DE102009050569B4 - Contact pin for use on lighting means and method for its production - Google Patents

Abstract

A method for producing a contact pin (01), in particular for use in lighting, comprising the following method steps: (A) forming a sheet metal strip (02) by profile rolling in several stages to form a largely closed tube (03, 04, 05); (B) Cutting the straight tube (05) to length to form the contact pin in the form of a hollow cylinder (06) (C) Slitting the contact pin (01) on the luminaire pull1) to form a plurality of segments (12), which are guided by slots ( 11) are separated and are used to fix the contact pin (01) on the lighting means by bending the segments (12) radially outwards, the saw cut (11) lying in a plane displaced parallel to the axis of the contact pin (01), and where a slot (11) is formed through the gap (07) formed by the edges of the sheet metal strip on the hollow cylinder (06).

Description

The invention relates to a method for producing a contact pin for use on lighting means, wherein initially a metal strip is formed into a tube and this is cut to the contact pin below.

Various methods for the production of contact pins are known from the prior art. A common method is to produce the contact pin contour from a rod material. This can be done first by a forming process and / or by machining. By this method, a great freedom of design for the shape of the contact pin is achieved. Among other things, the required tolerance in terms of the outer diameter can thus be achieved in a simple manner.

The disadvantage here, however, is the complex and expensive processing method. Since only short cycle times are possible, this leads to a high unit price of the contact pin.

As an alternative, systems are known from the prior art, in which from a settlement of the contact pin by a plurality of successive forming processes of the finished contact pin is formed. The required development as starting material for the forming process is punched out of a sheet metal plate for each individual contact pin. The conversion from a planar material to the finished contact pin requires a variety of follower tools to create the round body. These many tools require the corresponding frequent change from a tool nest in a subsequent tool nest. This requires complicated automation in order to enable economical production.

In order to keep the effort within limits, a plurality of contact pins is usually produced at the same time. For this purpose, remains during punching a plurality of developments via webs connected to a transport grid. Thus, the transfer from a tool nest into the following tool nest also takes place simultaneously for a plurality of contact pins. This measure is also required to ensure the necessary precision when inserting into the tool nest. This transport lattice can comprise both a plurality of developments as well as a plurality of deformation stages in the process sequence.

Regardless of the fact that a considerable cost advantage has already been achieved in contrast to the made of solid pin, the problem remains with the grid, which in turn means a large proportion of waste material used for the production of the contact pins.

For this the writing beats US 2005/0136754 A1 First, to form a slotted tube from a sheet metal strip. In subsequent multi-stage forming process by means of pressing and rolling tools upsetting processes are performed on the slotted tube. The later contact pin is formed by the compression process, a federal government. Furthermore, areas of reduced diameter are formed. In these, the separation of the sectionally transformed endless tube is carried out in the individual contact pins.

Although it is indicated in the document that by means of pressing and rolling tools, a change in the diameter while achieving a high quality is possible, the implementation has in practice, however, shown to be very expensive, especially in terms of the number of process stages. In particular, an inevitably incomplete enclosure in the continuous tube during shaping leads to a deformation starting from the initially round shape, in particular due to the existing slot.

The mounting of pins is exemplified in the Scriptures US 2,454,326 A presented. Here, the contact pins are inserted into a lower tool and the housing of the lighting fixture placed over it. The end of the contact pin to be fastened in the housing projects beyond the housing inside. With a multi-stage stamping tool the end is bent up by means of expanding mandrels with cutting edges and at the same time cut. Thus, several wings are formed, which come to rest on the inner housing wall. Thus, the secure attachment is given in the housing.

The problem with the previous version, however, is that relatively high forces for bending and separating the end of the contact pin are required. These lead to the requirement of a particularly accurate and stable recording of the contact pins and thus complicate the mounting of the contact pins on the housing of the lighting fixture.

For the use of mainly very small material thickness suggests the font DE 36 10 086 A1 also the use of an endless tube formed from sheet metal strips as a contact means. Here, in the housing used, the end of the contact means is expanded by an expanding mandrel, starting from the seam of the slotted tube, a V-shaped notch is formed.

The EP 057 633 A1 describes a contact element that is formed by machining. To produce two slots at the end of the contact element, which serve to receive transverse to the contact element extending wires, the contact element at one end with a provided by the axis of the contact element extending saw cut.

To improve the widening of the end of the contact pin, however, recourse is again made to the known method with individual sheet metal sections. In this case, the endless sheet strip is separated meandering in two halves. This results in the later segments at the end of the contact pin. From the sheet metal strip first individual sheet metal sections are generated and this subsequently transformed into a tube. Thus, however, the production costs increase considerably.

In this respect, it is an object of the present invention, starting from the known system of the prior art with individually formed sheet metal pins this further develop to the effect that no waste is produced. It is important to allow easy mounting of the contact pin in the lighting fixture.

This is realized by the method according to claim 1 according to the invention and in this case generates the contact pin according to the invention according to claim 9.

Advantageous embodiments are the subject of the dependent claims.

A method according to the invention is proposed for the production of contact pins for use on illuminants, with which the task of eliminating the waste is solved. An essential feature is the process sequence with a first forming process in which a continuous sheet metal strip is formed by profile rolling in several stages to form a substantially closed tube. This essentially endless tube is cut to length in a subsequent process step.

In a frequently encountered use of the contact pin this is riveted in the base of the electrical device or the lighting means. In this case, the sleeve of the contact pin is bent in the housing behind the wall to the outside.

According to the invention, therefore, the Nietansatz consists of several segments instead of a hollow cylinder. Accordingly, slots are made in the sleeve at the second end. This is done in the inventive embodiment by at least one saw cut, which generates parallel to the axis with a cut two slots. In this case, a slot is already formed by the fact that the gap is present in the sleeve.

Thus, the contact pin according to the invention for use on lighting means, wherein the contact pin forms a hollow cylinder at least in sections. The hollow cylinder is required in order to be able to guide and contact a contact element, usually a wire, of the luminaire. The basic feature of the contact pin is that this hollow cylinder is formed from a portion of a profile-rolled sheet metal strip. The result of the manufacturing process is that the edges of the metal strip form a gap on the hollow cylinder, whereby the gap is consequently parallel to the longitudinal axis of the contact pin. According to the invention, the contact pin has a plurality of slots at the end. These significantly improve the subsequent use and assembly of the contact pin in the housing of the lighting fixture. A particular advantage of the manufacturing method according to the invention is the unchanged low production costs despite the now simplified to be mounted embodiment.

In general, the contact pin will be hollow throughout and is surrounded only by the lateral surface. However, it is also conceivable to provide the contact pin with further elements or further reshape.

As intended use of the contact pin, only illumination means are initially provided from the existing field of application. However, it is equally conceivable to use such a contact pin for other purposes. This is especially true for use in the functional task as on one side often easy to install plug-in contact for making an electrical connection, the second side is intended to be firmly connected to an electrical device or means. Thus, it is obvious that the term lighting means is not limited to lighting, but in terms of the purpose of the contact pin.

In an advantageous embodiment, the deformation in the first step is initially carried out by two, in particular more than two, first pairs of rollers. Here are the axes of the first pairs of rollers perpendicular to the plane of symmetry of the metal strip in the transformation. The plane of symmetry is in a perpendicular manner perpendicular to the metal strip and passes through the center of the metal strip or the tube formed below. The arrangement of the first pair of rollers, a progressive deformation is achieved mainly in the direction perpendicular to the metal strip. Advantageously, the edges of the sheet metal strip are first bent and form a first portion on both sides of the gap of the later resulting tube. Subsequently, the forming is continued until the middle of the metal strip.

In a subsequent forming another, second pair of rollers is required to form the largely closed tube. In this case, the axes of the second roller pair are advantageously perpendicular to the sheet metal strip plane. The sheet metal strip plane is the plane that runs through the undeformed metal strip. By this arrangement it is achieved that the partially formed to the pipe sheet metal strip is further closed and a tube is formed with a groove.

It should be noted that advantageously the pairs of rollers are aligned in parallel or perpendicular to the sheet metal strip plane. However, it is also possible to reject it to a small extent and to replace a required pair of rollers by a plurality, at least two, which are arranged alternately on both sides of the parallel or vertical axis, for. B. 10 ° pivoted to the left and in the following 10 ° to the right.

In order to achieve an exact cylindrical shape, the first process step is extended in a particular embodiment in the following to additionally a contour smoothing after the forming. For this purpose, the largely closed tube is guided with groove from the previous forming process through a first receptacle. Through this recording, the diameter of the tube is reduced and the existing groove is reduced in width. Accordingly, the receptacle has a diameter in the outlet of the receptacle, which is smaller than the diameter of the tube supplied before recording. For supporting and centering, a cylinder comes to rest inside the tube. This is not exactly to be understood as a cylinder, inasmuch as there is a slight conicity, which is reduced from the tube inner diameter before this process step to the tube inner diameter after the process step. The connection of the cylinder is advantageously carried out before recording, wherein the cylinder is connected via a connection through the groove in the tube fixed to the first receptacle.

To produce the necessary tolerance accuracy of the tube, this tube with a reduced groove width is guided in the following in a further process step through a second receptacle. For this purpose, in particular a tensile force is applied after the second shot to the finished calibrated tube. As a result, an exact outer diameter is achieved with the required tolerances. If the groove width has not previously been reduced to the minimum in the process step, the groove width is reduced to the gap at the latest by this calibration process, in which the two edges of the sheet metal strip substantially touch.

It should be noted that in the technical embodiment, the first receptacle and the second receptacle structurally form a unit.

In the contact pin forms a first end, a contact portion, the intended plug-in contact and is designed to be assembled and disassembled many times. A second end, a mounting portion on the other side of the contact pin, is provided to be fixedly connected to the electrical component.

According to an advantageous embodiment, the first end is slotted by means of a saw cut. Thus, at least two or more slots are introduced into the end of the contact pin at the first end.

In the standard version as a contact pin, it is necessary that the first end of the contact pin has a tapered end in the manner of an insertion bevel to allow safe easy use of the contact pin. For this purpose, a taper is advantageously formed at the first end by means of a further process step. This is done in a simple design by a compression process. In addition, the taper is provided to connect the conductor or the cable by soldering or welding to the contact pin in the region of the taper. If the first end of the hollow cylinder is first slotted at the first end, this facilitates the diameter reduction.

If special accuracies with regard to the inner diameter in the area of the welding with the wire are required, it is also possible to subsequently calibrate the taper through mandrels or if necessary to machine it by a cutting process.

The first end is particularly intended to create the taper at the fusion with the wire. In this process, the end is further rounded so that a safe and easy installation in the application of the contact pin is given.

When used as a contact pin in lighting means, the assembly in this lighting means is simplified in that a covenant in approximately the middle of the contact pin, or depending on the embodiment in deviating position, is present. This collar forms a stop, which defines the exact axial position in the manufacture of the lighting means on the one hand when inserting the contact pin in the intended opening in the lighting means. On the other hand, the federal government forms the fixation of the contact pin in the lighting means when it is fastened by means of rivets therein.

This collar is created by a compression process of the contact pin. As a result, the length of the abgesägten pipe section is reduced, and the sleeve expands locally forming the radially projecting collar. Alternatively, it is also possible to provide this process step before, if used, process steps of sawing and upsetting to form the taper. In this regard, the order is irrelevant. Optionally, the compression processes to form the taper and to form the collar can also be done simultaneously.

In order to enable easy mounting of the contact pin in the socket in the manufacturing process of the electrical means, it is advantageous if in a further method step, the second end is formed into a cone. The cone is not to be understood in the obvious way as an exact rotational envelope surface, since this is formed by the bending of the segments in the radial direction inwards.

In a further use, it is also possible to pour the contact pin in an injection molded part. For this purpose, advantageously at the second end an anti-rotation and pull-out protection is generated, which is represented in the form of wings, which are produced by bending the segments.

Although the component is virtually burr-free by the method according to the invention, the contact pin can be deburred by a subsequent final method step.

As a starting material for this process according to the invention, a straight sheet metal strip is required. Of less importance is the length of the metal strip, with a long length is more advantageous over a shorter length, insofar as fewer process interruptions are the result. The metal strip may optionally be designed as a flat sheet material, but is advantageously supplied wound up on a coil. In this respect, it is necessary in a step before the actual deformation of the tube to unwind the metal strip from the coil and straighten it by a system so that it can be fed to the process step according to the invention.

By means of the method according to the invention, it has been possible to produce a contact pin according to the invention which can be produced without waste and can thus be produced even more cost-effectively than the contact pin known from the prior art.

In the following figures a possible use of the method according to the invention is outlined with the following steps:

1 shows the first process with the transformation of the sheet metal strip to the pipe with gap;

2 shows a possible embodiment with further follow-up processes to form an embodiment of the contact pin.

Furthermore, exemplary variants of contact pins are shown in the following figures:

3 shows various embodiments of a contact pin according to the invention;

4 shows a plan view of an embodiment.

In 1a is outlined that the output of the method according to the invention is a substantially straight sheet metal strip 02 is required. This can be straightened after settlement of a coil of a straightening system.

The 1b1 outlined an advanced embodiment of the method according to the invention with the sequence of the transformation by means of three first pairs of rollers 13a.1 & 13a.2 → 13b → 13c ,

The 1b2 outlined in the extended embodiment, the following transformation by means of a second pair of rollers 14.1 & 14.2 to the pipe with a groove.

The 1c1 outlined in a further extended embodiment, the following transformation by means of a first shot 15 into which the pipe with the groove 03 is introduced and after leaving the diameter and the groove width are reduced to the tube with reduced groove 04 , Inside the tube with the groove 03 is a cylinder 16 which has a connection 17 connected to the recording (not shown).

The 1c2 sketched in the further embodiment, the subsequent transformation by means of a second recording 18 into which the tube with reduced groove 04 is introduced and after leaving the diameter of the nominal size and the groove width are reduced to the gap and thus the pipe with the gap 05 form. It is essential that in this case a tensile force is exerted on the tube with gap and consequently the tube is pulled through the second receptacle.

In the 2 is an exemplary embodiment of a contact pin 01 illustrated with an exemplary sequence of advantageous for the production process steps. First, the pipe with the gap 05 cut to length and forms the hollow cylinder 06 , This is subsequently slit on a first side by sawing 11a , A first upsetting process reduces the length, and a waistband 08 arises. A second upsetting process reduces the first side and creates a rejuvenation 09 , Again, the component is now sawed on the second side, and there is again a slot 11b and corresponding segments. By a final forming process, the segments are bent inwards and form a cone 10 ,

The 3a shows an exemplary embodiment of a contact pin 01 consisting of the hollow cylinder 06 which according to the inventive production a gap 07 has. In about the middle is the federal government 08 , and at the first, lower end is a rejuvenation 09 shown. At the second, upper end are three segments 12 formed by slits 11 and the gap 07 are separated and a cone 10 were formed.

The 3b . 3c and 3d show further possible embodiments of contact pins 01 ,

The 4 shows a plan view of the exemplary contact pin 3a , It can be seen that the covenant 08 radially above the hollow cylinder 06 survives. Likewise, the gap 07 clearly, which runs over the entire contact pin length. To separate the segments 12 a saw cut is attached, which with a cut two slots 11 generated.

Claims (12)

Method for producing a contact pin ( 01 ), in particular for use on illuminants, comprising the following process steps: (A) forming a metal strip ( 02 ) by roll forming in several stages to a largely closed tube ( 03 . 04 . 05 ); (B) cutting the straight tube ( 05 ) for forming the contact pin in the form of a hollow cylinder ( 06 ) (C) Slots of the contact pin ( 01 ) at the end facing the illumination means by at least one saw cut ( 11 ) for forming a plurality of segments ( 12 ) through slots ( 11 ) are separated and the fixing of the contact pin ( 01 ) on the illumination means by radially outward bending of the segments ( 12 ), whereby the saw cut ( 11 ) in a direction parallel to the axis of the contact pin ( 01 ) and a slit ( 11 ) through the gap formed by the edges of the metal strip ( 07 ) on the hollow cylinder ( 06 ) is formed. A method according to claim 1, characterized in that in step (A) (Aa) first a deformation by at least two, in particular more than two, first pairs of rollers ( 13 ), wherein the axes of the first pairs of rollers ( 13 ) perpendicular to the plane of symmetry of the sheet metal strip ( 02 ) are in the transformation; (Ab) and wherein in a subsequent forming by at least one second pair of rollers ( 14 ) the sheet at least substantially to a pipe ( 03 . 04 . 05 ), wherein the axes of the second roller pair ( 14 ) perpendicular to the sheet metal strip plane ( 02 ) lie. A method according to claim 2, characterized in that after the step (Ab) in step (Ac) first a contour smoothing takes place, for which purpose the pipe ( 03 ) by a first shot ( 15 ), whereby in this case inside the tube ( 03 ), especially before the first recording ( 15 ), a cylinder ( 16 ) comes to rest, the cylinder ( 16 ) fixed with the first shot ( 15 ) connected is; (Ad) and in the following the final calibration takes place, for which purpose the tube ( 04 ) by a second recording ( 18 ), and wherein in particular a tensile force after the second recording ( 18 ) on the finished calibrated tube ( 05 ) is applied. Method according to one of claims 1 to 3, characterized in that after step (B) one end of the contact pin ( 06 ) by at least one saw cut ( 11 ) is slotted. Method according to one of claims 1 to 4, characterized in that after step (B) a first end is compressed, wherein a taper ( 09 ) is formed. Method according to one of claims 1 to 5, characterized in that after step (B) by a compression process, the length of the tube ( 06 ) is reduced from step (B) and at the same time a radially projecting collar ( 08 ) between the two ends of the contact pin ( 01 ) is produced. Method according to one of claims 1 to 6, characterized in that after step (C), the second end is deformed such that this a cone ( 10 ). Method according to one of claims 1 to 7, characterized in that before the step (A) of the sheet metal strip is unwound from a sheet metal coil and is guided through a system, after leaving the sheet metal strip ( 02 ) is substantially straight in the strip direction. Contact pin ( 01 ) for use on illuminants, wherein the contact pin ( 01 ) at least partially a hollow cylinder ( 06 ), in which a contact element, in particular a wire, of the illumination means is contactable, wherein the hollow cylinder ( 06 ) from a section of a profile-rolled sheet metal strip ( 02 ) is formed, wherein the edges of the sheet metal strip a gap ( 07 ) on the hollow cylinder ( 06 ) parallel to the longitudinal axis of the contact pin ( 01 ), characterized in that the contact pin ( 01 ) has an end facing the illumination means, said end having a plurality of segments ( 12 ) through slots ( 11 ), in particular the slots ( 11 ) a bend of the segments ( 12 ) allow radially outward, thus the contact pin ( 01 ) to fix the lighting means, with a slot ( 11 ) through the gap ( 07 ) on the hollow cylinder ( 06 ) is formed and that at least two slots ( 11 ) in a direction parallel to the axis of the contact pin ( 01 ) shifted plane lie. Contact pin ( 01 ) according to claim 9, characterized in that the contact pin ( 01 ) in an area between the two ends at least one collar ( 08 ), whereby the federation ( 08 ) a stop for use of the contact pin ( 01 ) forms in the lighting means. Contact pin ( 01 ) according to claim 9 or 10, characterized in that the contact pin ( 01 ) has a first end facing away from the illumination means, the first end having a taper ( 09 ) owns. Contact pin ( 01 ) according to one of claims 9 to 11, characterized in that the segments ( 12 ) at the second end in the direction of the illumination means to a kind of cone ( 10 ) are formed.

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