US1047986A - Screw-driving machine. - Google Patents

Description

A. RAIGHE.

scmzw DRIVING MAGHINB.

APPLICATION FILED JULY 8, 1907. 1,047,986 Patented Dec. 24, 1912.

2 SHEETSr-SHBBT l.

A. RAICHE.

SCREW DRIVING MACHINE.

APPLICATION FILED JULY 8, 1907.

1,047,986. Patented Dec.24, 1912.

2 SHEETS-SHEET 2.

UNITED STATES rATE-NT oFFIoE.

ANDREW EAIcrtE, or QUINCY, massAcnosErrs, AssIG oB. T0 NORMAN MARSHALL, 01 WEST NEWTON, MASSACHUSETTS.

SCREW-DRIVING MACHINE.

Specification of Letters Patent. Patented Dec. 24;, 1912;

Application filed. July 8, 1907. Serial No. 382,678.

To all whom it may concern:

Be it known that I, ANDREW RAICHE, a

citizen of the United States, residing at Quincy, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Screw-Driving Machines; and I do hereby-declare the following to he a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to machines for inse'rting screws and its object is to provide a machine of this class which shall be simple in construct-ion and efiicien't in action and by which'the screws may be readily and conveniently inserted in the parts which are to receive them or are to be boundtogether thereby.

While certain features of the invention may be embodiedin machines for inserting various forms of screws, the. invention may be employed with a special advantage in machines specially adapted for inserting screws suchas are commonly used for connecting the metallic parts of electric switches, cutouts and similar devices to the porcelain bases on which such parts are mounted. The various features of the invention will accordingly be explained in connection with such a screw driving machine. a

In the machines whichhave' heretofore been used for inserting the screws in assembling the parts of electric devices such as abovereferred to, it has been the practice to position the work below the screw driving mechanism so that the screws are inserted from the upper side of the work. WVith machines of this construction the screw driving mechanism and the screw feeding mechanism, in case such mechanism is employed, is directly above the work where it interferes with the view of the work and with the convenient positionin of the work with relation to the screw drlving mechanism. In case the screws are to be passed through holes in the porcelain base and to engage metallic pieces, this construction of machine also requires the use of more or less complicated devices for positioning the metallic piece and base in proper relation to each other. In such case also the metallic piece into which the screw is driven is covered by the porcelain base and the operator is therefore unable to inspect the work or to determine whether the screw has been prop-- erly inserted and driven home.

In accordance with one of the principal features of the present invention, the work is supported above or in front of the screw driving mechanism in position where the parts are in full view of the operator and may be under constant inspection. The screw is inserted from below or behind, and in case two parts are to be secured together the threaded part is on top or in 'front so that it may be readily placed in proper position with relation to the hole in the other part without the use of any positioning devices, if found desirable. The parts are also where they may be inspected and held by the operator during the driving of the screw so that the work may be inspected as it is being performed and a the parts insured.

In accordance with a further feature of the invention, the screws are delivered to the inserting devices below the work support by a carrier which travels back and forth between said devices and the end of a feed or delivery chute down which the screws slide or are fed. In a machine especially designed to insert screws having headed ends, the feed chute is in the form of a guideway along which the under sides of the head slide, the shanks depending through a slot formed in the guideway. In such case the screws are delivered by the guideway in a substantially vertical position with proper uniting of the heads up and the screw at the end of the guideway is taken by the carrier and transferred to the inserting devices. As the carrier moves from the end of the guideway to the inserting devices, itacts to invert the screw so, that the screw is delivered to the inserting devices with the head down and in proper relation to be inserted in the work by an upward movement of the inserting devices This manner of feeding and insorting the screw also forms one of the features of the invention.

In accordance with the further features of the invention, the inserting devices comprise a receiver for the screw and a driver arranged to work through the receiver. The receiver is preferably in the form of a sleeve surrounding the driver and extending beyond its upper end so that a chamberus formed above the end of the driver forv the reception of the screw and of a size to main-' tain the screw substantially in line with the driver. The screw may be deposited in this receiving chamber by the carrier above described or by an other suitable device adapted to deposit individual screws therein with the head down. The screw is presented to the work by the forward movement of the receiver and driver and is driven into the work by the movement of the driver through the receiverythe driver being rotated as it moves through the receiver.

The various features ofthe invention will be readily understood'from the accompanying drawings and the detailed description of the machine illustrated therein.

In these drawings Figure 1 is a side elevation of a machine embodying the features of the invention in their preferred forms; Fig. 2 is a detail showing the frictional drive for the screw driver spindle; Fig. 3 is an enlarged partial side elevation, certain of the parts being shown in section; Fig. 4 is a plan view of the devices shown in Fig. 3, the supporting table being removed; Fig. 5 is a view similar to Fig. 4 showing the carrier in position at the end of the feed chute; and Fig. 6 is a side elevation with the parts in the position shown in Fig. 5.

The machine illustrated in the drawings is especially designed and intended for inserting the screws utilized for connecting the metallic parts to the porcelain bases of electric switches, rosettes, cut-outs, etc. In this machine the parts to be connected together are supported upon the upper surface of a work supporting table 1, where they may be conveniently positioned by the operator and where the parts are in full view and may be under constant inspection.

The table is shown arranged in a horizontal position, but it will be understood that it may be tilted more or less toward a vertical position as may be found most convenient forthe operator. In any case the support is between the work and the screw driving -mechanism so that the screw is inserted from back of the support and the threaded part of the work is away from the support and in view of the operator.

The devices for presenting the screws to the work and inserting them therein consist of a screw driver 2 secured in the end of a vertical spindle 3 and a sleeve 4 which is mounted on the screw driving spindle and is so arranged that it projects beyond the end of the screw driver, thus forming a receiving chamber 5 for receiving and carrying the screw s. The sleeve 4 is connected with the spindle by means of pins 6 which project through slots 7 formed in the sleeve and the sleeve is held yieldingly in position by means of a spring 8 interposed between the end of the spindle 3 and an internal shoulder 9 formed in the sleeve. The spindle is rotated by means of a pulley 10 mounted upon the spindle and connected therewith by means of frictional engaging jaws 11 pivoted to the pulley and ad ustably held in engagement with the spindle by means of an ad usting screw 12. The pulley 10 may be driven by a belt 13 passlng over the pulley and over idle pulleys 14.

The screw driving splndle and sleeve 4 are moved upward to carry the screw to the work and to insert the screw therein by the operation of a treadle 15 wvhich is connected by means of a link 16 with one end of a lever 1 the other end of which is connected by a pin and slot connection 18 with the lower end of the screw driving spindle. The u per end of the link 16 is connected with t e end of the lever 17 by a pin and slot connection 20 of such a character that there is a limited lost motion between the link and lever at the beginning of the downward movement of the pedal 15, the purpose of which will be explained hereafter.

The screws to be inserted are separated from the mass of screws within a hopper 21 by any suitable and well known mechanism.

The devices for causing individual screws to pedal 15. The screws separated from/tithe mass of screws within the hopper 2 1 s lide down the guideway 22, the heads of the screws resting upon the upper surface of the guideway and the shanks of the screws depending through a slot 25 formed in the guideway. A guard plate 26 overlies the heads of the screws and retains them in the guideway. The series of screws within the guideway are prevented from passing out of the lower end of the guideway by 'means of a retaining finger 27 the upper end of which is normally in front of the lower end of the guideway. This retaining finger is ivoted at one side of the guideway and is eld in normal position against a stop 28 by a spring 29.

Individual screws are taken from the end of the guideway 22 and deposited in the receiving chamber 5 at the upper end of the sleeve 4 by means of a carrier mounted to travel back and forth between the end of the guideway and the receiver and to turn the screws over or invert them so that they are deposited in the receiver with their heads down as indicated in Fig. 3. This carrier consists of a carrier head 30 provided with a supporting ledge 31 for receiving the head of the screw and with a recess 32 to receive the shank of the screw. When the carrier is in position at the end of the guideway as indicated in Figs. 5 and 6, the ledge 31 is substantially flush with the upper'surface of the guideway and the recess 32 registers with the'slot in the end of the guideway so that the screw at the end of the series in the guideway enters the recess and is supported upon the ledge 31. At this time the retaining finger 27 is held back out of the way b the engagement of the carrier 30 therewit as indicated in Fig. 5. vided with a retaining plate 33 pivoted thereon and held normally against a stop 34 by a spring 35. With the parts in the position indicated in Figs. 5 and 6 the outer end of the retaining plate 33 overlies the head of the screw. The carrier is also provided with an arm 36 pivoted on the side opposite to the side to which the retaining plate 33 ispivoted and provided with a laterally extending finger 37 arranged to pass in front of the recess 32 as indicated in Fig. 4 and thus prevent the escape of the screw from the recess as the carrler is moved from the end of the guideway into position to deposit the screw in the upperend of the tube 4. The arm 36 is acted upon by a spring 38 which tends to hold the arm against a stop 39 and in position with the finger 37 in front of the recess 32. When the parts are in the position indicated in Figs. 5 and 6 the arm 36 is held in position to leave the recess 32 open by means of a stationary arm 40 which is arranged to engage a lug 41 on the arm.

The carrier is secured upon the end of a shaft 42 which'is mounted in a rotary head 43 and carries a pinion 44 which meshes with a stationary gear 45. The rotary head 43 is formed on the upper endof a shaft 46 to the lower end of which is secured an arm 47. The arm 47 is connected by means of a link 48 with the upper end of a lever 49,

the lower endof which engages a cam 50.

dicated in Fig. 4, the spring also acting to maintain the lever 49 in engagement with the cam 50. The cam 50 is mounted on a stud 52 and is provided with an arm 53 connected by means of a link 54 with the treadle 15.

Assuming the parts to be in the posit-ion indicated in Figs. 1, 3 and 4 and that a screw 3 has been deposited in the upper end of the tube 4, the operator places the work in position on the work support 1, bringing the screw hole through which the screw is to pass over an opening 55 in the support. The work supporting table may be provided with pins or other devices 56 for assisting the operator in properly positioning the work. Having positioned the work the operator forces down the treadle 15. During the first movement of the pedal the cam 50 acts through the lever 49 and rod 48 to swing the head 43 in a direction to move the Thecarrier is procarrier 30 out of the ath of the tube 4 and screw driver 5, the tu e 4 and screw driving into the hole in the porcelain base or other piece of work. When the tube 4 engages the work its upward movement is arrested and during the continued upward movement of the screw driving spindle, the screw 8 is forced through the hole in the porcelain and by the rotation of the screw driving spindle is driven into the screw threaded hole in the metallic piece which is to be secured to the porcelain. When the screw has been driven home the pulley 10 slips on the screw driving spindle so that the force with which the screw is driven will depend upon the friction between the arms 11 and the screw driving spindle, which friction may be adjusted to suit the requirements. During this 'upwardmovement of the screw driving spindle and sleeve 4 the movement of the carrier toward the left in Fig. 4 continues until the carrier is brought into the position indicated in Fig. 5 where it rests against the stop 57 and where the recess 32 is in register with the slot in the feed chute for the screws. As the carrier moves from the position indicated in Fig. 4 to the position indicated in Fig. 5, the carrier is inverted or given a half revolution by the en- 10o gagement of the pinion 44 with the stat-ionary gear 45. As the carrier approaches the position indicated in Fig. 4 the lug 41 on the arm 36 engages the arm 40 so that the arm 36 is swung back to carry the retain- '105 ing finger 37 from in front of the recess 32 in the end of the carrier. The carrier also engages the retaining finger 27 moving it back out of position so that the screw at the end of the series of screws in the feed chute may slide forward into the recess 32 asindicated in Fig. 6.

After the screw has been driven the operator releases the pedal 35 and the parts return to the position indicated in Figs. 3 and 4. As the carrier moves from the position indicated in Fig. 5 to the position indicated in Fig. 4, the retaining finger 37 passes in front of the recess 32 so as to prevent the escape of the screw from the recess 12 0 and as the movement of the carrier continues the carrier is inverted. As the carrier is inverted or given a half revolution the head of the screw is supported upon the retaining plate 33 and thus the escape of .12 the screw is prevented. As the carrier comes i into the position indicated in Fig. 4 the retaining plate 33 strikes against the tube-4 so that it is swung back releasing the screw as the recess 32 comes into position above the end of the tube 4 so that the screw is deposited in the upper end of the tube as indicated in Fig. 3. The forward position of the carrier is determined by an adjustable stop screw 58 arranged to be engaged by the side of the rotary head 43 as lndicated in Fig. 4.

The work may be held upon the work support 1 against the thrust of the screw driving devices .by the operator, but it is preferred to provide a work holding device which engages and holds the work against this thrust so that the operator is relieved from the work of holding the parts in position during the driving of the screw. One form of such work holding device 'is indi-- cated in Fig.1. As here shown, the work holder comprises an arm 59 which is pivoted at 60 to the frame-and is arranged in such position that it may be depressed to engage the work and may be moved back out of the way after the screw has been driven to enable the operator to conveniently remove the piece of work into which the screw has been driven, and to position 'a new piece of work ready for the next driving operation. The work holding arm or lever 59 is operated at proper intervals from the lever 17 which imparts the vertical movements to the screw driving mechanism. The connection between the work holding arm and lever consists of a rod 61, the upper end of which is pivoted to an arm 62 extending rearwardly from the arm 59 and the lower end of which slides through a block 63 pivoted on the lever 17. A spring 64 surrounds the rod 61 and is interposed between the block 63 and a collar 65 secured to the rod. When the operator has properly positioned the work and depresses the treadle 15, the upward movement of the lever 17 causes the work holding arm 59 to be forced down into engagement with the piece of Work into which the'screw is to be driven, the spring 64 yielding to allow the continued movement of the lever 17 after the work holding arm has engaged the work. When the pedal 15 is released and the lever 17 returns to the position indicated in Fig. 1, the work holding arm 59 is swung back into the position indicated in Fig. 1 by the weight of the rod 61.

WVhile I prefer to employ the specific construction and arrangement of parts shown and described, it will be understood that the arrangement and construction of the parts may be varied to suit the requirements of the particular machine in which the features of the invention are to be embodied and the specific form of fastening devices which are to be operated u on.

Without attempting to point out in detail the various constructions in which the invention may be embodied, what I claim is l. A machine for. inserting fasteners having in combination, an inserting mechanism, a feeding mechanism, a carrier provided with a ledge for supporting the head of a fastener and a recess for the shank of the fastener, means for moving the carrier from the feeding mechanism to the inserting mechanism and inverting the carrier, substantially as described.

2. A machine for inserting fasteners having in combination, a feed chute for the fasteners, an inserting mechanism, a carrier provided with a ledge for supporting the head of the fastener and a recess for the shank of the fastener arranged to register with the end of the feed chute, a movable retaining plate overlying the head of the fastener, mechanism for moving the carrier from thefeed chute to the inserting mechanism and inverting the carrier, and means for operating the retainin plate to release the fastener when in register with the inserting mechanism, substantially as described.

3. A machine for inserting fasteners having in combination a feed chute for the fasteners, an inserting mechanism, a carrier provided with a ledge for supporting the head of the fastener, a recess for the shank of the fastener, a retaining plate opposite the ledge, and a retaining finger for closing the recess, means for moving the carrier back and forth between the feed chute and inserting mechanism and inverting the carrier, means for withdrawing the finger as the carrieucomes to the feed chute and means for withdrawing the retaining plate as the carrier comes to the inserting mechanism, substantially as described.

4. A machine for inserting screws having in combination screw driving devices, a work support arranged over the screw driving devices, a work holding device for holding the work against the thrust of the screw driving devices, and means for moving the work holding device into and out of engagement with the work, substantially as described.

In testimony whereof I aflix my signature, in presence of two witnesses.

IRA L. FISH, N.-D. McPHAIL.

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