US 3752311 A
A sorting device for helical springs for sorting springs equipped with a mounting leg and comprising a conveyor for the springs, a feed duct arranged to receive springs from the conveyor, a supporting element mounted in the feed duct, for supporting springs thereon, a sensor piston operated by a pressure source and arranged to engage with a spring resting on the supporting element whereby the piston moves to different positions depending on whether the mounting leg of the spring is in the correct or incorrect position, means for transferring a spring having its mounting leg in the correct position to a station for further processing and means for ejecting a spring having its mounting leg in the incorrect position.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Kobusch et a1.
SORTING DEVICES Inventors: Klaus Kobusch; Arno Manke, both of Bielefeld, Germany [7 3] Assignee: APEG-Hochdrucktechnik,
Brackwede, Germany  Filed: Mar. 22, 1972  App]. No.: 236,930
 Foreign Application Priority Data Mar. 24, 1971 Germany .1 P 21 14 125.3
Feb. 17, 1972 Germany P 22 07 346.7
[5 6] References Cited UNITED STATES PATENTS 3,221,857 12/1965 Keller 198/33 R X 51 Aug. 14,1973
3,603,441 9/1971 Ansell 193/41 Primary ExaminerRichard A. Schacher Att0rneyBeaman & Beaman 7 1 ABSTRACT A sorting device for helical springs for sorting springs equipped with a mounting leg and comprising a conveyor for the springs, a feed duct arranged to receive springs from the conveyor, a supporting element mounted in the feed duct, for supporting springs thereon, a sensor piston operated by a pressure source and arranged to engage with a spring resting on the supporting element whereby the piston moves to different positions depending on whether the mounting leg of the spring is in the correct or incorrect position, means for transferringa spring having its mounting leg in the correct position to a station for further processing and means for ejecting a spring having its mounting leg in the incorrect position.
23 Claims, 9 Drawing Figures IGMQIQQDI Patented Aug. 14, 1973 7 Sheets-Sheet 1 Fig. 1
Patented Aug. 14, 1973 '7 Sheets-Sheet 2 F i g. 3
Patented Aug. 14, 1973 7 Sheets-Sheet 5 Patented Aug. 14, 1973 '7 Sheets-Sheet 6 Patented Aug. 14, 1973 3,752,311
7 Sheets-Sheet 7 SORTING DEVICES BACKGROUND OF THE INVENTION The invention relates to a sorting device for helical springs for sorting out springs equipped with a mounting angle and having a position suitable for further processing.
In such sorting devices it is necessary to determine whether the holding angle of the helical spring being checked is on the correct side for further processing. Helical springs of this kind are made with widely varying diameters by coiling spring wire, and the ratio between length and diameter may have widely varying values. Correspondingly, these helical springs have configurations which may have very different mechanical stabilities in accordance with their dimensions and spring properties. For this reason, it is a very difficult and hitherto not yet satisfactorily solved problem to place them into a certain position which is suitable for further processing, and particularly for installation under predetermined tension or compression.
It is already known to solve this problem by photoelectric scanning. However, this requires very expensive equipment and has the difficulty that the bodies do not have fixed defined outlines, but may change their profile resiliently. It is also known to provide such helical springs on one side with a mounting leg. This leg is formed by angling one of the two wire ends on one side radially in the direction of the centre axis. However, this mounting leg must not be bent or changed in any way by any subsequent processing step. Hitherto, all tests to use this mounting leg as a criterion for sorting into the correct mounting position have remained unsuccessful Owing to this requirement.
SUMMARY OF THE INVENTION The invention has the object of providing an auto matic sorting device which meets these requirements in such a way that it uses the position of the mounting leg for sorting out those helical springs from a plurality of springs, which have the correct position for further processing. The other springs are returned to the input of the device until all helical springs can be used up. During handling neither the springs nor the mounting legs must be damaged.
According to the invention this object is realised in that a feed duct is arranged downstream of a conveyor and has at its end a supporting element, wherein a sensor piston, actuated by a pressure source, is mounted above the spring resting on the supporting element, and wherein the correct and the incorrect position of the mounting leg cause a corresponding ejector piston to be connected to the pressure source.
In a practical realisation of this principle a feed duct is adapted by means of guides and a terminal supporting element, by means of an oblong hole, as well as a correct" duct by means of guide strips to the diameter of the helical springs to be sorted.
According to a further feature of the invention, the correct" duct is mounted in the operating direction of a correct" piston, and a return duct, leading back to the conveyor, in the direction of an incorrect piston.
According to a further feature of the invention, a guide of the correct duct has a chamfer also leading back into the return duct.
In particular, the invention provides a pressure source which is connected through a waiting unit and a manually operated actuating valve with a clock generator.
A sensor piston may be connected with the clock generator, wherein its delivery side is connected through a "correct" valve in the inoperative position with the other side of the control piston of a switching valve, while the cylinder behind the sensor piston communicates with the other side of this switching piston.
Furthermore, the control slide of an ejector valve may be connected through a first delay valve and a second delay valve with the pressure conduit.
The invention desirably achieves the undisturbed cyclic operation by making the delay times for the response of the first delay valve, of the sensor piston valve, of the switching valve, and of the second delay valve adjustable by one-way delay members, each consisting of a non-return valve and an adjustable restriction mounted in parallel.
The advantages of the invention consist particularly in the fact that the functioning of the sorting device remains unaffected by the elastic, mechanically unstable nature of the helical springs. The mounting leg, used as sorting characteristic, is a solid body which provides a fixed physical support for the sensor pin of the sensor piston according to the invention, thereby eliminating faulty operation. All parts of the arrangement are of strong construction, and malfunctioning due to wear or deformation of parts cannot occur. Of particular advantage is the pneumatic circuit of the device which enables economic, reliable and fast operation to be accurately adjusted by setting time constant members in all essential components. The springs themselves are not mechanically stressed by the sorting, and their shape and properties are fully maintained.
The device according to the invention makes it possible to sort helical springs in such a manner that they are placed into a suitable position for further processing. However, helical springs in the wrong position must be ejected so frequently that they reach the feed duct finally in the correct position. This results in a delay for every helical spring in the incorrect position until it may be injected into the correct duct in the correct position. Since the position of helical springs in the feed duct is more or less accidental, it may happen that several helical springs are consecutively in the wrong position. This may lead to interruptions in the processing station where temporarily no helical spring in the correct position is available.
It is accordingly a further object of the invention to provide a device for the automatic sorting of cylindrically shaped parts, for example helical springs with mounting legs, whereby the cylindrical parts are sorted in such a way that they can be supplied to a place of use without interruption in the correct position.
This object is realised in that the supporting element is a slide adapted to be moved by a first adjusting mech anism and receiving in a first position a cylindrical part, and arranged in a second position opposite a retaining device which grips and holds the cylindrical part, whereupon the slide is moved by the first actuating device back into the first position, the holding device is adapted to be moved by a second adjusting mechanism to and from a place of use, the holding device is mounted rotatably and retains by means of the first control device in the case of a correct signal the cylindrical part in a first position at the point of delivery, while retaining by means of the second control device in the case of an incorrect signal the cylindricalpart in a position rotated through 180 relative to the first position.
By means of the device according to the invention it is possible to sort automatically cylindrically formed parts, and more particularly helical springs with mounting legs or bent ends, or cylindrical parts with cylindrical sections of bores with different diameters, in such a way that they are successively supplied in the correct position to a place of delivery from where they may be transported to a device for further processing.
After it has been ascertained by the sensor piston whether the cylindrical part has been supplied from the feed duct in the correct position, and a corresponding correct or incorrect signal has been produced, the slide is placed into a position in which the holding mechanism may grip and retain the cylindrical part.
In a preferred embodiment of the invention, the slide contains a fluid operated piston with a piston rod, and has a pocket formed in accordance with the cylindrical part in which the part is retained, and the piston rod is adapted to move through an opening in the base of the pocket and pushes in the second position of the slide the cylindrical part into the holding device when the piston is operated. The holding device may comprise, for example, two spaced apart leaf springs which are bent in such a way that they can retain the cylindrical part by embracing its circumference. The distance between the leaf springs may be variable to provide an adaptation to different outer diameters of cylindrical parts. The leaf springs may also be replaced by springloaded claws which also have a variable spacing.
The fluid operated piston with piston rod in the slide may also be omitted by constructing and moving the holding device in such a way that it can remove the cylindrical part from the pocket.
After the cylindrical part has been received in the holding device, the slide returns into the first position. Then the holding device carries the cylindrical part to the place of delivery. The correct or incorrect position of the cylindrical part has already been determined during the check with the sensor piston. Hence, the holding device transports the cylindrical part in its position to the place of delivery if the position has been identified as being correct. An incorrect signal actuates one of the control devices in such a manner that the part is rotated in the holding device through 180, so that it reaches the place of delivery again in the correct position.
The rotation of the cylindrical part from the incorrect into the correct position may be effected in various ways. Thus, the cylindrical part may be rotated thgough 180 by suitable means with the holding device still in its starting position. The rotation may also be effected during the passage to the place of delivery or at the place of delivery. Furthermore, the holding device may rotate the cylindrical part through a certain angle, both in the case of a correct signal and of an incorrect signal. It is only essential that an incorrect" signal causes a rotation through 180 against the correct" signal position.
According to a further feature of the invention, the piston of the second adjusting device has a first straight groove extending parallel to the axis of the piston, and has additionally a second spiral groove extending around 180 of the circumference of the piston, wherein the control device has a plunger adapted to be brought into engagement with the first groove and the second control device has a plunger adapted to be brought into engagement with the second groove. When this piston, the piston rod of which has gripping means for the cylindrical part, is actuated, one or the other plunger engages into the associated groove, so that the piston moves as a function of the checking sig nal of the sensor piston, either under maintenance of its angular position, or with an angular rotation through for transporting the cylindrical part to its place of delivery. Preferably, the piston comprises a return spring whereby it may be moved away from the place of delivery.
The place of delivery may comprise, for example, a receiving mandril which is also operable by fluid pres sure and which receives the cylindrical part, e.g., a helical spring, in its correct position and delivers it to a processing station.
Preferably, the acutation and the control of the device according to the invention are performed by fluid medium elments, for example by pneumatic elements. This requires particularly switching valves and pneumatic delay members, so that the individual operating pistons are actuated at the correct timing during the operation cycle.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described, by way of example, with reference to the accompanying drawings in which:
FIG. I is a cross-section of a helical spring along the line l--I in FIG. 2; 1
FIG. 2 is a plan view of a helical spring;
FIG. 3 is a plan view of one embodiment of a sorting device according to the invention;
FIG. 4 is a cross-section along the line IVIV in FIG.
FIG. 5 shows a pneumatic circuit diagram of the sorting device shown in FIGS. 3 and 4;
FIG. 6 is an axial cross-section through another embodiment of a sorting device according to the invention;
FIG. 7 is a cross-section of the device shown in FIG. 6 but with the slide in another position;
FIG. 8 is a cross-section taken along the line A-D in FIG. 7; and
FIG. 9 shows a circuit diagram for the pneumatic control for the sorting device shown in FIGS. 6 to 8.
DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings, the spring 1 coiled from wire terminates in a mounting leg la. The springs to be sorted are introduced into a feed duct 2- by a conveyor, for example, an oscillating conveyor. They slide through the duct 2 and come to rest on a support element 3. A sensor piston 4 is arranged in a cylinder 34 above the support element 3. At the start of the sorting process, the sensor piston 4 moves down. If the mounting leg la of the spring resting on the support 3 is at the bottom, the piston passes through the whole length of the spring 1, until it reaches the mounting leg Ia, thereby triggering off a pressure pulse acting on a correct" piston 5. When the sensor piston has moved back, this correct" piston advances and pushes the spring into a correct duct 6 for further processing.
If, on the other hand, the mounting leg la of the spring 1 is at the top of the spring, the sensor piston 4 is stopped in a higher position by resting on this leg. It triggers off a pressure pulse actuating an incorrect piston 7. After the sensor piston 4 has moved back, the incorrect piston 7 moves forward and moves the spring into a return duct 8, from which it passes back into the feed conveyor and continues to return to the sorting device until it reaches the correct position and may be pushed into the correct" duct 6.
The width of the feed duct 2 is adjusted by guides I0 and II to match the diameter of the springs to be sorted. The width of the correct" duct is adjusted correspondingly by guides 12 and 13. The guide 13 is provided with a chamfered surface 9. If no springs are withdrawn for some time from the correct duct 6 for further processing, the springs overflow from the duct 6 andpass down the surface 9 into the return duct 8 where they are returned to the conveyor and thus back into the feed duct 2. The guides 10 to 13 are adjusted by means of screws 14. The support member 3 is provided with an oblong hole by means of which it is adjustably mounted in the casing. The whole device is closed by a cover plate 15.
In the example shown in FIGS. 3 and 4, the sorting device is controlled by pneumatic means. Compressed air is supplied from a compressed air source 21 to a waiting unit or accumulator 22 (FIG. 5). This unit may contain a conventional pressure reducing device, a pressure gauge and a water separator.
A manually operated valve 23 opens the path for the compressed air into a conduit 24 and from here into a further conduit 25 for a clock generator, and simultaneously into a conduit 27 leading to a first delay valve 28 and to an ejector switching valve 29.
After operating the valve 23, the sensor piston 4 is actuated from the conduit 25 through a sensor piston valve 30. A conduit 31 applies simultaneously a preparatory pressure to the control slide of a control valve 33 through a one-way delay member 32 consisting of a variable restriction and a non-return valve mounted in parallel thereto. In consequence of the restriction by the delay member 32, the same switches only after the lapse of a predetermined adjustable delay period.
The sensor cylinder 34 operates the sensor piston 4 until said piston comes to rest on the spring 1 resting on the support element 3. Assuming that the mounting leg 1a of this spring is on the wrong side, i.e., on the side facing the viewer in FIG. 3, the sensor piston cannot advance far enough to open a conduit 35 leading from the cylinder 34. This conduit is affected by atmospheric pressure through the spring-loaded side of the piston. On the other hand, a duct 36 leading from the cylinder 34 is pressurised and affects through a correct valve 37, which in this case is not actuated, the control slide of a switching valve 38 causing the same to switch over.
Meanwhile, the control slide of valve 33 has responded through the conduit 31 and the delay member 32, causing conduits 39 and 39a to be pressurised. Through a conduit 40 and a second delay member 32a of the clock generator 26, the operation of the switching valve 30 is prepared, but takes place only after the lapse of an adjustable delay time.
Through the conduit 39 and a delay member 43 acting only on one side, a valve 41 responds after the lapse of the variable delay time and actuates through a second delay valve 42 the ejector valve 29. Through the reverse switching valve 38, the ejector piston 7 is operated and ejects the inverted spring 1 into the return duct 8. Meanwhile the sensor piston valve 30 has responded and has switched off the sensor piston 4. Now also the second delay valve 42 responds through its delay member 43a to cut off the ejector valve 29 from the first delay valve 28. The ejector valve 29 returns to its inoperative position. The sensor piston valve 30 has also depressurised the control slide of the valve 33, causing the same to return to its inoperative position and thereby to depressurise conduits 39 and 390. Now the sensor piston valve 30 also returns into its inoperative position, and a new cycle starts with the downward movement of the sensor piston 4.
If the mounting angle 10 is in the correct position in the spring 1 located under the sensor piston 4, i.e., in FIG. 1 on the side remote from the viewer, the sensor piston 4 comes to rest thereon in a position in which the conduit 35 communicates with the pressure side of the piston. The pressure in the conduit 35 prevents the switching valve 38 from being switched and operates the correct valve 37. When the injector valve 29 responds in the manner described above, piston 5 is actuated and delivers the spring into the correct duct 6. All other steps are as described above.
The device shown in FIGS. 6 to 9 has a base body 1 having on the left and right side a receiving duct 11 for helical springs of which one end 101' is bent radially inwardly. In the embodiment shown, helical springs 100' are only located in the left receiving duct 11'. The base body 1' comprises also a slide 2 adapted to be reciprocatingly moved along a slide guide 12'. The slide 2 is adjusted by means of a pneumatic cylinder 22 located in a cylinder mounting 13' on the base 1'. The base 1 also comprises a cylinder mounting 13 for an adjusting cylinder 31' of a sensor piston 3'. The bottommost helical spring 100' in the receiving duct 11 slides into a cylindrical pocket 23' in the slide 2. In this position, the longitudinal axis of the sensor piston 3' coincides substantially with the longitudinal axis of the helical spring. Under corresponding actuation by the adjusting cylinder 31', the sensor piston 3' can enter into the helical spring in the pocket 23' if the bent end 101' is located at the remote end of the spring. If this is not the case, the sensor piston 3' is prevented from carrying out this movement by the bent end 101".
Between the receiving ducts 11' there is a cylinder 15 in which a further piston 4' is displaceably mounted. At the lower end of the piston 4' is a holding device 6 with two spaced-apart, substantially parallel retaining springs 61' whose free ends have an inwardly bent section The springs 61' are adapted to receive and to retain a helical spring (see FIGS. 6and 7).The slide 2' comprises a further pneumatic adjusting cylinder 21' in which a piston 25' with a piston rod 26' is slidably mounted. The piston 25 is spring loaded by a spring 27. A section of the piston rod 26' with smaller diameter passes through a bore 28' in the slide? tf minating in the pocket 23'. By means of the piston 25', the helical spring 100' can be lifted in the pocket 23 in order to be pushed between the leaf springs 61 of the holding device 6' (FIG. 7) if the slide is in the second position relative to the holding device 6'.
The piston 4' has a first straight groove 43, extending parallel to the longitudinal axis of the piston, and a second spiral groove 44 extending over of the circumference of the piston 4. In the position of the piston 4 shown in FIGS. 6 to 8, plungers 53 and 54 are located opposite the associated groove ends and can be brought into engagement with the groove by means of pneumatic cylinders 51 and 52' respectively. The cylinders 51' and are mounted in a cylinder mounting 16 on the base 1'. The plungers 53 and 54' are guided in guides 161'.
The piston 4 is suspended from a return spring 41', whose other end is mounted on a holding pin 18 At this end there is also a pneumatic connection 12' for the pp y of mp ss djit o t e Pi$ t 1. In FIGS- 7 and 8 a feed magazine 9' and an intermediate part? are shown between the feed magazine 9' and receiving duct 11'. In FIG. 7, the feed magazine 9' is shown vertically and horizontally, and in the latter case the intermediate part 8 forms an are into the receiving duct 11'. This drawing of the feed magazine has the object of demonstrating that the device operates independently of the position, and that it is only necessary to supply the helical springs in a suitable manner to the receiving duct 11.
The operation of the device shown in FIGS. 6 to 8 will now be briefly described. With the slide 2' in the position of FIG. 6, a helical spring 100' passes into the pocket 23' of the slide. The sensor piston 3' is actuated and either enters into the interior of the helical springs, or is prevented from doing so, in accordance with the position of the inwardly bent end 101 of the helical spring 100'. A correct or incorrect signal is accordingly derived from the position of the sensor piston 3. Then, the adjusting cylinder 22' is operated for pushing the slide 2' into a position below the holding device 6. By the subsequent actuation of the piston 3', the piston rod 26' pushes the spring 100' between the springs 61' of the holding device 6'. The slide 2' returns into the starting position with the pocket 23' facing the intake duct 11' (FIG. 6). Then the piston 4' is moved by pressure in the downward direction. The signals derived from the sensor piston 3' are used for actuating the adjusting cylinders 51' and 52'. A correct" signal leads to the operation of the plunger 53' which engages into the groove 43'so that the piston 4 moves down, while maintaining its angular position. A mandril 7', operable by a pneumatic system not shown, receives the helical spring and transports it to a processing station, not shown. An incorrect" signal causes the actuation of the plunger 54', so that, during its downward movement, the piston rotates through 180. In this manner, the helical spring, having originally the wrong position, has now again the correct position, Guides 63 and 64 on opposite sides of the holding device 6 engage during the downward movement of the piston 4 an indexing surface 19 which ensures the accurate alignment of the helical spring.
The function ofa pneumatic control for the device in accordance with FIGS. 6 to 8 will now be explained. A source 013 of compressed air acts through a unit 01, containing normally a pressure reducer, a pressure gauge, and a water separator, on a manually operated valve 02. When the valve 02 is switched on, the air pressure acts through a valve 014 on the sensor piston 3' in the cylinder 31'. The main valve 02 is also connected to a clock generator 03 and a switching valve 08 which allows pressure to be applied to the cylinder 51' for the plunger 53 if it is not prevented from doing so by a further valve 07 which is connected to a valve 014 of the clock generator 03. When the cylinder 52 is pressurised, the plunger 54 engages into the spiral groove 44'. The pressure of the valve 014 is connected via a delay member 015, comprising a variable restric tion, and non-return valve by-passing the same, to a further valve 016 of the clock generator 03. When the valve 016 is switched by the pressure from valve 014, it allows the pressure from the pressure source to pass to a valve unit 04 comprising a valve 017 and a delay member 018. Initially, the pressure passes through valve 017 and through a valve 06 to the adjusting cylinder 22' for the slide 2' and after delay through the delay member 012, also consisting of a variable restriction and a non-return valve, to the adjusting cylinder 21 for piston rod 26', at a time at which the pocket 23' of the slide 2' is located under the holding device 6. In consequence, the cylinder 21 pushes by means of the piston rod 26 the helical spring from the pocket 23 between the leaf springs 61'. Meanwhile a delay member 05, associated with the valve 06, responds for switching the valve 06 and terminating the pressurisation of the working cylinders 21 and 22', and to pessurise the cylinder 15 for the piston 4. The pressurisation is again delayed through a delay member 011 in order to wait for a return movement of the cylinders 21 and 22, and therefore of the piston rod 26 and of the slides 2'. A valve 010, delayed by a delay member 09 is operated for pressurising a cylinder 71' for the receiving mandril 7. This takes place at the moment at which the piston 4' of the cylinder 15' has reached its lowest position. Meanwhile, a delay member 019, associated with the valves 014 and 016, has applied the pressure passing through the valve 016, to the valve 014 in order to separate the same from the pressure source 013. The valve 016 is moved back with a delay governed by the delay member 015, so that the valve 107 is no longer pressurised and the piston 4 can return its starting position. Simultaneously, the valve 010 is returned so that also the piston of the cylinder 71 can return the mandril 7. The sensor piston 3' has already returned into its starting position after the switching valve 014 has been disconnected from the pressure source. When the pressurisation of the valve 014 has been terminated through the delay member 019, the sensor piston 3' is again pressurised and a new cycle starts.
When the sensor piston 3 does not move beyond the duct 029 which is connected with the working cylinder 21 the valves 08 and 07 are not set by this connection, so that the working cylinder 52' remains in operation and the plunger 54' engages into the groove 44. During a movement of the piston 4', the latter, therefore, rotates through about its longitudinal axis. If on the other other hand the sensor piston 3 passes beyond the duct 020, the latter is also pressurised and causes the valves 07 and 08 to switch, so that the cylinder 51 is now pressurised and the plunger 53' engages into the groove 43'. The piston maintains now during its movement its angular position.
What is claimed is:
1. A sorting device for helical springs for sorting springs equipped with a mounting leg, said sorting device comprising conveyor means for said springs, a feed duct arranged to receive springs from said conveyor means, a supporting element mounted in said feed duct, a sensor piston adapted to be operated by a pressure source and arranged to engage with a spring resting on said supporting element whereby the piston moves to different positions depending on whether the mounting leg of said spring is in the correct or incorrect position, means for transferring a spring having its mounting leg in the correct position to a station for further processing and means for ejecting a spring having its mounting leg in the incorrect position.
2. A sorting device as claimed in claim 1, in which said feed duct is arranged to receive helicai springs to be sorted and is adjustable to conform with the diameter of the springs to be sorted by means of guide strips.
3. A sorting device as claimed in claim 2 in which said supporting element is located at the end of the feed duct and is provided with an oblong hole by means of which said element may be adjustably mounted.
4. A sorting device as claimed in claim 1, in which a piston means and a correct" duct are provided for springs having the mounting leg in the correct position and a piston means and a return duct leading back to the conveyor are provided for springs having the mounting leg in the incorrect position.
5. A sorting device as claimed in claim 4, in which a guide having a chamfer is provided between said piston means and the return duct.
6. A sorting device as claimed in claim 1 in which a pressure source is connected by an accumulator unit and a manually operable main valve with a clock generator.
7. A sorting device as claimed in claim 6, in which said sensor piston is connected with said clock generator and its pressure side is connected through a correct valve in the inoperative position with .one side of the control slide of a switching valve, whilst the cylinder in the sensor piston communicates with the other side of the control slide of said switching valve.
8. A sorting device as claimed in claim 7, in which the control slide of an ejector valve is connected through a first delay valve and a second delay valve to the pressure source.
9. A sorting device as claimed in claim 7, in which the delay times for the response of said delay valves are adjustable through one-way delay members each consisting of a non-return valve and an adjustable restriction mounted in parallel.
10. A device for the automatic sorting of cylindrical parts, and more particularly for helical springs with mounting legs or cylindrical parts with central bores of different diameters, comprising a feed duct with a support element at its end on which rests a cylindrical portion with its surface, a sensor piston whose axis substantially coincides with the axis of a cylindrical part resting on the support element, a positional sensing device which produces as a function of the position of the sensor piston relative to the cylindrical part a correct or an incorrect signal, and two control devices of which one is adapted to be actuated by a correct signal and the other by an "incorrect signal for the differential treatment of cylindrical parts in the correct or incorrect position, said support element comprising a slide movable by a first adjusting device receiving in a first position a cylindrical part, and located in a second position opposite a holding device whereby the cylindrical part is gripped and retained, whereupon the slide is moved back by said first adjusting device into said first position, said holding device being movable by a second device to and from a place of delivery, and said holding device being rotatably mounted and serving to retain by means of a first control device in the case of a correct" signal the cylindrical part in a first position at the place of delivery, and in the case of an incorrect signal retains by means of a second control device the cylindrical part at the place of delivery rotated through relative to the first position.
11. A device as claimed in claim 10, in which the slide contains a fluid operated piston with a piston rod and a pocket corresponding to the cylindrical part and in which the same is arranged to be retained, said piston rod being arranged to be moved through an opening in the bottom of the pocket and to push in the second position of the slide said cylindrical part into the holding device when the piston is operated.
12. A device as claimed in claim 11, in which the holding device has two spring-loaded, spaced-apart grippers which retain the cylindrical part.
13. A device as claimed in claim 12, in which the holding device has two parallel spaced-apart leaf springs the free ends of which have projections, whereby the cylindrical part held between the leaf springs is prevented from sliding out.
14. A device as claimed in claim 13, in which the distance between the leaf springs is variable.
15. A device as claimed in claim 10, in which said second device is a operated piston which can be moved into a position rotaticii through 180 by operating one of the two control devices.
16. A device as claimed in claim 15, in which the piston of the second device has a first straight groove extending parallel to the axis of the piston and a second spiral groove extending around 180 of the circumference of the piston, one control device having a plunger adapted to engage with the first groove and the other control device having a plunger which is adapted to engage with the second groove.
l7. A device as claimed in claim 16, in which the spiral groove has straight end sections.
18. A device as claimed in claim 16, in which the plungers are connected with fluid operated pistons.
19. A device as claimed in claim 15, in which a return spring is provided for the piston which is arranged to withdraw the piston from the place of delivery.
20. A device as claimed in claim 15, in which an index surface is provided against which rest at choice two opposite surfaces during the movement of the piston to the place of delivery in order to provide alignment for the cylindrical part.
21. A device as claimed in claim 10 and including a movable receiving mandril at the place of delivery for receiving the cylindrical part.
22. A device as claimed in claim 10, in which the cy' lindrical part is a helical spring with a radially inwardly angled end.
23. A device as claimed in claim 10 and including a pneumatic control with a pressure source and valves associated with the individual fluid operated pistons, a pneumatic clock generator, and pneumatic delay members associated with the valves for the timing of the valve operation, and thereby of the actuation of the pistons by the pressure source.