Method for feeding fastening elements

Abstract: The invention relates to both a method and a device for feeding fastening elements (1) with a first and a second end, in particular rivets, preferably blind rivets, wherein a fastening element (1) is transported to a junction point (3) at a given orientation by a feed channel (2), and leaves the junction point (3) preferably with the first end in front via a first channel (7) or with the second end in front via a second channel (8).

Description: The invention relates to a method for feeding fastening elements. In the course of rising automation in manufacture, devices have been developed by which fastening elements are automatically brought into connection with at least one structure. By the name fastening element is understood fastening elements which are designed preferably asymmetrically with respect to a central plane. These can be, for example, rivets, screws, nails or similar. From DE 44 23 165 C2 a method and a device for feeding fastening elements are known. Each fastening element is introduced via a feed device against the drive-in direction of a ram into a holder. From WO 95/28242 a device is known, in which each fastening element is supplied by a feed channel, which runs substantially transversely to the direction of movement of the ram. For the fastening device both according to DE 44 23 165 and according to WO 95/28242, feed devices are necessary, by which each fastening element is transported to the fastening device at a given orientation by the feed channel. This means that different feed devices are necessary for each fastening device. From DE-A1 30 09 667 it is also known a method for feeding fastening elements with a first and second end, in which fastening elements one by one are transported through a feed channel to a junction point in one of two possible orientations. By impinging the fastening element at the junction point from opposite sides with pressurized air it is caused to leave the junction point with the first end in front via one of two opposite ends of a split discharge channel. Based on this, the object of the present invention is to present a method for feeding fastening elements, by means of which insertion of different fastening devices is enabled. This object is achieved according to the invention by a method with the features of claim 1. Advantageous developments and configurations of the method according to the invention are the subject of the respective dependent claims. For feeding fastening elements with a first and a second end, in particular rivets, preferably blind rivets, to a fastening device, it is proposed in the method according to the invention that at least one fastening element is transported at a given orientation to a junction point by a feed channel, the junction point having a first channel and a second channel opposite it. Depending on whether the at least one fastening element is to be transported with its first end or with its second end at the front, the first or the second channel is impinged with a pressure medium, in particular compressed air, and the fastening element leaves the junction point with the first end in front via a first channel or with the second end in front via a second channel. By using this method according to the invention, fastening devices can be equipped with fastening elements which require a feed of fastening elements with differing orientations. By using this method it is also concluded that a device is necessary for feeding fastening elements which operates by the method according to the invention. According to an advantageous development of the method, it is proposed that the fastening elements are transported singly to the junction point. This enables the process to run without interruption. According to yet another advantageous development of the method, it is proposed that, following on from one fastening element, a further fastening element is supplied to the junction point when the previous fastening element has left the junction point. This enables selective feed of fastening elements to the fastening devices. According to yet another advantageous development of the method, it is proposed that the fastening elements are brought from the feed channel to the junction point in a connecting channel. In particular it is proposed that the fastening elements slide into the junction point on a portion of the connecting channel adjacent to the junction point. This has the advantage that the fastening elements arrive in the junction point automatically. To prevent the fastening elements situated in the connecting channel and/or in the feed channel from being pushed out of these when the junction point is impinged with a pressure medium, it is proposed, according to yet another advantageous development of the method, that at least the feed channel is closed off at least during the pressure impingement. The feed of fastening elements to the junction point is effected preferably by means of a movable ram. Preferably the ram is movable between two end positions. In particular it is proposed that in a first end position it opens the feed channel, so the ram can take hold of a fastening element. In a second end position the ram preferably has a sealing effect, so at least the feed channel is closed off and sealed. Not part of the invention, a device for feeding fastening elements with a first and a second end, in particular rivets, preferably blind rivets, is proposed wherein the device has a feed channel and at least one junction point connected to the feed channel. The junction point has a first channel and a second channel opposite it. The first or the second channel can preferably be connected to a pressure medium source, so a fastening element situated in the junction point can be removed from the junction point by the corresponding channel, depending on whether the pressure medium source is connected to the first or the second channel. Preferably the device has a connecting channel connecting the feed channel to the junction point. In particular the connecting channel has a portion adjacent to the junction point, which is inclined downwards with respect to a horizontal line. This portion forms a kind of slide, on which a fastening element can slide into the junction point. A movable ram is provided for selective and sequential transport of fastening elements from the feed channel to and into the junction point. Further details and advantages of the invention are explained using the embodiment shown in the drawings. Figure 1 shows schematically a device that could be used for implementing the method of the invention in a front view. Figure 2 shows the device of figure 1 in a sectional representation along the intersection line A-A. The device that could be used for implementing the method of the invention comprises two basic bodies 9, 10, which are connected to one another. The basic bodies 9, 10 have a dividing plane 11. The device has a feed channel 2. The feed channel 2 is designed partially in basic body 9 and partially in basic body 10. The cross-sectional shape of the channel is adapted to the fastening element 1, which is supplied to the feed channel 2 via a conduit not shown. In the embodiment shown the fastening element 1 is shown in the form of a blind rivet. The basic body 9 and the basic body 10 have respectively a connecting branch 12, which can be connected in each case to a conduit, not shown. The conduit can lead to a fastening device, not shown, or to a pressure medium source. The branch 12 communicates with a first channel 7 or with a second channel 8, which form a junction point 3. The junction point 3 is connected to the feed channel 2 via a connecting channel 4. The connecting channel 4 has a portion 5, which is inclined downwards with respect to a horizontal line. A ram is movably arranged inside the connecting channel 4. The ram is preferably movable between two end positions. In the one end position the ram 6 opens the feed channel 2, so a fastening element 1 can arrive in the connecting channel 4. By displacing the ram 6 in the direction of the junction point 3, the fastening element 1 is transported towards the junction point 3. When the fastening element 1 reaches the portion 5, which runs diagonally downwards, the fastening element 1 slides on this portion into the junction point 3. The ram 6 has reached its second end position. Preferably the ram 6 seals off the cross-section of the feed channel 2. Depending on whether the fastening element 1 is to be transported with its head 13 or with the mandrel 14 at the front, the first or the second channel 7 or 8 is impinged with a pressure medium, preferably with compressed air, so the fastening element is transported to a fastening device, not shown, either with the head at the front or the mandrel at the front. After the fastening element has been removed from the junction point 3 and the pressure medium supply has been stopped, the ram 6 is driven back into its first end position, so it opens the feed channel 2 again. Movement of the ram 6 preferably occurs depending on a control, not shown, which is connected to a fastening device. Preferably the fastening device has sensor agents, by which is verified whether the fastening element has reached the fastening device. If this is the case the control is triggered via a signal, so the ram 6 is driven back into its first end position via an actuation device, not shown.

Claims: Method for feeding fastening elements (1) with a first and a second end, in particular rivets, preferably blind rivets, in which at least one fastening element (1) is transported to a junction point (3) by a feed channel (2), the junction point (3) having a first channel (7) and a second channel (8) opposite it, characterised in that the at least one fastening element is transported to the junction point at a given orientation, and depending on whether the at least one fastening element is to be transported with its first end or with its second end at the front, the first or the second channel is impinged with a pressure medium and the at least one fastening element then leaves the junction point (3) with the first end in front via the first channel (7) or with the second end in front via the second channel (8). Method according to Claim 1, characterised in that the fastening elements (1) are transported to the junction point (3) singly. Method according to Claim 1 or 2, characterised in that following on from one fastening element (1), a further fastening element (1) is supplied to the junction point (3), when the previous fastening element (1) has left the junction point (3). Method according to Claim 1, 2 or 3, characterised in that the fastening elements (1) are brought from the feed channel (2) to the junction point (3) in a connecting channel (4). Method according to Claim 4, in characterised in that the fastening elements (1) slide into the junction point (3) on a portion (5) of the connecting channel (4) adjacent to the junction point (3). Method according to one of claims 1 to 5, characterised in that the pressure medium is compressed air. Method according to Claim 6, characterised in that at least the feed channel (2) is closed off at least during the pressure impingement. Method according to one of claims 1 to 7, characterised in that a fastening element (1) is brought to the junction point (3) by a movable ram (6). Method according to claim 7 or 8, characterised in that the ram (6) is moved between two end positions, wherein in a first end position it opens the feed channel (2) and in a second end position closes it off and seals it.

Inventors: ROESSLER ANDREAS, ROESSLER, ANDREAS
Applicants: NEWFREY LLC
Application year: 2000
Main classification: B21J15
IPC codes: B23P19, B21J15