US2534140A

US2534140A - Manually applied power-driven machine for automatically delivering and driving a fastener

Info

Publication number: US2534140A
Application number: US8355A
Authority: US
Inventors: Edgar S Moore
Original assignee: AIR A FEED EQUIPMENT Inc
Current assignee: AIR A FEED EQUIPMENT Inc; AIR-A-FEED EQUIPMENT Inc
Priority date: 1948-02-14
Filing date: 1948-02-14
Publication date: 1950-12-12
Anticipated expiration: 1967-12-12

Description

Dec. 12, 1950 E. s. MOORE 2,534,140

NANUALLY APPLIED PowER DRIvEN MACHINE FOR AuToMATIcALLY DELIVERING AND DRIVING A FASTENER Filed Feb. 14, 1948 5 sheets-sheet 1 lll/I/l//l/l lll( Dec. 12, 1950 E. s. MOORE 2,534,140

MANUALLY APPLIED POWER DRIVEN MACHINE FOR AUTOMATICALLY DELIVERING AND DRIVING A FASTENER Filed Feb. 14, 194e 5 sheets-sheet 2 noentor Gttorneg Dec. 12, 1950 E. s. MOORE 2,534,140

MANUALLY APPLIED POWER DRIVEN MACHINE FOR AUTOMATICALLY DELIVERING AND DRIVING A FASTENER Y Filed Feb. 14, 1948 5 Sheets-Sheet 3 :inventor dgar moore Dec. l2, 1950 E. s, MOORE 2,534,140

' MANUALLY APPLIED POWERl DRIVEN MACHINE FOR AUTOMATICALLY DELIVERING AND DRIVING A FASTENER Filed Feb. 14, 1948 5 Sheets-Sheet 4' nnentor S. moore Bg L`.`\

Cittorneg Dec. l2, 1950 E. s. MOORE 2,534,140

MANUALLY APPLIED PowER DRIvEN MACHINE FOR AUTOMATICALLY DELIVERING AND lDRIVING A FASTENER Filed Feb. 14, 1948 5 Sheets-Sheet 5 R EST lhg fic-x3 11d' A-C E; D R IVE (536 2 133 c J "D 13 5' HIL(- 110 (Z-Ffgz v11.5' D

:Snuentot dgar 5m oor@ 8u Gtforneg Patented Dec. 12,l 1950 MANUALLY APPLIED POWER-DRIVEN MA- CHINE FOB. AUTOMATICALLY DELIVERING AND DRIVING A FASTENEB.

Edgar S. Moore, Toronto, Ontario, Canada, assiznor to Air-A-Feed Equipment, Inc., Worcester, Mass., a. corporation of Massachusetts Application February 14, 194s, serial No. 8,355

(ci. iii-s2) 17 Claiml. 1

This invention relates to a manually controlled power driven machine for automatically delivering and driving a fastener, such .as a screw, nail r rivet. i

Various mechanisms have vbeen proposed here- 'tofore for feeding and drivingvnails, rivets or screws 4in which the fastener. isv forced by air pressure through a tube to a driving head where, if the fastener isa nail, it is driven into position by a reciprocatinghammer, or if a screw, it is rotated by a flexible shaft driven by air in a separate tube. The controls have been effected by a third power line separate from the tubes. The operation of such a machine is complicated by the multiplicity of tubes and flexible elements employed for the operating mechanism, since the operator may be Vhampered by the various lines getting tangled or the liability of air leakage and -power trouble. "Screws have been fed to the driving head by mechanical devices which present various problems in their manufacture and use.A Also, the screw driver has been rotated by an electric motor,which must be stopped and started repeatedly. -Such `devices are not as efflcient as one operated by compressed air; and the primary purpose of this invention is to provide a satisfactory construction which will serve vfor feeding .and driving fasteners as required by the manual control of the device.

Another object of this invention is to provide a4 single hose line for conveying the fastener to the driving head and delivering air to operate the driver.

A further object is tocombine with a pneumatic feeding mechanisman electrical power control which insures that the feeding and driving mechanisms are adequately coordinated.

Another object is toprovide fastener feeding and driving mechanisms which are so operated and controlled that double triggering is prevented and which insures that only one fastenercan be'fedat a time and a second cannot be fed until vafter the first has been driven into position and the driver is inoperative and readyto receive the next fastener.

A further object is to provide a manually operated device which is completelyautomatic in its controls, so that a `fasteneris' supplied and air pressure admitted to2 force the .fastener to the driving head only when the driver has been returned to a rest'position` andso that any partial movement A,of the driver" in 'either' direction willl notcause feeding of a second fastener. l

A furtherobject' is toprovide a control for a fastener feeding'and driving` mechanism in which 5 .2 the starting and stopping of the controlled elements is positive and sharply defined as distinct from the slow movements incident to pneumatic devices requiring that the air pressure be built up to an operating point.

A further object is to provide a single air hose line in which the electric control wires are carried thereon or preferably concealed so as to provide a simple design of light weight which minimizes the fatigue of the operator and provides a construction that is readily handled and flexibly manipulated. l

Further objects will be apparent to one skilled.

quence with the operation of the driving head. AThis control is erlectedby an electrical controlling mechanism operated by movement of the driving head which governs the automatic mech- .'anism that feeds the fasteners from a hopper or other supply. This construction preferably employs a pneumatically operated feeder which delivers the fastener to an air pressure hose line,

in which the movement of the feeder is automatically controlled by a valve controlled by a solenoid which in turn is governed by a switch controlled power line. The switch control .is operated by manual movement of the driving head as required for driving the fastener, and the fastener feeding mechanism cannot be operated until the driving head has been brought back to a rest position after the previously fed fastenerl has been driven into place.

Referring to the drawings, which illustrate one embodiment of this invention as applied to driving screws:

Fig. 1 is an elevation partly in section of an air driven screw driver and the screw feed tube;

Fig. '2 is a vertical section through a casing. partly broken away, showing afeed hopper and a. screw feeding mechanism which delivers a screw to a feed tube connected with the driving head of Fig. 1;

Fig. 3 is a top plan view of the hopper and feed mechanism of Fig. 2;

Fig. 4 is, a detail largely in section of the solenoid controlled screw feeding mechanism;

Fig. 5 is a fragmentary sectional detail of the screw feeding plunger in its left-hand screw retaining position;

Fig. 6 is a, sectional detail of the plunger in its right-hand delivering position;

Fig. 7 is a sectional view of the `screw feeding mechanism in the position of Fig.

Fig. 8 is a similar sectional view of the feeder in the position of Fig. 6;

Fig. 9 is a top plan detail of part of Fig. 1 showing the cam controlled microswitches on the driver;

Fig. 10 is a similar view at right angles to Fig. 9;

Fig. 11 is an end. view of the driver gun stock;

Fig. 12 is a detail on the line I2-I2 of Fig. 2;

Figs. 13, 14 and 15 are diagrammatic wiring diagrams indicating the operation of the control switches; and

Figs. 16,and 17 are respectively longitudinal and transverse sections through the air hose line.

The construction illustrated comprises a power rotated screw driver I0 (Fig, 1) which is rotatably and slidably movable into driving engagement with the head of a screw I I held within retaining pivoted jaws I2 that are carried by a head I3. The screw 1s fed into a driving position through'a tube I4 which opens into an enlarged cavity I5 in the top portion of the driving head immediately below the screw engaging end of the screw driver. The screw is fed to the tube I4 through a flexible rubberpipe I6 whichv has a diameter somewhat larger than the head of the screw but yet small enough so that pneumatic pressure against the screw head will drive the screw forward.

The screw or other fastener to be driven is y derived from a supply reservoir Il (Figs. 2 and 3) arranged to carry a considerable supply thereof. These screws depend by their heads (Figs. 2 and 12) between a pair of spaced inclined tracks i8, and they slide automatically to a position where they are held by the straight at portion of a reciprocable guard i9 shaped to engage or to release the end screw 20, as the-guard is moved. When the guard is moved to release the end screw (Fig. 3), a reciprocable knife 2l, mounted in a slot in each rail I8, is interpositioned to stop the next screw 22 and hold the remaining screws on the slide rails. The guard bar Il has a recess 23 at its end shaped to permit a screw to 'escape from the rails when the curved recess is opposite the end screw, as shown in Figs.

3 and 5. When released, the screw falls into an opening in the carrier 23 of the feeding mechanism of Figs. 4 to 8 which is arranged to deliver the screw at the right time to an inclined tube 25 (Fig. 2) suitably mounted within the reservoir housing 26 and which connects with the feeding tube I6. -The curved guard portion 23, when located (Figs. 3 and 5) opposite to the rails I3, directs the end screw 20 to a cylindrical opening 30 in the carrier, which is so arranged that it may be moved to deliver the screw to the top of the tube 25.

T'he screw feeding carrier 28 is a plunger or piston reciprocably mounted in a cylindrical chamber 3| in a casing. The passage 30 is a substantially vertical hole drilled radially through the piston. The lower end of the hole 30 is normally closed by the cylindrical casing 3l when the parts are in the inoperative position of Figs. 4 and 7. Reciprocation of the piston 28 towards the right brings the hole 30 over the upper end of the tube 25, so that a screw which has been previously delivered into that hole 3U will drop into the tube 25 (Fig. 8). Air under pressure is introduced from pipe 33 into the top of the pipe 25 to drive the screw to the operating head I3 of Fig. l. l

When the fastener has reached the driving head, the driver I0 is ready to be reciprocated or moved to drive the screw home. Rotation or reciprocation of the` driver may be accomplished by standard constructions. For example, the screw driver may be rotated by means of an air motor or turbine, or other suitable motor (not shown), which is mounted in the casing 34 (Fig. 1). The air motor is operated by compressed air admitted through the air pipe 35 that connects with a. side passage 36 in the tube I6. The air to this turbine may be suitably controlled by a trigger 31 operating a poppet valve 3B that is held by a spring 38 in a normally closed position but is lifted by means of the bell-shaped, pivoted trigger lever 31.

The screw driver Ill is releasably connected to the turbine through a suitable clutch made up of the clutch part 4I pinned to the screw driver shaft I0 and a further meshing clutch part 42 that is connected` to the turbine. These clutching parts are normally held apart by means of a spring 43 until the screw driver Iii has been thrust downwardly against the screw II and the pressure forces the two parts of the clutch into interlocking engagement. Various suitable or standard constructions may be employed for the clutch and the driving mechanism that rotates the screw driver.

A primary feature of this invention involves so coordinating the various mechanisms that a screwllsalways presented in proper position for engagementlby the screw driver, but improper operation. offthe screw driver will not cause or lpermit twoscrews to be jammed into the head at the same time or permit the mechanism to fail to deliver a screw when required. The control mechanism is'such that the. piston 28 (Figs. 4 to 8) is moved tofdeliver a screw to the pneumatic pipe lines 2 5, Ii only after the driver I0 has operated to drive the previous screw into position and the screw driver has been returned to an inoperative position. A further feature of this invention involves the use of a single pneumatic supply line for feeding the screw into driving position and for operating the screw driver.

The driver casing (Fig. 1) is slidably mounted relative to the pipe line I4, I6. That is, the casing 34, which carries the air motor and the gun handle 44', is mounted by means of a clamp 45 iixed on a sleeve 48 that surrounds and slides on the cylindrical tubular air conducting metal pipe casing 4l integral with the air line I4. A helical compression spring 43 surrounds and engages a shoulder on the pipe' I4 and the end of the sliding sleeve 46. and so tends to hold the screw driver I0 and its supporting casing in the retracted position of Hg. l.

Located between the inlet opening 36. which feeds air to the turbine, and the reciprocable sleeve 48 (Fig. 1), is a rotary cylindrical valve 50 having a radial hole therethrough, which normally connects the passage I6 with the tube 41 through which the screw is fed to the driving head. The valve member has pivots 6I on its ends carried in bearing holes in two opposed plates 52 that are pressed into position on a flat portion of the tube casing 41, thus rotatably supporting the rotary valve. One of the valve pivots has a lug 54 (Figs. 1, 9 and 10) which projects into the path of a striker pin 55 that projects from the side of the cam arm 56 mounted 6 25, and thus the screw is blown down the screw feeding pipe line to the head I2.

The release of the end screw from the carrier rails I8 is controlled by movement of the carrier piston 28. The barrier or guard I9 (Fig. 3)

e is secured to an arm 1I afiixed to the end of the removal of the striker pin 55. The rest position of the gun is such that the valve 50 is open to the passage of a screw when the spring 48 has urged the clamp and casing 34 to the extreme right which brings the parts into the positions shown in Fig. 9.

It will, therefore, be seen that a screw will pass Anormally through the rotary valve 50 when the screw driver is in the retracted position of Fig. 1; but when the gun handle 44 oi the screw driver is pushed to the left to engage the driver Ill with the screw Il, this causes the pin to move towards the left and release the valve lug 54 and let the valve 50 rotate to the closed position of Fig. 10, which is at 90 to the open position of Fig. 2. This shuts oil the air from the pipe line I4 and permits the full pressure to go through pipe 35 into the turbine casing to rotate the turbine when the trigger is held open or moved to an open position. If desired, that pipe line may be connected always with the turbine. It is, however, preferable that the screw driver be not rotated until it has come into engagement with the screw head. When the manual pressure is released from the screw driver casing, then the spring 48 returns it to its inoperative or rest position, where the pin 55 engages the valve contact 54 and opens the valve 50 to the screw feeding position. n

When the gun handle and screw driver move back to the rest position of Figs. 1 and 9, the fastener feeding piston 28 and associated parts (Figs. 4 to 8) are caused to move so as to deliver a fastener to the supply tubes leading to the driving head I2. This piston 28 is moved in opposite directions by air under pressure derived from a reciprocable valve 68, which controls the flow of air entering through the inlet pipe 33. This valve comprises two spaced cylindrical pistons 6I and 62 that are slidably mounted within a cylindrical valve casing 63 into which the inlet pipe 33 opens. The piston rod has 'a portion of reduced diameter to provide an annular chamber 64 communicating always with the inlet pipe 33. The end chambers outside of the pistons open to the outside air through holes in the valve casing 65. A port 66 communicates with the piston chamber 3| at the left of the screw feeding piston 'or plunger 28 for delivering air tomove the piston to the right when the valve piston 6I has been moved to the left to connect the space 64 with the port 66. Another port 61 connects the chamber 64 with the space at the right of the screw carrier 28 when the'valve is moved to the right, and

thus drives the screw delivering piston to the left, as shown in Fig. 4.

When the carrier piston 28 is in the left-hand positionof Figs. 4 and 7,v the hole 30 is located for receiving the end screw 29 delivered from the rails I8, and that screw is held in the compartment 30 until the piston is moved towards the right (Fig. 8) to deliver the screw to the pipe line 25.` When the hole 30 comes into communication with the pipe line 25, air is at the same time admitted from the pressure chamber 64 through a port 68 (Fig. 6) to an annular space 69 formed by cutting a slot in the piston 28. This space communicates at that time with the top of pipe piston rod 12 that slidably projects outwardly through the casing wall from the screw feeding piston 28. The arm 1I is slidably supported on a rod 13 secured to and projecting from the wall 14 of the piston casing. The guard I9 is so located and of such length that when the piston 28 is at its right-hand position (Fig. 8), the side of the guard I8projects closely adjacent to the ends of the slide rails I8 and thus holds the end screw 20 in place. Wiien the piston 28 is moved towards the left (Figs. 3 and 7), the guard I9 is withdrawn from its guarding position and the end screw 28 can drop off the rails.v The knife 2| is at the same time interposed between

screws

20 and 22 to keep the remaining screwson the rails. The knife 2|l is carried by a curved arm 14 secured to the reciprocable member 1I, and it has its forward knife edge so located that it is thrust between the

screws

20 and 22 just before screw 2D can fall off the rails. Thus, only one screw can drop into the opening 30 of the piston 28 when the latter is in its left-hand position.

'I'he screws in the hopper I1 are in a haphazard arrangement and may be below the level of the rails I8. In order to feed them to the slide rails, I provide a vertically reciprocable elevator comprising two spaced parallel plates 15, as shown in Figs. 2 and 12. These plates are suitably carried by a cross member 16 mounted between slide ways 11 on the side of the casing, and the plates are arranged to pass upwardly through a slot in the floor 18 of the hopper. The plates 15 are vertically reciprocated by means of a vertical pusher pivotally connected to a horizontal lever 82 of the first degree. This lever is pivoted at 83 on a fixed arm 84 and connected through a pivot 85 with a vertically reciprocable piston rod 86. The piston rod 86 is connected to a piston 81 that is vertically reciprocated in a suitable piston casing 88. The chamber beneath the piston 81 receives air from the pipe line 89 which connects with the right-hand end of the piston chamber 3| (Fig. 4) so that the piston 81 moves up when the valve 60 causes the piston 28 to move towards the left.

Air is admitted to drive the piston 81 upwards when the valve compartment 64 is in the position of Fig. 4 and the plunger 28 is at the left and the screws are held stationary on the rails. A pipe 9| connects the left-hand compartment in the casing 3l with the chamber above the piston 81, so that when the plunger 29 is moving to the right. air is at the same time admitted to the top of the piston chamber above the piston 81. Thus the piston 81 serves to move the top of the elevator 15 to and from a position above the rails I 8, and a number of the screws are moved upwardly by the inwardly beveled top faces 93 of the elevator plates 15 to positions where some of the screws will fall into position on the rails when the elevator descends. A tension spring 94 suitably secured to the lower end of the pusher 80 and a stationary part of the casing helps to support the weight of the elevator. A compression spring 95 surrounds a vertical piston rod 96 which carries at its lower end a piston 91 in an air cushioning compartment or dash- The rod 96 is suitably secured to the 7 elevator. This aids in taking up the shock incident to the movement of the elevator.

To prevent the screws from becoming jammed between the elevator plates and rails, I have mounted a pusher on the rails. which is reciprocated by a pusher rod |0| (Fig. 2). The

pusher is cut away centrally (Fig. 12) so as to move freely above the heads of screws properly depending between the rails, but it serves `to knock loil the rails any screws that are lying crossways thereon. The rod |0| has its lower end hooked into a bell crank lever |03` (Fig. 3) suitably plvoted at I on a stationary member. The other end of the lever is shaped as a fork |05 within which is mounted a lug |05 projecting vertically from the arm ll that terminates in the knife 2|. Thus. the pusher |00 is given a momentary quick movement to kick away any screws that happen to be out of place whenever the piston 2l is reciprocated to the left for receiving another screw.

A positive control of the cycle'of operations is effected byv means of switches and a solenoid which moves the valve 00 of Figs. 3 and 4. This comprises a solenoid ||0 of standard construction which has its core |I| pivotablyvconnected l valve to the left against the pressure of the compression spring.

The solenoid and its valve are operated in a timed sequence by means of a suitable power circuit ||4 (Figs. 13Y to l5) controlled by a relay ||5 which is in turn controlled by two microswitches H6 and ||l of standard construction. The microswitch ||6 is of the normally open type, and the other switch l1 is normally closed, as shown in Fig. 14. These switches are operated by two cams and |2|. The cam |2| is a rod formed as a prolongation of the part 56 which carries the striker arm 55 and is mounted on the reciprocable casing 45 of the screw driver (Figs. 1, 9 and 10). The longer cam |20 has a short thickened end portion |22 and a cutaway portion |23.` When the projecting button |25 of the normally closed microswitch ||1 is opposite the cutaway portion |23, then the switch is closed. That is, the movable metal contact arm carrying the button |25 is suitably "positioned by a compression spring |26 so that it is normally held in contact with the stationary contact |21 of the switch. The cam |22 serves to thrust the parts out of contact against the force of the spring |26. The other switch ||6 is similarly constructed, but with its spring |28 holding it normally open, the parts being so arranged that the movable metal arm carrying the button |23 is held normally out of contact with the stationary member |30 of the switch. When the cam arm |2| strikes the button |23. the switch members are forced into contact, as shown in Fig. 13. It will be understood that various mechanisms may be employed for these microswitches and that the drawings and the above description are to be considered as diagrammatic of the switch operation. v

The relay H5 is a double pole, single throw switch of suitable construction which comprises thesolenoid |32 having a core that is adapted to pull down on the spring held arm |33 when energized and close the two sets of contacts |34 and |35. The tension spring |33 or the resilient nature of the contact arms holds the relay normally open. When the mlcroswitches are in the normal rest position of Fig. 13, current i'lows through the valve operating solenoid I0, since the microswitches are both closed. As shown in Figs. 9, 10 and 1l. the two mlcroswitches are mounted back to back on a stationary portion of the casing surrounding the valve 50. with the spring pressed buttons held normally distended where they may be struck by the parallel cam arms |20 and |2| which reciprocate with the clamp casing 45 thatI is attached to the gun stock of the screw driver.

The operation of the electrical control mechanism is best understood by reference to Figs. 13. 14 and 15. Assuming that a screw is already in the driving head and that the screw driver is at rest, as shown in Figs. 1, 9 and 13, the microswitches are both closed and the solenoid III remains energized and holds the valve ll at the left which causes the piston 28 to stand at the right where its screw `massage 30 remains empty and out of a feeding relation with the rails Il. The operator places the screw driver in` position for driving the screw into the woodwork and then presses forward on the gunhandle u (Fig.

l). This moves the screw driver casing carrying the cams |20 and |2| to the left against the compressional force of the spring I3 (Fig. 1) As the operator presses forward on the screw driver, the short cam |2| moves from the position of Fig. 13 to that of Fig. 14 where it releases its microswitch IIB, and the switch arm |2| moves out of contact with the second switch part |30. This kills the relay circuit of switch IIB, but the normally closed switch remains closed and still energizes the relay, so that its contacts remain closed and the valve solenoid ||0 does not move. But when the operator forces the screw driver to its iinal operating position where -it engages the screw the micro-switches take the open positions of Fig. 15 where the normally closed switch ||1 is opened and the normally open switch H6 remains open. This causes the valve solenoid I0 to be deenerglzed, with the result that the valve is moved to the right (Fig. 4) by its spring ||3 and the iluid pressure forces the screw piston 23 to the left so that it may receive another screw in its compartment 30. The screw 20 is released from the rails by movement ci' guard I3 to the left, and the screw drops into the pocket 30 in the piston 23. This screw cannot be delivered to the driving head luntil the operator lets up on the handle M since the relay and switch circuits are all open.

When the screw has been driven into position, the operator lets up on the gun handle and the spring 48 (Fig. l) forces the handle to the rest position. Then the mlcroswitches are operated by the cams in the reverse order. That is, the part |25 of the normally closed switch falls oil the cam |22 on the long cam and it now closes, but this does not close the relay circuit since only the switch I6 can do it. The cam arm |2| is so short that switch I8 is not closed until the screw driver has nearly reached a rest position. Also, the passage through valve 50 is not opened by lug 55 (Fig. 9) until the screw driver has returned to rest. When the switch ||5 closes at the rest position (Fig. 13), this serves to close the relay and energize the solenoid H0, which now pulls the valve to the left and the screw feeding piston is moved to the right and delivers the screw 20 to the air tube 25 and it is blown down through tube I3 and the open passage of valve 50 to the driving head, where it is gripped and held by the spring pressed Jaws I2. This screw, therefore. goes to the operating head only when the deviceis at rest, and no partial movement in either direction ofthe gun can. feed a new screw. The double cycle of movement of both switches prevents this. vThat is, switch ill has to close before switch I I1 iseifective, and the latter holds the relay closed after switch H8 has opened. Hence, this'series movement is one in which switch H1 isset in a closed position but cannot hold the relay closed until the short camk closes switch IIB. l

The electric control wires are preferably mounted on the air hose line I6 through which the fastener isfed; and in order that the wires may be out of the way and-not subject to injury or entanglement with other parts or breakage. they are preferably wrapped closely around the air hose line or embedded in ay rubberized fabric structure solas to be entirely concealed, as shown in Figs. 16 and 17. This construction comprises the two wires i Il arranged hellcally around a rubber tube portion |40 and held in position by a fabric layer Hl and further protected by an outer coating of rubber |42. Thishelical arrangement of-the wire in a flexible hose pipe insures that the wire may be readily bent with the hose and without injury to the wire or interference with the electric circuit,

By means of this electric control, I have provided a positive acting mechanism which acts quickly and precisely in accordance with the movement of the gun stock and associated driver. If-the operator should press the gun control trigger 31 at the wrong time, nothing detrimental can happen, since the fastener feeding mechanism is 'wot operated from that trigger but solely by the position of the driver relative to a stationary casing carrying the hose line. Also, if the operator should move the driver gun stock back and forth through an incomplete cycle, nothing can happen, since the use of two switches and their controlling cams with the double pole relay makes it imperative that the driver be moved in an orderly manner through its complete cycle of pushing the fastener into place and then retreat to a position of rest. l

The feed of the fastener from the hopper is also positive, in that `the parts are fed serially and in an orderly manner to a position near the reciprocable'piston 28, and they are released one at a time into the cavity 30 in the piston and there heldin storage while the driver is being operated and so are ready to be moved quickly into position for delivery to the pneumatic pressure tube 25 the instant that the gun has been returned substantially to rest. There is no delay in this delivery of the fastener, and the operation is positive and compulsory. The timing Vis such that after the-screw has passed through the valve and the driver is pushed forward manually, the

Y lug on the short cam arm releases the valve 50, and the valve thenturns to deliver the maximum of air pressure to the rotary motor for rotatingthe screw driver when it reaches the head of g the screw. Itis immaterial asto whether the operatorholdsthe trigger of the gun and opens the poppet valve, since the clutch is not engaged until the driver engages the screw and provides back pressure to move the clutch parts together.

As will be understood, a. suitable source of pneumatic pressure is provided, such as a 'compressed air storage tank and a power actuated compressor automatically controlled to maintain a given pressure inthev tank, and the air delivery tube 33 is suitably connected to the, tank byv a pipe line including a flexible hose that permits a substantially freemovement of the hopper or fastener supply magazine.` v The casing 28 may be mountedon wheels i (Fig..2) for transportation around the plant. 'I'he wheeledcasing is normally located convenient to the air supply line and the tube Il notas imposing limitations on the appendedY claims.

deliver the fastener to said tube, means including a motor connected to move the carrier between the receiving and delivering positions, motor control mechanism rendered effective by movement of the head towards a driving position which automatically causes ,the motor to move the carrier to onefposition and remain there during driving of a fastener and to move to the other position whenl the headY becomes inoperative, and mechanism operated in timed relation with the carrier movement lwhich causes a single fastener to be delivered `from the magazine to the carrier when the latter is ina receiving position. v

2. A mechanism according to claim 1 in which the motor and its control mechanism comprises a fluid pressure 'operated motor and a control y valve therefor which is biased to hold the motor operated carrier in a fastener delivering position and means rendered operative by movement of the driving head to a driving position which reverses the valve and causes the carrier to move to a fastener receiving position andl torexnain there until the driving head moves to an inoperative position.

3. A mechanism according to claim 1in which the motor and its control mechanism comprises a motor havingV a fluid pressure actuated piston connected to reciprocate the carrier, a valve controlling the motor which is`biased to hold the piston stationary vand maintainA thecarrier ina fastener receivigposition, a'solenoid to move the valve and means controlled by 'manual movement of the driving head to a `rest position which energizes jthe solenoid vfor shifting the valve and causing the carrier toA move to deliver a fastener. I

4. A mechanism according to claim 1 'comprising a reciprocable Vagitator inthe magazineand associated mechanism to select a single fastener and deliver it to the carrier, pneumatically 0perated motors to actuate the agitator, move the carrier and drive` the fastener, compressed air conduits to said-motors and valves therein controlled by movement o f'the drivingl head relative -to` the tool body vwhi'chvcauseoperation of the motors in avtimed relationship.

5. A fastener feeding and driving mechanism l1 comprising a normally stationary magazine for fasteners. a manually movable tool having a body, a power motor thereon for driving a fastener and a fastener supporting head which is movable relative to the body from an inoperative to a driving position when pressed against the work, a single flexible tube for pneumatic prsure connected to the tool and which serves to deliver a fastener to the head, delivery mechanism for depositing in the tube a fastener selected from the' magazine, a motor connected to actuate the delivery mechanism, means including an electrical device for controlling the de.

livery motor and a circuit therefor having a switch on the movable tool, switch actuating mechanism on the tool controlled by movement oi' the head when pressed against the work, and means including a valve governing the flow of air through the tube which is controlled by movement of the head for causing a fastener to be blown through the tube to the head when the latter is in an inoperative position.

6. A mechanism according to claim 5 in which the power motor on the tool for driving the fastener is operated by pneumatic pressure and comprising a short conduit carried by the tool which connects the single tube with the motor for driving the same and a valve operating device on the tool for closing the air passage to the head and causing the motor to operate when the tool is pressed against the work.

7. A fastener feeding and driving mechanism comprising a relatively movable tool body and a driving head for supporting a fastener in a driving position, a stationary fastener supply magazine remote from the head, a pneumatic tube for receiving a fastener from the magazine and delivering it to the head under air pressure, feeding mechanism having a carrier movable between two positions to receive a fastener from the magazine and deliver it to the tube. a manually applied power operated driver carried by and movable with the body between inoperative and driving positions, an electrical control device associated with the feeding mechanism and including a circuit rendered operative by relative movement of the tool body and head, and a power operated motor governed by the control device which moves the feeding mechanism from .a receiving to a. delivering position when the driver is inoperative and to a position of receiving. and holding a fastener when the driver is moved towards and is in a driving position.

8. Apparatus according to claim 7 comprising a carrier reciprocable from a fastener receiving to a delivering position, a fluid pressure motor to move the carrier, a valve controlling the motor. a solenoid to'rnove the valve, and an electrical circuit including a switch governed by movement of the driver towards an inoperative position which causes operation of the valve so tener supporting and driving head slidably mounted on the body, a relatively stationary fastener supply magazine remote from the head, a single flexible tube for compressed air from a supply source arranged `to receive a fastener from the magazine and connected to deliver it to the head under pneumatic pressure, electrically controlled delivery mechanism which delivers a fastener from the magazine to the tube, an electric control for said delivery mechanism including a lswitch mounted to be operated by relative movement of the body and head which causes a fastener to beidelivered to the tube only when the driving head is in an inoperative position and means including a pneumatically operated motor on the tool body driven by air from said tube which serves to drive the fastener in the head.

11. A mechanism according to claim 10 com- 26\prising an air conduit connecting the motor with as to feed a fastener to the head when the driver` the ilexible tube, a valve controlling the air flow, and means operated by relative movement of the head and body which moves the valve to a position where it causes air under pressure in the tube to blow a fastener to the head while the head is in an inoperative position and to a second position where it closes the passage to the head and directs the air to the motor to drive the fastener.

12. A fastener feeding and driving mechanism comprising a driving head for supporting a fastener, a driver movable between driving and inoperative positions, a pneumatically operated motor to operate the driver, a single flexible tube for compressed air from a supply source which serves for supplying air to operate the motor and for delivering a fastener to the head under pneumatic pressure, a relatively stationary fastener supply magazine remote from the head, feed mechanism having a carrier movable to receive a fastener from the magazine and deliver it to the tube, a motor to move the carrier, an electrical device controlling the carrier motor, a circuit including said electrical device and a switch associated with and governed by movement of the driver to and from an inoperative position which causes the carrier motor to receive a fastener when the driver is applied to drive the work and to feed a fastener to the tube only when the driver moves towards an inoperative position, and means controlled by movement of the driver which causes air in said tube to blow a fastener to the `driving head when the driver is inoperative and thereafter to operate the driving motor.

13. Apparatus according to claim 12 comprising electrical circuit wiring arranged on the flexible y tube and bendable therewith which connects the switch and the carrier motor controlling device.

14. Apparatus according to claim 12 in which the electrical control circuit comprises a normally open switch, a normally closed switch and a relay governed by the switches, and associated cams mounted to operate the switches successively in response lto movement of the driver in either direction which `reduire that the driver move through a full cycle ofdriving a fastener and returning to rest before the fastener delivery i mechanism can deliver another fastener.

15. Apparatus according to claim 12 vin which the electrical device includes a solenoid biased to a non-energized position' and the carrier motor includes a valve positioned by the solenoid, and a circuit including a switch controlled by movement of the driver which energizes the solenoid and holds the carrier in a delivering position while the driver is inoperative.

16. A screw feeding and driving mechanism comprising a manually applied and freely movable tool body, a fastener supporting and driving head on the body, a fastener driver which is slidably movable relative to the head to engage and` drive a fastener therein, a motor on the body which operates the driver, means for controlling the motor, a relatively stationary fastener supply magazine remote from the tool body, a single flexible tube connected to the tool head which is arranged to receive a fastener from the magazine and deliver it to the head under pneumatic pressure, delivery mechanism which delivers a selected fastener from the magazine to the tube, an electrically governed motor for operating said delivery mechanism and an electrical control device governing said delivery mechanism including a circuit, a switch therein and means for actuating the switch which is mounted to be operated by relative movement of the head and driver, said control deviceinsuring that a fastener is delivered to the head only when the driver is in a nondriving position.

17. A screw feeding and driving mechanism according to claim 16 comprising a pneumatic motor to operate the driver, a conduit for conducting air from the tube to the motor, a valve for controlling the air ilow in the tube and means operated by relative movement of the head and driver which causes the valve to divert the air to operate the motor when the head is pressed against the work and to direct the air through the tube to blow a fastener to the head when the pressure ofthe head against the work is released.

EDGAR. S. MOORE.

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

UNITED STATES PATENTS Number Name Date 1,014,639 Colwell Jan. 16, 1912 1,441,250 Smith Jan. 9, 1923 1,499,887 Snyder et al. July 1, 1924 1,618,367 Dick Feb. 22, 1927 1,703,458 Ruff Feb. 26, 1929 1,774,030 McLaughlin Aug. 26, 1930 1,813,697 Dellaree July 7, 1931 1,980,967 DeMooy Nov. 13, 1934 2,255,827 Snyder Sept. 16, 1941 2,261,134 Blah Nov. 4, 1941 2,373,992 Billinghurst Apr. 17, 1945 2,471,793 Stull May 31, 1949