DE1204911B - Method and device for the production of heat, corrosion and erosion-resistant protective coatings made of aluminum or an aluminum alloy on metallic objects, in particular engine valves, by immersion in a molten metal bath - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

C23c

German class: 48 b -1/08

Number:
File number:
Registration date:
Display day:

Sch 24483 VI b / 48b

July 30, 1958

November 11, 1965

The invention relates to a method for producing heat, corrosion and erosion resistant Protective coatings made of aluminum or an aluminum alloy on metallic objects, in particular engine valves, by immersion in a molten metal bath, with the formation of an alloy sufficient heat exposure between the base and the coating metal and subsequent Removal of the excess coating metal by mechanical means, which is characterized is that the coated objects immediately after the end of the thermal effect with rotating Wire brushes are brushed off until essentially all of it has not alloyed with the base metal molten plating metal is removed from the surface and only a thin more uniform Coating remains. The invention also relates to a device for carrying out the method.

Valves, such as those used in internal combustion engines, are susceptible to attack Exposed to combustion gases, especially if the fuels contain lead compounds. Of the The valve disc in the combustion chamber is subject to rapid oxidation and due to the combustion gases Exposed to heat corrosion. This leads to failure of the valves due to corrosion of the valve seat surface or the neighboring parts.

It is known that aluminum and its alloys are exceptionally heat-resistant and wear-resistant Coatings form when mixed with base metals such as iron, steel, cobalt, nickel alloys, Molybdenum, tungsten, titanium or the like are alloyed, which have such a high melting point that aluminum and its alloys can be applied molten.

If the valves are to be coated with a metal, such as aluminum or its alloys, that diffusively diffuses with a base metal to overcome the aforementioned difficulties, control of the thickness of the alloy formed on the valve is essential. Such regulation of the thickness of the alloy layer on the surface of the valve is important, since the difference in the expansion coefficients of the alloy layer and the base metal can cause stresses that lead to peeling or flaking off. In addition, because the alloy layers are hard and brittle, thicker layers are more prone to cracking than thinner ones. Flaking or cracking can be caused by vibration, impact or thermal shock and lead to the method and apparatus for manufacturing
heat, corrosion and erosion resistant
Protective coatings made of aluminum or one
Aluminum alloy on metallic objects, in particular engine valves
Immersion in a molten metal bath

Applicant:

Edward Peter Schreyer, Ridgefield, Conn .;

Marshall George Whitefield,

Garden City, N. Y. (V. St. A.)

Representative:

Dr. W. Beil and A. Hoeppener, lawyers,

Frankfurt / M.-Höchst, Adelonstr. 58

Named as inventor:

Edward Peter Schreyer, Ridgefield, Conn .;

Marshall George Whitefield,

Garden City, N. Y. (V. St. A.)

Claimed priority:

V. St. v. America July 30, 1957 (675 085)

Corrosion of the underlying base metal and failure of the valve.

If the excess aluminum remaining on the alloy layer formed is a relative As the aluminum forms a thick layer, it tends to have a lower melting point than the alloy has to diffuse further into the base metal when it is exposed to the heat of the combustion gases Use of the valve is suspended, so that the alloy layer becomes thicker, what the above-mentioned Has disadvantages. In addition, if such an excess, unalloyed aluminum is not uniformly thick, the subsequent alloying of the same when using the object, or if it is subjected to a balancing heat treatment prior to use, an undesirable one Inequality in the thickness of the alloy layer result.

509 737/316

Treatment in molten salt has already been attempted to remove the excess aluminum been. In such a salt bath treatment, however, the drainage is usually insufficient and cannot be regulated reliably. As a result, the resulting article may be excessively thick or have uneven alloy and / or aluminum coatings that provide the desired protective Do not possess properties. In addition, there is a risk of subsequent corrosion as a result the salt bath treatment.

In addition, the salt bath treatment is relatively difficult to carry out and increases the for overdrawing required time with a corresponding reduction in operating speed.

The invention now offers a relatively simple method and a correspondingly simple device for covering metallic objects such as valves and other components that are exposed to high temperatures and are exposed to corrosion, with corrosion, heat and erosion resistant coatings predetermined thickness made of aluminum or an aluminum alloy. Thereby the coating layer for all components that are coated in one operation, practically the same thickness, and the objects are relatively quick and practically without excess and / or uneven coating material, which with undesirable increase in the Thickness of the alloy layer could diffuse into the base metal, coated.

According to the invention, the metallic object, for. B. a valve, a coating made of aluminum or an aluminum alloy which covers practically its entire effective area. While pulling on at a temperature which is so high that diffusion occurs in the base material alloy with this to form the desired protective coating. Once the protective cover When it has reached the desired sufficient thickness, the excess molten aluminum becomes removed from the surface of the valve by brushing with high-speed wire brushes, wherein they also cause the aluminum to be evenly distributed over the entire object.

In one embodiment of the invention, the valve, while the aluminum coating is immersed Applied in a molten bath, vibrated to join the aluminum with the item and the time required to coat the item increases to decrease.

In the drawings, the devices for performing the method are shown.

F i g. 1 is a front view of the device;

F i g. Figure 2 is a rear view of the device;

Figure 3 is a side view of the device as seen in the direction of line 3-3 of Figure 1;

Fig. 3a shows a section along the line 4-4 of Fig. 1;

F i g. Figure 4 is a partial side view looking in the direction the line 4-4 of Figure 1;

Fig. 5 is a plan view with the support members and support plate for the article omitted;

Figure 6 is a fragmentary view taken in the direction of line 6-6 of Figure 2 showing the actuation mechanism of the object holder;

Fi g. Figure 7 is a cross section taken along line 7-7 of Figure 2;

Fig. 8 is a cross-section taken along line 8-8 of FIG Fig. 2;

F i g. Fig. 9 is a plan view of the engine structure;

FIG. 10 shows a section along the line 10-10 of FIG. 2.

1 shows the device on a rectangular base plate 11 which has a rectangular opening 12 below which the molten bath container P is located.

Between the uprights 13, which are attached to each side of the base plate 11 and above by cross braces 14 are connected and which preferably have a U-profile, in openings 15 is a shaft

16 arranged, which has a drum attached to it

17 turns. Each end 18 of the shaft 16 is rectangular, as shown in Fig. 3, and lies in an elongated Slot 19 in an adjustment block 21 which is fastened by screws 22 to the associated stand is. Each of the blocks 21 has a pair of vertically aligned bores 23, one in each Screw 24 is seated, the head of which has a spout into which a socket wrench for turning the associated Screw fits. The inner ends of the screw are for pressing against the square ends

18 of the shaft 16 set up so that the vertical position thereof can be adjusted.

The drum 17, see Figs. 1 and 2, has a pair of side plates 27, 28 which are shown in Fig. 3 as octagonal and have transversely aligned openings 29 through which a shaft 18 extends. the Plates 27, 28 are held at a certain distance from each other by several connecting rods 31, their threaded ends extend through the plates and through nuts 32 are attached.

Axial movement of the drum 17 on the shaft 16 is ensured by adjusting ring 33 on each side of the Plates 27, 28 which are fastened on the shaft 16 by set screws 34 are prevented.

Spindle plates 35 extend between side plates 27, 28. Four spindle plates are shown for illustrative purposes; each is essentially rectangular. They are labeled 35 ^ 4, 35B, 35C and 3SD. The spindle plates extend between pairs of the longitudinally opposite edges 36 of the plates 27, 28 which are equidistant from one another and are mounted so that they can move slightly in the direction parallel to the axis of the shaft 16.

To enable this movement, each plate 35 has a pair of spaced-apart pairs Depressions 37 (Fig. 2). One end of a pin 38, which is attached to the plates 35, is seated in each of these is attached by a set pin 39. The pins 38 extend through aligned openings 41 in FIG the plates 27 and 28 and a spring 42 at each end of the plate inserted into aligned openings 43 Seated in plates 35 and plates 27, 28, the plates 35 centered between the plates 27, 28, permitted but a movement of the same so that the connected vibrator 45, which is described below, the associated plate 35 can vibrate, but the vibration with respect to the other Plates 35 limited to this plate.

Like F i g. 1 shows the housing 46 of the preferably air powered vibrator 45 is through the screws 47 attached to the blocks 48 which are attached to the inside of the associated plate 35.

Each of the vibrators 45 is connected to an air line 51 which extends through an associated opening in plate 28 to a pipe connector 52 (Figs. 1, 2 and 10) extending in one of the side walls 53 of a rectangular valve block or manifold 54 extends which has a central has opening through which the shaft 16 extends, the block 54 being attached by screws 56 the outer surface of the plate 28 is attached.

As shown in Figures 2 and 10, the valve block 54 has a central portion 58 and two side portions 59, which enclose the middle part between them and hold the pack 61 in position. The end of the shaft 16 has an axial bore 62 close to the plate 28, which is threaded 63 at the outer end is provided and serves to receive an air line 65 (FIG. 1). Into the inner end of the bore 62 leads a transverse arcuate recess 66, the outer end of which has a greater width, and the middle part 58 of the block 54 has four radial ao bores 67, which are individually connected to a pipe connector 52 are connected (Fig. 10).

In this way, only one of the connecting pieces 52 is connected to the recess 66 at a time, and in the embodiment shown the connecting piece 52 connected to the plate 35, when it is in position B (FIG. 3), is connected so that only the vibrator 45 is driven in this position.

Each of the plates 35 carries a plurality of spindles 71, four of which are shown. Since all the plates 35 and the associated spindles 71 are identical, only one of the spindles on the plate 35 D (FIG. 5) needs to be described in detail.

As shown in Fig. 5, each spindle has an outer sleeve 72 which extends through a press fit in a matching opening 74 in the plate 35 D-fitting sleeve 73. The part of the sleeve 72 which extends beyond the plate 35 D is surrounded by a gear 75 which is fastened to the sleeve 72 by a wedge 76. To prevent vertical movement of the sleeve 72 in the socket, a snap ring 77 is located in an annular groove 78 in the sleeve 72 on the two opposite sides of the gear 75, and a thrust washer 79 surrounding the sleeve 72 rests against the lower surface of the socket 73.

Slidably in each of the sleeves 72 a pull rod 81 is arranged, which at its outer end Head 82, against which one end of a coil spring 83 presses, while the other end of the same rests against end 84 of the sleeve and normally pushes the pull rod outward.

The inner end 85 of the tie rod 81 is internally threaded to receive the corresponding one Threaded end 86 of a tension sleeve 87 of conventional design.

The clamping sleeve 87 is longitudinally slotted at 88 in the usual manner, and its outer end 91 is conical, to press against the correspondingly conical inner surface of the sleeve 72, so that upon an outward movement the pull rod 81 under the pressure of the spring 83 closes the clamping sleeve and in the usual way Way clamped.

As described above, four spindles 71 are mounted on 6g of each plate 35. For rotating at the same time the spindles in the same direction are three intermediate gears 94, 95 and 96, which can be rotated Stub shafts 97 attached to the plates 35 are journalled and in engagement with the two gears 75 at the toad and right side of the plate (Fig. 1) stand. Here, the gear 95 is in mesh with the two middle gears 75. When rotating of the gear 95 in one direction, the gears 75, which drive the spindles 71, are in the opposite direction Rotated direction.

Means are provided for moving the tie rods 81 inwardly against the pressure of the spring 83 for the purpose of opening the tensioning sleeve 87. This process, which takes place in position A (Fig. 3), is carried out in the embodiment shown by means of a series of cams 101 (Fig 2 and 6), which are pinned to the shaft 16 at 102 and aligned with the corresponding spindles 71. Each of the cams has a protruding portion 103 which is aligned with the spindles 71 when they are in position Λ (.

Each of the spindles is assigned a rocker arm 104 which is linked to one end of a rocker arm rod 105 which extends between the plates 27,28. The free end of each rocker arm has a protruding one Finger 106 between the head 82 of each tie rod 81 and the surface 107 of the associated Cam 101 is arranged, as in F i g. 6 is shown.

When the drum is rotated to the left into the position shown in Fig. 6, when the finger 106 of the rocker arm 104 slides over the cam surface 107, the rocker arm 104 is moved outwards or in counter-clockwise rotation around its pin 105, around the pull rod 81 inwards against the tension of the spring 83 to press. Thus, when the drum has been rotated, for example, into position A (FIG. 6), the projection 103 has moved the pull rod into its outermost position to fully open the tensioning sleeve 87.

There are facilities available for gradual Rotate the drum by 90 ° so that the plates 35 are switched from position to position. For this purpose, as shown in FIG. 1, 2 and 3, an elevator operated for example by compressed air 112 hinged with one end at 113 to the stand 13 on the right side of the device, like is shown in Fig. 1 so that it can oscillate about an axis parallel to that of the shaft 16 lies. The piston rod 114 of the elevator 112 carries an adjustable pawl at its lower end 115, which has a drive finger 116 at its lower end. The edge of the latch between your finger 116 and the upper end 117 of the same is recessed at 118 to produce a clearance for the Drum drive pin 119.

As shown in Fig. 3, four such drive pins 119 are arranged, which extend sideways outward extend from plate 27 near the periphery thereof. The bolts are arranged so that if they are initially grasped by the pawl finger 116 and this by the actuation of the elevator 114 is moved downwards, the drum is rotated by 90 °.

Devices are provided by which the pawl finger 116 for engagement with successive Drive pin 119 is brought into the drive position during the upward movement of the pawl. To this Purposes is a coil spring 121 is provided with one end on the stand 13 and with the other on

Elevator 112 is attached approximately at 122. As a result, the spring 121 stops when the pawl is raised the recessed portion 118 of the pawl against the upper bolt 119 (Fig. 3), and if the lower Has passed the end of the recess on the upper bolt 119, the spring 121 pivots the elevator and the pawl inwardly around the pin 113 so that the finger 116 is aligned with the top pin 119 and can push against it when the elevator 112 is started.

Means are provided to guide the pawl 115 as it moves through the elevator 112. To this end, as in Figures 1, 3 and 3A is shown, a pair of L-shaped rods 125 held together by bolts 126 by bolts 127 on upper end of the elevator 112 attached. The legs 128 of the rods 126 are closely spaced disposed from each other, and as shown in Figs. 3, 3A, one attached to the pawl 115 extends Pin 129 in this space to guide the pawl when it is moved back and forth.

Means are provided for locking the drum after each rotation thereof by one 90 ° angle to ensure correct switching. To this end, as in Figs. 1 and 3 is shown, a toggle 131 hinged at 132 to a block 133 which, as shown in FIG. 1 is shown on Stand 13 is attached to the right side of the device. Between the toggle lever 131 and the Block 133 inserted and attached to the latter is a spacer block 134, which the toggle lever with the end 135 of the pawl aligns vertically. The spacer block is provided with a stop 136, against which the horizontal leg 137 of the toggle lever is normally at right angles below the Influence of the coil spring 138 is applied, one end at 139 on the leg 137 and with the other is attached to the base plate of the device.

Therefore, when the pawl 115 has been moved to its lowermost position, as shown in FIG. 1 is shown the end 135 of the same against the leg 137 which forms the limit of the downward stroke of the elevator. As a result, the lower pin 119 (Fig. 3) between the finger 116 of the pawl and the inclined Surface 141 of leg 142 of the toggle lever held for the purpose of correct switching of the drum.

If the drum 17 should have moved faster than the pawl, so that the lower pin 119 hit the inclined surface 141 before the end 135 of the pawl hits the finger 137, the toggle lever would already turn to the right from the position shown in Fig. 3 against the tension of the Spring has been waved. As a result, the drum will not switch properly. But if the Pawl 115 has completed its downward stroke and its end 135 abuts against finger 137, becomes the toggle lever turned to the left until the leg 137 rests against the stop 136. This causes the drum rotated back into their correct 90 ° position, whereupon they switch to the one described above in this position Way is locked.

To ensure that the drum is reliably locked in every switching position, an additional Lock provided. This is shown in FIG. 1 and 2 and consists of a likewise air-powered Elevator 151 attached to a stand 13 located on the left side of the device as shown in FIG. The piston rod 152 of the elevator 151, which is arranged vertically, runs through aligned openings in guide blocks 153. The lower end 154 of the piston is formed so that that it engages in a groove 155 in one of four locking blocks 156 provided, the on the outer surface of the plate 28 are aligned with each of the spindle plates 35 thereof. the Groove 155 is arranged in such a position that with each rotation of the drum through 90 °, as described above, the groove 155 is directed upwardly in alignment with the piston 152, which upon actuation of the elevator is moved into the groove.

Brushes for removing excess coating material from those under treatment Objects are provided. These are used in the exemplary embodiment shown placed on the objects in position C, as shown in FIG. To this end is a pair as shown in Figs. 2, 3, 7 and 8 Plates 161 are respectively attached to each post 13 and extend perpendicularly thereon. The plates extend outwardly from the uprights 13 to the rear of the device, and one perpendicular Guide track 162 is on each of these plates by screws 164 on the outer vertical edge thereof attached. A motor support plate 165 is slidably disposed in the guideways extends transversely between plates 162.

On the outer surface of plate 165 (Figs. 3 and 9) is also a preferably air driven one Motor 166 mounted, which has a vertical shaft 167 on which a worm 168 is mounted. These The worm meshes with a worm wheel 169, which is mounted on the shaft 171, which is rotatable is placed on the plate 165 in the center thereof. A drive gear 172, which is used to drive the drive gear, is also seated on the shaft 171 95 to align perpendicularly on each of the plates 35 so that it can be driven by the gear 172 can.

The motor shaft 167 also carries a gear 175 which meshes with an intermediate gear 176, F i g. 9, which is in engagement with a gear 177 of a right-angled drive 178 and the Shaft 179 of the same rotates. The shaft extends through an opening in a brush plate 181, the extends between a pair of arms 182 connected at 183 to a pair parallel to the motor plate 165 from extending arms 184 are hinged. The between the right angle drive 178 and The portion of the shaft 179 located on the plate 181 is flexible to permit pivoting movement of the arms 182 is possible, through which the position of the plate 181 is adjusted.

On the protruding end 185 of the shaft 179, a pair of wire brushes 186 are attached for brushing of the object being treated. A gear 187 is attached to the shaft 179, which is via an intermediate gear 188 in engagement with a gear 189 which is on a Shaft 191 is attached, which also extends through a brush plate 181 and a pair of wire brushes 186 '.

The brushes 186 and 186 'are arranged to be against the pairs of objects on the right and Press the left side of the plates 35 and brush them off. Devices are provided for and reciprocating plate 165 to drive

9 10

gear 172 of the same against gear 95. When the drum continues to rotate, when it has moved and moved to move the brushes 186 and has traveled substantially 90 °, the 186 'strikes the objects. In the shown end 135 of the pawl 115 (Fig. 3) against the Schenführungfonn, these devices consist of kel 137 of the toggle lever 138 for locking the BoI - a lifting gear 192, which is air-operated and which is 119 in position, wherein the drum has now been rotated to sen upper end on the cross member 14 of the frame 90 °, is mounted with the valve V in sunk and depends from this. right position up to under the base plate

The elevator has a piston rod 193 which is stretched as shown in Fig. 3 where it fits into the

immersed in a block 195 of molten aluminum of the container P by a set screw 194

which, as shown in Fig. 2, are attached to the io.

Plate 165 is attached. Then the elevator 151 is started and

To reduce the size of the reciprocating piston 152 in the associated groove 155 reciprocating the plate 165 and the elevator 192 located thereon in block 156 to lock the drum in its borrowed device is in position. The elevator 112 is provided in the opposite direction by a counterweight 201 which, when actuated transversely, extends across the front of the system to retract its column, as in bens 114 and to move the pawl Fig. 1 upwards. 1 is shown. The counterweight 201 hangs on 115 so that her finger 116 is suspended by the spring 121 in cables 202 passing over pulleys 203 hanging from the cross member 14 one position immediately above the next bolt, the 119 being brought and ready for the Next cables are attached to brackets 204, which is at the ao duty cycle.
Plate 165 are attached as shown in FIG. At this time, it is as shown in FIG

There are devices provided for the clock is, the block 54 rotated so far that the bore

moderate operation of the various lifts, so 67, those with the spindles, which are now in operation

that the drum 17 rotated stepwise and in container P submerged valves V carry connected

is locked in each position, as well as the one that is locked, aligned with the arched recess 66

various other stages of application is so that the associated vibrator 45 is excited

Coatings are carried out. As all suitable and the associated plate 355 moves. This one

Means, such as a disk timer T, plate slidably seated on pins 38, vibrates

which responds to a number of air switches S , they easily, and due to the movable arrangement

can be used for this purpose, unnecessary 30 voltage of the other plates 35, these are only

a description of the same. vibrate slightly.

. . As a result of the valves V in the container communicated

Betnebsweise _th vibration adheres the aluminum on the whole

The surface of the valve is used in the embodiment shown, so that the valve is not a separate installation above a container P which has to remain in the bath for an excessive amount of time.
molten aluminum and has in the base plate 11 begins a rectangular opening 12, which with the base metal of the vender mouth opening M of the container P (Fig. 1) tils to the desired protective coating is directed. alloy. After a predetermined period of time,

As soon as the spindles 71 are in position Λ (Fig. 3) 4q, which depends on the time that the valves are in, the cam 101 (Fig. 6) should already remain against the molten bath, pressed by the desired thickness rocker arm 104, so that the clamping sleeves of the alloy layer are obtained which are empirically opened. If the stem 206 of the valve V is correct, the timer T again actuates the elevator 112 to fit in the open clamping sleeves to rotate the drum in such a way that the valve head is substantially 45 second angles of 90 °, and during the 90 ° - are aligned with each other and the timer T movement, the valves V are melted off. bad brought to position C. The drum 17

Since the drum 17 is locked at this time by the elevator 151 (Fig. 1) in its position as described above, the latter is locked and the timer T then sets the elevator to move its rod 152 out of the groove 155 50werk 191 started to lower the mounting plate of the associated block 156. Then 165 and also the motor 166 starts to rotate the lifting mechanism 112, the piston rod 114 of which is its shaft 167. The rotation of this shaft 167 has previously been raised, in order to move the rotation of the drive gear 172 piston rod 114 downwards. As a result, as well as brushes 186, 186 '. When the plate 165 is grasped by the finger 116 of the pawl 115 and 55 has been lowered sufficiently, the top of the tooth engages the bolt 119 (FIG. 3) and presses against it. Since the end 135 of the pawl 115 now no longer engages the leg 137 of the 71 and the valves V of the toggle lever 131 held by them, the brushes 186 also come at this point in time , lower pin 119 (Fig. 3) and therefore drum 186 'engages the valves and wipes the 17 no longer locked, and as the excess molten drum 60 on top rotates, lower pin 119 engages the leg of aluminum .

142 of the released toggle lever 141 and pivots it. After a predetermined period of time, the

While the drum 17 is started in the direction of the elevator and raises the plate 165,

(Fig. 6) is rotated, the rocker arms move whereby the gears 172 and 95 are disengaged

104 away from the projections 103 of the cams, and 65 den and prevent further rotation of the spindles.

the springs 83 of the spindles 73 move the tension members. The motor 166 is now switched off, and that

rods 81 and collars 87 inward to lock elevator 151 is started and

Blocking the valve stems in their position. triggers the drum. The elevator 112 is then

restarted to rotate the drum again to advance a new set of uncoated valves from position A to position B for immersion in the aluminum container and to advance the valves in the aluminum container to position C for brushing as described above.

As soon as the covered valves have been moved from position C to position D and then to position A, the clamping sleeves 87 are opened, as described above, so that the covered valves can be removed and replaced by new ones to be covered.

When using the method and the device according to the invention, the objects provided on their surface with a coating or a layer of an alloy of the desired thickness. The thickness of the alloy layer depends on the temperature of the molten coating material, which is determined by the temperature of the container, the duration during which the coating material remains molten, which is the amount of diffusing into the base material Coating material and the efficiency of the removal of excess material to prevent further diffusion in use. Given all of these variables without difficulty can be regulated, it is evident that once applying the same factors for objects of the same type, a protective layer has been formed on the object, on all of them Objects an almost identical protective layer is formed and relatively mass production is easy to do.

Objects which have been coated with the aid of the method and device according to the invention are hardly subject to oxidation, corrosion or erosion and therefore last for a long time Lifespan. The method and apparatus can also be used to cover other articles such as Turbine blades and valve guides, can be used.

Claims (4)

Patent claims: 1. Process for the production of heat, corrosion and erosion resistant protective coatings Made of aluminum or an aluminum alloy on metallic objects, in particular Engine valves, by being immersed in a molten metal bath, are used to form alloys sufficient heat exposure between the base and the coating metal and subsequent Removal of the excess coating metal by mechanical means, thereby characterized that the coated objects immediately after the end of the heat effect brushed off with rotating wire brushes until essentially nothing molten plating metal alloyed with the base metal is removed from the surface and only a thin, uniform coating remains. 2. The method according to claim 1, characterized in that the objects during vibration during diving. 3. Automatic device arranged above a container for the molten coating metal for carrying out the method according to claim 1, characterized by a drum (17) rotatably arranged about a shaft (16), the circumference of four arranged parallel to the shaft axis and on the side plates ( 27, 28) has fixed plates (35), on which spindles (71) with clamping sleeves (87) for inserting the metal objects to be coated are attached at regular intervals, by a lifting mechanism (112) for rotating the drum (17) in stages 90 ° each under control by a timer (T), the lifting mechanism (112) having a pawl (115) for locking the drum (17) at the respective treatment points (A, B, C, D) at which the onset of the Objects in the clamping sleeves (87), coating the objects in the molten metal bath (P), brushing off the excess coating metal using rotating wire brushes (186) and releasing the G objects from the clamping sleeves (87) takes place. 4. Apparatus according to claim 3, characterized by a force fit with the plates (35) connected vibrator (45). Considered publications:
German Patent Nos. 31 967, 827 147;
Swiss Patent No. 321260;
British Patent Nos. 757188, 779 972;
"Iron Age", 177, from January 12, 1956, pp. 74 to 77. For this purpose 2 sheets of drawings 509 737/316 11.65 © Bundesdruckerei Berlin