Patent GB-515148-A (GB)
Title: Apparatus for the metallising of objects in vacuo by metal vaporising or cathode sputtering
IPC: C23C14/56
Filed: 1938-05-25
Abstract: 515,148. Coating with metals. BOSCH GES., R., (formerly BOSCH AKT.-GES., R.). May 25, 1938, No. 15537. Convention date, May 29, 1937. [Class 82 (ii)] [Also in Group XL] In coating objects in vacuo by metal vaporization or cathode sputtering, the objects are subjected in a confined space to a preliminary relatively low vacuum during their passage to the high vacuum space in which the metallizing is effected. They preferably pass through further areas of lower vacuum on their way from the metallizing point to the point of discharge. Fig. 1 shows an apparatus in which the metallizing chamber 10, connected by pipe 12 to a high vacuum pump, is provided on the feed and discharge sides with chambers 13, 14 respectively, connected to preliminary vacuum pumps by pipes 15, 16. To facilitate the opening of the doors 17, 19, 20, 21, means may be provided for connecting chamber 10 to either of the chambers 13, 14, and for connecting these chambers to the atmosphere. In Fig. 2 the articles are carried through the apparatus by conveying devices 22, 28, 29, divided into compartments by partitions 24 and running on rollers 25. The articles are placed on one of the conveyers which is introduced into a chamber 21 and held by a stop 22<1>, while the chamber is brought to a low vacuum. The chamber 21 communicates by a door 27 with a tubular chamber of such a size that the partitions 24 on the conveyers divide it into nearly vacuum-tight - compartments. A diminishing pressure is produced in the compartments by pump connections 31...34, and high vacuum in the compartments at the lower end of the chamber by pump connections 35...38. Two conveyer devices are held in the tube by a stop 40, and advanced compartment by compartment, metallizing taking place in the space 41. The discharge side of the metallizing point is similar to the feed side. Fig. 4 shows an apparatus comprising an air-tight cylinder 42 in which rotates a wheel 43 having on its circumference compartments to hold the articles to be treated. An article is inserted at 44, passed through regions of decreasing pressure, produced by pump connections 49 ..51, to a high vacuum point 48 where metallization occurs, and then through gradually increasing pressure regions to a discharge 53. Rotation may be continuous or intermittent. In Fig. 5 the article is mounted on a conveyer device, which may be provided with rollers, and inserted into a compartment in a member 61. which can rotate in a cylinder connected to a low-vacuum pump. The member is rotated and the conveyer device passes into a tube in which it forms a compartment which is subjected to a series of diminishing pressures through pump connections 64..66, a high vacuum and metallization at 67, and a series of increasing pressures before passing into a discharge device 61<1> similar to the feed device 61. In Fig. 6 two pistons 69, 70, having compartments 71 &c. on their circumference for the articles to be metallized are moved to and fro in a chamber 68 having low-vacuum pump connections 75, 75<1>, 76, 76<1>, and high-vacuum pump connections 77, 77<1>, for the metallizing points. Fig. 8 shows an apparatus in which three pistons 81, 82, 83 work in the vacuum chamber 80. The piston 82 is moved by means of the pistons 81, 83, to which it can be connected when desired. An article is introduced at 94 and secured at 96 in a compartment at the lower end of the piston 82. The piston 83 is then moved to reduce the size of the compartment and is connected to the piston 82. The compartment is then pushed through a region of decreasing pressures, produced by pump connections 86 ... 89, the piston 82 being, at one point, connected to the piston 81 which is carrying a metallized article at 95, and, when the metallizing point 84 is reached, being disconnected from piston 83 and raised a little by piston 81 so as to enlarge the compartment for the metallizing operation. The piston 81 is disconnected from 82 and raised so that the previously metallized article at 95 can be discharged at 93. The article at 96 is discharged at 94 after metallizing by lowering the pistons 81, 82, 83. The metallizing of head lamp reflectors is referred to.