DE2731018C2 - Method and device for the production of self-locking nuts - Google Patents

Description

The invention relates to a method for producing self-locking nuts by applying at least a layer of thermoplastic material on the internal threads of the nuts, in which the nuts be transported along a processing line on which a thermoplastic powder is sprayed into them which melts on the threads as a result of their preheating and runs into a layer The invention also relates to a device for carrying out the method.

From US-PS 38 94 509 a device for the production of self-locking nuts is already known. In her nuts are first heated and then stored in receptacles of a carrier which transports the nuts along a processing line. Spray pipes are arranged on the carrier in a fixed association with the nuts carried by it in such a way that their free ends are aligned with an internally threaded region of the nuts. The other ends of the spray tubes are moved by the transport movement of the

The carrier is connected to a powder feed device within the processing line, which does the spraying the internal thread areas of the nuts with a thermoplastic powder, which is attached to the Thread turns as a result of their preheating melts and runs to a layer each, which during cooling stiffens. The self-locking effect of the nuts is due to the fact that they only work on one internal thread area achieved a respective nut applied layer of thermoplastic material.

For most uses, the locking action has been found to be as described above layer applied to only one internal thread area of a nut is sufficient. For certain purposes however, the achievable barrier effect was too low. By creating a thicker layer of thermoplastic material, the barrier effect can be increased slightly, the increase that can be achieved is limited, however, as an excessively thick layer application requires screwing the nut onto a threaded bolt

makes t <5 zcn impossible.

It is therefore an object of the invention to provide a way of producing self-locking nuts Application of thermoplastic material to the internal threads of the nuts to indicate with which the self-locking Effect of the nuts is significantly improved.

This object is achieved according to the invention on the basis of a method of the type mentioned at the beginning

- Solved that the nuts at at least one intermediate station of the processing line by a predetermined Angle are rotated around the axes of their threaded holes.

In the method according to the invention, analogous to the known method described above, first a layer of thermoplastic material on an internal thread area of a respective nut applied in sufficient thickness. Then the nut is at an intermediate station of the processing line, on which the thermoplastic powder is sprayed into it, by a predetermined angle around the Axis of their threaded hole rotated, so that the thermoplastic material on a further internal thread area is applied. This layer of thermoplastic material also has a sufficient thickness reached, the mother can at a further intermediate station of the processing line again by one are rotated predetermined angle around the axis of their threaded hole, with the result that the thermoplastic Material is applied to a third internal thread area of the nut.

Depending on the number of intermediate stations at which the nuts each by a predetermined angle around the Axes of their threaded holes are rotated, layers of thermoplastic material are placed on top of each two or more internal thread areas of the nuts applied.

- Because each layer of thermoplastic applied to the different internal thread areas Material a certain barrier effect is achieved by the simultaneous application of several Layers on the internal thread of a nut significantly increase their self-locking effect.

In a further development of the invention, a layer of thermoplastic material is applied after each application Material jnterbunden and spraying during the turning process of the nuts at the intermediate station

ψ Another layer of thermoplastic material is then applied! upset. The first birth

^ The spraying of thermoplastic material is particularly advantageous if the nuts during the

t; The turning process has also been lifted or shifted, for example, as this prevents

X that thermoplastic material is applied to undesired areas of the mother.

A device for carrying out the method, with a carrier for transporting the nuts, with at the

In a further development of the inventive concept, the spray pipes arranged in the processing line and with a powder feed device that can be connected to the spray pipes is constructed in such a way that a rotating device for turning the nuts is provided on the processing line, the structural design of which is the subject of further dependent claims

A preferred embodiment is explained in more detail below together with the figures.

Fig. 1 is a perspective view showing an apparatus for manufacturing self-locking nuts represents according to the invention;

F i g. 2 is a plan view of the FIG. 1 shown device with left parts to underlying To clarify features;

F i g. 3 is a cross section along III-III in FIG. 2 showing details of the construction;

F i g. Figure 4 is a cross section along IV-IV in Figure 4. 2, which shows further details of the construction: F i g. Figure 5 is a cross section along V-V in Figure. Fig. 4 showing this part of the structure in detail; FIG. 6 is a plan view showing a part of the structure singled out in FIG. 2 for clarification in shows on an enlarged scale;

F i g. 7 is a top plan view of the structure of FIG. 6;

F i g. 8 is a plan view showing another area of the i: FIG. 2 selected structure for clarification shows on an enlarged scale;

F i g. 9 is a top plan view of the FIG. Structure shown in Figure 8;

Fig. 10 is a perspective view of the apparatus shown in Fig. 1 with parts removed were to show underlying features;

F i g. 11 is a partial supervision of the in F i g. 10, on an enlarged scale, showing the operation of turning the nut shows;

F i g. Figure 12 is a partial top plan view of an apparatus similar to that of Figure 12. 1 on an enlarged scale, however with another embodiment a nut turning device;

F i g. 13 is a section as shown in FIG. 12, one based on the one shown in FIG. 12 stage shown below the stage Shows rotation of nut;

F i g. 14 is a schematic partial top view in the direction of the arrows at the end of the line XIV-XIV in FIG. 13. In particular in FIGS. 1 and 2, a device for producing a self-locking hexagonal nut N is shown, which generally has a rotatably mounted transport device in the form of a turntable or turntable 10, which rotates along a predetermined rotational path about its central axis in the direction of FIG. 1 and 2 arrows shown is movable

Since the table 10 is continuously rotated about a fixed bearing body 11, a point passes through 'The table 10 has numerous stationary work areas, which are referred to below as process stages

should.

During the first stage of the process, a feed chute 12 is set, which is down towards the surface of the table 10 is inclined, the hexagonal nut N on the table and during a next stage becomes a elastic thermoplastic material in powder form in two parts on angled apart Faces of the internally threaded surfaces of the nut applied. This stage is essentially through a vacuum hood 13 completed, the operation of which is explained in detail below.

During the next stage of the process a second accepts upwardly inclined chute 14, whose one end is the table mounted adjacent 10 Muttei N of the table 10, whereupon the located in the subsequent stage of the process, the 'm substantially between the settling station and the removal station The area of the table occupies the device for applying thermoplastic material to the

Nut Λ / is cleaned of remaining material and made available for the next work sequence.

It is from FIG. 1 it can be seen that the stationary bearing body 11 has a hopper 15 which receives the powdery elastic thermoplastic resin for application to the internal threads of the nut N; this procedure is explained in detail below.

According to FIGS. 2 to 5, the table 10 has a hub 16 with a plate 17 which, on its uppermost surface is attached, and a throat 18 for receiving a V-belt 19 with a (not shown) engine connected is. The hub 16 is in sliding engagement with the central bearing body 11 and is of the motor-driven V-belt 19, the hub being mounted in a pair of bearings 20,21.

Furthermore, FIGS. 2 to 5 show that the hub 16 has several openings 22 with a circular cross section

! 0, each of which has an inner opening to the bearing body 11 and at the opposite end a Receives tube 23, the tube and the opening together forming a conduit, as further below in is explained individually.

As best seen in Fig. 2, the outer circumference of the plate 17 has numerous V-shaped recesses or receptacles, each of which has a tongue 25 attached below, which extends from the respective

is receptacle or recess extends outwards and a pocket or cavity for receiving a hexagonal nut A / of the type shown. Each tube 23 has a U-shaped support plate 26, which is connected to it by welding or some other measure, and several screws 27 are used for connecting the support plate 26 to the plate 17, the respective tongue 25 being held therebetween. Every Tongue 25 has a circular opening and the outer end of the tube 23 is at an angle of approximately

Carried 45 ° upwards and extends through the circular opening in the tongue and a little over the Tongue to a position that brings the outer end of the tube into a hexagon nut that the from the respective V-shaped recess 24 formed pocket is received.

In particular in FIGS. 3, 4 and 5 it can be seen that the bearing body 11 has a hollow central opening 28 has, into which the hopper 15 is inserted, and which extends to a point in the vicinity of the bearing body floor extends. The central opening 28 is flanged to the outside near its center point and has a slot-shaped opening 29 which extends around the bearing body 11 essentially by 180 ° with the exception of a blocked section 29 (a) between the length of the slot-shaped opening 29 The slot leads from the flanged area of the central opening 28 to the outside of the bearing body 11 and is aligned with the openings 22 when the table 10 is attached to the bearing body 11. A conical divider

30 is attached in the flanged area of the central opening 28 and is on the wall of the opening in the

Fastened to the wall area which is not cut away by the slot-shaped opening 29. The divider 30 thus separates

the upper area of the opening 28 from the lower area over the entire circumference of the opening

With the exception of the area in which the slot-shaped opening 29 is attached. An inlet port 31 extends into the opening 28 at its lowermost end and is to a source for Pressurized fluid, such as. B. a (not shown) air pump connected.

Diametrically opposite the slot-shaped opening 29 and in the vicinity of the outer edge of the bearing body A number of vertical circular cavities 32, four in all, are attached to each other, which look best F i g. 2 can be seen. Each cavity 32 ends at its lower end in a chamber 33 with a larger Diameter and at its upper end at a second slot-shaped opening 34, which is similar to the diametrical opposite slot-shaped opening 29. In this case, the slot-shaped opening 34 extends from the outer circumference of the bearing body 11 over a circumference of approximately 150 ° to an inner wall 35, as in Fig. 2 can be seen. The slot-shaped opening 34 is aligned with the openings 22 and forms therefore a flow path from the tubes 23 through the chamber 33 to which a vacuum source (not shown) is connected when the tubes 23 are moved into the area over which the opening 34 is formed

As is particularly evident from the construction in FIGS. 3 and 4, the table 10 can be removed because of the removable Retaining plate 36, which is fastened by means of four screws 37, can easily be removed from the bearing body 11. if the screws 37 are removed, the holding plate 36 can be lifted off in front of the component; the table 10 can removed and then replaced by a table that can accommodate fasteners with Internal threads of a different size or shape than those received by the table 10 shown

be so, serve

Since it is necessary to create a sliding seat between the table 10 and the central bearing body 11, there is a very pronounced possibility that the material between the tubes 23 and the slot-shaped opening 29, or the tubes and the slot-shaped opening 34, will move tends to escape between the outer surface of the bearing body 11 and the inner surface of the hub 16 of the table. Therefore a pair of circumferential grooves 38 and 39 are formed in the hub 11 which extend completely around the hub A vertical bore 40 extends at a point which is adjacent to the inner wall 35 of the slot 34 from the bore 43 (40) and is connected to a compressed air source (not shown) for supplying pressurized fluid provided in the bore 40. Therefore, material that tries to find a path between the hub 16 and the Finding the bearing body 14 is prevented from any air flow from the grooves 38 and 39 into the openings 29 and 34 takes place

The F i g. 1 and 2 it can be seen that the vacuum hood 13 is divided into two for reasons of convenience only Parts is divided, the two parts taken together covering the area around the bearing body 11, wherein the slit-shaped opening 29 is formed, that is, the entire area on which the powdery thermoplastic resin supplied through the pipe 23 is all around covered by the hood 13 both parts of the hood 13 are formed essentially the same and therefore only the first, in FIG. 1 part shown in individually described.

Each hood portion has a chamber 44 which is provided by a vacuum generating device (not shown) is kept at negative pressure. A cover plate 45 extends from the hood 13 to a location above the table

10 to the outside, which serves to cover a nut N located on the table. In order to equalize the vacuum under the whole hood 13, several partitions 46 are provided in each part of the hood 13, which serve to form several separate vacuum spaces, each with substantially the same negative pressure as the space above the nut N, which is in the vicinity the hood opening is located.

The illustrated feeding device comprises the chute 12 which is mounted adjacent to the periphery of the table 10 and whose lowermost chute delivery surface is arranged at a slight distance from the surface of the plate 17 and has an outer rail 47 which extends over an inner rail 48, such as best from FIGS. 6 and * i 7 can be seen. The distance between the outer rail 47 and the inner rail 48 corresponds essentially to the width between the tips of the hexagonal region of the nut N which is fed to the table 10. Therefore, as shown in FIGS. 6 and 7, the nuts themselves wrench face to wrench face when they slide down the chute 12 and are therefore aligned to be received in the V-shaped receptacles 24 of the table K). A portion 49 of the chute 12 is made of a material having suitable non-inductive and refractory properties and extends through an induction coil 50, suitably wound and positioned adjacent the chute area, around a nut N, which slides through the area, to heat. The nut N can be fed by any suitable commercially available feeding device, e.g. By a vibrator or other type. Such devices are known in the art; they are of no importance for the description of the present invention and are therefore not shown.

vv JC ΠΊαΐΐ aiiS ι 'ί g. £ removes, iCGfiricn uic äüicinänucriOigciiucFi nuts, uic FiaCnc to FiaCiic äüSgcfiCutci

are to be regarded as a chain, the tips of which fit into the 120 ° recesses 24 of the plate 17, which the Appearance of a gear.

However, if one looks at any nut in the row of nuts on table 10, it can be seen that the surfaces of neighboring nuts with the walls of the receptacle that belong to the nut under consideration, form a deep slot, the side walls of which, formed by the surfaces of adjacent nuts, diverge due to the radial alignment of the nuts. The free space between the wrench flats the considered mother and the diverging walls of the receptacle give limited play for a rotation of the considered mother, which is of importance for the turning or turning of the mother, such as is explained below.

The rotation of the table 10 at a uniform speed serves as a speed control for the system. When a nut N reaches the lower end of the chute 12, it is lowered over the opening of an ear 23 and also increasingly comes into matching contact with the V-shaped receptacle 24 of the plate 17. When the table 10 then rotates, the mother continues to move forward. The nut is guided in close engagement with the 120 ° socket through the outer rail 47 of the chute 12, even at speeds of about 600 nuts per minute.

A similarly constructed slide 14 is attached to the side of the table 10 opposite the slide 12, as can best be seen in FIGS. 8 and 9 in conjunction with FIG. The chute 14 serves to remove the nuts N from the table 10 and is inclined similarly to the chute 12, the lowermost end, which in this case is the nut receiving end, is attached next to the head of the table 10 and has an outer rail 51 extending across the inner rail 52. Both rails have essentially the distance between the hexagon area of a nut N. The uppermost end of the chute 14 can - »o be left open, whereby the nuts / Vin can drop a container (not shown); it can lead to another chute or conveyor to transport the nuts to a subsequent processing or storage area.

In the particular construction of the chutes 12 and 14, the outer rail 47 forms the chute 12, as in FIG. 6 shown, a device to guide the nut Nm the correct position in the V-shaped receptacle 24 of the table 10, after which the nut by means of an elastic pressure device, such as. B. spring clips 60, can be held at the point that exerts a radially restraining force on the nuts.

In an intermediate area of the path between the chute 12 and the chute 14, which corresponds to the position of the blocked area 29foJ in the slot-shaped opening 29, a device for turning or turning the nuts is provided. In the case of hexagon nuts, the angle of rotation is 60 ° or a multiple of 60 ° corresponding to the radial angle between adjacent corners of the hexagon nuts. The rotary device shown is a resilient finger 62 which serves as a stationary jamming element and which is arranged to abut an outer surface 64 of a hex nut N near the outermost corner 66 as the nut is moved off the table , and generates a rotary motion that rotates the nut N from its original position, as shown in FIGS. 10 and 11 can be seen. The distance between the nut N being rotated and the divergent surfaces of adjacent nuts facilitates the initial rotational movement so that relatively little torque is required, as in FIG. 10 to rotate the nut N a little more than half the radial angle of 60 °, which is necessary to bring the corner 68 of the nut N into alignment with the angle of the receptacle 24. This initial movement brings the opposing surfaces 70 and 72 of the nut N into abutment against the surfaces 74 and 76 of the adjacent nuts and spreads them apart against the resilient restraining action of the spring 60. The pressure of the surfaces 74 and 76 against the corners 78 and 80 of the nuts N, which are being rotated, and the force of the spring 60 against the corner 82 of the nut N, complete the rotation and return the nut N in the rotated position into the receptacle with a new area of the thread surface exposed to the particles of heat-fusible resin coming out of the pipe 23. During the turning process, the blocked portion 29 (W, which serves as a shut-off device, allows air to pass through, but blocks the flow of resin particles through the pipe 23 to prevent resin from being applied to undesired surfaces of the nut It will be appreciated that a nut can be additionally rotated by providing additional rotators and suitable locked portions.

in order to obtain a larger distance between the resin applications or to obtain additional resin deposits.

When the nuts have been guided to the removal point, the outer rail 51 of the chute 14 serves to hold the nut in alignment with the receptacle 24 until the nut is lifted over the table and the Inner rail 52 serves, together with the rail 51, to bring the nut to its destination on the slide to feed.

In operation, the machine described above is first prepared by filling the hopper 15 with thermoplastic; Resin is provided in powder form. The material can be a powder, which is a mixture with a larger proportion of powdered polyamide resin, e.g. nylon 11, and a smaller proportion of

ίο Epoxy resin with such a particle size distribution is less than 2% of a sieve with 0.210 mm clearances Mesh size, about 90% are retained by a sieve with a mesh size of 0.105 mm and about 5% pass through a sieve with a mesh size of 0.044 mm.

The device for applying thermoplastic resin in powder form to the apparatus was designed as a funnel 15 shown; however, it can be seen that the material is removed from one for purposes of the present invention

is located source can be continuously brought into the bearing body 11 by means of a suitable line.

It will also be seen that the flow of resin material is through a valve or similar known device

is gauged to the flow rate according to the production rate, nut size, thread size or

Control temperature changes. When the material has been introduced into the Hi £ device, the device will c »··» »» »« »» «« * <»·» »<> voi # ,,,, mc · ι _η

μ of the chamber 33 and the bore 43 and the device for generating air pressure in the inlet opening 31

set in motion. Likewise, outside of the bearing body 11, the device for generating a vacuum in

the hood 13 is put into operation and the induction coil 50 is switched on to heat the nuts N,

while they are being led down the chute 12.

When these preparatory steps have been carried out, the machine is ready for use and the

The motor for driving the V-belt 19 and the device for feeding the nuts N onto the chute 12 are activated to begin machining a typical batch of nuts. When the table 10 rotates at about 10 revolutions per minute in the direction of the arrows according to FIG. 1 and 2, the nuts N are directed into the chute 12 and slide face to face through the induction coil 50, where each nut is heated sufficiently that the thermoplastic powder described above is in contact with it

comes to the threaded surface of the nut, sticks to it and is melted by the heat from the surface thereby forming a continuous plastic body. When a mother reaches Λ / table 10, it is held by the outer rail 47 on the chute 12 until it is in alignment with a V-shaped Reception 24 is and thereby brought into position over a respective tube 23 with its dispensing opening is arranged on the threaded opening of the nut. It is important that the receptacles 24 in such a

Distance are arranged so that the nut N from becoming wedged together, the table 10 is rotated at a constant speed (about 10 rpm) so that a small clearance between adjacent nuts N remains in the row of nuts and each mother Nbleibt about a half revolution or 3 seconds on the table, the dispensing opening of the tube 23 being arranged so that it protrudes slightly into the threaded opening of the nut

As the table 10 rotates, each tube 23 is moved so that its respective opening 22 is engaged with the Slit-shaped opening 29 comes and the nut lying next to the tube discharge opening becomes timely placed under the cover plate 45 of the hood 13 is air through the inlet opening 31 and into the lower Recessed area of the opening 28, where it flows into the slot-shaped opening 29. The air flows horizontally through a narrowing space after the slot-shaped opening 29 past the powder slot, which is of

the wall of the opening 28 and the conical divider 30 where it receives the powder and then flows through an expanding space. The powder is at a uniform rate after the powder slot and the converging and diverging spaces created by the air, while from the area of the central opening 28 in the vicinity of the divider 30 and into the slot-shaped Opening 29, give a slight suction effect or "venturi effect" to the powder slot, which is likely to

The slot-shaped opening 29 and its powder slot between the divider 30 and the opening 28 extend 180 ° around the bearing body 11, and the powder deposition on the first surface of the threaded surface of the heated nut takes place continuously with the movement of the Nut N after the section of the path that corresponds to the blocked section 29fa) instead of

Position back into the receptacle 24, with a new area of the threaded surface available for the deposition of powder during the part of the way away from the blocked section 29 (a) the deposition of the two parts appears to be important in developing a desired locking body. That is, on the surface on which the resin is deposited, the first soften

applied resin particles and stick to the hot thread surfaces and this softened resin is particularly effective in catching later applied resin particles progressively to reduce the resin deposition in the desired To build up thickness and contour and to supply softening heat from the hot thread surface, so that the particles applied later melt and so the applied particles melt into a coherent body and flow.

The thickness and, to some extent, the lateral dimensions of the resin deposits on the avengers can by the temperatures of the nuts, the feed rate of resin particles and air, and the length of time during which the resin particles are applied to the surfaces, d. H. the time it takes to be a mother to be transported along part of the Bchandlungsweg, controlled. The resin build-up will be

each applied thicker in their central area than in their edge area. If desired, the Deposits are applied in such a way that the edge areas of the deposits are in such a MhBc

'.''; overlap that the common thickness of the overlapping edge areas is approximately the thickness of the deposits

'Corresponds in their mileage areas, and so in the end an even order over the connected

Form the surface of the deposits, which gives a maximum blocking effect for the surface of the blocking trap. the ;. Deposits can of course also be controlled in such a way that they are essentially separate lock requests or

result in any state between separate orders and a single order.

In the embodiment shown, the table 10 has approximately 60 tubes 23 which each protrude into the nut Λ / at an angle of approximately 45 °. The powder is thus passed through the tube 23 and strikes against the internal threads of the nuts at a point slightly above the lowermost thread turn, and the air-powder flow is adjusted so that very little powder gets stuck on the uppermost thread turn. Since the tube 23 and the associated nut N are rotated together over the 180 ° segment, a constant, fairly even flow of powder is directed into the nut, except in the area of the intermediate station, where the nut is turned off and the flow of powder through the blocking section 29 ( a) is locked. Similarly, during the 180 ° segment, the vacuum hood 13 pulls excess material into the hood and away from the nut / V t. The "vacuum flow" through the inner opening in the nut and over the upper part of the nut prevents

that powder settles on the mother in other places than where it is directly from the tube 23 to the Mother turns meets.

- '■ After the "ear 23 and the associated ivluiier üie process stage left where the opening 22 in

j 'is aligned with the slot-shaped opening 29 (and accordingly also left the hood 13),

, they come in a small arc of about 15 °, where the opening is opposite the outer circumference of the

Bearing body 11 is and therefore the tube 23 is switched off in wesentlicnen. At about this point of the table movement the nut hits the leading edge of the chute 14 and, still in the V-shaped receptacle 24, aligns itself with the rail 21 of the chute. The nuts N are then brought into face-to-face abutment by the continuous movement of the table 10 and in a continuous flow

between the inner rail 52 and the outer rail 51 of the carriage 14 and so of the table 10 .'ι moved to a location.

During the next arc of the rotary path of about 150 °, the next process stage takes place, in which each tube 23 brings its opening 22 in correspondence with the slot-shaped opening 34, which with the . · 'Chamber 33 is connected to which vacuum is applied. So pulls during an arc distance of 150 °

Vacuum on the tubes 23, which draws all excess material from the tube 23 and the opening 22. <As one can imagine, with a tube 23 that is bent upwards at an angle of 45 °,

'. to distribute powdery material on the internal threads of nut N in the manner described,

Particles of the material impinge on the outermost surface of the pipe openings and therefore on a subsequent one Mother be deposited while the mother is brought to the table in a heated state and attached to the The loading opening of the tube has been moved past. In that the vacuum chamber 33 is provided, the pulls the material inward away from the opening of the tube 23, the materia! essentially from dcr opening removed and the likelihood of material in an undesirable location on a subsequent one Mother is deposited is thereby essentially eliminated

Another form of Mutterdreheinric "ing (see. Fig. 12, 13 and 14), which in connection with the mother-I transport arrangement according to FIG. 1 brau *, has a slide 84, which is from the arm 85 above the

·· -; Turntable 10 is held and the nuts / V out of their respective receptacles 24 while they

slide past the slide, and a movement device 86 which includes a wheel 88, as shown in FIGS. 12.13 BC and 14th shown, or another suitable arrangement, such as. B. a belt, a gas stream, a movable arm 'etc. can be to push the outer areas of the nuts forward and together with the slider

create torque to rotate the nuts. The angle of the slide can be such that it is approximately parallel to the leading inner end face of a nut N which is passed by the table 10.

\ i In the in the figures, in particular F i g. 14, the moving device 86 is a small wheel

ii 88, which is mounted on a shaft 89 and has an inclined nut support 90 with an angle which z. B.

y can form 40 ° with the horizontal. The wheel 88 is opposite the slide 84 and slightly less than one

§ Nut length further in the direction of movement of the table 10, so that when a nut N passes through the slide 84

ag is pushed out of its seat 24, the outer edge of the nut on the inclined nut support 90

t | sits on. The axle shaft 89 can be driven (not shown) suitable devices to a

Ij surface speed of the inclined oblique nut support 90 on the plane on which the nut is on

H the nut pad strikes to generate the larger, z. B. 1.5 χ greater than the edge speed of the table

f is 10

i | In a preferred form of this rotating device, a slide rail 92 is arranged to be engaged

ei come with the lower surfaces of the nuts, starting at a distance of 2 or 3 nut lengths before

Γ;) the nuts N reach the slide 84. This slide rail 92 has a slight rise to the

i! Nuts N approximately over the tongues 25 on which they rest, to lift and in the best position to engage

t | to bring the inclined nut pad 90 of the small wheel 88 when the nuts N by the action of the

Il slide 84 to be pushed outwards.

) | When operating this form of the rotating device, which is shown in FIG. 12 is shown, due to the inhibitory

U the action of the slide 84 on a nut Λ / ¹ , which is caused by the rotation of the table 10 against the slide

a is moved, two or three nuts pushed together in front of the slide 84 so that their neighboring

($ Faces are fully in contact; these two or three nuts move in a straight line out of the

'S recordings 24 on the edge of the table 10 tangentially to the outside. The pushing together of the nuts and the

f | tangential movement ensure a sufficient rotating surface for the nut N ¹ when they are on the slide 84 and

the wheel 88 is passed. In order to be able to follow the rotation of the nuts more easily, the corners of the nuts which are opposite the corners originally located in the receptacles 24 have been shown in FIGS. 12 and 14 marked with small circles. When the nut N ^{1 reaches} the slide 84 and is pushed outward by it, as one sets the Fig. 13 and 14 can be seen, the corner marked with a circle

the nut N ¹ opposite the corner that was in the receptacle 24, on the inclined nut support 90 of the small wheel (see Fig. 13 and 14) and since the speed of the nut support 90 is greater than the edge speed of the table 10, the corner is moved forward by wheel 88 while the corner adjacent to receptacle 24 is decelerated; this creates a torque that turns the nut in the direction of the arrow, so that a corner of the nut, that of the corner which was originally in the angle of the receptacle 24,

ι ο is adjacent, in the angle of the support 24 comes to rest

After the rotation through the desired angle has taken place, as described above, the rotation of the nut N ^{1 back} to a position in which its surfaces are in contact with the sides of a seat 24 of the table 10 is achieved by the inclination of the nut seat 90 of the wheel 88 is eased in the forward direction to the line between the centers of the table 10 and the wheel 88 and following the wheel 88 is preferably one Additional slide rail 96 is provided, which prevents undesired tilting when leaving the nut support 90 The inclined upper surfaces of the tubes 23 can also join. the mother back in the to bring desired close proximity to the sides of the receptacle 24 in the table. The following example illustrates an embodiment of the invention.

example

A continuous series of 9.5 mm hex nuts were placed face to face on a feed chute 12 a device according to FIG. 1 to 11, with the table 10 rotating at approximately 4.3 rpm and as Resin approx. 23 g / min of a mixture of powdered polyamide resin and a smaller proportion of epoxy resin were abandoned. The mixture had a particle size distribution such that less than 2% of a sieve 0.210mm mesh and about 90% was retained by a 0.105mm mesh screen and about 5% passed through a 0.044mm mesh screen. While sliding on the chute 12, the nuts were heated to about 284 "C by the high frequency induction coil 50 and then moved into alignment with the V-shaped receptacles 24 of the turntable 10, with their lower

End faces rested on the tongues 25 of the table and the lower openings of the nuts generally with the Openings in the tongues were aligned so that the dispensing ends of the particle-conducting lines or Tubes 23 reached into the open lower ends of the nuts to hold resin particles against the threaded surfaces to steer the nuts. As the table rotated, air and entrained resin particles flowed from the slot-shaped opening 29 through the tubes 23 and against the hot threaded surfaces and formed on first

Deposits in areas of the threaded surfaces of the nuts.

About half of the arch-shaped. On the way of the mats from the feed chute 12 to the feed chute 14, the flow of resin powder into the pipes associated with the nuts that reached this point was blocked by the section Tä (a) , and the nuts were turned with the rotating device 62 Turned a surface After the nuts had been turned and passed the turning device, the supply of resin to the pipes 23 associated with the nuts has been resumed by a

Build up deposit on another area of the thread surface. Nuts leading to the discharge chute

arrived, were lifted by the slide 14 from the support table 10 and followed by nuts that are used for

Slide reached, slide 14 pushed up. After cooling, the nuts were tested for their locking torque using the hexagon bolts

Grade 5 treated with zinc phosphate and finished with oil were used. The nuts were tightened to 14,225 N before the prevailing torque was measured.

For comparison, a number of identical nuts were used under the same conditions and with the same Machine treated, however, the locking section and the rotating device had been removed, so that all of the resin was applied on a single surface. The results of the torque tests with the

so nuts made using the method according to the invention or the device according to the invention and nuts made without the improvements of the present invention are summarized in the following table:

Assembly First Distance Fifth Distance

max / min max / min

Standard nuts) 775 402/280 314/186 Nuts turned by 60 °) 687 559/412 441/304 60 regulation 893 max 134/56 95/45

·) Average values of 5 tests in N · cm.

In summary, the invention relates to an improved device and an improved method for i> 5 Application of blocking orders made of elastic resin to objects with internal threads, such as B. nuts that have openings at both ends of the threaded area. This takes a support and processing arrangement, preferably a circular turntable with recordings, which are complementary to part of the Outer of a nut to be machined are a successive row of nuts on which on one

Temperature above the melting point of the resin to be applied, and moves the nuts,
whose axes are in the vertical direction and the openings at the upper and lower ends of the
Thread areas are essentially uncovered, on the way to machining, with tubes on the
Support and machining assembly of each nut are assigned to hold particles of thermofusible resin
up through the threaded opening of the nut against a portion of the threaded surface of the nut for a first application of resin on a face of the threaded surface as it is moved along
to apply a first part of the processing line, and a rotating device at an intermediate station of the
As soon as it reaches this position, the machining line rotates a nut by a predetermined value
Angle so that the tube associated with the nut directs resin against another face on the threaded surface to form a second resin deposit as it moves along another portion of the machining path. The temperature of the nut, the speed along the processing line, the
Supply of resin particles, the position of the rotating device and the angle of rotation can thus be correlated
brought about that a thin edge area of the first resin deposit with a thin edge area
the second resin deposit overlaps to such an extent that the total thickness of the resin in the
overlapping area corresponds approximately to the thickness in the central area of the first and second resin deposits 15

In addition 5 sheets of drawings

Claims (11)

Patent claims: 1. Process for the production of self-locking nuts by applying at least one layer made of thermoplastic material on the internal thread of the nuts, in which the nuts along a machining processing line are transported on which a thermoplastic powder is sprayed into them, which melts at the threads as a result of their preheating and runs into a layer, characterized in that the nuts (N) at at least one intermediate station of the processing line at a predetermined angle around the axes their threaded holes are rotated. 2. The method according to claim 1, characterized in that after applying a layer of ίο thermoplastic material, the spraying during the turning process of the nuts (N) is prevented at the intermediate station and that a further layer of thermoplastic material is then applied. 3. The method according to claim 2, characterized in that the layers of thermoplastic material are each applied thicker in their central area than in their edge area. is 4. The method according to claim 3, characterized in that adjacent layers of thermoplastic Material are applied overlapping in such a way that the layer thickness of the thermoplastic material in the area of the overlap corresponds approximately to the thickness of the layers in their central areas 5. Device for carrying out the method according to one of the preceding claims, with a carrier for transporting the nuts, with spray pipes arranged on the processing line and with a powder feed device connectable to the spray pipes, characterized in that a rotating device (62; 84 to 9ö) is provided for turning the nuts (N) 6. Apparatus according to claim 5, characterized in that a shut-off element (29a,) is provided for preventing the supply of the thermoplastic powder to the nuts (N) during the turning process of the nuts (N) 7. Apparatus according to claim 5 or 6, wherein the carrier has receptacles for the nuts, characterized in that the rotating device comprises a removal and insertion device (62, 84 to 96) for the nuts (N) 8. Apparatus according to claim 7, with a carrier in the form of a turntable which has V-shaped receptacles on its edge, characterized in that a pressure device (60) is provided through which the nuts (N) are resiliently held in their receptacles , and that a stationary inhibiting element (62) is arranged in the area of movement of the nut parts protruding from the edge of the rotary actuator (17) 9. Apparatus according to claim 7, with a carrier in the form of a turntable which has V-shaped receptacles on its edge, characterized in that the rotating device is a stationary arranged the respective nut (N) partially moving out of its receptacle slide (84) and a stationary, on the mother (N ) comprises movement device (86) acting in the circumferential direction thereof 10. The device according spoke 9, characterized in that the moving device (86 ) comprises an obliquely to the direction of displacement of the nut (N) inclined and at a relative to the peripheral speed of the turntable (17) greater speed driven nut support (90) 11. The device according to claim 10, characterized in that the nut support \ 90) is formed by the edge region of a wheel (88)