SEPARATING DEVICE OF AN OPTICAL TESTING UNIT

Abstract

A separating device of an optical testing unit for testing rotationally symmetrical test objects includes two corresponding pocket wheels, each having a plurality of pockets distributed uniformly over a circumference. The pocket wheels rotate synchronously in opposite directions about parallel axes in response to a drive. A continuous conveyor transports the test objects on a transporting plane. Depending on the geometry of the test objects, the distances between the respective pocket wheels and between the pocket wheels and the transporting plane are determined so that the test objects, which are fed via and accumulating section, are moved between the pocket wheels while being guided by two pockets of the two pocket wheels and are released by the two pockets downstream of an engagement section. Once released the test objects are accelerated to a higher transporting speed in an accelerating section of the continuous conveyor and are separated as a result.

Claims

1.-19. (canceled)

20. A separating device for separating test objects in a testing unit for the nondestructive and physical testing of the test objects, each of the test objects being rotationally symmetrical with respect to an object axis and having a bottom surface, a top surface, and a lateral surface extending between the bottom surface and the top surface, the separating device comprising: a continuous conveyor system having at least one conveyor configured to transport the test objects in a single row in a transport direction and in a transport plane, the continuous conveyor system having an accumulation section, an engagement section, an acceleration section, and a transport section arranged in succession in the transport direction in the transport plane; two pocket wheels, each having a plurality of pockets distributed uniformly over a circumference, the two pocket wheels are rotatable about respective axes; a drive rotating the two pocket wheels synchronously in opposite directions about the respective axes; wherein the engagement section extends between the two pocket wheels and a spacing between the axes of the pocket wheels and a spacing of the pocket wheels from the transport plane are determined so that the lateral surface of each of the test objects contacts one pocket of each of the two pocket wheels when the each of the test objects in the engagement section; a control system adjusting a speed of rotation of the pocket wheels relative to a speed of the at least one conveyor, wherein a transport speed of the test objects in the accumulation section and the engagement section is lower than a transport speed of the test objects in the acceleration section and the transport section; wherein the control system is part of a control loop that ensures that the accumulation section immediately upstream of the engagement section is maintained in an undisrupted state; and a sensor monitoring the accumulation section for gaps between the test objects, wherein the control system reduces the rotational speed of the pocket wheels as a countermeasure when a gap is detected.

21. The separating device as claimed in claim 20, wherein the at least one conveyor of the continuous conveyor system includes a belt conveyor moving the test objects in at least the acceleration section and the transport section.

22. The separating device as claimed in claim 20, wherein the at least one conveyor of the continuous conveyor system includes a belt conveyor moving the test objects in at least a first part of the accumulation section, the engagement section, the acceleration section, and the transport section.

23. The separating device as claimed in claim 21, wherein the continuous conveyor system further includes a flow conveyor moving the test objects in the accumulation section and the engagement section.

24. The separating device as claimed in claim 22, wherein the continuous conveyor system further includes a flow conveyor moving the test objects in at least a second part of the accumulation section.

25. The separating device as claimed in claim 21, wherein the belt conveyor includes a double track belt.

26. The separating device as claimed in claim 20, further comprising lateral guides extending in the transport direction and arranged parallel to one another above the transport plane, the lateral guides guide each of the test objects on opposing sides of the lateral surface of the each of the test objects.

27. The separating device as claimed in claim 26, wherein the lateral guides extend at least along the accumulation section.

28. The separating device as claimed in claim 26, wherein the lateral guides are arranged along the engagement section above the pocket wheels.

29. The separating device as claimed in claim 26, wherein a spacing between the lateral guides is adjustable.

30. The separating device as claimed in claim 20, further comprising an overhead guide arranged above the transport plane guiding the top surface of each of the test objects.

31. The separating device as claimed in claim 30, wherein the overhead guide extends along the engagement section and at least partially along the acceleration section.

32. The separating device as claimed in claim 30, wherein a spacing between the overhead guide and the transport plane is adjustable.

33. The separating device as claimed in claim 21, wherein at least a section of the belt conveyor is a vacuum belt conveyor.

34. The separating device as claimed in claim 20, wherein the pockets of each of the pocket wheels are bounded by simply curved surfaces having a corresponding curvature.

35. The separating device as claimed in claim 20, wherein the drive comprises a servomotor.

36. The separating device as claimed in claim 20, wherein a spacing between the axes of the pocket wheels is adjustable.

37. The separating device as claimed in claim 20, wherein the pocket wheels are identical and the axes of the two pocket wheels extend parallel to each other and perpendicular to the transport plane.

Description

[0061] The invention is explained in greater detail below with reference to the drawings. In the drawings:

[0062] FIG. 1a shows a side view of a separating device without a drive,

[0063] FIG. 1b shows a perspective view of the separating device according to FIG. 1a with a transparent representation of the guide elements,

[0064] FIG. 1c shows a representation corresponding to FIG. 1b with guide elements,

[0065] FIG. 1d shows a representation corresponding to FIG. 1b with the guide elements removed,

[0066] FIG. 2 shows a plan view of the separating device according to FIG. 1c, and

[0067] FIG. 3 shows a perspective view of the separating device with a drive.

[0068] The separating device is a component of a testing unit (not shown completely for the sake of clarity) for the optical testing of corresponding test objects (1) which are rotationally symmetrical with respect to an object axis (1.1). The test objects (1) are, for example, closure caps for beverage containers. The test objects, which are rotationally symmetrical with respect to an object axis (1.1), all correspond to one another. They have a bottom surface (1.2), a top surface (1.3) bounded by the upper edge of the test object, and a lateral surface (1.4) extending between the bottom surface (1.2) and the top surface (1.3). The separating device comprises a continuous conveyor system (2) with a transport plane (2.1) (cf. FIG. 1a). The test objects (1) are transported in a single row in a transport direction (2.2) in the transport plane (2.1).

[0069] The separating device further has two matching pocket wheels (3.1, 3.2), which are rotatable about axes (3.3) perpendicular to the transport plane (2.1). In the exemplary embodiment illustrated, the pocket wheels (3.1, 3.2) have ten pockets (3.4) distributed uniformly over the circumference. All the pockets (3.4) of both pocket wheels (3.1, 3.2) are bounded by simply curved surfaces having a corresponding curvature. The tooth-like transitions (3.5) between adjacent pockets (3.4) are greatly rounded.

[0070] A drive (4), which makes the pocket wheels (3.1, 3.2) rotate synchronously in opposite directions about the parallel axes (3.3), is illustrated in FIG. 3. The drive (4) comprises a servomotor (4.1) having a drive pinion. Connected to the pocket wheels (3.1, 3.2) for conjoint rotation therewith are drive shafts (4.2), which are mounted in a supporting structure (4.3) and are each connected to a gear wheel (4.4) at the ends opposite the pocket wheels (3.1, 3.2). Furthermore, a toothed deflection pulley (4.5) is rotatably mounted on the supporting structure (4.3). Via a toothed belt (4.6), the drive pinion of the servomotor (4.1) drives the gear wheels (4.4, 4.5), which make the drive shafts (4.2) and thus the pocket wheels (3.1, 3.2) rotate synchronously in opposite directions about the parallel axes (3.3, 3.4).

[0071] In the exemplary embodiment illustrated, the continuous conveyor system (2) of the separating device has on the input side a flow conveyor (5) which transfers the test objects (1) to a belt conveyor (6). The flow conveyor (5) conveys the test objects in the transport direction (2.2) on a sliding plate (5.1) by means of an air flow. Lateral guides (5.2) extending parallel to one another are arranged in the transport direction (2.2) above the transport plane (2.1) in such a way that the lateral guides (5.2) guide each test object (1) on opposite sides of the lateral surface (1.4). The flow conveyor (5) connects the separating device to an upstream sorting device (not shown), in which the test objects are transported by means of an air flow.

[0072] The test objects are transferred from the flow conveyor (5) to a belt conveyor (6), which, in the exemplary embodiment illustrated, has a circulating double track belt (6.1). The belt conveyor (6) comprises a supporting structure (6.2), a drive station (6.3) and a deflection station (not shown for the sake of clarity) for the two conveyor belts of the double track belt (6.1). The upper strand of the two conveyor belts of the double track belt (6.1), together with the sliding plate (5.1) of the flow conveyor (5), forms the transport plane (2.1) of the continuous conveyor system (2). The supporting structure (6.2) is designed as a closed channel, in which there is a vacuum. The vacuum acts on the bottom surfaces (1.2) of the test objects (1) via a longitudinal slot (6.5).

[0073] Two guide profiles (6.6) extend in the transport direction (2.2) above the transport plane (2.1) in the region of the conveyor belt conveyor (6). The guide profiles (6.6) each have a horizontal and a vertical section, wherein the two horizontal sections form an overhead guide (6.7) and the two vertical sections form the lateral guides (6.8) for the belt conveyor. The height of the guide profiles (6.6) and their spacing from one another are determined in such a way that the lateral guides (6.8) guide each test object (1) on opposite sides of the lateral surface (1.4), and the overhead guide (6.7) guides the top surface (1.3) of each test object (1).

[0074] As can be seen in particular from FIGS. 1a, 1b and 1c, the two guide profiles (6.6) each have, in the region of the pocket wheels (3.1, 3.2), a notch (6.9), through which the pocket wheels (3.1, 3.2) extend in the direction of the transport plane (2.1).

[0075] It can be seen in the plan view according to FIG. 2 that an accumulation section (7), an engagement section (8), an acceleration section (9) and a transport section (10) are arranged in succession in the transport direction (2.2) in the transport plane (2.1) of the flow conveyor (5) and of the belt conveyor (6). The accumulation and transport sections (9, 10) are not shown completely.

[0076] In the accumulation section (7), the test objects (1) bear against one another in a single row at their lateral surfaces (1.4). The spacing (A) between the object axes (1.1) of the test objects (1) corresponds. The accumulation section (7) serves to equalize the transport flow of the test objects (1) between the sorter and the optical test in terms of quantity and time, to which a constant number of test objects per time unit, for example 60 test objects per second, must be fed at a uniform spacing (A). Via the accumulation section (7), the test objects (1) are fed without gaps to the two pocket wheels (3.1, 3.2). The spacing between the parallel axes (3.3) of the pocket wheels (3.1, 3.2) and the vertical spacing of the pocket wheels (3.1, 3.2) from the transport plane (2.1) is determined in such a way that the lateral surface (1.4) of each test object (1) comes into contact with in each case one pocket (3.4) of the two pocket wheels (3.1, 3.2) in the engagement section (8). FIG. 1d shows how the two cooperating pockets (3.4) of the two pocket wheels (3.1, 3.2) form a nest surrounding the test object (1) at the lateral surface (1.4) in the course of the further rotation, and transport the test object (1) through the engagement section (8) and release this at the end of the engagement section.

[0077] The separating device has a control system (not shown) for adjusting the speed of rotation of the pocket wheels (3.1, 3.2) relative to the speed (v.sub.B) of the belt conveyor (6) in such a way that the transport speed (v.sub.A) of the test objects (1) in the accumulation and engagement section (7, 8) is lower than the speed (v.sub.B) of the belt conveyor (6) which corresponds to the transport speed of the test objects (1) in the transport section (10). The transport speed (v.sub.A) of the test objects (1) in the accumulation and engagement section (7, 8) corresponds to the peripheral speed (U) of each test object (1) resulting from the speed of rotation of the pocket wheels (3.1, 3.2). In the exemplary embodiment illustrated, the speed of rotation of the pocket wheels is controlled by means of the drive (4) and the speed of the belt conveyor (6) is controlled by means of the drive station (6.3).

[0078] Both the air flow of the flow conveyor (5) and the frictional forces exerted on the bottom surfaces (1.2) of the test objects (1) via the double track belt (6.1) of the belt conveyor (6) generate a back pressure in the accumulation section (7). The pocket wheels (3.1, 3.2) rotating at a controlled speed of rotation prevent the test objects (1) in the accumulation section (7) and the engagement section (8) from unimpeded transport at the higher speed of the belt conveyor and of the air flow until they are released at the end of the engagement section (8) by virtue of the rotation of the pocket wheels (3.1, 3.2) and are accelerated in the acceleration section (9) to the speed (v.sub.B) of the belt conveyor (6).

[0079] The number (n) of test objects separated per unit of time depends on the number of pockets in the pocket wheels (3.1, 3.2) and on the speed of rotation of the pocket wheels. However, the spacing (B) between the test objects (1) after separation depends on the speed difference between the transport speed (v.sub.A) in the accumulation section (7) and the speed (v.sub.B) of the belt conveyor in the transport section.

[0080] In order to stabilize the position of the test objects (1) on the transport section (10) and to shorten the acceleration section (9), the longitudinal slot (6.5) via which a vacuum acts on the bottom surface (1.2) of the test objects (1) extends from the engagement section (8), via the acceleration section (9), to the transport section (10). However, no vacuum is effective in the accumulation section (7) because it would impair the accumulation of the test objects. The effect of the vacuum can also be dispensed with in the engagement section (8). Vacuum support is useful for test objects with a closed or at least partially closed bottom surface.

[0081] The surface of the double track belt (6.1) of the belt conveyor (6) has a coefficient of friction which is matched to the requirement of an accumulation section (7) and which allows the test objects (1) in the accumulation section to slide over the surface.

[0082] In one advantageous embodiment of the invention, the accumulation section (7) is monitored by means of a sensor for any gaps in the transport flow. Any gaps can lead to the test objects not being correctly received by the pockets (3.4) of the two pocket wheels (3.1, 3.2), with the transitions (3.5) instead striking the lateral surfaces (1.4) of following test objects (1). If a gap is detected, it is possible, for example as a countermeasure, for the speed of rotation of the pocket wheels (3.1, 3.2) to be reduced to ensure that the gap closes again.

TABLE-US-00001 No. Designation 1 Test objects 1.1 Object axis 1.2 Bottom surface 1.3 Top surface 1.4 Lateral surface 2 Continuous conveyor system 2.1 Transport plane 2.2 Transport direction 3.1 Pocket wheel 3.2 Pocket wheel 3.3 Axis 3.4 Pocket 3.5 Transitions 4. Drive 4.1 Servomotor 4.2 Drive shafts 4.3 Supporting structure 4.4 Gear wheel 4.5 Deflection pulley 4.6 Toothed belt 5 Flow conveyor 5.1 Sliding plate 5.2 Lateral guide 6 Belt conveyor 6.1 Double track belt 6.2 Supporting structure 6.3 Drive station 6.4 Spacing 6.5 Longitudinal slot 6.6 Guide profile 6.7 Overhead guide 6.8 Lateral guides 6.9 Notch 7 Accumulation section 8 Engagement section 9 Acceleration section 10 Transport section