EP0039949B1 - Self-acting screw feeding device - Google Patents

Abstract

Apparatus automatically feeds screws to a screw-in tool of a screwing mechanism, especially a rapid constructional screwing mechanism. To simplify the feed of screws, a feed channel is provided which is arranged to provide relative movement between it and the screwing mechanism in the direction of the axis of the screwing tool. The screws gravitate along the channel. A container is fixedly connected with the screwing mechanism. A spring biases the feed channel and the screwing mechanism apart (up to a stop) until the screw pin is disengaged above the screw head. To screw-in the screw, the screwing mechanism is displaced downwardly toward the feed channel.

Description

The invention relates to a device for the automatic feeding of screws from a container to the screw pin of a screwdriver, in particular a quick-action screwdriver, with a movable relative to the screwdriver in the direction of the central axis of the screwdriver, made of two spaced apart, related to the container and thus also in relation to the screwdriver by means of wall parts guided by means of a guide device, via which screws can be fed from the container to the screw pin of the screwdriver, and with a spring switched on between the feed channel and the screwdriver, both of which press as far apart as possible until they stop the screw pin is loosened above the screw head.

For screwing in screws, e.g. B. of wood screws in wooden panels or wooden strips, especially for fixing chipboard on floors, quick-action screwdrivers are used, with which the single screw can be screwed in mechanically without a screwdriver (manual operation). Such a quick-action screwdriver has a similar shape to a hand drill and has an opening at the front end into which a screw pin can be inserted and fastened, which screw pin is designed at its free end such that a Phillips-head screw, e.g. B. can be screwed in. While the screw is being screwed in, the drive of the quick-action screwdriver is coupled to the screwdriver pin or screw pin protruding from the quick-action screwdriver, and after tightening the screw, the coupling between the drive and the screw pin is released, whereby the screw pin remains stationary. against which the drive motor turns even further. As mentioned, Phillips head screws are mostly used as screws.

In the past, the operator placed each screw individually on the free end of the screwdriver pin or screw blade; this was very time consuming and the number of screws screwed in per unit time was therefore low. To accelerate this process, devices have been developed in which the individual screws are automatically fed to the screwdriver pin. In such an embodiment, the screws are inserted into a belt webbing which is wound up and placed in a drum which can be fastened to the quick-action screwdriver. The belt is designed as a U-shaped plastic belt, the leg ends of which are slotted, into which slots the screws are inserted, in such a way that each screw runs parallel to the belt web and perpendicular to the legs between the latter. The belt is then guided out of the magazine, which is designed as a drum, to an automatic feed device, into which the belt is inserted and which is fastened to the quick-action screwdriver. The device has a first part, which is directly on the hallway during the scrubbing process. B. is put on; a second part, which is guided relative to the first part, is firmly connected to the quick-action screwdriver and between the two parts there is a spring which tries to push the two parts apart. When the screw is screwed in, the two parts are moved against each other against the pressure of the spring, causing the screw to be screwed down into the plank.

In general, up to approx. 150 screws with one magazine filling can be processed with such devices. The operation of the device is very simple and the work, i.e. screwing in, can be carried out quickly. It is clear that equipping the belt with the individual screws makes the price of each screw processed in the end more expensive if one takes the price of each individual screw as a basis. In addition, because of the elasticity of the belt, the fastening of the individual screws in the belt ultimately means that the head of each screw must be pushed through the slots across the legs, which causes the legs to bend open - naturally not "tight", which creates the danger that individual screws in rough operation on the construction site can fall out before processing and, depending on the transport conditions, also during transport and are therefore lost. If, for example, a heavy part falls on the screw belt or on the container in which the screw belt is transported, the screws contained in the belt in question are at least partially lost or must be screwed in individually.

From FR-A-1 424 671 a quick-action screwdriver and a device for feeding screws to the screw spindle of the quick-action screwdriver of the type mentioned at the outset are known, which is designed as a compressed air device which is connected to an adapter via a spindle and a spring connected therebetween which feeds the screws of the screw spindle from the side. A container is provided on the screwdriver, in which there is a feed trough which is formed from two wall parts which are kept at a distance and to which a flexible hose connects, through which the screws are individually fed to the adapter. Since the screwdriver is designed as a pneumatic screwdriver, it is not suitable for being quickly transported from one assembly site to another assembly site at a construction site. Because the screws are fed to the screw spindle via the bendable hose, which can lead to congestion, or at least to very rapid wear of the hose, the device is ver Relatively complicated and fragile and therefore not ideal for construction sites: it is not "suitable for construction sites". The object of the invention is to provide a high-speed screwdriver of the type mentioned, in which commercially available screws packaged in packs of approx. 500 etc. can be used directly without the use of a belt or a similar device, a commercially available one with electricity operated quick-action screwdriver can be releasably connected to the feed device. Furthermore, the device should be suitable for construction sites, that is to say can be used on construction sites where stationary facilities are not expedient.

This object is achieved in that a tensioning device is connected to the container, by means of which the screwdriver can be releasably clamped to the container, that the wall parts end directly at the screw region of the screw pin and a mounting foot for setting up the wall parts and thus the device on the Have floor that the distance between the wall parts is expanded in the area of the screwing point so that a screw head fits through, and that in the area of the screwing point a permanent magnet is provided, which aligns a screw in the area of the screwing point immediately below the screw pin in the screwing direction.

The device according to the invention can mainly be used only for screwing in screws downwards. Horizontal screwing and such an upward is not possible in this form because of the arrangement and design of the container for receiving the screws and the design of the feed trough. Nevertheless, the advantages of the device can be optimally used in such screwing work in which screws have to be screwed in downwards or slightly obliquely to the vertical, for example when fastening chipboard to the floor or similar screwing cases in joinery shops, etc. As is known, this work comprises a very large part the work to be carried out with quick-action screwdrivers. In any case, however, with such screwing work running vertically downwards or screwing work running slightly obliquely, a significant saving in costs can be achieved in comparison with the known devices, in particular during later use.

Because the screwdriver itself can be easily detached from the device, since there is only one connection or coupling in the form of the clamping device - in contrast to the device according to FR-A-12 42 671, in which two couplings must be provided - , and that, in addition, all components are easily accessible for maintenance, the device according to the invention can be used particularly well on such construction sites, in which the number of square meters of the floors to be covered is comparatively small. The device can be optimally used, especially in old buildings in which floor areas often measure barely more than 50 square meters and in which new planks have to be inserted in the course of a renovation.

Further advantageous refinements and improvements can be found in the subclaims.

The operation of the device is as follows: screws that are not stored in a magazine, that is, screws that are commercially available in packs of 500, are filled into the storage container, in which they are randomly mixed up. By means of the feed trough which is generally arranged at the bottom of the container, the screws are initially arranged spatially in such a way that the screw heads slide on the upper edges of the feed trough while the screw body hangs down due to the force of gravity. Alignment of the screws is further supported by the movement of the feed channel together with the quick-action screwdriver relative to the container. In other words, if the screwdriver is pressed down relative to the feed trough during the screwing-in process, then a certain vibration of the screws inside the container inevitably occurs, as a result of which the screws or at least a few with their screw body get between the wall parts of the feed trough. This process is further supported by pressing the screwdriver down frequently. The screws then slide down towards the screw pin, to which they are fed individually and in the correct position after passing through a separating device. Alignment of the screws in the area of the screw pin and holding them in the area of the screw pin (this is necessary because the feed trough is expanded in this area so that the screw heads would simply fall through) is done using a rod-shaped permanent magnet that is directly outside the range of motion is aligned and arranged parallel to the direction of movement of the screw pin and, as already mentioned above, aligns the individual screw by magnetic attraction. This causes the screw head to lie exactly under the screw pin and by pressing down the quick-action screwdriver - the container and the wall parts or components that have the feed channel rest on the floor with a support - the screw can be screwed in while the quick-action screwdriver drive motor is running. Because of the spring, the feed trough is moved again when the quick-action screwdriver is raised so that it gets under the bottom of the container; a new screw gets into the area of the screw pin and can be screwed in again. Manual feeding of screws to the screw pin is then no longer necessary.

The invention and further advantageous refinements of the same are to be explained and described in more detail with reference to the drawing, in which an exemplary embodiment of the invention is explained and described.

• Figur 1 einen Teilschnitt durch den Schnellbauschrauber gemäß der Erfindung, gemäß Linie I-I der Fig. 2,
• Figur 2 einen Schnittansicht der Vorrichtung nach Fig. 1 gemäß Linie 11-11,
• Figur 3 eine Schnittansicht gemäß der Linie 111-111,
• Figur 4 eine Schnittansicht gemäß der Linie IV-IV, der Fig. 3,
• Figur 5 eine Schnittansicht gemäß der Linie V-V,
• Figur 6 eine Ansicht in Pfeilrichtung A der Fig. 5,
• Figur 7 eine Schnittansicht der Anordnung gemäß Linie VII-VII der Fig. 6.

It shows :

• 1 shows a partial section through the quick-action screwdriver according to the invention, according to line II of FIG. 2,
• FIG. 2 shows a sectional view of the device according to FIG. 1 along line 11-11,
• FIG. 3 shows a sectional view along the line 111-111,
• FIG. 4 shows a sectional view along the line IV-IV, FIG. 3,
• FIG. 5 shows a sectional view along the line VV,
• FIG. 6 shows a view in the direction of arrow A in FIG. 5,
• FIG. 7 shows a sectional view of the arrangement along line VII-VII of FIG. 6.

1 shows a partial section of a device according to the invention. One can see a quick-action screwdriver 10, which is clamped vertically downward in a clamping element 14 with a clamping element 12 projecting downwards. The clamping element 14 is detachably fastened on the upper side of a carrier 16, which carrier 16 is fastened by means of a welded connection 18 to a container 20, perpendicular to the front side wall 22 thereof (cf. FIG. 4). The container 20 has an approximately rectangular shape and, as can be seen from FIG. 3, is provided at the bottom with obliquely downwardly inclined bottom walls 24 and 26, which not only run obliquely towards the center line, but also from the rear wall 28 front to the front side wall 22. The two bottom walls end in a bend 30 or 32, which leave a distance D between them, protrude through the two opposite wall parts 34 and 36 or protrude between the two bends 30 and 32. The two wall parts, of which only the wall part 34 can be seen in FIG. 4, are by means of a bar 38 indicated on the left in FIG. 4 and a further bar 40 (see FIG. 2, which, depending on the production, with the two wall parts can be formed in one piece) held at a distance, which distance is d. This distance d is larger by a certain amount than the screw body 42, but smaller than the screw head 44, so that, as can be seen from FIG. 4, the screw head slides on the upper edge 46 of the wall parts. The upper edges of the wall parts thus together form the feed channel for the individual screws. This feed trough, which is also to be designated by the reference number 46, is inclined parallel to the bottom walls 24, 26 towards the screwing area, so that the individual screws can slide down the inclined plane while working.

The inclined plane widens in the area of the screw-in point 48 in such a way that a circular passage 50 is formed, into which the feed channel 46 or the intermediate space 52 opens out between the wall parts 34, 36, which area 50 is so large in diameter that the Heads 44 of the screws can fall through. In the area of the screw-in point 48 there is a rod-like permanent magnet 54 which is oriented in the screw-in direction and which, as shown in FIG. 4, with its magnetic attraction pulls a screw 42/44 and aligns it precisely with the fast-action screwdriver 16. It can be seen from FIG. 4 that a screw pin 56 is clamped in the clamping element 12, the free end of which is provided with a screwdriver attachment 58 which is adapted to the slot or the cross recess on the screw head. The permanent magnet 54 is aligned such that the screw 42 adhering to it is aligned with its axis with the axis of the screw pin 56.

The device can be seen in FIG. 4 before the screwing process begins. To screw it in, the screwdriver 10 must be pressed in the direction of the arrow F, the container 20 being moved over the wall parts. So that this can be carried out optimally, a holding wall 60 is fastened to the container 20 parallel to the wall parts 34, 36, on the free end of which a guide bar 62 is fastened parallel to the screwing direction, which ends in a c-shaped groove 64. On the bar 40, in turn, a T-shaped shape 66 is formed, which is guided in the recess 54 and this slides. Also attached to the carrier 16 is an angled guide element 68 which projects into the path of the screw pin 56 and encompasses it, such that the screw pin engages through an opening 70 in the guide element. Between the carrier 16 and a stop 71 attached to the bar 40 or to the wall part 36, a compression spring 72 is arranged, which is designed as a helical spring and engages around a pin 74 which is also used for guidance. The guidance of the wall parts or onto the container and the quick-assembly screwdriver therefore takes place on the guide bar 62 or between the two bevels 30 and 32.

It can thus be seen that the two components, container with quick-action screwdriver and retaining wall 60, can be displaced relative to the pressure of the helical spring 72 relative to the wall parts 34 and 36 in the direction of arrow 11, the edge 76 of the wall parts opposite the edges 46 being vertical in the area of the screw-in point to the screwing direction and in the area of the feed channel 46 parallel to the latter, whereby the latter areas and the feed channel form an acute angle a with the horizontal. The edges 76 therefore have an inclination to the horizontal so that the device can be tilted or inclined. The angle a at the feed trough must not be too small, otherwise the screws will slide down due to the tear to be overcome exercise force between the edges 46 and the screw heads 44 is prevented; the angle a therefore results simply from the friction between heads 44 and edge 46. Of course, the feed trough need not be parallel to the edges 76; it has proven to be expedient for the manufacture of the wall parts 34, 36. An adjusting screw 78 is screwed onto the underside of the carrier 16 in the region of the guide element 68, a helical spring 80 being provided between its head and the guide element 68. The screw 80 serves to set the maximum path between the fully deflected position (relaxed spring) and the fully screwed-in position (not shown in the figures).

2 shows a separating device which is known as such from VDI 3240. To form this separating device, a 1-shaped support element 82 is fastened to the wall part 36; On the outer surface of the opposite wall part 34, a sheet metal plate 84 is provided, on which guide pins 86 and 88 are fastened, which guide pins extend through both wall parts 34, 36 and are firmly connected to a further guide plate 90 on the other side of the wall part 36. The guide plate 90 partially protrudes into the holding wall 60 and so that this is possible, the holding wall 60 has a recess 92, which is formed by pressing out a tab 94, which tab forms an inclined surface 96, which together with the Holding wall 60 presses the guide plate 90 together with the guide rods 86 and 88 transversely to the wall parts 34, 36 in the direction of arrow F 1. Separating pegs 98 and 100 are located between the guide pegs 86 and 88. A tension spring 106 is arranged between an extension 102 on the guide plate 84 and a peg 104 on the element 82, said tensioning spring 106, which separates the separating device and in particular the two holding or guide plates 84 and 90 always applied in the opposite direction of the arrow F 1, so that the guide plate 84 always abuts the outer surface of the wall part 34. The separating pin 98 is now dimensioned such that it only slightly projects beyond the inner surface of the wall part 36, so that there is sufficient space between the inner surface of the wall part 34 and the end of the separating pin 98 for the passage of a screw. In the position shown, the separating pin connected to the plate 84 is designed such that it covers the distance d, so that in the position shown, a screw comes to rest in the space between the two separating pins and is held there. When the quick-action screwdriver 10 is pressed downwards, the tab or the inclined surface 96 runs onto the guide plate 90 and presses it in the direction of the arrow F1, so that the free end of the separating pin 98 at least partially gets into the inner wall of the wall part 34, whereas the free end of the separating pin 100 practically retracts into the inner surface of the wall part 34 and thus the screw lying between the two separating pins clears the way down to the area 48. Then the screw pin is still in the area 48 in the screwed-in position and when the screwdriver is released, the separating device moves into the position shown in FIG. 2; the screw located between the pin 100 and the area 48 (which previously touched the screw pin) reaches the permanent magnet 54, whereas a new screw slides into the area between the two separating pins; the separation pin 100 prevents it from sliding further. An approximately U-shaped bracket 108 is formed on the guide plate 84, which in the rest state, that is to say in the position shown in FIG. 2, reaches into the interior of the area 48, thereby locking the separating device as soon as a screw sticks to the magnet, so that a second one Screw cannot slip.

The wall parts 34 are dimensioned such that they lie below the base 24 in the state shown in the figure (relaxed coil spring 72). If the screwdriver 10 is pressed down together with the carrier and the container 20, the upper edge or the upper edge 46 of the wall parts 34 or 36 passes over the bottom 24, as can be seen for example from FIG. 3 , is shown in a position as ^g after completion of the screwing-ung forms. The upper edges 46 of the two wall parts 34 and 36, as can be seen, clearly protrude from the bottom parts or bottom walls 24 and 26, respectively.

The relative movement of the wall parts 34 and 36 has the consequence that the front wall 22 must be provided with a slot. This slot is visible in FIG. 5 and is designated by the reference number 10. So that in the relaxed state, that is to say in the state shown in FIG. 4, the screws cannot fall out through the slot to the front, an extension 112 is fastened to the wall parts and is guided in a groove 123 in the interior of the wall 22 and in the region the edges or the feed trough 46 has an opening 114 which virtually forms a bridge passage and is dimensioned such that the screw heads 44 can easily slip through. This extension can also be called a slide.

So that no screw jam forms in the area of the slider 112, a boom spring-like steel spring 116 is provided on the inner wall or inner surface of the front wall 22, the free end 118 pointing towards the upper edge 46 is chamfered, so that each screw is also suitable Form is preceded.

In summary, the mode of action The arrangement can be described as follows: As many screws as you like can be inserted into the container as the container can hold. The screwdriver 10 is then pressed down for the first time, the container shifting against the wall parts 34 resting on the floor until the upper edge of the wall parts 34, 36 projects beyond the bottom walls 24, 26.

It can be assumed that the first time at least one screw with its screw body has fallen between the two wall parts and slips on the edges 46 towards the separating device. Then the screwdriver is released or raised, whereby the wall parts 34, 36 are pressed down due to the spring force 72. By reattaching the fast screwdriver 10 with the wall parts 34 on the floor, there is a shaking effect, as a result of which further screws with their screw bodies fall between the wall parts 34, 36 and slip under. When the screwdriver is then fully depressed, the first screw comes between the two separating pins 98 and 100, and a second screw lies against the separating pin 98 from the outside; Instead of a single separating pin 98 or 100, two can also be arranged one above the other (see FIG. 4, where this was considered expedient because of a better alignment of the screw bodies 42). After releasing again, the quick-action screwdriver moves together with the screw pin 56 in the direction of the arrow F1, so that the free end 58 of the screw pin 56 comes to lie above the feed channel 56. As a result, the screw that has passed the separating pins 100 can slide against the permanent magnet 54, on which it is aligned so that its axis is aligned with the axis of the screwing pin 56. By pressing the screwdriver 10 down and by striking the free end 58 on the upper surface of the screw head 44, the free end 58 engages with the slots or the slot of the screw head, so that the screw can be screwed downward in the direction of arrow F into the ground . After letting go of the screwdriver 10, the next screw comes to rest against the permanent magnet and the screwing-in process can be repeated.

Claims (7)

1. An apparatus for the automatic feed of screws (42, 44) from a container (20) to a screw bit (56) of a screwing device (10), in particular of a high speed screwing device, having a feed channel (46), which is movable relative to the screwing device (10) in the direction of the central axis of the screwing device (10), is formed by two wall parts (34, 36), which are maintained at a distance from each other, and are guided by means of a guide device (60, 62, 64, 66) relative to the container (20), and thus also relative to the screwing device (10), and by way of which channel, screws (42, 44) can be fed from the container (20) to the screw bit (56) of the screwing device, and having a spring (72), which is connected between the feed channel and the screwing device and presses the two parts away from each other until they reach an abutment so that the screw bit (56) is in the released state above the screw head (44), characterized in that the container (20) is connected to a locating fixture (14), by means of which the screwing device (10) can be rigidly clamped to the container (20) so as to be detachable, in that the wall parts (34, 36) end directly at the screwing region of the screw bit (56) and have a mounting base for assembling the wall parts (34, 36), and thus the apparatus, on the floor, in that in the region of the screw place the distance of the wall parts (34, 36) is widened so that a screw head passes through, and in that in the region of the screw place a permanent magnet (54) is provided, which in each case aligns a screw in the region of the screw place directly below the screw bit (56) in the screwing-in direction.

2. An apparatus according to claim 1, characterized in that the wall parts (34, 36) are formed at their lower edge at least partially approximately parallel to the feed channel (46).

3. An apparatus according to one of the preceding claims, characterized in that an adjusting screw (78) is provided which delimits the path, over which the screwing device (10) can move in relation to the feed channel (46).

4. An apparatus according to one of the preceding claims, characterized in that in the region of the screw place a separating device (98, 100) is provided by means of which the screws (42, 44) may be fed individually to the screwing region.

5. An apparatus according to claim 4, characterized in that the separating device (98, 100) is connected to a U-shaped member (108), one of whose limbs is directed towards the screwing-in region and is coupled in such a way to the separating device that when a screw (44) is in the screwing-in region the separating device is blocked.

6. An apparatus according to one of the preceding claims, characterized in that inside the container (20) in the region of the feed channel (46) means (116, 118) are provided which are used for prearranging each screw (42, 44) on the feed channel (46).

7. An apparatus according to claim 6, characterized in that an approximately L-shaped steel spring (116) is provided as means for prearranging the screws (42, 44), and one of its limbs is secured to the inner wall of the container (20) and its other limb (118) ends in the region of the feed channel (46), the distance of the other end of the limb from the feed channel being slightly greater than the height of a screw head (44).

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