SCREW FORWARDING DEVICE FOR A SCREW FEEDER

Abstract

A screw forwarding device for a screw feeder including a base plate, a vibration mechanism including at least one spring and a vibration motor connected to the at least one spring, a rail for receiving screws, the rail being connected to a first end of the at least one spring, the at least one spring being arranged at an oblique angle to the rail. The screw forwarding device includes further a fastening mechanism for rigidly connecting a second end of the at least one spring to the base plate, whereby a movement path of the vibration mechanism, during a use of the screw forwarding device, defines a plane of movement, whereby the base plate is oriented substantially parallel to the plane of movement defined by the vibration mechanism.

Claims

1.-9. (canceled)

10. A screw feeder comprising a base plate and a screw forwarding device rigidly mounted to the base plate, the screw forwarding device comprising a vibration mechanism comprising at least one spring and a vibration motor connected to the at least one spring, a rail for receiving screws, a fastening mechanism for connecting the vibration mechanism to the base plate, the rail being connected to a first end of the at least one spring and a second end of the at least one spring being connected to the base plate via the fastening mechanism, the at least one spring being arranged at an oblique angle to the rail, the vibration mechanism defining a movement path of the rail, when the vibration mechanism is in use, said movement path being arranged in and defining a plane of movement, characterized in that the base plate is oriented substantially parallel to the plane of movement defined by the vibration mechanism, wherein the plane of movement and the base plate are oriented substantially vertical and wherein the vibration mechanism has a first mass and the base plate has a second mass and wherein the relation between the first mass and the second mass is from 1:6 to 1:15, preferably from 1:7 to 1:12 and more preferably from 1:8 to 1:10

11. The screw feeder according to claim 10, wherein a shortest distance measured between the base plate and the vibration mechanism is smaller than 5 cm, preferably smaller than 3 cm and more preferably smaller than 2 cm.

12. The screw feeder according to claim 10, wherein the second mass of the base plate is from 5 kg to 15 kg, preferably from 7 kg to 13 kg and more preferably from 8 kg to 10 kg.

13. The screw feeder according to claim 10, further comprising at least two springs, a bridge and a foundation, wherein the bridge is interconnecting the at least two springs at their respective first ends and wherein the foundation is interconnecting the at least two springs at their respective second ends, wherein the vibration motor is connected to any of the bridge or the at least two springs.

14. The screw feeder according to claim 10, wherein the at least one spring is a plate spring.

15. The screw feeder according to claim 10, wherein the base plate comprises pre-drilled holes or adapters and the fastening mechanism comprises bolts, screws and nuts for screwing the vibration mechanism to the base plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will now be described, for exemplary purposes, in more detail by way of an embodiment(s) and with reference to the enclosed drawings, in which:

[0038] FIG. 1 schematically illustrates a perspective view of a screw feeder comprising a screw forwarding device according to the invention;

[0039] FIG. 2 schematically illustrates a side view of the screw feeder with the screw forwarding device according to FIG. 1;

[0040] FIG. 3 schematically illustrates a front view of the screw feeder according to FIGS. 1 and 2; and

[0041] FIG. 4 schematically illustrates a top down view onto the screw feeder according to FIGS. 1 to 3.

DETAILED DESCRIPTION

[0042] The figures illustrate an embodiment of a screw feeder 1 comprising a base plate 2 and, mounted to the base plate 2, a step feeder unit (8), a screw forwarding device 4 or vibration unit and a separator unit 6.

[0043] The base plate 2 comprises at least four cantilever arms 10, which extend horizontally or at an angle of more or less 90° from a lower end of the base plate 2. Two cantilever arms 10 extend from each side of the lower end or bottom of the base plate 2. The cantilever arms 10 may comprise feet 22.

[0044] Alternatively to the cantilever arms 10 a foundation plate 40 arranged orthogonal to the base plate 2 may be used. In the illustration in FIGS. 1 to 4 a combination of cantilever arms 10 and a foundation plate 40 is illustrated, whereby the feet 22 are arranged close to corners at a bottom of the foundation plate 40. It is however clear that either only a foundation plate 40 with feet 22 or only cantilever arms 10 with feet 22 at their respective free ends can also be used.

[0045] Referring now to FIGS. 1 and 2, the screw forwarding device 4 comprises a vibration mechanism 18 and a fastening mechanism 16. The fastening mechanism 16 is used to connect the vibration mechanism 18 to the base plate 2 and comprises bolts, screws and nuts 24 that engage with pre-drilled holes 14 in the base plate 2. The fastening mechanism 16 may comprise another solution such as adapters, form-fit solutions and the like that connect the vibration mechanism 18 to the base plate 2. Alternatively, the vibration mechanism 18 may be directly welded or glued (not shown) to the base plate 2.

[0046] The vibration mechanism 18 comprises two plate springs 26, a vibration motor 28, a foundation 30 and a bridge 32. The foundation 30 is connected to the base plate 2 via the fastening mechanism 16 and the foundation 30 comprises adapters or the like to receive the bolts 24 of the fastening mechanism 16. The two plate springs 26 are connected to one another with their respective first ends 38 via the bridge 32, as best visible in FIG. 2. In FIG. 2 the rail 20 is also well visible and also the angle α, at which the rail is arranged versus a horizontal plane. The angle α is measured between the horizontal plane and a longitudinal axis of the rail 20. The angle α can have a value of 0 degrees, from 1 to 15 degrees, from 2 to 14 degrees or for instance 4, 5, 6, 7 or 8 degrees.

[0047] The screw forwarding device 4 further comprises a rail 20 that is connected to the bridge 32 of the vibration mechanism 18. The rail 20 is best visible in FIGS. 3 and 4 and it is used to convey screws with their threads downwards towards the separator unit 6. When the step feeder unit 8 moves the screws upwards towards the vibration mechanism 18, the screws are conveyed onto a plate that is vibrating, driven by the vibration mechanism 18, and from that plate the screws fall into the rail 20, where they are conveyed further by vibration to the separator unit 6. The separator unit 6 comprises a conveyor 44, which can be designed as a tube or pipe operated pneumatically for conveying the screws further to a tool. Other forms of conveyors 44 such as conveyor belts or (magnetic) rails may be used.

[0048] When the vibration motor 28 is activated, the vibration mechanism 18 defines a movement path 42 that is indicated in FIG. 2. The movement path 42 defines a circular—, an oval—or a round-rectangular path in a plane of movement, as indicated in FIG. 2. This movement path 42 leads to the conveying of the screws in the rail 20. The plane of movement is oriented orthogonal to the foundation 30 of the vibration mechanism and goes through the rail 20. The movement path 42 is in general defined by the orientation of the plate springs 26. These plate springs 26 are normally parallel to one another and inclined in order to generate a movement path in one direction, such as for example towards the right in FIG. 2. In the example illustrated in FIG. 2 the movement path 42 is also defined by the angle α. However, even if the angle α is 0 degrees the inclination of the plate springs 26 will lead to a forward movement of the screws towards the separator 6. Thus, the vibration unit 4 can forward the screws independent of the angle α. Typical frequencies of the vibration unit 4 are typical from 20 to 200 Hz, such as for example 50 Hz, such as for example 100 Hz or such as for example 120 Hz.

[0049] The base plate 2 is arranged at least more or less parallel to the plane of movement defined by the vibration mechanism 18. With at least more or less it is meant that the angle between the plane of movement and the base plate 2 is preferably 0° with a tolerance of +/−15°.

[0050] Using another definition, the base plate 2 and the plane of movement defined by the vibration mechanism 18 may be arranged vertical and parallel to one another, vertical and parallel with the same tolerance as stated above.

[0051] The fastening mechanism 16 is configured to arrange the vibration mechanism 18 comparably close to the base plate 2, so that the shortest distance between the base plate 2 and the vibration mechanism 16 is less than 3 cm. This comparably short distance is well illustrated in FIG. 3, where the base plate 2, the vibration mechanism 18 and the fastening mechanism 16 are visible.

[0052] For the sake of simplicity and also for understanding purposes, the separator unit 6 is not shown in FIG. 3. It is also clear from FIG. 3, how the cantilever arms 10 are extending from the base plate 2, namely in an at least more or less 90° angle versus the base plate 2, two cantilever arms on either side of the base plate 2.

[0053] With the above described build-up of the screw feeder 1, rubber cushions or absorber elements can be avoided, since the arrangement of the screw forwarding device 4 is chosen to be on the base plate 2, which is substantially parallel to the movement path 42. The vibration can further be dampened and eliminated by choosing a relationship between first mass of the vibration mechanism 18 and a second mass of the base plate 2 in a smart way of approximately: 1:4 to 1:18, preferably from 1:6 to 1:16 and more preferably from 1:8 to 1:10. Meaning that the second mass of the base plate 2 is at least four times heavier than the second mass of the vibration mechanism 18 but not more than eighteen times heavier.

[0054] The invention has now been described according to one embodiment. Modifications, which could be performed by the skilled person and within the general idea of the invention are herewith however also included in this document.