generating head housing and a spring operable between a bolt in the slide and the pin.
Lubrication durîng operation of the generating head is provided through a lubrication fitting secured to spindle mounting structure through which lubricating fluid is placed inside of the spindle and generating head during rotation o~
the spindle. Sealing means are provided to prevent leakage of the lubricating fluid out of the generating head.
Coolant is passed through axial passages in the - generating head to a wor~piece.

~1~715~4 Thus, the present invention is broadly defined as a facing and boring head adapted to be secured to a spindle for rotation therewith comprising at least one slide transversely slidably supported on one end o the h0ad, an actuating member positioned centrally of the head, means operable between the actuatin~ member and slide ~or producing movement of the slide transversely o~ the head on movement of the actuating ~ember axially of the head and a cutting tool for facing secured to the slide and means for simultaneously boring while facing comprising one end of the actuating mem-ber extending axially beyond the outer end of the head and a boring tool secured to the one end of the actuatîng member.
Figure 1 is a partially broken away elevation view of a generating head constructed in accordance with the invention.
Figure 2 is a partial end view of the generating head illustrated in Figure 1, taken in the direction of arrow 2 in Figure 1~
Figure 3 is a partly hroken away end view of the generating head illustrated in Figure 1, taken in the direc-tion of arrow 3 in Figure 1.
Figure 4 is a partial section view of the gener-ating head illustrated in Figures 1-3, taken substantially on the line 4--4 in Figure 3.
Figure 5 is a partially broken away elevation view of the generating head illustrated in Figures 1-4 showing a coolant passage therein.
Figure 6 is a longitudinal section view of a generating head constructed in accordance with the inven-tion for simultaneous boring and facing operations, takensubstantially on t~e line 6--6 in Figure 7.

B7~34 Figure 7 is a partly broken away end view of the generating head illustrated in Fi~ure 6, taken in the direc-tion of arrow 7 in Figure 6.
Figure 8 is a partial section view o:~ the gene~~
ating head illustrated in Figures 6 and 7, taken substan-tially on the line 8--8 in Figure 7.
Figure 9 is a partial seckion view of a modifica-tion of the generatinq head illustrated in Figure 6 showing alternate key means for preventing rotation of the actuating member while permitting axial reciprocation thereof.
- Fi~ure 10 is a partial elevation view of the gener-ating head illustrated in Figures 6-8, together wi-th a par-tial section view of the spindle structure to which it is secured and showing structure for automatically lubricating the generating head in operation in accordance with the invention.
Figure 11 is a partial section view of the facinq head illustrated in Figures 1-3 showing the facing head of Figures 1-3 in conjunction with the structure or lubricating the facing head while it is rotating as shown in Figure 9.
The generatin~ head 10 i.llustrated best in Figures 1-4 includes a housing 12, an actuating member 14, cam or - gear member 16, slides 18 and 20, keepers 22, 24 and 26, pin structure 28, key 30, and cover 32.
The housing 12 has a bore 31 extending axially therethrough having different diameter portions, as shown best in Figure 1. Recesses 34 are provided extending across one end of the housing 12 for recelvinq the slides 18 and 20 : - 5 -~8~8~

for movement transverse to the axis o~ rotation o~ the generating head 10.
The actuating member 14 is generally cylindrical and, as shown best in Figure 1, includes a ~ey~ay 36 e~tend-ing longitudinally thereo~. Actuating member 14 has externalhelical cam teeth 38, illustrated best in Figure 2, extend-ing along the length thereof. The actuating member 14 is adapted to receive the threaded end o~ an actuating rod through a spindle in the threaded recess 40 in one end face thereof.
Cam member 16 includes a hollow cylindrical body portion 42 extending axially of the actuating member and a flange portion 44 extending transversely of the head 10 and perpendicular to a spindle (not shown) to which the head 10 is adapted to be secured for rotation therewith and is shown best in Figures 1 and 3. ~elical cam teeth 46, shown best in Figure 2, are provided on the radially inner surface of the cylindrical body portion 42 of the cam member 16 whereby the cam member 16 is caused to rotate about the axis of genera-tion 86 of the generating head 10 on axial movement of theactuating member 14.
The cam member 16 is mounted for rotation relative to the housin~ on the bearings 48 and 50. The cam member and bearings are secured in axial position relative to the housing by the nut 52 and screw 56.
Slides 18 and 20 are shaped in cross section~ as shown best in Figure 1. Openings 58 are provided in the slides 18 and 20 to receive biasing springs 60 therein, as 8~

best shown in Figure 4. The openings 58 are ~ur~her slotted at 62 to permit movement o the slides 18 and 20 past the pin 64, as will be considered subsequentl~, on movement of the slides transversely of the generating head. Each o~ t~e slides 18 and 20 is also provided with a slot 66 0xtending transversely thereacross for receiving the rectangular por-tion 68 of the pin structure 28 therein. The slots 70 and threaded openings 72 in the slides 18 and 20 are provided to permit securing of cutting tools thereto for facing oper-ations or the like.
As shown, the keepers 22 and 26 are elongated rectangular members secured to the housing 12 by convenient means such as bolts 74. Both the keepers 22 and 26 as well as the housing 12 are recessed to provide access for the bolts 76 which are used to secure the generating head 10 to the end surface of a spindle or the like for rotation about the axis of rotation 86 of the housing 12~
The keeper 24 extends across the center of the generating head 10, as shown best in Figure 3. The keeper 24 is generally T-shape in cross section, as shown best in Figure 1. The depth o~ the T stem is less in the center than at the ends, again as shown best in Figure 1, to accommodate the for~ard end of the actuating member 14. A stop screw 78 extends centrally through the keeper 24 to limit the forward movement of the actuating member 14 in operation. The bolts 80 at both ends of the keeper 24 secure the Xeeper 24 to the housing 12~ The keepers 22 and 26 in combination with the keeper 24 maintain the slides 18 and 20 secured to the housing l~Z~aJ8~

12 for txansverse movement across the end 54 o~ the gener-ating head 10.
As shown, the key 30 is secured in a slot 82 in the housing 12 and is held in a predetermined position o~
the cover 32 by the bolts 84. Cover 32 is secured over ~e end 85 of the generating head 10 by means of the bolts 88, shown best in Figure 2.
Again as shown best in Figure 4, the spring 60 is positioned within the opening 58 through the slides 18 and 20 and is held in place therein by means of the bolt 66 having the threaded head 68. The axial position of the bolt 66 may be changed to vary the compression of the spring 60. The bolt 66 is locked in adjusted position by means of a set screw 90 and brass plug 91, illustrated best in Fig-ure 3~ In operation, the spring acts between the pin 64 and the head 68 of the bolt 66 to bias the slides in one direction over the full length of the slides transversely of the generating head 10.
The generating head 10 is provided lubrication manually through the radially extending lubricating fitting 92 and passage 94 in the housing 12. Sealing means 96 extend around the slides 18 and 20, as shown best in Figure 1, to prevent loss of lubricating fluid from the generating head 10 on movement of the slides 18 and 20. Automatic lubrica-tion of the generating head 10 may, while it is rotating, also be accomplished by structure such as that of Figure 10, as will be considered subsequently.

In overall operation, the generating head 10 is secured to one end face of a spindle of a boring machine or the like b~ the bolts 76 and the actuating member 14 is coupled to an actuating rod extending through the center o the spindle by screwing the actuating rod i~to the khreaded recess 40 in the actuating member 1~. Then, with cutting tools as desired secured to the slides 18 and 20, when the actuating rod is moved axially to axially move the actuating member 14, the cam member 16 is caused to rotate in the bearings 48 and 50 to arcuately move the pin structures 28 and to thus cause simultaneous sliding movement of the slides 18 and 20 in opposite directions and sliding movement of the rectangular head 68 of the pin structures 28 within the slots 66 in the slides. The cutting tools secured to the slides 18 and 20 are thus caused to move transversely of the generating head 10, as desired.
In this mov~ment it will be noted that the slides 18 and 20 are biased in one direction for the entire movement of the slides 18 and 20. Thus, as shown best in solid lines in Figure 3, with the pin structure 28 in one of its limiting positions with the flange 44 of the cam member 16, the spring 60 biases the slide to the left and the slide 18 is in its leftmost position, as shown in Figure 4~ On rotating of the cam member 16 into its alternate limiting position, as shown by the broken lines in Figure 3, the pin structure 28 is moved to the right and ultimately assumes a position similar to that shown in Figure 7 wherein the slide 18 is in its rightmost position. The slide 18 is continually biased to ~L~ Z~7~
the left by the spring 60 during this entire movement. Con~
sequently, no backlash is permitted and there is no unbalanced slide and/or cutting tool action as the center o gravity o the slide and cutting tool crosses over ~he cent~r o~ y~avi~
of the generating head assembly. Thus, chatter and/or damaged surfaces on pieces being machinecl at this point in a machining operation are substantially eliminated by the generating head structure of the invention. Further, the bias on the slides compensates for wear in the generating head 10. Thus, the generating head will have a longer life and more precision control of start and stop positions of the generating head are possible.
The modified generating head 10 shown in Figure 5 includes a tube 91 secured in keeper 24 by screw 93~ Tube 91 extends into passage 94 in actuating member 14 and is sealed by seal 97 in the internal groove 99 in passage 95~ With such structure, coolant may be passed through actuating mem-ber 14 and tube 91 axially of the generating head 10 to a workpiece as desired.
The embodiment of the generating head 100 illus-trated in Figure 6 permits both boring and ~acing of a workpiece, for example, simultaneously. ~s shown in ~igure 6, the generating head 100 again includes a housing 102, an actuating member 104, a cam member 106, and slides 108 and 110 held in place in the housing 102 by keepers 112, 114 and 116. The pin structures 118 are rotatably secured in the cam member 106 and serve to cause the slides 108 and 110 to move transversely of the generating head 100 on axial -:LO-1~'2~

movement of the actuating member 104 relative to the housing 102, as above.
Also as above, the slides 108 and 110 are biased by means of a spring 120 in one direction over t~e ~ti~e movement thereof operating between the bolt 122 and pin 124 secured in the slide 108 and housing 102, respectively.
Backlash is again thus minimized in the generating head 100, and wear and the effect of relatively moving centers of gravity is compensated for, as indicated above.
The actuating member 104 illustrated best in Fig-ure 5 has a portion 126 which extends beyond the end surface 125 of the generating head 100 which includes both slots 128 and threaded openings 130 whereby a boring tool may be mounted thereon.
Further, in the generating head 102, a key 132 is secured to the actuating member 104 and moves in a keyway 134 in a member 136 held in a fixed position with respect to the housing 102 in operation as ~or example the spindle.
Again, then, as the actuating member is moved for-ward to ef~ectuate boring with a boring tool secured to the portion 126 thereof, the cam member 106 is caused to rotate in the bearings 138 and 140 held in position by the lock nut 142 to rotate the pin structures 118 and thus cause the slides 108 and 110 to slide transversely of the generating head, whereby facing tools secured to the slides 108 and 110 can perform a facing operation simultaneously with the boring operation.

Coolant may be passed to a workpiece through the passage 14~ in the actuating member 104 axially of the gen-erating head 100.
The embodiment 100 o~ the ~eneratiny head 100 is shown secured to a spindle 160 in Fiyure 9. Th~ spindle 1~0 is rotatably mounted in a stationary member 162 in bearings ~ 164. An annular lubricating member 164 is bolted to the - stationary member 162 by bolts 166. A lubrication passage - 168 is provided in member 164 to receive a lubricating fitting (not shown~. The passage 168 terminates in an annular groove 170 in ~he spindle 160 which in turn communi-cates with spindle passage 172. Annular seals 174 and 176 :~
are provided between member 164 and spindle 160.
In operation, lubricant under predetermined pressure may be passed through passage 168, groove 170 and passage 172 to lubricate the generating head 100 and spindle -: 160 while the generating head is operating and the spindle is rotating.
The modification of the embodiment 100 of the generating head illustrated in Figure 10 is exactly the same as the embodiment of Figures 6-8 except that the key 144 has been positioned in a recess 146 in the keeper 151 and is held therein by bolt 148. The key 144 e~tends into a keyway 150 in the actuating member 152 to permit axial movement of the actuating member 152 with respect ts the housing 154, while preventing relative angular movement between the housing and the actuating member as beforeO

It will be understood that other embodiments and modifications of the invention are contemplatedO It is the intention to include all such embodiments and modifications within the scope of ths invention as are defined by the appended claims.

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A facing and boring head comprising a housing, at least one slide transversely slidably supported at one of the facing head, means for securing a facing tool to the slide, and actuating member positioned centrally of the facing head, means positioned between the actuating member and slide for producing transverse movement of the slide on the facing head on movement of the actuating member relative to the slide to effect facing with the facing head and means for securing a boring tool to the head for simultaneously boring while facing with the facing and boring head.

2. Structure as set forth in claim 1, wherein one end of the actuating member extends axially beyond the one end of the facing head and the boring tool is secured to the one end of the actuating member.

3. Structure as set forth in claim 1, and further including means for securing the facing head directly to a spindle for rotation therewith.

4. Structure as set forth in claim 1, and further including means for securing the housing directly to the spindle from the front of the facing head.

5. Structure as set forth in claim 1, wherein the means operable between the actuating member and slide for movement of the slide transversely of the facing head on movement of the actuating head is cam means.

6. Structure as set forth in claim 1, wherein the movement of the actuating member for producing movement of the slide transversely of the facing head is movement of the actuating member axially of the facing head.

7. Structure as set forth in claim 1, and further including means for restraining the actuating member from rotating relative to the housing.

8. A facing and boring head, comprising a housing, at least one slide transversely slidably supported on one end of the facing head, means for securing a facing tool to the slide, an actuating member positioned centrally of the facing head and means positioned between the actuating member and slide for producing transverse movement of the slide on the facing head on movement of the actuating member axially of the facing head to effect facing with the facing head, including external cam teeth on the actuating member, a cylindrical cam member sleeved over the actuating member having internal helical cam teeth meshed with the cam teeth on the actuating member and means for transversely moving the slide on rotation of the cam member positioned between the cam member and slide, and means for securing a boring tool to the head for simultaneous boring while facing with the head.