US2477701A

US2477701A - Variable feed for drilling apparatus

Info

Publication number: US2477701A
Application number: US528101A
Authority: US
Inventors: Robert A Mccallum
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1944-03-25
Filing date: 1944-03-25
Publication date: 1949-08-02
Anticipated expiration: 1966-08-02

Description

Aug. 2, 1949. R. A. M CALLUM 2,477,701

VARIABLE FEED FOR DRILLING AEPARATUS Filed March 25, 1944 Patented Aug 2, 1949 UNlTE'DfSTATESJ P TENT orFicE 1 it Q VARI BLE FEED Fzfifime I J Robert A. McCallum, Michigan City, ma, assignor to Joy Manufacturing Company, a corporation of Pennsylvania Application March 25, 1944, Serial No. 528,101

18 Claims. '(cl. Ii-424.8)

My invention relates to drilling apparatus, and more particularly to feeding means for such apparatus.

It is customary to provide for a drilling apparatus a feeding means including intermeshing feed screw and nut elements rotatable relative to each other to effect feed. These elements are usually mounted to rotate on flxed axes, and means are provided for rotating one or both at such speeds as to produce the relative rotation necessary to effect the desired rate of feed.

If, .as contemplated by my invention, both of the elements are mounted for rotation and are "adjustable to rotate on a common axis or on spaced parallel axes, it will be seen that, where one is caused to rotate by its threaded engagement with the other, there will be a difierence in the rates of rotation varying directly with the spacing of the axes. When the elements rotate on a common axis their rates of rotation will be the same, but, when one of the elements is moved transversely from the position in which the elements are concentric, the pitch diameters of the two elements are different and the rates of rotation vary by a corresponding amount. By providing the threads of the elements with inclined engaging surfaces, a pressure tending to move the elements into their coaxial positions will be obtained, this pressure varying directly with the feeding pressure. If yielding means are provided for moving the elements out of their coaxial posi tions to effect feeding, it will be seen that the elements will be forced against the yielding means toward their coaxial positions when the feeding pressure reaches a predetermined value.

An object of my invention is to provide an improved drilling apparatus. Another object of my invention is to provide a drilling apparatus having improved feeding means. Still another object of my invention is to provide an improved feeding means having feeding elements threadedly engaging each other and movable relative to each other for varying the rate of feed. Yet another object of my invention is to provide in an improved feeding means for a drilling apparatus, inter-meshing feed screw and nut elements adjustable to rotate on a common axis or on spaced parallel axes while maintaining threaded engagement. Another object of my invention is to provide an improved feeding means having feed screw and nut elements adjustable transversely relative to each other for varying the rate of feed, and having yielding means for regulating the transverse adjustment of the elements. Still animproved feeding means operative automatically to limit the feeding pressure. Other objects of my invention will hereinafter more fully appear. In the accompanying drawing, in which there is shown one illustrative embodiment which my invention may assume in practice:

Fig. 1 is a longitudinal sectional view through a portion of a drilling apparatus having my improved feeding means.

Fig. 2 is an enlarged fragmentary sectional view showing my improved feeding means, and taken on the plane of Fig. 1.

Fig. 3 is a fragmentary sectional view similar to Fig. 2 but showing parts of the feeding means in difl'erent positions.

Fig. 4 is across sectional view taken on the planes of the line 4-4 of Fig. 3.

In the illustrative embodiment of my invention there is shown in Fig. 1 a portion of a drilling apparatus, generally designated I, the drilling apparatus being herein of the bit rotating type and comprising an elongated screwlike member 2 adapted to effect rotation and feeding of a bit, not shown. It will be understood that the member 2 may as well act merely as a feed screw for feeding a drill mechanism or some other mechanism relative to its work. The feed screw 2 extends through a sleeve-shaped member 3 which is rotatably supported at its ends by

bearings

5 and 6 mounted within a casing 8. Attached in any suitable manner to the ends of the casing are caps l and II having openings l2 and I3 through which the feed screw extends. Formed in the feed screw along its length are grooves ll which receive keys l fixed to the sleeve-shaped member 3 so that the feed screw and the member 3 are caused to rotate together but are permitted to move longitudinally relative to each other. supported by the sleeve member 3 at points spaced along its length are bearings It on which beveled gears l1 and I 8 are journaled. Formed integral with the gears I1 and I8, respectively, at their adjacent sides are clutch teeth and 2|, and a clutch member 23 is slidably mounted on the sleeve member 3 and is provided at its ends with teeth 25 .adapted to intermesh with the teeth.

20 or 2!. The sleeve member 3 and the clutch member 23 are connected, as by a key 26, for rotation together. Extending through an opening in the side of the casing 8 is a power shaft 28 carrying a beveled gear 29 which meshes with the gears l1 and I8. The power shaft is rotatably supported by a bearing 30 mounted in a frame 3| which is attached, as by T-bolts 32.

other object of my invention is to provide an to a collar 33 fixed in any suitable manner to the side of the casing 8. It will be seen that a rotation of the gear 28 will cause the gears l1 and II to rotate in opposite directions, and that the sleeve member 8 may be caused to rotate in either direction by sliding the clutch member 23 in one direction or the other into engagement with the teeth 28 or 2 i. The clutch member may be moved manually to its different positions by any suitable actuating member, not shown, extending into an annular groove 38 formed in the clutch member. The power shaft 28 may be the shaft of an electric motor attached to the frame II. or may be connected through a suitable transmission mechanism to any power unit.

Operatively connected to the feed screw are feeding means, generally designated 31, for effecting longitudinal movement of the feed screw. This feeding means includes a feed nut 88 having internal threads 38 intermeshing with threads 48 formed on the outer surface of the feed screw. The

threads

38 and 48, respectively, are provided with inclined side surfaces 4| and 42 which engage each other during the feeding of the bit, and the threads are so formed that the feed nut and the feed screw may be moved transversely relative to each other out of coaxial relationship, as shown in Fig. 3. The feed nut 38 is rotatably supported by a ball bearing 44 which has its outer ring clamped between

plungers

48 and 48 fitting within diametrically

opposite openings

41 and 48 in the side walls of the casing 8. The point of support of the feed nut by the bearing 44 is such that the forces on the feed nut are in balance, and the nut is held at all times with its axis parallel to the axis of the feed screw. A plate 49 is bolted over the opening 41, and an adjusting screw 80 is threaded through an opening in the plate into engagement with a movable abutment 8| between which and the plunger 48 a spring 82 is arranged. The opening 48 is covered by a plate 84. and a spring 88 acting between this plate and the plunger 48 holds the latter against the outer ring of the bearing 44. Attached to the upper end of the feed nut is an annular member 81 for clamping the inner ring of the bearing 44 against a shoulder 58 formed on the feed nut. Below the feet nut is a sleeve-shaped member 88 rotatably supported by a ball bearing 8| in a position to be engaged at its upper end by the lower end of the feed nut. The inner ring of the bearing 8| fits between a locking ring 88 and a shoulder 84v on the sleeve member 88 so as to prevent longitudinal movement of the latter, and the outer ring of the bearing is held in the casing 8 by the cap I I and a locking ring 88. Surrounding the feed nut is a sleeve member 61 yieldably held in engagement with the outer ring of the bearing 44 by a spring 88 acting between the lower end of the sleeve member and the outer ring of the. bearing 8i. Supported within the lower end of the sleeve member 3 and the inner ring of the bearing 8 is a thrust collar 18 adapted to be engaged by the upper end of the feed nut for limiting the upward movement of the latter. The sprin 88 and the sleeve member 81 operate to hold the bearing 44 so that the upper end of the feed nut engages initially the lower end of the thrust collar 78. The feeding pressures set up during normal operation of the machine act to hold the feed nut more firmly in engagement with the thrust collar. The adjacent ends of the feed nut and the thrust collar are provided. respectively, with inclined surfaces H and 12 which act in the same manner as the surfaces on the threads 89 and 40 to produce a feeding pressure when the feed nut is moved out of coaxial relationship with the feed screw. The thrust collar and the sleeve member are spaced apart a-sufflcient distance to permit a slight longitudinal move ent of the feed nut. Projecting through an 0 ng in the casing 8 is a plunger 13 adapted to have its inner end moved into a recess I4 in the feed nut for holding the latter against rotation and eflecting rapid feed of the feed screw. A spring 18 acting between the casing 8 and the plunger 13 urges the latter outwardly toward its released position.

The operation of the mechanism described is as follows: The power shaft 28 is caused to rotate and drive the gears I1 and it through the gear 28, and the clutch member 28 is moved into engagement with the

clutch teeth

28 or 2| to effect rotation of the feed screw 2 in the desired direction. The feed screw may be fed rapidly as it rotates by forcing the plunger 18 into the recess 14 in the feed nut so that the latter is held stationary. When the plunger 13 is released from the recess 14 and the feed nut is in a position coaxial with the feed screw, the feed nut and the feed screw will rotate at the same speed and no feeding of the screw will take place. If the adjusting screw 881s screwed in to compress the spring 82 and increase the force of the plunger 48 against the outer ring of the bearing 44, the bearing and the feed nut will be moved trans- .versely against the action of the plunger 46, and,

since the thread surfaces 4| and 42 are inclined, the threads will engage each other theoretically in line contact at the side where the threads of the feed nut are nearer to the axis of the feed screw. It will be seen that the

threads

39 and 40 will then roll on unequal pitch diameters, the feed nut rotating slower than the feed screw and causing a feeding of the latter. The feeding pressure on the feed screw produces a force, by reason of the inclined thread surfaces, which tends to move the feed nut against the action of the plunger 48 toward a position in which it is coxial with the feed screw. Since the screw 80 may be adjusted to vary the yielding pressure on the plunger 48, an automatic control is obtained for limiting the feeding pressure to any desired value.

As a result of my invention there is provided animproved feeding means adapted for use with a drilling apparatus. It will be noted that a rapid feed or a variable slow feed may be obtained, the feeding means being operative automatically to vary the slow feed so that the feeding pressure does not exceed a predetermined value. It will be noted further that the slow and rapid feeding of the screw may be obtained in either direction.

While there is in this application specifically described one form which the invention may assumein practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new arid desire to secure by Letters Patent is:

1. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements. the supporting means for one of said elements permitting movement of said element transversely relative to the other 0f said elements, means for moving said last mentioned element transversely relative to the other of said elements, and means for rotating one of said elemen 2. In a feeding device, in combination. a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements,

the supporting means for one of said elements ineluding yielding means permitting movement of I said element transversely relative to the other of said elements, and means for rotating one of said elements.

3. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means permitting movement of said element transversely relative to said feed screw element, and means for rotating said feed screw element.

4. In a feeding device. in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements,

the supporting means for one of said elements ineluding yielding means permitting movement of said element transversely relative to the other of said elements, means for adjusting said yieldable supporting means so that the element yieldably supported thereby is urged toward a position in which its axis is in spaced parallel relation with the axis of the other of said elements, and means for rotating one of said elements.

5. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means permitting movement of said element transversely relative to said feed screw element, means for adjusting said yieldable supporting means so that the feed nut element is urged toward a position in which its axis is in spaced parallel relation with the axis of said feed screw element, and means for rotating said feed screw element.

6. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means permitting movement of said element transversely relative to said feed screw element, manually controlled means operable to effect a holding of said feed nut element against rotation, and means for rotating said feed screw element.

7. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut element, the supporting means for one of said elements including yielding means permitting movement of said element transversely relative to the other of said elements, manually controlled means operable to eiiect a holding of one of said elements against rotation, and means for rotating the other of said elements.

8. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for one of said elements permitting movement of said element between positions in which its axis coincides with and is in spaced parallel relation with, the axis of the other of said elements, means for moving 6 said movable element between said positions, and means for rotating one of said elements.

9. In a feeding device, in combination, a feed screw element. a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for one of said elements including yielding means adapted to support said element so that it is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of the other of said elements, and means for rotating one of said elements.

10. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means adapted to support said element so that it is'movable between positions in which its axis coincides with andis in spaced parallel relation with, the axis of said feed screw element, and means for rotating said feed screw element.

11. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for one of said elements including yielding means adapted to support said element so that it is movable between position in which its axis coincides with and is in spaced parallel relation with, the axis of the other of said elements, means for adjusting said yieldable supporting means so that the element yieldably supported thereby is urged toward a position in which its axis is in spaced parallel relation with the axis of the other of said elements, and means for rotating one of said elements. Y

12. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means adapted to support said element so that is is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of said feed screw element, means for adjusting said yieldable supporting means so that the feed nut element is urged toward a position in which its axis is in spaced parallel relation with the axis of said feed screw element, and means for rotating said feed screw element.

13. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut element, the supporting means for said feed nut element including yielding means adaptedto support said element so that it is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of said feed screw element, manually controlled means operable to effect a holding of said feed nut element against rotation, and means for rotating said feed screw element.

14. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, means for rotatably supporting said feed screw and nut elements, the supporting means for one of said elements including yielding .means adapted to support said element so that it is movable be- 7 tween positions in which its axis coincides with and is in spaced parallel relation'with, the axis of the other of said elements, manually con- .trolled means operable to efiect a holding of one of said elements against rotation, and means forrotating the other of said elements:

15. In a feedingdevice, in combination, a feed screw element, a' feed nut element threadedly engaging said feed screw element, the threads of said feed screw and nut elements having radially inclined engaging surfaces arranged to permit longitudinal and transverse movements of said elements relative to each other, means for rotatably supporting said feed screw. and nut elements, the supporting means for one of said elements including yielding,means adapted to support said element so that it is movable bea tween positions in which its axis coincides with and is in spaced parallel relation with, the axis of the other of said elements, and means for rotating one of said elements.

16. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, the threads of said feed screw and nut elements having radially inclined engaging surfaces arranged to permit longitudinal and transverse movements of said elements relativeto each other, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means adapted to support said element so that it is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of said feed screw element, and means for rotating said teed screw element.

17. In a feeding device, inv combination. a feed screw element, a feed nut element threadedly engaging said feed screw element, the threads of said feed screw and nut elements having radially inclined engaging surfaces arranged to permit longitudinal and transverse movements of said elements relative to each other, means for rotatably supporting said feed screwand nut elements including yielding means adapted to.

support said element so that it is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of the other of said element, means for adjusting said yieldable supporting means so that the element yieidably supported thereby is urged toward a position in which its axis is in spaced parallel relation with the axis of the other of said elements, and means for rotating one of said elements.

18. In a feeding device, in combination, a feed screw element, a feed nut element threadedly engaging said feed screw element, the threads of said feed screw and nut elements having radially inclined engaging surfaces arranged to permit longitudinal and transverse movements of said elements relative to each other, means for rotatably supporting said feed screw and nut elements, the supporting means for said feed nut element including yielding means adapted to support said element so that it is movable between positions in which its axis coincides with and is in spaced parallel relation with, the axis of said feed screw element, means for adjusting said yieldable supporting means so that the feed nut element is urged toward a position in which its axis is in spaced parallel relation with the axis of said feed screw element, and means for rotating said feed screw element.

, ROBERT A. McCALLUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 788,716 Hammond et al. May 2, 1905 924,122 Williams June 8, 1909 949,163 Stapley Feb. 15, 1910 1,589,307 Svebilius June 15, 1926