WO2015068147A1

WO2015068147A1 - Dispenser of a wire of a solderable material for soldering pens

Info

Publication number: WO2015068147A1
Application number: PCT/IB2014/065956
Authority: WO
Inventors: Andrea MORONI STAMPA; Patrick SCHÄR
Original assignee: Sefa Sa
Priority date: 2013-11-11
Filing date: 2014-11-11
Publication date: 2015-05-14
Also published as: CH708830A2; CH708830B1

Abstract

Dispenser (1) of soldering wire for soldering pens (30) of the type comprising a pen-like body and a soldering electrode, said dispenser comprising a body shaped so as to rest on the pen body (41) of the soldering pen; an inlet for a wire of solderable material inside a guide tube (33) and a nozzle (4) for dispensing the wire which, during use, is directed towards the electrode (32) of the soldering iron, further comprising a motor-driven device inside the body of the dispenser (1) for imparting a feeding movement to said wire, directing it into said dispensing nozzle (4).

Description

DISPENSER OF A WIRE OF A SOLDERABLE MATERIAL FOR SOLDERING PENS

Field of the invention

The present invention relates to the field of soldering pens. The invention relates in particular to a device for dispensing the wire of soldering material which can be used with various types of pen solders.

Prior art

Soldering pens (or pen-type soldering irons) are well known in the art and are widely used for example in the assembly of circuit boards and electrical or electronic components.

A soldering pen comprises essentially a pen-shaped body, which can be easily gripped with one hand and is provided with a heating thermoelement. The soldering material which is used with these devices consists generally of a wire of metal or metal alloy with a low melting point, typically a tin-containing alloy. For example, in the electronics sectors, a wire of tin alloy with a diameter of between about 0.5 and 1.5 mm is commonly used.

The fully-manual procedure involves holding the soldering iron with one hand and the soldering material in the form of a wire or rod with the other hand. Such a procedure has evident drawbacks, namely poor practicality since both hands must be used and poor precision with regard to dispensing of the soldering material. Therefore automatic wire dispensing systems have been developed.

The most common systems comprise a unit which is separate from the soldering iron and which has inside an electric motor able to impart the desired feeding movement to the wire. Normally, said unit also houses the reel of wire. A guiding spout is fixed to the soldering pen, in the vicinity of the heating element, and is connected to the main unit via a flexible tube inside which the wire runs.

The feeding device inside the main unit typically functions by passing the wire into contact between a wheel operated by a stepper motor and an oppositely arranged pressure wheel, all the above being manually operated via a pushbutton or a pedal.

These systems are at present widely used, but have a number of drawbacks. A first drawback consists in the fact that the feeding device acts on the wire far from the dispensing point, i.e. substantially operates by means of a pushing action. As a result the response of the system is not satisfactory and there is a relatively high risk of the wire jamming, getting stuck or bending, especially when small-diameter wires are used and/or the guide tube has tight bends. The wire is subjected to compressive stresses and may easily undergo irreversible bending deformation, thus becoming no longer usable. In such cases, the operator wastes valuable time correctly repositioning the wire and/or eliminating the damaged wire.

It should be noted that soldering pens are used for precision work which still requires some manual input, in some cases provided by specialized operators, and where the labour cost is significant. There is therefore the need to attempt to eliminate or reduce drawbacks which may cause waste of time and increased costs. Moreover damage to the wire also results in a cost owing to the wasted material.

Another drawback of the systems of the prior art is that, in the region of the two oppositely arranged wheels, a relatively long portion of wire is exposed without any guiding support. Loading a new reel of wire is a delicate operation since it is necessary to ensure that the wire correctly enters the guide tube downstream of the two wheels, and said operation is not always successfully performed at the first attempt. Usually the operator must make several attempts, resulting in wasted time. Soldering irons which incorporate both the wire driving device and the feeding reel are also known. A substantially gun-like soldering iron, which incorporates a wire feeding device, is described for example in the patent US4793541.

These soldering irons do not have the problem of the wire being stressed by a pushing force, but they are heavy and costly and may create difficulties for the operator who is used to work with a soldering pen which, by nature, is small and light, adversely affecting the quality of the work. Moreover, in a company which, for example, has one or more soldering lines which use pen devices, this solution would require replacement of the entire machine park at a high cost.

Summary of the invention

The object of the present invention is to overcome the drawbacks described above and improve the ease of use and the efficiency of soldering pens.

The invention aims in particular to provide a device for feeding the wire of soldering material, which solves the aforementioned drawbacks and which is applicable in a practically universal manner to most soldering pens.

The object is achieved by means of a wire dispenser for soldering pens according to claim 1 , comprising a base shaped so as to rest on the pen-like body of a soldering pen; an inlet for a wire of soldering material and a dispensing nozzle for the output wire; a motor-driven device for imparting a feeding movement to said wire, directing it into said dispensing nozzle.

The body is shaped so as to be adaptable universally to various types of soldering pens present on the market, in particular those intended for the field of manufacturing electrical and electronic circuit boards. In a preferred embodiment, the base of the dispenser has a longitudinal concavity for resting on the substantially cylindrical pen body of the most common soldering pens. More preferably, the base of the dispenser is provided with suitable flanges arranged along the sides of said longitudinal concavity and intended to rest on the pen body of the soldering iron. For example a pair of front flanges and a pair of rear flanges with a preferably trapezoidal shape are provided. The applicant has found that these pairs of flanges allow stable supporting on the pen body of the soldering iron, with suitable adaptation to most of the soldering pens which are commercially available.

Preferably, the body of the dispenser is substantially symmetrical with respect to a vertical longitudinal plane so that it may be used equally with the right hand or the left hand. The dispensing nozzle is preferably interchangeable. Even more preferably, the dispenser according to the invention comprises a device for finely adjusting the axial position of said nozzle. By operating this fine adjustment device, for example by means of a screw, the operator may position with precision the output section of the nozzle at the tip of one heating element of the soldering iron, so that the wire dispensed is correctly subjected to the action of said heating element.

According to another aspect of the invention, the dispensing nozzle terminates in an output mouth with a substantially triangular cross-section, which allows automatic centring of the wire. A further aspect of the invention relates to the wire guide in the vicinity of the zone of contact with the feeding mechanism housed inside the dispenser.

One of the objects of the invention in fact is to improve guiding of the wire in said zone. For this purpose the dispenser comprises a sleeve for guiding the wire towards the zone of contact with the feeding mechanism, said sleeve having a tapered or spout-like end which precisely directs the wire towards the mechanism. Moreover, it is preferably provided with a second sleeve, downstream of the feeding mechanism, arranged to receive the soldering wire after contact with the feeding mechanism and provided with a flared or funnellike inlet mouth for facilitating insertion of the said wire. The term "feeding mechanism" is understood as referring to the means which act directly on the wire, imparting the desired forwards movement, and which may consist of two oppositely arranged wheels.

During use, the dispenser is fixed to the soldering pen for example by means of an elastic strap. The wire is supplied for example from a reel and is guided up to the dispenser by means of a flexible tube.

The invention offers various advantages. The feeding mechanism acts on the wire close to the soldering point and therefore the wire contained inside the flexible guide tube is subjected essentially to a pulling force. This solves the problems of jamming which affect the prior art. The shape of the dispenser and the interchangeable and adjustable dispensing nozzle are such that they may be universally fitted to existing soldering pens. The operator may continue to use the soldering iron which he/she is accustomed to, but with greater productivity; the machine park along an assembly line may be updated at low cost and with immediate benefits. Insertion of the wire, or replacement thereof, may be performed more rapidly owing to the improved wire guiding system in the vicinity of the feeding mechanism.

The invention also relates to a soldering apparatus, in particular for the production of electrical and electronic components, comprising a soldering pen and a wire dispenser as described. The invention also relates to a kit for updating a soldering pen, comprising a soldering wire dispenser according to the accompanying claims.

The advantages of the invention will become clearer below, with the aid of the description of a number of preferred, but non-limiting embodiments. Description of the figures

Fig. 1 is a side view of a dispenser of a wire of soldering material for soldering pens, according to a preferred embodiment of the invention. Figs. 2 and 3 show, respectively, a front view and rear view of the dispenser according to Fig. 1.

Fig. 4 shows a detail of the dispenser according to Figs. 1-3.

Fig. 5 shows a cross-section along a longitudinal plane of the dispenser according to Figs. 1-3.

Fig. 6 shows a detail, on a larger scale, of Fig. 5.

Fig. 7 shows the bottom part of the shell of the dispenser which houses a number of internal components.

Fig. 8 shows a cross-section through the joint for connecting the dispenser according to Fig. 1 to a tube for guiding the wire of soldering material.

Fig. 9 shows the dispenser during use with a soldering pen. Detailed description of a preferred embodiment

Figures 1-3 show a dispenser of soldering wire for soldering pens, denoted generally by the reference number 1.

The dispenser 1 has a base 2 which is shaped so that it can be fitted onto a soldering pen, and advantageously has a concave longitudinal part 2a (Figs. 2 and 3) so that it can be easily adapted to the cylindrical pen body of the soldering pens which are commercially available.

The dispenser 1 is provided at the rear with an inlet 3 for receiving a flexible tube for guiding and protecting the soldering wire.

The internal feeding device, which will be described below, directs the wire into a front nozzle 4 of the dispenser 1 , said nozzle 4 being hollow and suitably shaped. Said nozzle 4 is interchangeable and its position can be adjusted by means of a fine adjustment mechanism operated by a screw 5, this allowing the nozzle 4 to be moved forwards or backwards so as to position the output mouth 6 of said nozzle at the desired point. To allow universal adaptation to soldering pens of the most common type, the dispenser 1 comprises advantageously a plurality of support flanges which cooperate with the concave base 2, allowing the most stable position to be found, substantially independently (within certain limits) from the shape and diameter of the pen body of the soldering iron. In the example, the dispenser 1 comprises a pair of front support flanges 7 and a pair of rear support flanges 8, which extend from the base 2 and have a trapezoidal shape.

The shell of the dispenser 1 has a tapered front part 9 which houses a pushbutton 10 for controlling feeding of the wire, and a part 11 for housing the motor-driven system. Said part 11 has a recess 12 for receiving an elastic strap or other equivalent means for performing fastening to the pen body of a soldering pen.

As can be noted from the views in Figs. 2 and 3, the body of the dispenser 1 is substantially symmetrical with respect to a vertical longitudinal plane P (Fig. 2). As a result of this symmetry, it may be used equally well with the right hand or with the left hand and is therefore suitable for both right-handed and left- handed persons.

The output mouth 6 of the nozzle 4 is preferably triangular, as can be more clearly seen in the detail of Fig. 4. The triangular cross-section allows automatic centring of the soldering wire S which rests on the two sides 13 of the triangle.

The device which performs feeding of the wire is now described with reference to Figs. 5, 6 and 7 which show a particularly preferred embodiment.

Said device essentially comprises a motor-driven roller (or wheel) 21 and a counter-roller 20. Said rollers 20 and 21 , according to a technique known per se, may comprise teeth designed to engrave the surface of the wire in order to facilitate melting thereof. The roller 21 is moved by a stepper motor also housed inside the dispenser 1 and operated by means of the pushbutton 10. In the region of the rollers 20 and 21 there is a zone 22 where the soldering wire S is exposed (and not guided inside a tube) and is into contact with the surface of the said rollers.

Guiding of the wire is however ensured by two sleeves 23 and 24, which are upstream and downstream, respectively, of said zone 22 where the wire is exposed. The first sleeve 23 guides the wire S towards the rollers, while the second sleeve 24 picks up the wire again in order to keep it guided through the front part of the dispenser towards the external nozzle 4.

Said first sleeve 23 (Fig. 6) terminates in a tapered end 25, forming a spout which precisely guides the wire S towards the zone 22 for interaction with the rollers. The second sleeve 24, instead, has a tapered, funnel-shaped or flared inlet mouth 26 which substantially faces the end 25 of the first sleeve 23 and facilitates insertion of the wire S and compensates for any deviation of said wire from the ideal position.

In this way it is possible to reduce to a minimum the area of wire which is not guided and most prone to bending, getting stuck, etc., which risks jamming the entire mechanism and requiring manual action in order to remedy the situation. Moreover, the operation of inserting the soldering wire S before starting operation, or replacement of the wire if necessary, is facilitated. This improved wire guiding system has proved to be more reliable and safer than the prior art.

It can be seen how the second sleeve 24 guides the wire S into the nozzle 4, the body of which extends longitudinally inside the dispenser (Figs. 5 and 7).

The reference number 27 indicates the shell, for example made of plastic, of the dispenser. The reference number 28 indicates a substantially L-shaped support bracket of the motor-driven roller 21. The reference number 29 in Fig. 7 indicates a bottom plate of the dispenser body.

Fig. 8 shows a preferred design of the connection between the dispenser and a flexible tube for containing and guiding the wire S and an electric power supply cable. Said connection is formed with a flexible tube 30 which comprises a first tube 31 made of non-adhesive material, such as Teflon or an equivalent material, inserted inside a further tube 32 connected to the rear inlet 3 via the aforementioned sleeve 23. The electric power supply for the dispenser 1 may be provided, for example, by a twin-core cable inserted inside the aforementioned tube 32, parallel to the tube 31 made of non-adhesive material. This solution ensures a more orderly and cleaner working area, reducing the number of cables and/or tubes required for the manual soldering process.

Fig. 9 shows the dispenser 1 during use with a generic soldering pen 40.

Said soldering pen 40 is known per se and need not be described in greater detail; it comprises essentially a pen-like body 41 terminating in a thermoelement 42 which, during use, heats up to a temperature suitable for melting the wire S.

The soldering wire is wound around an external reel (not shown) and is guided up to the dispenser 1 inside a flexible tube which is formed preferably as the tube 30 shown in Fig. 8 and also provides the electric power supply.

The dispenser 1 is fastened to the soldering iron 40 by means of an elastic strap 43 which is positioned inside the recess 12. From the figure it can be understood how, owing to the concavity of the base 2 and the lateral support flanges 7 and 8, the dispenser 1 is stably positioned on the pen body 41 of the soldering iron, being able to be adapted to different forms and/or diameters of said pen body. The dispenser 1 may thus be practically universally used with a wide range of soldering pens.

It can also be noted how fine adjustment of the front nozzle 4, by means of the screw 5, allows precise positioning of the wire dispensing mouth 6 in the vicinity of the tip of the heating element 42.

During use the operator holds with one hand the assembly consisting of soldering iron 40 and dispenser 1 ; by pressing the pushbutton 10 the desired degree of dispensing of the wire S of solderable material is obtained. The invention thus achieves the objects mentioned above.

Claims

1. Dispenser (1) of a wire of a solderable material for soldering pens, said dispenser being characterized in that it comprises: a base (2) shaped so as to rest on the pen-like body of a soldering pen; an inlet (3) for a wire of soldering material and a dispensing nozzle (4) for the output wire; a motor-driven device (20, 21) for imparting a feeding movement to said wire, directing it into said dispensing nozzle (4).

2. Wire dispenser for soldering pens according to claim 1 , characterized in that said base (2) of the soldering iron has a longitudinal concavity (2a) which can be adapted to various types of soldering pens with a cylindrical pen body.

3. Wire dispenser for soldering pens according to claim 2, characterized in that said base of the dispenser comprises flanges (7, 8) on the sides of said longitudinal concavity and intended to rest on the pen body of the soldering iron.

4. Wire dispenser for soldering pens according to claim 3, characterized in that it comprises a pair of front flanges (7) and a pair of rear flanges (8).

5. Wire dispenser for soldering pens according to claim 3 or 4, said flanges (7, 8) having a trapezoidal shape.

6. Wire dispenser for soldering pens according to any one of the preceding claims, the body of said dispenser (1) being substantially symmetrical with respect to a vertical longitudinal plane for allowing use equally well with the right hand or with the left hand.

7. Wire dispenser for soldering pens according to any one of the preceding claims, said wire dispensing nozzle (4) being removable and interchangeable.

8. Wire dispenser for soldering pens according to any one of the preceding claims, comprising a device for fine adjustment of the axial position of said dispensing nozzle (4) with respect to the body of the dispenser.

9. Wire dispenser for soldering pens according to any one of the preceding claims, said wire dispensing nozzle (4) having a terminal portion with an output mouth (6) having a substantially triangular cross-section for obtaining an automatic wire centring effect.

10. Wire dispenser for soldering pens according to any one of the preceding claims, comprising a first sleeve (23) for guiding the soldering wire towards a feeding mechanism, said first sleeve having a tapered or spout-like end (25).

11. Wire dispenser for soldering pens according to claim 10, also comprising a second sleeve (24) for guiding the wire downstream of said mechanism, and said second sleeve having a tapered or funnel-like inlet mouth (26) for receiving the soldering wire after it has passed through said feeding mechanism.

12. Wire dispenser for soldering pens according to claim 10 or 11 , said feeding mechanism comprising at least one motor-driven roller (21) and an opposite counter-roller (20).

13. Kit for updating a soldering pen, comprising a dispenser of soldering wire according to any one of the preceding claims.

14. Kit according to claim 13, comprising a tube made of non-adhesive material (31) for guiding the soldering wire and an electric power supply cable for operation of the dispenser, which are inserted inside a single support tube (32).

15. Soldering apparatus, in particular for the production of electrical and electronic components, comprising a soldering pen (40) and a device (1) for dispensing soldering wire according to any one of claims 1 to 12.