CH324252A

CH324252A - Method of manufacturing a dial for a watch and a dial obtained by this method

Info

Publication number: CH324252A
Authority: CH
Inventors: Frund Alfred; Frund-Droz Rose
Original assignee: Nardac S A
Priority date: 1955-12-07
Filing date: 1955-12-07
Publication date: 1957-09-15

Description

  

  Procédé de     fabrication    d'un cadran pour montre et cadran obtenu par ce procédé    Le procédé selon l'invention est caracté  risé par le fait que l'on frappe, un flan métalli  que pour y former simultanément, sur     une    face,  des signes horaires en relief et, sur l'autre face,  des cavités pour la fixation des pieds de cadran,  que l'on chasse les pieds dans lesdites cavités,  que l'on soude les pieds en passant le cadran  au four et, enfin, que l'on plane le cadran en  se servant de la matrice utilisée pour la frappe  des signes en relief.  



  Par     ce    mode de frappe, les emplacements  des pieds sont repérés avec une grande exacti  tude ; il n'y a aucun risque que les pieds soient  décalés par rapport aux signes horaires.  



  Le procédé selon l'invention peut être, par  exemple, réalisé de la manière suivante  On découpe d'abord dans de la tôle de lai  ton des     flans    de formes et dimensions appro  priées ; ces     flans    sont ensuite frappés à l'aide  d'une étampe dont la matrice fournit des signes  horaires en relief sur l'une des faces de flan,  tandis que la contre-matrice crée, sur la face  opposée, à l'aide de poinçons dont elle est mu  nie, des protubérances présentant chacune une  cavité centrale cylindrique qui correspond à  l'emplacement d'un pied de cadran. Chaque  protubérance a donc la forme d'un collet en  tourant une cavité.

   Ensuite, au moyen d'une  potence, on chasse dans chacune des cavités    un pied de cadran et, après avoir glissé sur  chacun de ces derniers une bouclette ou an  neau en fil de soudure d'argent, on passe le  cadran au four électrique pour opérer la sou  dure des pieds.  



  Lorsque l'opération de soudure est termi  née, on plane le cadran à l'aide des outils ayant  servi pour la première frappe, après avoir en  levé de la contre-matrice les poinçons qui     ont     créé les cavités ; on peut aussi se servir d'un  outil identique à la contre-matrice,     mass    pré  sentant un logement en correspondance de  chaque pied. Cette opération de planage pro  voque, de plus, un refoulement du métal du  flan contre les bases des pieds, ce qui conso  lide ultérieurement les pieds de cadran. Le ca  dran subit ensuite les opérations de finissage  habituelles.  



  Lorsque l'on fabrique le cadran à partir  d'un     flan    suffisamment épais, on peut renoncer  aux     protubérances    et frapper les cavités direc  tement dans le corps du     flan.  



  Method of manufacturing a dial for a watch and a dial obtained by this method The method according to the invention is characterized by the fact that a metal blank is struck in order to simultaneously form thereon, on one side, hour signs in relief and, on the other face, cavities for fixing the dial feet, which the feet are driven into said cavities, the feet are welded by passing the dial in the oven and, finally, that the the dial is leveled using the matrix used for striking the signs in relief.



  By this typing method, the positions of the feet are marked with great accuracy; there is no risk that the feet will be offset from the hour signs.



  The method according to the invention can be, for example, carried out in the following manner. Blanks of appropriate shapes and dimensions are cut out first from the brass sheet; these blanks are then struck using a stamp, the die of which provides hour signs in relief on one of the blank faces, while the counter-die creates, on the opposite face, using punches which it is fitted with, protuberances each having a central cylindrical cavity which corresponds to the location of a dial base. Each protuberance therefore has the shape of a collar by turning a cavity.

   Then, by means of a gallows, one drives out in each of the cavities a base of dial and, after having slipped on each of these last a loop or ring of silver welding wire, one passes the dial to the electric furnace to operate on hard feet.



  When the welding operation is finished, the dial is leveled using the tools used for the first strike, after having lifted the punches which created the cavities from the counter-die; it is also possible to use a tool identical to the counter-matrix, with a mass having a housing in correspondence of each foot. This leveling operation also causes the metal of the blank to be pushed back against the bases of the feet, which subsequently consolidates the dial feet. The ca dran then undergoes the usual finishing operations.



  When the dial is made from a sufficiently thick blank, the protuberances can be dispensed with and the cavities struck directly in the body of the blank.

Claims

CLAIM I Method for manufacturing a dial for a watch, characterized by the fact that a metal blank is struck in order to simultaneously form thereon, on one side, hour signs in relief and, on the other side, cavities for fixing the dial feet, which the feet are driven into said cavities, the feet are welded by passing the dial through the oven and, finally, the dial is leveled using the die used for striking relief signs. SUB-CLAIMS 1.

Process according to Claim I, characterized in that, for the leveling operation, the counter-die is also used after having removed the punches which have created said cavities. 2. Method according to claim I, charac terized in that, for leveling, a tool identical to the counter-matrix is used, but having a corresponding housing of each foot of the dial. 3. Method according to claim I, charac terized in that, during the first strike, a projecting collar is simultaneously formed around each of said cavities. CLAIM II Dial obtained according to the process according to claim I.