US2189422A

US2189422A - Combined drilling and tapping machine

Info

Publication number: US2189422A
Application number: US227296A
Authority: US
Inventors: George W Irwin
Original assignee: TOLEDO GENERAL Manufacturing Co
Current assignee: TOLEDO GENERAL Manufacturing Co
Priority date: 1938-08-29
Filing date: 1938-08-29
Publication date: 1940-02-06
Anticipated expiration: 1957-02-06

Description

G. W. IRWIN COMBINED DRILLING AND TAPPING MACHINE Feb. 6, 1940.

Filed Aug. 29, 1938 Mom;

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Patented Feb. 6, 1940 UNITED stares COMBINED DRILLING AND' TAPPIN G MACHINE George W. Irwin, Holland, Ohio, assignor to The i Toledo General Manufacturing Company,

Toledo, Ohio, a corporation of Ohio Application August 29, 1938, Serial No. 227,296

7 claims.v (o1. 10--136) This invention relates to machines for drilling and tapping and an object is to produce a new and improved machine of this character which can be used either for drilling or for drilling and tapping without the use of troublesome or costly attachments or adapters ordinarily necessary to convert a drill press into a tapping machine.

Another object is to produce a'machine of the above character powered by a reversible motor which is controlled by a single switch rendering the machine operative for use as a drill press or as a tapping machine for drilling screw threaded holes and in the latter case, the motor is automatically reversed after the operation is completed, provision being made by a simple manual adjustment to render the machine suitable for either type of work.

A further object is to produce a control for a machine of the above character having the new and improved features of construction, arrangement and operation hereinafter described.

For purposes of illustration but not of limita tion, an embodiment of the invention is shown on the accompanying drawing in which Figure 1 is a side elevation partly in section of a machine for drilling and tapping;

Figure 2 is an enlarged transverse sectional view on the line 2-2 of Figure 1; and

Figure 3 is an enlarged fragmentary View of the switch box and associated parts, the cover of the box being removed and also showing the adjustable stop for actuating the switch after the tool has completed its operation.

The illustrated embodiment of the invention comprises a combined drill press and tapping machine having a supporting standard ii] on the upper portion of which is mounted a reversible electric motor H on the shaft of which are a series of pulley wheels 12 from which an endless belt l3 extends to a series of pulley wheels I4, these wheels being of varying sizes as shown. The pulley wheels M are suitably fixed to a vertically disposed driven shaft l5 which drives the tapping or drilling tool it, the drive mechanism being disposed within a quill H which in turn is mounted for vertical reciprocatory movements within a sleeve Ha which in turn slides vertically within a guide 13 that is suitably secured to the standard. The sleeve Ha has rack teeth IS with which a pinion Z0 meshes, the latter having a. crank (not shown) for initially adjusting the position of the parts vertically with respect. to the work. W. The quill I I has rack teeth llb with which a, pinion 2| meshes and by which the, tool It is advanced and retracted relative to the work W in the operation of the machine. The mechanism for rotating the tool forms no part of the present invention and maybe of any standard or well-known construction so that further descripion thereof is not considered necessary.

The pinion 2i is mountedon a transverse shaft 22 which hasan elongate opening 22a through' which a pin 23 secured to the pinion 2i projects to enable a slight amount of lost motion to take place between these parts. The shaft 22 is"dis-- 2i and operates normally to retract and hold the tool Hi to its uppermost or normal position. It will be noted that the cup 25 has an annular groove 28 into which extends a screw 29 for holding the cup 25 in its adjusted position.

The opposite end of the shaft 22 extends into a housing 30 to which a cover plate Si is suitably attached. Disposed within the housing 30*is a switch 32 which is suitably connected to and controls the reversible motor I I. The detail construction of the switch forms no part of the present invention and suflice it to say that the switch in cludes a button 33 which, when depressed a very slight amount, operates to reverse the direction of rotation of the'motor H. Switches of this general character are well-known in the art and are frequently referred to as micro-switches. The switch 32 is supported on one end of an L-shaped arm 34 which is pivoted on a screw 35 secured to the housing 30.

A set screw with asfiat end portion 38a and a knurled head 37 is carried by the housing; 30. An adjusting screw 36b is threaded through the arm 34 and bears against the end portion 36a; the arrangement being such that. an accurate adjusted position of the arm 34 may be secured by a slight rotation of the screw 36b.

Secured to the inner end of the shaftv 22 isa. pin 39 on which is mounted a disc Ml of leather or other suitable material which abuts against. the end of the shaft 22 and an eccentrically mounted metallic disc M which bears against the leather washer. A coil spring vd2 on the pin 39 is interposed between the disc 4! and a nut 43 on the end of the pin and serves to hold the disc 4t frictionally in engagement. with the. washer: or

disc 40. The area of greater radius of the disc 4| is on the side of the pin 39 toward the switch 32 and formed in the edge portion of the disc 4|, facing the switch button 33, is a notch in which seats one end of a pin 44, the opposite end of which abuts against the switch button 33. In the region of the button 33 is a guide member 45 which receives the pin 44 in a laterally elongate opening 46 which enables the pin 44 to rock in one direction or the other.

The disc 4| is formed with a notch 41 into which a pin 48, fixed to the housing 30, extends thus limiting the rotating or turning movements of the disc 4| in either direction. Obviously only a slight turning movement of the disc 4| is permitted but that movement is suflicient to cause depression of the switch button 33.

In operation, it will be understood that by turning the handle 26 in one direction or the other, the pin 44 is moved slightly longitudinally a suiiicient amount to depress the switch button 33 thereby to reverse the direction of rotation of the electric motor II. This is accomplished by imparting frictionally through the non-metallic washer or disc 40 a turning movement to the disc 4| and in the limited movement of the latter, due to the eccentric mounting of the disc 4|, the pin 44 is rocked and during such rocking movement, a slight longitudinal movement is imparted to it. Thus, in turning the handle 26 to move the tool |6 into operative engagement with the work W, the disc 4| will turn with the shaft 22 thereby actuating the switch button 33 and cause the tool l6 to rotate in the proper direction. Then, if desired, the handle 26 may be turned in the opposite direction which imparts movement to the disc 4| in an opposite direction again depressing the switch button 33 and again reversing the direction of rotation of the motor. Provision is also made for automatically reversing the direction of rotation of the motor after the tool I6 has moved or advanced a predetermined distance. For that purpose, a screwthreaded rod 49 is carried by the quill H and passes freely through a hole in a bracket 5s. A knurled nut 5| is adjustable on the rod 45. The quill advances toward the work W with the tool I6, and the nut 5| engages a spring arm 52 secured to the switch arm 34 and rocks the switch arm in a clockwise direction (Figure 3), thereby to force the switch button 33 against the pin 44 in orderto depress the switch button and thus reverse the direction of rotation of the motor II. It is important to observe that when the switch arm 34 is rocked to cause reversal of the motor H, the rotation of the quill l! in the reverse direction will thereupon reverse the direction of rotation of the pinion 2!. This, in turn, causes the shaft 22 to reverse its movement which, through the non-metallic washer 40, causes the disc 4| to rock in the opposite direction and thereby hold the pin 44 in the desired position, thereby militating against the motor again reversing its direction of rotation before the tool l6 has been completely retracted from the work W.

It is obvious that the position of the nut 5| may be adjusted so that the motor i will be automatically reversed in the manner described substantially when tapping has been completed and of course the reversal of the direction of rotation of the tool I6 is necessary when the machine is used for tapping purposes in order that the tool IS can unscrew itself from the work.

When the machine is used solely as a drill press, reversal of the direction of rotation of the tool I6 is not desired and to set the machine so that the motor I will rotate only in one direction, the knurled head 3? of the screw 36 is turned to move the flat end 38a away from the screw 3% to allow the switch 32 to swing by gravity in a counter clockwise direction and thus move the button 33 away from the pin 44. It will be apparent that in this position, the pin 44 can not depress the button so that the machine will op-- erate continuously in one direction in the usual manner of a drill press.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claims.

What I claim is:

1. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor operatively connected to the tool, a manually operated rotatable shaft operatively connected to advance the tool, a switch operable when actuated to reverse the operation of the motor, a rotatable disc associated with and actuated by said shaft and disposed in eccentric relation thereto, means for limiting the rotative movements of said disc in opposite directions, and an operative connection between said disc and switch enabling actuation of the latter upon turning of said disc.

2. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor operatively connected to the tool, a switch operable when actuated to reverse the operation of the motor, a rotatable shaft operatively connected to advance the tool, a rotatable member frictionally associated with and actuated by said shaft and arranged eccentrically thereto, stop means for limiting the turning movement of said member in opposite directions, and an operative connection between said member in the region of the greater radius thereof and said switch enabling actuation of the latter upon turning of said member in either direction.

3. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor operatively connected to the tool, a switch operable when actuated to reverse the operation of the motor and including a depressible button, a manually operated rotatable shaft operatively connected to advance the tool, a rotatable disc adjacent one end of said shaft and disposed eccentrically thereto, spring means urging said disc toward the shaft,

a non-metallic disc interposed between said shaft and rotatable disc, stop means enabling limited turning movements of said rotatable disc in opposite directions, a pin loosely fitting at one end in a notch in said rotatable disc in the region of its greater radius and having its opposite end in abutting relation to said switch button, and means to hold said pin in position and enable limited rocking movements.

4. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor operatively connected to the tool, a switch operable when actuated to reverse the operation of the motor and including a depressible button, a manually operated rotatable shaft operatively connected to advance the tool, a rotatable disc adjacent one end of said shaft and disposed ec-' centrically thereto, spring means urging said disc toward the shaft, a IlOIl-lllEl-hlllCdlSC interposed between said shaft and rotatable disc, stop means enabling limited turning movements of said rotatable disc in opposite directions, a" pin loosely fitting at one end in a notch in said rotatable disc in the region of its greater radius and having its opposite end in abutting relation to said switch button, means to hold said pin in position and enable limited rocking movements, a pivotal mounting for said switch including an outwardly extending arm, and adjustable means movable with said tool engageable with said arm thereby to rock said switch and cause said pin to depress the button to cause reversal of the motor upon predetermined movement of the tool.

5. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor operatively connected to the tool, a switch operable when actuated to reverse the operation of the motor, a rotatable shaft operatively connected to advance the tool, a rotatable member frictionally associated with and actuated by said shaft and arranged eccentrically thereto, stop means for limiting the turning movement of saidv member in opposite directions, an operative connection between said member in the region of the greater radius thereof and said switch enabling actuation of the latter upon turning of said member in either direction, and means responsive to predetermined advancing movement of the tool to operate said switch to cause reversal of the motor.

6. In a machine of the class described having a rotary tool mounted for movement toward and away from the work, a reversible motor opera,- tively connected to the tool, a switch operable when actuated to reverse the operation of the motor, a rotatable shaft operatively connected to advance thetool, a rotatable member frictionally associated with and actuated by said shaft and arranged eccentrically thereto, stop means for limiting the turning movement of said member in opposite directions, an operative connection between said member and said switch enabling actuation of the latter upon turning of said memher in either direction, and means responsive to predetermined advancing movement of the tool to cause reversal of the motor.

'7. In a machine of the class described having a rotary tool mounted for movement toward and away. from the work, a reversible motor operatively connected to the tool, a switch operable when actuated to reverse the operation of the motor, a rotatable shaft operatively connected to- GEORGE W. IRWIN.