DE2543900A1 - DEVICE FOR AUTOMATICALLY TURNING IN A SCREW - Google Patents

Description

Γ. jmL .- # HYS.

HÖGER - LEGAL LAW - GQ1ESS3ACH - HAECKER

PATE NTANWALT = IN STUTlSART

A 41 391 m

m - 163

15th September 1975

Babette Dixon
Rural Route No. 1
Belvidere, Illinois / USA .

Device for automatically screwing in a screw

The invention relates to a device for automatic screwing a screw or other threaded fastener into a workpiece with a motorized in Rotation offset screwdriver and with a telescopic viewfinder above the latter, the end of which on the screw or the like can be put on and against the action of an elastic bias from its advanced normal position in a

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withdrawn position is movable.

In particular, the invention has to do with a machine which contains a screwdriver with a motorized screwdriver. A viewfinder is assigned to the screwdriver. A device is also provided to transfer screws from a charging station to a Transfer station in which the screws are in position relative to the viewfinder before they are screwed into the workpiece to be brought. The viewfinder holds the screws aligned with the screwdriver and engages the screwdriver with the screw head.

Automatic devices of this type are from the US patents 3,279,045 and 3,675,302 are known. In these devices, the screwing tool is fixed on a stand mounted and automatically slidable back and forth with respect to the workpiece for the purpose of screwing in the screws. In another embodiment of such a device the screwing tool is held by hand and moved manually relative to the workpiece. A widely used device of the the latter type works semi-automatically, i.e. the screws are not fed to the viewfinder automatically but are instead first screwed into the workpiece manually and then fully screwed in with the screwing tool. Such a semi-automatic Tool includes a relatively simple, tubular viewfinder that telescopes over a screwdriver and is normally held in an advanced position under the action of a resilient bias. In in this position it can be telescoped over the head of the screw. Presses while driving the screw

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the screw head against the viewfinder and moves it parallel to the axis of the screwdriver into a retracted one Location. When the screwdriver is released from the screwed-in screw, the viewfinder automatically returns to its advanced position Normal position and is ready to be placed on the next screw.

It is primarily the object of the invention to provide a new and improved device for automatically screwing in a To propose a screw in a workpiece that is particularly suitable for manual operation, is simpler in its structure and more fail-safe than previously known devices this works Art.

The object is achieved according to the invention in that a Feeding device is provided, which feeds the screws and brings them into position in alignment with the viewfinder, and the Feed device adjustment members are assigned to the. Viewfinder before inserting the screw into the retracted Spend position and let it return to its normal position after inserting the screw.

A preferred embodiment of the invention is generally characterized by the following features: a screw is passed through a flexible tube is blown into the gripper of a feeder, which is a hand-held device for automatic Screwing in a screw is assigned. The grippers are then moved forward to move the screw relative to a align the retractable, tubular viewfinder so that the viewfinder can be pushed over the screw. The seeker surrounds the screwing tool provided in the device, in

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usually a screwdriver. The grippers hold the screw as it begins to screw in and then sweep back to take the next screw from the flexible tube. The machine includes the following equipment: (a) means for placing the screw relative to the flexible tube and blowing the screw therethrough Pipe; (b) means for moving the grippers back and forth on different paths, causing the grippers to pull the screw place be in the viewfinder and hold and guide the screw while it begins to be turned; (c) a facility for temporarily withdrawing the viewfinder while the gripper is advancing so that the screw is in position relative to the viewfinder can be brought that the latter can be telescoped over the screw head; (d) a facility for the automatic control of the forward and backward movement of the gripper depending on the forward or backward movement retracted position of the viewfinder and (e) a device for controlling the opening and closing of the gripper, whereby the Grasp the screw while it is being fed in and while it is beginning to be screwed in before it moves away from the Loosen the screw again.

Further features and advantages of the invention are as follows: With the aid of the device according to the invention, relatively short screws can be carried out at a comparatively high speed be driven. The feed device provided according to the invention can also be added to existing, semi-automatic screwing tools are attached, so that with such a screwing tool each screw quickly and accurately can be fed to the viewfinder and held there before after retracting the viewfinder over a small distance

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is driven away. The movement of the seeker between his normal advanced position and his withdrawn position Position is preferably used to control the displacement of the feed device through which the screws can be fed to the viewfinder from a charging station. The movement of the feed device is advantageously used for this purpose exploited to first retract the viewfinder to thereby place the screw aligned with the viewfinder, and then to allow the viewfinder to return to its normal position, in which it telescopes onto the newly introduced screw is attachable.

Essential features of the invention consist in the structure, arrangement and mode of operation of the feed device through which the screw is aligned with the viewfinder to make the screw more stable during the start of driving the screw in Position in the viewfinder, after which the feeder is withdrawn from the viewfinder and the screw before the can hinder further screwing in of the screw. The feeder has a pair of opposing grippers which are controlled in such a way that they first tighten the screw in the corresponding phases of the machine cycle then just hold it loosely and finally let go of it completely. According to the invention there is also a device proposed which receives the screws from a remote supply and takes them quickly to a charging station nearby the screwing tool transferred. The transfer takes place in that the screws with compressed air through a flexible Hose are blown, which runs between the mentioned device and the screwing tool. This is where the screws with a prescribed orientation through the hose

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blown, even if the screws are so small that they tumble inside the hose. Another one The feature of the invention is a reciprocating cartridge which has a small screw through the flexible tube or the hose is conveyed while the screw is correctly oriented. This cartridge unloads the screw on the Charging station and then returns through the pipe to pick up the next screw from the supply.

The following description of preferred embodiments The invention is used in conjunction with the accompanying drawing and the claims for further explanation. Show it:

Fig. 1 is a perspective view of a device for automatically screwing in screws or other threaded fasteners;

2 shows a partial side view of a screwing tool and a feed device on the inventive Device, the individual parts taking such positions that the machine cycle can begin;

3 shows a partial side view of the feed device; Fig. 4 is a partial section along the line 4-4 in Fig. 2;

FIG. 5 shows an enlarged cross section along FIG Line 5-5 in Figure 2;

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Fig. 6 is a partial section along the line 6-6 in Fig. 5, but with the parts drawn in the positions they were used during the beginning Make contact of the screw with the workpiece;

Figure 7 is a partial sectional view taken along line 7-7 in Figure 6; .

Fig. 8 is a partial sectional view taken along line 8-8 in Fig. 6;

Fig. 9 is a partial sectional view taken along line 9-9 in Fig. 5, but with the parts in positions are drawn, which they occupy after the start of screwing in the screw;

FIG. 10 is a rear view of the individual parts of FIG. 9;

11 shows a view similar to FIG. 2 in an enlarged manner Scale showing parts of the feeding device returning to its charging station, in which she receives a new screw;

FIG. 12 shows an enlarged rear view of individual parts from FIG. 11; FIG.

13 shows an enlarged side view of individual parts from FIG. 11, but with the individual parts in FIG Charging station are arranged and receive a new screw;

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Figure 14 is a rear view of the parts of Figure 13;

15 shows an enlarged side view of parts from FIG. 2, but in a displaced position;

16 is a view similar to FIG. 11, but with the machine parts during the beginning Advance of the new screw from the loading station are shown;

FIG. 17 shows an enlarged rear view of parts from FIG. 16; FIG.

Fig. 18

and 19 views similar to FIG. 6 showing successive positions of the machine parts during the last phase of feeding a new screw from the loading station;

FIG. 20 shows an enlarged view of individual parts of the feeder shown in FIG. 1; FIG.

Figure 21 is a view similar to Figure 20, but with certain parts in displaced positions;

22 shows an enlarged partial sectional view along the line 22-22 in Figure 20;

FIG. 23 is an enlarged fragmentary sectional view taken along;, line 23-23 in Fig. 21;

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24 shows a view similar to FIG. 23 with a modified one Feeder in which the screws by means of a cartridge through the feeder line be conveyed through;

Fig. 25 is a perspective view of a cartridge and

Fig. 26 is a diagram showing how the cartridge and screw arrive at the loading station; to transfer the screw into the gripper of the feeding device.

The device 30 shown in the drawing (Figure 1) for automatically driving screws 31 or other threaded fasteners into holes in a workpiece 33, which is held in a horizontal position by a holder 34, comprises a screwing tool 35, which is from can be held in the hand of an operator and brought into any position over the workpiece. Afterward the screwing tool is manually shifted downwards to drive the screw and then disengaged upwards returned with the screw. If the workpiece is not in a horizontal position, the operator can Turn the screwdriving tool so that it is aligned at right angles to the workpiece and then screw in the screws by the tool is moved towards and away from the workpiece. However, the invention can also be applied to such devices apply in which the screwdriver is attached to a fixed bracket and automatically by power-operated means is floating. Machines of this type are described in the patents mentioned at the beginning.

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The screwing tool 35 of the device 30 is of a commercially available type. When using it, the screw must first be screwed a little by hand into the workpiece, after which the full tightening of the screw with the help of the semi-automatic Tool 35 takes place. The screwing tool 35 comprises an elongated housing 36 which has a (not shown) e.g. has a rotary motor driven by compressed air, which has a screwdriver 38 (Figs. 6 and 7) with a cutting edge

39 drives. The cutting edge fits into a slot in the head of the screw 31. The screwdriver 38 is telescopic inserted into the housing 36 and protrudes downward out of this. A finder 40 in the form of a tubular sleeve is telescoping or slidably arranged over the lower end of the screwdriver and holds the head of the screw aligned with the cutting edge 39 when the cutting edge seeks to enter the slot in the screw head and drive into engagement with the screw.

Apart from a ring 41 (Fig. 7), the purpose of which will be explained later, the viewfinder 40 is identical to viewfinders, as used on conventional, semi-automatic screwdriving tools. As can be seen from Fig. 7, the viewfinder is

40 slidably supported in the lower end portion of the housing 36, telescoping over the lower end of the screwdriver 38. A rotation of the viewfinder is prevented by a screw 43 which is screwed into the housing and into a Slot 44 protrudes in the upper end portion of the viewfinder. A coil spring 45 arranged in the housing 36 presses on the upper end of the viewfinder 40 and presses it into its extended or advanced relative to the cutting edge 39 of the screwdriver 38 Normal position (Fig. 2). If the viewfinder is in this

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Location is, its lower end protrudes downward over the cutting edge 39 and can telescope over the head of the Screw 31 protrudes to hold the screw in its driving position with the screwdriver 38 aligned. The lower The end of the viewfinder has a recess 46 (Fig. 7), the side wall of which closely surrounds the screw head, and the bottom of a determined downward shoulder that can be placed on the surface of the screw head. Accordingly the recess 46 captivates the screw head against radial and upward movement relative to the Finder and helps keep the screw head in axial alignment with the screwdriver so that its The cutting edge can enter the slot in the screw head.

The screw 31 is screwed in by moving the tool 35 downwards, the screw head from the recess 46 des.Suchers 40 is added. If the The screw is first pressed against the workpiece 33 and then closed is stopped by this, the screw head presses against the upper wall surface of the recess and temporarily stops one further downward movement of the viewfinder. With continued downward movement of the screwing tool 35, the housing and screwdriver 38 move relative to the stopped viewfinder downwards so that the viewfinder assumes an upwardly retracted position with respect to the screwdriver (Fig. 6) and the end of the cutting edge 39 is exposed. As the viewfinder approaches your retracted position, the cutting edge will touch .the screw head, which leads to an upward pressure being exerted on the screwdriver 38. This pressure causes the opening of a (not shown) compressed air

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valve, so that compressed air via a line 47 (Fig.1) to The drive motor of the screwing tool 35 flows. Thus, the screwdriver begins to turn, engages with the Screw and screw this into the workpiece. The housing 36 move while the screw is being driven in. the Screwdriver 38 and finder 40 together with the screw downwards until the screw is in its end position in the workpiece is brought. The tool 35 is then lifted upwards from the screw, as a result of which the motor is automatically switched off and the viewfinder 40 is returned to its advanced normal position by the spring 45 (FIG. 2).

According to an essential aspect of the invention, the application a conventional screwing tool 35 of the type described above in a device 30 with a relatively simple and compact feed device 50 (FIG. 3) are considered, this feed device 50 the screws 31 not only spends automatically in the viewfinder 40, but also telescoping each screw in the viewfinder and in alignment with it the screwdriver while the screw is beginning to be screwed into the workpiece 33. As a result of this particular and advantageous feeding and holding function of the feeding device 50, the screws can automatically be in the conventional, however, difficult-to-load finders 40 can be placed. You will be doing this during the critical period of the the beginning of screwing is held under extremely stable control and guidance.

The feed device 50 according to the invention is attached to a carrier 51, which in the embodiment shown partly from two vertically and horizontally

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Spaced side walls 53 and 54 consists of the are in turn arranged on the rear of the tool 35. Storage forks 55 and 56 (Fig. 2) on the front of the carrier 51 serve to support the upper or middle part of the housing 36, while the lower housing part on the carrier 51 is held by means to be described later. An elastic band 57 is stretched around the upper part of the housing and anchored to the upper bearing fork 55 so that the housing is firmly pressed into the fork. An axial shift of the housing is prevented by a washer 59 which fits into a circumferential groove 60 of the housing and is held by a vertically directed screw 61. The screw 61 is screwed into the upper fork 55 and can be adjusted vertically, making the washer with the grooves of different types semi-automatic Screw tools can be aligned.

The feed device 50 comprises a holder, which in the illustrated embodiment of two opposite Grippers 63 is formed. These grippers can take up a screw 31 in a loading station 64 (FIG. 13) and on it down and forwards into an insertion station 65 (FIGS. 2 and 18) to bring the screws into their screwing-in position in which it is in telescopic relationship with the viewfinder 40. In addition to their movement between the Loading and introduction stations, the grippers 63 are also mounted in such a way that they are between a closed and an open position (Fig. 14 and 10) are pivotable, in which the grippers hold the screw shaft and let go. The screw is fed to the grippers when they are in the loading station 64 and in the closed position (Fig. 13 and 14). To this end

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a flexible plastic tube 66 runs in the carrier 51 in such a way that that the lower or output end 67 of the tube lies in the loading station 64. After the grapple up and back After returning to the charging station, a screw is pushed with the shaft first by means of compressed air through the tube blown so that it slides between the grippers and from these for the purpose of the subsequent transfer to the Bringing station 65 is held. Insertion of the screws into tube 66 and blowing the screws through this tube is done with the aid of a feeder 70 (FIGS. 1, 20 to 23), which will be described later.

Each gripper 63 comprises a substantially vertical arm 71 (FIGS. 9 and 10), at the lower end of which an upper projection 73 in the form of a quarter tube and a lower finger 74 of smaller diameter in the form of a half tube are, wherein the projection 73 and the finger 74 are connected by a downwardly tapering half-cone 75. When the grippers are closed and in the introduction station 65 according to FIG. 5, the projections 73 loosely encompass the rear side of the viewfinder 40, the screw head rests on the inner surface of the half-cones 75 and the fingers 74 encompass and hold the screw shaft.

In order to store the grippers 63 in such a way that they are between the loading and insertion stations 64 and 65 and also between their The open and closed positions are movable, comprises the feed device 50 a displaceable carriage which is arranged between the side walls 53 and 54 of the carrier 51. at the illustrated embodiment, the carriage has a

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One-piece construction and consists of two horizontally spaced and vertically extending slide parts 76 (Fig. 3, 9 and 10), the rear sides of which are connected to one another by a one-piece web 77. Each sled part has a downwardly protruding, lower leg 79 (Fig. 9) as well as an upwardly and outwardly curved, upper leg 80. At the upper end part of the lower leg of each slide part a tubular eyelet 81 is provided between two similar eyelets 83 are arranged at the upper end of the adjacent gripper 63. Through every sentence of the aligned An axle journal 84 runs through the eyes and holds the gripper in such a way that it is laterally between the open and closed positions is pivotable on the associated slide part.

As can be seen from FIGS. 3, 9 and 17, an upper roller 85 is between the ends of the upper leg 80 of each carriage part 76, while a similar, lower roller 86 is mounted at the lower end of each lower leg 79. The · Rollers 85 and 86 run in upper and lower cam tracks 87 and 88 (Figs. 16 and 17), which are defined by slots, which are formed on the inner sides of the side walls 53 and 54 of the carrier 51. The lower group of cam tracks is offset downwards and forwards compared to the upper group. The rollers and tracks work together in such a way that the carriage parts 76 and the grippers 63 are guided when the latter between the loading station 64 and the introduction station 65 can be pushed back and forth.

Each of the upper cam tracks 87 first runs downwards, then forwards and downwards and then downwards again, and

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in the order from top to bottom. The side walls of each upper roller conveyor are the length of the conveyor parallel to each other and at a distance from each other which is essentially the diameter of the associated upper roller

85 corresponds. In this way the upper rollers 85 are forced to to run on the same path in each case when the grippers 63 move from the loading station 64 forward and down to the loading station 65 and from there return up and back to the charging station. The lower cam tracks 88, on the other hand, are designed in such a way that the lower rollers 86 are caused to move forward and backward Each gripper describes different ways. The reason for this will be described later.

As shown in FIG. 9, each lower cam track 88 includes an upper, downwardly directed portion, the width of which is about Corresponds to the diameter of the associated lower roller 86, so that the roller follows the same path when it is in this upper part of the cam track runs down or up. Each cam track 88 widens below the upper part a width which is substantially larger than the diameter of the roller 86 and includes a lower edge that initially quite steeply downwards and forwards and then forwards in a direction which is essentially radial to the viewfinder 40 is. The radially extending part of the lower edge of the lower cam track 88 is shown in FIGS. 9 and 13 with the Reference numeral 90 is provided and is located near the lower one End of the cam track. When the grippers 63 are moved downwards and forwards to the loading station 65, each roll runs

86 on the lower edge of the associated cam track 88. During the return to the loading station 64, the gripper runs

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each roller 86 on the upper edge of the cam track 88. This upper edge comprises a vertical portion 91 (Figs. 9 and 13), which adjoins the lower end of the track 88 and relatively to the viewfinder 40 runs axially. This vertical part 91 goes in a generally upward and backward direction Part over, which in turn leads to the upper part of the cam track 88.

In order to move the grippers 63 back and forth between the stations 64 and 65, there is a pressure medium cylinder at the upper end of the carrier 51, preferably a compressed air cylinder 92 (Fig. 1,2 and 4) attached. This cylinder has a long rod 94, which can be moved back and forth up and down when a pressure medium (compressed air) in the lower or upper part of the cylinder is admitted via lines 95 (Fig. 2). The lower end of the rod 94 is connected to a block 96, which is guided for the purpose of an up and down movement through slots 97 (Fig. 4), which on the inside of the walls 53 and 54 of the carrier 51 are formed. A linkage 99 bent down and forward is at the top at 100 pivotally connected to the block 96 and at its lower end at 101 to the upper ends of the upper legs 80 of the Slide parts 76 are articulated. In this way, downward movement of the rod 94 causes the carriage parts 76 and the Gripper 63 to move down and forward into the introduction station 65 while a retraction of the rod 94 after at the top returns the gripper up and back into the loading station 84. While the gripper is advancing, the Rod 94 over the curved linkage 99 and the curved legs 80 of the slide parts 76 in such a way that the slide

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25439Π0

share a counterclockwise force is communicated, which tends to move the slide parts counterclockwise to rotate the upper rollers 85 so that the lower rollers 86 against the lower edges of the lower cam tracks 88 are pressed. Conversely, the rod 94 applies a clockwise force to the carriage parts 76, when the grippers return to the loading station 64, causing the grippers to rotate clockwise about the upper rollers 85 will. This in turn causes the lower rollers 86 to travel along the upper edges of the lower cam tracks 88 .

The grippers 63 begin their downward and forward-facing Movement together with a new screw 31 from the loading station 64 immediately after the previous one The screw is screwed in and the screwing tool 35 is lifted upwards, so that the viewfinder 40 is relative to the screwdriver 39 can return to its advanced normal position. An important feature of the invention is that the movement the gripper 63 from the loading station 64 into the introduction station 65 causes the advanced viewfinder 40 to move temporarily move up to its retracted position so that the new screw 31 is brought under the viewfinder and in their rotation position can be placed under the viewfinder and aligned with this. The viewfinder will look after this brought down into its advanced position, automatically and telescopically downwards over the head of the newly fed screw pushes.

The viewfinder 40 is temporarily withdrawn by a coupling 103 (FIG. 6) which is connected to the viewfinder 40

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and operated by one of the lower rollers 86 when the carriage parts 76 slide down and out, in order to rotate the grippers 63 into the introduction station 65. Part of the coupling 103 is from the aforementioned ring 41 formed on the viewfinder 40. This ring 41 is pushed over the viewfinder and rigidly attached there. Under this ring protrudes an inwardly protruding, horizontal finger 104 (FIGS. 6 and 7), which at the lower end of a vertically extending Lifting rod 105 is arranged. The latter is for the purpose of a free sliding up and down in a recess 106 of an arm 107 out, which in turn is anchored to the side walls 53 and the carrier 51 and a semicircular fork 109 to hold the lower end portion of the housing 36 on the bracket 51.

The upper end of the lifting rod 105 has an outwardly protruding, horizontally extending extension 110 (FIGS. 6 and 7), which cooperates with a crank lever 111. This has an arm 113 extending substantially horizontally on, which is under the extension 110 and normally rests on a stop 114 at the upper end of the arm 107. The connection between the extension 110 and the crank lever 111 takes place via a screw 115, which is in the extension is screwed in and rests against a ball 116, which in turn is provided on the arm 113 of the crank lever.

As shown in FIG. 6, the crank lever 111 is arranged on the outside of the wall 53 and around a bearing pin 117, which is attached to this wall, can be pivoted. The crank lever 111 further comprises a substantially vertical one directed arm 119, the inside of which is rigid with a

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Sprue 120 (Figs. 18 and 19) is connected. This sprue extends into the carrier 51 via an opening 121 in the side wall 53. The sprue 120 is in the way which is traversed by the adjacent, lower roller 86 when the grippers 63 down and out of the loading station 64 advance to the loading station 65.

During the final portion of this advance movement, the rollers 86 run on the substantially radial part 90 the lower cam tracks 88 and cause the grippers 63, to move the screw 31 substantially radially towards the viewfinder 40. After entering the radial part 90 engages the roller 86 adjacent to the side wall 53 hits the rear side of the sprue 120 and then passes under the sprue, so that the crank lever 111 clockwise (see Fig. 18) is pivoted. The roller 86 thus acts as a cam. As a result of this pivoting, the ball 116 causes the Screw 115 raises the lifting rod 105 in the recess 106 and thereby causes the finger 104 to move against it puts the ring 41 and raises it. As a result, the viewfinder 40 is in its retracted position against the action of the spring 45 raised and now no longer forms an obstacle for the newly arriving screw 31, so that this is the last, radially running piece of their way in their screwing position below the viewfinder can cover. If the screw this Has reached position, the lower roller 86 moves into the end of the lower cam track 88 and comes from the bottom of the sprue 120 free; so that now the crank lever 111 can pivot freely in the counterclockwise direction. Accordingly the spring 45 can expand again and can

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snap the viewfinder 40 back down to its advanced position (Fig. 19), whereby the end of the viewfinder slides down over the screw head and rests on it, while the grippers 63 continue to hold the screw shaft. In this way it allows for temporary withdrawal the viewfinder while the screw is being fed in so that this screw can be placed under the viewfinder while the subsequent advancement of the viewfinder causes it to lie over the screw head.

Furthermore, according to the invention, the normal, from the viewfinder 40 in each case exactly before and after the The reciprocating movement performed by screwing in the screw 31 is used to reduce the reciprocating movement of the grippers 63 between the charging station 64 and the introduction station 65 to trigger. This is done in the embodiment described in that the ball 116 is used as a valve, which by switching back and forth between an open and a closed position triggers pneumatic signals through which the pressure medium flow through lines 95 and to the ends of the Cylinder 93 is controlled.

As shown in Fig. 6, the ball 116 is in a cavity 121 arranged in the upper arm 113 of the crank lever 111. This cavity opens on the top of the arm 113. The cavity 121 stands with a horizontal conduit 123 in FIG Connection formed in the arm 113 and in turn is connected to a flexible line 124 via a nipple 125. A stream of compressed air flows continuously in the Line 124.

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When the viewfinder 40 is in its advanced normal position before a screw 31 is driven in, the ring 41 is supported downwards against the finger 104 of the lifting rod 105, as shown in FIG. 2 with the solid lines and in FIG. 6 with the dashed lines Lines is shown. Thus, the screw 115 on the upper extension 11o presses downward against the one acting as a valve Ball 116, so that the ball rests on the bottom of the cavity 121. The ball thus closes the line 123 and prevents compressed air from escaping from the line 124.

When the screw 31 is initially pressed against the workpiece 33 the viewfinder 40 moves back in the course of its normal movement and pulls the ring 41 upwardly off lower finger 104 of the lifting rod 105 away (see Fig. 6). Accordingly, the lifting rod 105 is no longer on one Upward movement is prevented and does not exert any influence on the ball 116 Print out more. Therefore, the pressure in line 123 forces the ball and lift rod 105 upwards and lifts the ball off, so that air exits line 124 through cavity 121. The resulting flow of compressed air through the Line 124 actuates a control valve (not shown) which controls the pressure in the upper end of the cylinder 93 relaxes and introduces compressed air into the lower end of the cylinder. Accordingly, the rod 94 is withdrawn and begins to move the grippers 63 up and back toward the loading station, immediately after pulling back the viewfinder. The lower end of the cylinder remains under pressure as long as the viewfinder is in its withdrawn position. Thus, the grippers are moved into the loading station and there while the screw is being screwed in held. When the grippers reach loading station 64,

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a probe 126 (compare FIGS. 11 and 15) pushes itself on Block 96 in a line 127 and closes it. The line 127 runs into the carrier 51 and also receives a stream of compressed air. The closure of the end of the line 127 by the probe 126 creates a pneumatic one Signal which is fed to the feeder 70. This causes another screw 31 to pass through the Tube 66 and into the fingers 74 of the gripper 63 is blown (Fig. 13).

When the screw 31 to be screwed in is firmly tightened, the screwing tool 35 is lifted from the screw so that the viewfinder 40 is pushed down into its normal position can jump back. During the last part of this movement, the ring 41 rests against the lower finger again 104 (Fig. 6 and 7) of the lifting rod 105 and causes the screw 115 on the upper extension 110, the ball 116 in the To press cavity 121 down into the closed position. Of the Compressed air flow through line 124 is thus interrupted, which generates a signal which in turn controls the aforementioned control valve causes the lower end of the cylinder 93 to be depressurized and pressurized air into the upper end of the cylinder initiate. Accordingly, the rod 94 is now extended and pushes the gripper 63 down and forward in the insertion station 65 in order to place the new screw 31 in the viewfinder 40. The top of the cylinder remains under pressure, so as to hold the grippers in the loading station 65, the grippers holding the screw shaft until the screw against the workpiece 33 is pressed, which in turn triggers the viewfinder to be pushed back and the ball 116 to open will.

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From the preceding it follows that the normal pushing back of the seeker 40, which takes place when the screw 31 is first pressed against the workpiece 33, to this is used to trigger the return movement of the grippers 63 in the loading station 64, during the subsequent advancement of the viewfinder 40 after completion of the screwing operation is used to advance the gripper into the insertion station initiate. However, it is important that the temporary withdrawal and subsequent advancement of the Seeker, which takes place while the screw is being fed, does not change the position of the ball 116. So that will also the advancement of the grippers 63 to the introduction station 65 by this temporary retraction and advancement of the viewfinder 40 not interrupted. When the lower roller 86 engages the sprue 120 to pivot the crank arm 111 clockwise and to withdraw the viewfinder 40 temporarily, the ball 116 pushes up against the screw 115 in the upper extension 110 of the lifting rod 105 (Fig. 18). Thus, the ball 116, the screw 115 and the lift rod 105 move together with the Viewfinder 40 upwards and, since the ball and the screw are in contact with one another under pressure, the ball remains in the closed position in the cavity 121, so that the escape of compressed air from the line 124 is prevented. Move in a similar way the ball 116, the screw 115 and the lifting rod 105 all together downward when the roller 86 comes free from the underside of the sprue 120 so that the spring 45 the Viewfinder 40 can advance. The ball 116 thus remains in its seat in the cavity 121 when the viewfinder is advanced into its Location returns. If the viewfinder then does is withdrawn by pressing on the screw 31, the ring 41 simply moves upward from the lower finger 104

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•. 25439Π0

the lifting rod 105 away. This enables the compressed air in line 124 through the valve formed by ball 116 in FIG
Effect and to move the lifting rod 105 relative to the stationary crank lever 111 by a short distance upwards, so that the ball can open the cavity 121 and thus trigger a blowing of compressed air from the line 124. Accordingly, ring 41 and lower finger 104 on lift rod 105 provide a dead gear connection that allows ball 116 to remain in the closed position when the viewfinder is withdrawn by crank 111 and lift rod 105, which on the other hand, a stationary behavior of the crank lever and an opening of the ball are permitted as soon as the viewfinder is pressed open as a result of the
Screw 31 is withdrawn onto the workpiece.

According to a further important feature of the invention, the grippers 63 of the feed device 50 are in their closed position
biased and held in this position, the grippers firmly grip the screw 31 during the advance of the same to the introduction station 65 and precisely control what happens during
the start of driving the screw continues, the latter can be rotated. Eventually the
Gripper slightly off the screw and move axially on the
Seeker 40 after their return movement from the loading station 65 has begun. This effect is caused by the spring pressure that causes the grippers to move in
the introduction station 65 can be kept closed. While
of their final engagement in the loading station becomes the
The spring pressure is released and the grippers are clamped mechanically.

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15th September ₁₉ 75 -26-? 543 900

The spring pressure is imparted to the grippers 63 with the help of a so-called horseshoe spring 129 (FIGS. 9, 10 and 12), which has a a substantially U-shaped strip of spring metal capable of being in spreading relationship with the grippers and to get out of this relationship again the pressure is communicated to the grippers or removed from them again. The spring 129 is with its legs 130 in essentially on the outside of the gripper. A web 131 of the spring is supported by a tang 133 which is integral with is the web 77 of the slide members 76 and protrudes downward therefrom.

As shown in Figures 9 and 14, two arms 134 are pivotable pivotally mounted by means of pins 135 on the lower legs 79 of the slide members 76. These arms are still pivotally connected by pins 136 to the ends of legs 130 of spring 129, the arms between the side walls 53 and 54 and the outer sides of the spring legs. The spring legs 130 take the pegs 136 with a slip in this way are able to slide laterally on these pegs so that they are in relation to the arms 134 can move back and forth.

The arms 134 are used to pivot the spring 129 on the slide parts 76, so that the spring between two Positions can be swiveled up and down. In one position (Fig. 13 "landing position") the spring rests on the grippers at. In the other position (Fig. 9 "detachment position") the spring is separated from the grippers. To pivot the To bring about a spring between the two positions mentioned,

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are additional plates 137 (Fig. 5 and 6} on the outer surfaces of the side walls 53 and 54 are screwed in the vicinity of the lower end portions thereof. Each plate includes a lip 139, which lies under the lower edge of the adjacent side wall. Generally, the inner edge of each lip 137 is with the inner surface of the associated side wall coplanar. The upper end of each lip, however, has a gate 140 (FIGS. 5,6 and 9), which extends inwards from the side wall and whose beveled, lower edge has a stop surface 141 forms. Furthermore, an inwardly directed stop 143 is provided at the lower end of each lip, which has a beveled, has upper edge serving as a stop surface 144.

When the grippers 63 are in the loading station 64, .is the spring 129 in its placement position shown in Fig. 13, with its legs 130 close to raised surfaces 145 to the The outer sides of the grippers 63 (Fig. 14) are in contact. The raised surfaces 145 are wedged fairly tightly between the legs 130, so that the legs are pressed against the arms 134, which in turn against the inner sides of the side walls 53 and 54 are pressed. Accordingly, the spring 129 is loaded and exerts an inward pressure on the grippers 63 so that their fingers 74 are in the closed position in which the fingers touch each other and a tubular chuck Form for receiving the shaft of a screw 31. When the screw 31 passes through the tube 66 and into the gripper (cf. 13 and 14) is blown, the screw shaft moves between the fingers 74 and separates the fingers somewhat from one another. In this way, the screw shaft is separated from the spring-loaded

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fingers tightly clasped.

When the grippers 63 from the loading station 64 in the direction of the As the introduction station 65 advances, the spring pressure on the grippers is maintained with the exception of the gripper movement the last stretch of the way shortly before the introduction station 65. The fingers 74 thus hold the screw shaft firmly and convey it good guidance and control of the screw during its rapid advance towards station 65. Because of these fixed mounting of the screw, the good guidance is even 'guaranteed when the screwdriver 35 is inclined or horizontal position.

During the last part of the approach movement of the screw 31 into the introduction station 65, the lower ends of the Arms 134 on the stop surfaces 144 of the stop 143 on the Lips 139 and are thereby stopped. This stop causes the arms and spring 129 to move counterclockwise to pivot the pins 135 as the grippers 63 continue to advance. The spring 129 is on this Way with respect to the gripper in their detached position. With the spring 129 stopped and the further advancement Grippers move out the raised surfaces 145 on the grippers between the spring legs 130, so that the spring from is separated from the grippers and no longer biases them into their closed position. Just before the surfaces 145 out of their Get out position between the spring, however, they move between the inner sides 146 of the stop 143 on the lower ends of the lips 139 (see Fig. 5) where they are mechanically clamped. Therefore, the attacks keep the Grippers in their closed position while the screw

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31 is finally brought into the introduction station 65 and placed in the viewfinder 40. The fingers 74 encompass the screw shaft and hold the screw in the viewfinder until the operator begins to screw in the screw.

When the operator presses the screw 31 against the workpiece 33 and the viewfinder 40 moves back to the To initiate return movement of the grippers from the introduction station 65, the lower claws 86 move on the axially extending parts 91 of the lower cam tracks 88 upwards and cause the fingers 74 of the grippers 63 to follow Move it at the top or axially along the screw shaft. The fingers 74 do not grip the screw shaft as tightly when the Grippers 63 are pinched by the stops 163 as if the grippers are closed by the spring 129. Accordingly the fingers 74 can slide up along the screw shaft and the screw can move within the Twist fingers when the fingers are first withdrawn and the cutting edge 39 begins to screw in the screw. The upwardly retracting fingers 74 still grasp the screw shaft until the screw with an or is screwed two turns into the workpiece. In this way, the fingers impart one to the screw for so long Guidance until it has started turning and it is now guided through the viewfinder 40 alone.

When the fingers 74 move upward along the screw shaft begin, the raised surfaces 145 on the grippers 63 begin to move out of their position between the stops 143 (see Fig. 9) to move out upwards. As soon as the surfaces 145 are clear of the stops 143,

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the grippers are no longer pinched and, since the spring 129 is still in its released position, the grippers are

63 free to pivot into its open position and to detach the fingers 74 from the screw (FIG. 10). This pivoting occurs when the half-cones 75 strike the end of the viewfinder 40 for the first time. Once the grapple 63 are open, they remain in this position as long as the fingers 74 are first up along the Withdraw the viewfinder. They are then withdrawn backwards from the viewfinder along a path that is essentially indicated by line 147 in FIG.

The grippers 63 remain open until they pass the last part of their way into the loading station 64. At this point in time the ends of the arms 134 grip the stop surfaces 141 of the Sprues 140 and cause the spring 129 to pivot downward into the contact position and stop there. This occurs when the grippers complete their return movement to the loading station 64 (FIG. 13). During this movement cam surfaces 149 (FIGS. 9 and 13) engage the ends of the raised surfaces 1.45 on the spring legs 130 and close the grippers 63, while at the same time the legs are spread apart so that the surfaces 145 between the Push the legs and put the gripper under spring pressure. Accordingly, the spring is now back on the gripper as soon as they move into the charging station

64 have completed.

With the exception of the feeder 70, all are now basic elements of the device 30 described. The following, summarizing Explanation serves to explain the working cycle of the

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to describe direction as a whole. At the beginning of each cycle, the grippers 63 are in the introduction station 65 by the Inner sides 146 of the stops 143 clamped in the closed position and hold a screw 31 in a telescopic relationship to viewfinder 40 (see FIGS. 2 and 5). In the first step of the cycle, the operator manipulates the tightening tool 35 so that the screw 31 is pressed against the workpiece 33. If then the tool 35 downwards is moved, the viewfinder 40 begins to retreat as shown in Figs. As soon as the viewfinder is withdrawn Has reached position, the cutting edge 39 of the screwdriver presses against the screw head and begins to close Turn so that the screw starts driving.

Moving the viewfinder 40 to its retracted position moves the ring 41 upward from the lower finger 104 the lift rod 105 (compare FIGS. 6 and 7) and gives the lift rod and the ball serving as a valve free for the purpose of an upward movement. Accordingly, the air pressure in line 123 lifts the ball off Cavity 121 from so that air can escape from the line 124. This causes the retraction movement of the rod 94, whereby the grippers 63 begin their upward and backward return movement towards the loading station 64.

During the first part of this return movement, the lower rollers 86 run on the vertically extending parts 91 of FIG lower cam tracks 88 (see FIG. 9) and cause the fingers 74 of the grippers 63 to move upwards or axially on the shaft slide along the screw 31. The fingers 74 hold it

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the screw continues in the viewfinder 40 and ensure that the screw is guided until it starts to screw in in the workpiece 33 has started.

When the grippers 63 continue their upward movement, the raised surfaces 145 slide upwards out of their position between the stops 143 and release the grippers so that they pivot into their open position as soon as the half-cones 75 of the grippers hit the screw head and the hit the lower end of the viewfinder 40 (compare FIGS. 9 and 10). Thus, fingers 74 open so that they disengage from the screw and clear of viewfinder 40 .

After opening the fingers 74, the grippers 63 begin

move backward on track 147 (Fig. 11) away from viewfinder 40, continuing their upward / downward movement, when the lower rollers 86 run on the upwardly and backwardly inclined parts of the lower cam track 88. The grippers then move up into the loading station. When the grippers approach this station, the arms grip 134 on the sprues 140 (see FIG. 11) and become stopped thereby, so that a further upward movement of the spring 129 is prevented. During the last part of the Return movement of the grippers push the surfaces 145 between the legs 130 of the spring 129, as in FIGS. 13 and 14, and in this way apply the spring to the grippers 63. The grippers are thus under tension in held their closed position.

The last phase of movement of the gripper 63 in the loading station brings the probe 126 (Fig. 15) into the line 127, which

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is thereby closed. The signal triggered in this way and forwarded to the feeder 70 now causes that another screw 31 is fed through the tube 66. The screw shoots through under the action of the compressed air the tube 66 and passes between the fingers 74 of the closed grippers (compare FIGS. 13 and 14).

The total return movement of the grippers 63 from the loading station 65 in the charging station 64 takes place at high speed and takes place during that time in which the first screw 31 is screwed into the workpiece 33 (see FIG. 11). Accordingly, a new screw must be placed between the grippers in the loading station 64 before the first screw is fully driven is. However, a certain amount of time is required to move the new screw through the tube 66 into the gripper 63 blow, beginning with the point in time at which the probe 126 closes the line 127. To ensure that the Grippers do not move in the direction of the introduction station 65 until the required "blow-in time" has passed a pneumatic signal (not shown) due to the signal triggered by the probe 126 when the line 127 is closed Timer activated. This timer automatically causes that only after a time interval which is greater than the maximum required "blowing time" is, the cylinder 9 3 comes into action In this way the gripper is prevented from even then cannot be moved towards the loading station 65 if an "advance" signal is generated on line 124. In this way, the grippers are prevented from returning to the introduction station 65 before a sufficient one Time has passed within which a new screw

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can be blown through line 66 into the gripper.

After the first screw 31 has been completely screwed into the workpiece, the operator takes the screwing tool 35 off the screw. As a result, the spring 45 pushes the viewfinder 40 into its advanced normal position (see Fig. 16). The ring 41 engages the lower finger 104 of the lift rod 105 (Fig. 16 and 17) and moves this rod down, thereby causing the screw 115 on the upper protrusion 110 is to push the ball 116 down until it rests on the bottom of the cavity 121. As a result, there is now no air more escapes from the line 124, the advance signal is triggered. Assuming the pneumatic timer has expired, the rod 94 of the cylinder 93 is now advanced, whereby the advance movement of the gripper 63 is initiated to transfer a new screw from the loading station 6 4 to the insertion station 65. During the largest Part of this forward movement, the spring 129 keeps the fingers of the grippers 63 tightly taut around the screw shaft, so that the screw receives reliable guidance and is prevented from jumping up. The lower ones continue to run Rolls 86 along the lower edges of the lower cam tracks 88 during this advancement, causing the screw experiences a generally radially directed movement towards the introduction station 65.

Once the lower rollers 86 in the radial parts 90 of the Beginning to enter the lower cam track 88, one of the rollers 86 engages the sprue 120 (see FIG. 18) and pivots the crank lever 111 clockwise. This raises the lift rod 105 and temporarily moves the viewfinder

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40 in its retracted position so that the screw 31 is below of the viewfinder and can be placed in alignment with it. As long as the viewfinder 40 is withdrawn, the Arms 134 on the stop surfaces 144 of the stops 143 (see FIG. 19) and prevent further movement of the spring 129. As the grippers 63 continue to advance, the surfaces 145 slide out of position between the Spring legs 130 out and get between the inner surfaces 146 of the stops 143. Thus, the spring force of detached from the grippers 63 so that they open freely can if they are then returned to the charging station 64 will. The stops, however, continue to keep the grippers in the closed position while the grippers are in motion move on the last part of their path into the loading station 65.

When the grippers 63 have completed the last part of their advance movement, the lower rollers 86 move behind them Stop 120 (see Fig. 19), whereby the crank lever 111 is released again and turns counterclockwise pivoted. As a result, the lifting rod 105 can move up again return below. At this point in time, the spring pushes the viewfinder 40 down into its advanced normal position and in telescopic relation to the head of the newly supplied screw 31 (compare FIGS. 2 and 19). This is a work cycle ended and the viewfinder 40 and the gripper 63 continue to hold the newly fed screw until the Operator initiates the next cycle by pressing the screw against workpiece 33.

A typical duty cycle needs to be complete

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Expires only about 1.5 seconds. The duration of the working cycle depends of course on the length of the screw 31, the pitch of the screw thread, the speed of rotation of the screwdriver 38 and the response time that the Operator needs to lift the screwdriver 35 upwards after the screw has been completely screwed in. As soon as the screwing tool is lifted off, a new screw is fed to the viewfinder 40 almost immediately and is normally already placed in the viewfinder before the operator puts the screwdriver 35 over the next hole in the Can position workpiece 33. Accordingly, the screws can be screwed in at high speed. the Operating speed of the device 30 is further increased by the fact that the screw through the lower end of the viewfinder 40 and not through a lateral opening in the viewfinder, as is the case with others Machines is the case. When the screw is placed in the end of the viewfinder, the vertical distance between screw heads and cutting edge 39 of screwdriver 38 can be reduced so that the cutting edge presses against the screw head and with it their rotation begins after the viewfinder 40 is withdrawn only over a very short stroke. This short stroke distance The viewfinder also enables better control and guidance of the screw through the viewfinder and the screwdriver blade during the critical phase of the start of screwing. Therefore, even relatively short screws can be driven and the screwing tool 35 can be used in any orientation without the control about .the screws to be screwed in is lost.

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The feeder 70, which is responsible for inserting the screws 31 into the tube 36 and blowing the screws through this tube is shown in Figs. 1 and 20-23. It comprises a housing 160 / which is one of a corresponding drive supported in circulation supply funnel 161, in which a Supply of screws is stored. After leaving the funnel 161, the screws migrate to the end one at a time a downward sloping guide track 163, where a Positioning device 164 detects the first screw in each case and moves it away from the guideway for introduction into the pipe 66 convicted. The tube 66 is held by the housing 160 and leads to the screwing tool via an opening 162 in the housing 35. A suspension device (not shown) is provided between the feeder 70 and the screwing tool 35, which the support of the tube 66 and the various lines 47, 95, 124 and 127 is used, these lines to a guide pneumatic (not shown) control unit in the vicinity of the housing 160.

The positioning device 164 is essentially the same as that disclosed in U.S. Patent Application No. 4,64627, dated April 26, 1974. It includes a pair of fingers 165 (Figs. 21 and 22) that wrap around the first screw in the Enclose guide way 163 and capture it when the Fingers at the end of the guideway, as shown in Fig. 21, are brought into position. The fingers and the one they gripped The screw is then initially guided outwards on a path that is aligned with the guide track 163. This is followed by an upward movement at right angles to this into a position (compare FIGS. 20 and 22) and aligned with the inlet end of tube 66. After

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With your fingers open to release the screw, sweep fingers back to track 163 to grip the next screw.

The mechanism for moving the fingers 165 back and forth and for opening and closing the fingers is in the previous one mentioned patent application and need not be explained here in detail. Suffice it to say that these movements take place as a function of the forward and backward pivoting of a linkage 166 (FIGS. 20 and 21), which is connected to the fingers 165 and is attached to an oscillating shaft 167. The latter is rotatable in the housing 160 stored and moves back and forth when the rod 169 a pneumatic cylinder 170 is advanced and withdrawn. The cylinder 170 is fixed in the housing 160.

According to a further feature of the invention, the pass Finger 165 the screw 31 a head 171 (FIGS. 20 to 23), which then brings the screw into the tube 66 and the end of this tube closes so that the screw by means of compressed air, which through the head 171 into the tube is introduced, can be blown through the tube. The head 171 is mounted in such a way that it emerges from a first Position (Figs. 20 and 22) in which he receives the screw from fingers 165, in a second position (Figs. 21 and 23), in which he brings the screw into the pipe, can be moved. When moving between these positions, the runs Head 171 on a track, the upper portion of which coincides with the track on which fingers 165 run when they move move over the end of their advance stroke and then in the opposite direction through the first part of their return

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hübes.

As shown in Fig. 22, the head 171 comprises a cylindrical one Member which can slide in a recess 173 of an arm 174 for the purpose of limited up and down movement is stored. The head is held in the recess 173 by upper and lower snap rings 175, over the head is one The coil spring 176 is pushed and clamped between the underside of the arm 174 and the lower snap ring so that Me pushes the head downwards, but still allows the head to slide upwards in the recess 173.

A bore 177 (FIG. 22), in which a tubular fitting 179 is rigidly attached, runs axially through the head 171. A holding device in the form of an elastically flexible sleeve 180 made of rubber, plastic or the like is in the Bore 177 and slid over the lower end of the armature 179, with the lower end of the sleeve 180 down over the end the armature 179 also runs. When the head 171 is in its upper position, shown in Figure 22, the fingers place 165 the head of a screw 31 in the lower end part of the Sleeve 180 when fingers move away from track 163 and reach the end of their forward stroke. The sleeve 180 is dimensioned so large that it grips the screw head elastically and in this way holds the screw in place afterwards fingers 165 have opened and withdrawn from their position below head 171.

When fingers 165 retract, arm 174 will follow moved down so that the head 171 and that grasped by it

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Screw 31 downwards in the direction of the receiving screw The end of the tube 66 can be moved. A rigid pipe extension 181 (FIG. 22) is pushed into the pipe 66 and anchored to the housing 160 by means of an arm 183. if when the head 171 moves downward, its lower end rests against an O-ring 184, which is at the upper end

of the extension 181 is arranged. In this way, the head 171 seals the upper end of the tube 66, as shown in Fig. 23, away. At the same time, the sleeve 180 places the screw 31 in the extension 181. Compressed air is then supplied via a line 185 (FIG. 20) is inserted into a passage 186 (FIG. 23) that extends through the fitting 179. The air pushes you Screw out of the elastic sleeve 180 and shoot it through the tube 66 (compare the dashed illustration in FIG. 23) at high speed into the grippers 63 waiting in the loading station 64. The inner diameter of the tube 66 corresponds almost exactly to the diameter of the screw head. Therefore, the compressed air can easily blow the screw through the pipe. As the tube made of flexible plastic or the like the screw is unlikely to become jammed in the pipe. If the screw head is something is too big or has a protruding burr, the material of the pipe will give way, so that the screw through the Pipe can pass through. Should the screw nevertheless get stuck in the pipe, the spring 176 on the head releases after, when a corresponding air pressure builds up in the pipe 66. The spring 176 then allows the head to be in the Recess 173 moves upward away from the extension 181, so that the pressure relaxes. Thus, the spring prevents the build-up of such high air pressure that the screw with Force being blown through the pipe and possibly the

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Operator injured.

After the screw 31 has been blown through the pipe 66, the arm 174 is moved upwards and the head 171 is moved from the extension 181 into the position shown in FIGS withdrawn. The fingers 165 then place a new screw in the sleeve 180, thereby preparing the next cycle is.

To move the head 171 up and down, the arm 174 is connected to a block 187 (FIG. 22) which in turn moves up and down Is slidably mounted on two guide rods 189. These Guide rods are attached to the housing 160. The postponement of the head 171 takes place depending on the actuation of the cylinder 170. A linkage 190 (Fig. 20) is rigid with the Rocking shaft 167 connected and pivotably articulated to a second linkage 191, which to the guide rods 189 runs towards. The linkage 191 is pivotably connected to an arm 193 which projects radially from a hub 194 (FIG. 22). The hub is mounted in such a way that it can swing back and forth on a pin 195 protruding from the housing. With the Hub 194 is rigidly connected to a second, radially protruding arm 196, which is articulated to one end of a linkage 197, the other end of which is pivotably connected to the arm 174. When the rod 169 is advanced to rotate the rocker shaft 167 clockwise and the fingers 165 from the head Pulling off 171, the rods 190 and 191 and the arm 193 pivot the hub 194 in a clockwise direction. The arm 196 and that Linkage 197 thus move the head 171 downwards. The head 171 and fingers 165 move together over one a short distance down. Then move

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the fingers at right angles to the head and in the direction of the guideway 163, where they come free from the head 171.

When the rod 169 is withdrawn, the head 171 begins its upward movement as the fingers 165 begin to move outwardly away from the track 163. As soon the head is free from the fingers, the latter start their upward movement and spend the screw 31 into the sleeve 180. The linkage 166 is designed in such a way that the fingers 165 with respect to the head 171 during the time in which both the fingers and the head are moved upwards, make an accelerating movement. To this Way, the fingers "overtake" the head and allow the screw to be placed in the sleeve 180 in time which the head and fingers each reach the end of their stroke.

The following is a description of the mode of operation of the adjuster 70 with reference to the operation of the screwing tool 35 described. At the beginning of a working cycle, the head 171 is in its upper, retracted position and the Fingers 165 hold a screw 31 in the sleeve 180 (cf. Figures 20 and 22). If the viewfinder 40 moves back after the screw has been pressed against the workpiece 33, that will be Signal, which is generated in line 124 to trigger the return movement of grippers 63, continues to be used initiate the advancement of the rod 169 in the cylinder 170. Accordingly, fingers 165 retract during the Head 171 migrates downwards and produces the aforementioned seal on the extension 181 of the tube 66 (compare FIGS. 21 and 23).

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When the grippers 63 return to the loading station 64 and the probe 126 closes the line 127, this is the result Signal resulting in the line activates the pneumatic timer and simultaneously causes compressed air is introduced into line 185. Now the screw 31 in the sleeve 180 is out of this and through the tube 66 blown through and transferred to the waiting gripper 63. After a sufficient blowing time has passed, the runs pneumatic timer and closes the flow of compressed air through line 185. If then the signal in the line 164 is generated to advance the gripper 63, the rod 169 of the cylinder 170 is caused to retract. This results in an upward movement of the head 171 and a simultaneous advancement of the fingers 165, whereby a new screw is placed in the sleeve 180.

In FIGS. 24 to 26, a modified device is shown in accordance with of the invention shown, with parts that with parts of the. described device 30 are analogous, the same, however have reference numerals provided with a prime. The modified embodiment includes a feeder 70 'which is shown in FIG Is able to feed screws 31 'of such size and shape, that these screws can overturn in the pipe 66 'and can be blown with their head first into the gripper 63 '. This overturning of the screws is prevented by that they are received by a cartridge 210 while being blown through the tube 66 '. After removing the Screw in the loading station 64 ', the cartridge 210 is returned through the tube 66' under vacuum.

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In particular, the cartridge 210 comprises an elongated, tubular shape Element made of resilient material with a widened upper end 211, the outer diameter of which is exactly corresponds to the inner diameter of the tube 66 '. When the head 171 'is in its upper, retracted position, the cartridge 210 is within a bore 213 (Fig. 24) in the armature 179 ′ and held there releasably in an elastically flexible element, for example in an O-ring 214. In this position of the cartridge, the fingers of the transfer mechanism place the screw in the lower, open one End of the cartridge with the screw head gripped and held in place by the elastic material.

When the head 171 'is lowered, the cartridge 210 and the screw 31' it engages are positioned as shown in FIG. 24, with the cartridge lying immediately above the extension 181 'of the tube 66'. When compressed air is introduced into the line 186 ¹ , the cartridge is blown out of the bore 213 and shot into the tube 66 'so that it carries the screw through the tube into the loading station 64'. The length of the cartridge relative to the inner diameter of the tube 66 'is dimensioned such that the cartridge cannot overturn within the tube. In this way, the screw is transferred to the loading station with its shaft first.

When the cartridge 210 is at the loading station 64 '(see Fig. 26) arrives, its lower end strikes the upper sides of the fingers 74 'of the gripper. This way the cartridge will stopped abruptly. However, the screw 31 'continues to move due to its inertia. Accordingly, the flies

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Unscrew from the cartridge surrounding it and place itself between fingers 74 '. When the pneumatic timer expires, is in the line 185 ", the passage 186 'and the Tube 66 'creates a vacuum (negative pressure) so that the cartridge 210 is sucked back through tube 66 'and returns into bore 213 before head 171' is withdrawn upward to allow a new screw to be inserted into the cartridge.

609819/0297

Claims (1)

m - 150 15th September 1975 Patent claims: I./Device for automatically screwing in a screw or another threaded fastener in a workpiece with a motorized in rotation Screwdriver and a telescopic viewfinder above the latter, which counteracts the action of an elastic pretension from an advanced normal position in which its lower end over the screw or the like. got into a withdrawn Position is movable, characterized in that a feed device (50) is provided, which is to be rotated The screw (31) feeds in automatically and brings it into the screwing position, aligned with the lower end of the viewfinder (40), and that the feed device (50) adjusting members (41, 86, 104, 105, Ulf 120) are assigned which the viewfinder (40) in front move the screw (31) into the retracted position and move it into its normal position Let it return as soon as the screw (31) is in the screwed-in position. 2. Apparatus according to claim 1, characterized in that the feed device (50) has two opposite, movable back and forth between a closed and an open position, the screw (31) holding or releasing gripper (63) which are mounted on a carriage (76), the in turn between a loading station (64), in which the grippers (63) are loaded with the screw (31), and a Bringing station (65), in which the grippers (63) bring the screw (31) into the screwing position, movable is, and that the carriage (76) when entering the introduction station (65) by stop means (86, 120) and by am Lifting means (105) attacking the viewfinder (40) triggers the pivoting of the viewfinder into its retracted position. - 2 - 609819/0297 A 41 391 m ^ Γ 25439Π0- m - 150 September 15, 1975 - 3. Apparatus according to claim 2, characterized in that the stop means have a roller (86) mounted on the carriage (76) and the lifting means is operated by the roller (86), am Include viewfinder (40) engaging lever linkage (105, 111). 4. Apparatus according to claim 2 or 3, characterized in that the lifting linkage actuated one of the roller (86) Lever (111) and a between this lever and the viewfinder (40) arranged lifting rod (105) comprises, and that between Lifting rod (105) and the viewfinder (40) a dead gear exists such that the viewfinder (40) between its normal and its retracted position is displaceable without moving the lever (111). 5. Apparatus according to claim 2, 3 or 4, characterized in that the lever (111) has a signaling device (116, 124) carries that when the lever (111) does not move with the displacement of the viewfinder (40) between its normal and withdrawn position between a first and a second state can be switched back and forth, but in the same way The state remains when the viewfinder (40) is pulled back from the lever (111) and the lifting rod (105) from normal to retracted Position is shifted, and which initiates the to and fro movement of the grippers (63) between the stations (64, 65), when it is toggled between the two states. 6. Apparatus according to claim 5, characterized in that the signaling device is a valve arranged on the lever (111) (116, 121) includes that when the viewfinder (40) is moved back and forth by the lever (111) there is no accompanying movement 609819/0 2 m - 150 September 15, 1975 - · 3 "" - issued, opened and closed, but unchanged remains when the viewfinder (40) by the lever (111) and the lifting rod (105) in the retracted position is moved. 7. Device according to one of the preceding claims, characterized in that the viewfinder (40) through the Pressing the screw (31) against the workpiece (33) releases the screw and the movement caused by it in its retracted position via control and drive means (116, 124, 93) causes the feed device (50) into the Loading station (64) to receive a new screw (31), while the subsequent return movement of the Viewfinder (40) in its normal position the advance of the feed device (50) loaded with the new screw (31) into the Infeed station (65) triggers. 8. Apparatus according to claim 7, characterized in that the control means has a valve ball (116) and one between the latter and the viewfinder (40) arranged lifting rod (105) and the lifting rod (105) during the reciprocating movement of the viewfinder (40) the opening and closing of the valve ball (116) triggers. 9. Device according to one of the preceding claims, characterized in that the gripper (63) so from the carriage (76) are guided that they are on a substantially radial path to the viewfinder (40) in the introduction station (65) and the introduction station (65) on a path running essentially axially parallel to the viewfinder (40) leave again. 6098 19/0297 Ub A 41 391 m ^ 25439Π0 m - 150 September 15, 1975 - £ "- 10. Device according to one of the preceding claims, characterized in that the carriage (76) carries rollers (86), which run in cam tracks (88), of which a first part (90) is essentially radial and a second part (91) is in the runs essentially axially parallel to the viewfinder, and that the rollers (86) when the gripper (63) enters the introduction station (65) in contact with the first part (90) of the cam track and in engagement with it when it leaves this station the part (91) of the cam track are held in engagement. 11. Device according to one of the preceding claims, characterized in that the grippers are assigned a spring (129) is that it keeps closed when leaving the charging station (64) that means (134, 143, 145) the spring pressure during the last part of the infeed movement of the grippers (63) in the introduction station (65) so that further means (146) on the carriage (76) during this last movement piece and during the dwell time of the grippers in the Jf'p se
bring station (65) / continue to hold in the closed position, and that the clamping of the grippers (63) when leaving the insertion station (65) is releasable so that the grippers can open freely with their axially parallel movement with respect to the viewfinder (40). 12. Device according to one of the preceding claims, characterized in that the on the shaft of the screw (31) gripper (63) resting on the screw shaft while the screw is beginning to be screwed in and at turn the screw further into its open position. 609819/0297 A 41391m ^ 25439Π0 m - 150 September 15, 1975 - * f- 13. Device according to one of the preceding claims, characterized by means (149) which when the gripper (63) runs back into the loading station (64) the spring (169) again bring it into contact with the gripper (63) and thereby hold it in the closed position. 14. Device according to one of the preceding claims, characterized in that the gripper is in the closed position holding spring (129) is a horseshoe spring, the legs of which can be brought into and out of engagement with the grippers. 15. Device according to one of the preceding claims, characterized in that the charging station (64) with the end of a Pipeline (66) is connected and at the end of the line (66) facing away from the charging station (64) a screw (31) engaging device (171) is provided which is in sealing contact with the pipe end can be brought, and that the device (171) with a compressed air line (185) is connected to the supply of the screw (31) in the charging station (64) blowing compressed air. 16. The apparatus according to claim 15, characterized in that the device (171) has a member (180) for 'detecting a Includes screw (31) and is reciprocable with respect to an end piece (181) of the conduit (66), and that the device (171) is assigned a positioning mechanism (164) for introducing a screw (31), if the means (171) is remote from the end of the conduit (66). 17. Apparatus according to claim 15 or 16, characterized in that that the device (171) has a bore (177), - 6 - 6 09819/0 297 A 41 391 m. * ^ 25439Π0 15th September 1975 which is aligned in all positions of the device with the line (66) is, and that an elastically flexible sleeve (180) is arranged in the bore, which via a screw (31) can be pushed and thereby holds it in place with a resilient grip. 18. Device according to one of the preceding claims, characterized in that a cartridge (210) is provided, the outer diameter of which is at most slightly smaller than the inner diameter of the line (66 ¹ ), that this cartridge (210) resiliently from the device (171 ¹ ) can be fixed and a screw (31 ¹ ) receives that the cartridge together with the screw (31 ') detected by it out of the device (17I ¹ ' and through the line (66 *) can be blown through that on the one in the ^{Stop means (74 1} ) are provided at the end of the line (66 ') located at the loading station (64 *), which stop the incoming cartridge (210), the screw (31 *) being separated from the cartridge due to its inertia and being removed from the line ( 66 *) emerges, and that the line (66 ¹ ) can be connected to a vacuum source, whereby the cartridge (210) can be sucked back ^{through the line (66 1} ) to the device (171 ^1). 19. The apparatus according to claim 18, characterized in that the cartridge (210) by an elastically resilient element (214), which is about the cartridge is slidable, can be held in the device (171 ¹ ), and the cartridge (210) has a tubular end which can be ^{slipped over the screw (31 1} ). 20. Device according to one of the preceding claims, characterized in that the device (171) by spring means (176) can be pressed against the end of the line (66) and itself "- 7 - bü9ö19 / U2 m - 150 September 15, 1975 - ^ r- automatically lifts off the pipe end when in the pipe (66 ') an unacceptably high pressure builds up. 609819/0297