Method and machine for the engraving of articles.

The present invention relates to a method for carrying out, at an order site, the engraving of an article with a bent/curved surface, for example a ring, in which the orderer sends to the order site instructions regarding the article and the engraving, and in which an article corresponding to the article instructions is produced, or is selected from among articles produced beforehand, and is applied in computer-controlled engraving equipment. The latter can be supplied with the engraving instructions and is designed to emit control signals, depending on the latter, to an engraving machine forming part of the equipment. The invention also relates to an engraving machine for carrying out the method. The machine can be controlled by means of the control signals from the computer equipment, in which the engraving instructions for the article with the bent/curved surface can be input.

PRIOR ART

The engraving of rings for example has hitherto normally been carried out in the shop in which the ring or the like is offered for sale. The ring engraving has in this respect been carried out by hand and has hitherto con- stituted a genuine craft.

Computer-controlled engraving equipment is previously known, and it is also known to use control signals emanating from computer equipment to produce engraving on the flat surfaces of articles. The control signals in this respect control the head of an engraving needle which is brought into cooperation with the material of the article and is then guided along the latter.

DESCRIPTION OF THE INVENTION

TECHNICAL PROBLEM

There is a general requirement to rationalize and improve the selling and other handling of rings and similar articles which are to be provided with some kind of engraving adapted to the customer. The production of the article or ring and the engraving thereof have hitherto been carried out at different sites, and great gains in terms of rationalization are to be made by being able to coordinate these functions/operations effectively.

There is also a requirement for an effectively operating engraving machine in which it is possible, while retaining good results, to considerably speed up the engraving work which has hitherto been carried out manually.

SOLUTION

The aim of the present invention is to provide a method permitting more effective selling of rings and other articles with bent or curved surfaces which are to be provided with individual engravings. Instead of each shop keeping a large sale collection or having its own work¬ shop, it is proposed in accordance with the invention that only sample collections need be kept in each shop. The taking of measurements and instructions will be carried out in the shop, and the ordering of both the ring (or the like) and the engraving will be carried out at a central site which, in addition to the production function, thus also provides the engraving service.

The feature which may principally be regarded as charac- terizing a method according to the invention is that the produced or selected article is secured in a member which is designed rotatable in its own plane and forms part of the engraving machine, in that the computer equipment is

activated in order to emit the control signals which are received by first and second control members, likewise forming part of the machine, for the said rotatable member and for a device supporting an engraving member/engraving needle, and in that the rotatable member and the device are controlled in coordination by the control signals in order to obtain an engraving, corresponding to the input instructions, on the bent or curved surface of the article.

The invention also proposes an engraving machine which makes it possible to engrave rings and other articles with bent/curved surfaces in an effective and economical manner. The machine is preferably made in such a way that it can be adjusted to different ring diameters, ring thicknesses etc. By using computer equipment which is known per se, different type faces can be selected from this program in a manner known per se.

A machine which can be controlled by means of control signals received from the computer equipment can prin- cipally be regarded as being characterized in that it comprises a member which is rotatable in its own plane and is preferably disc-shaped, which member is designed with attachments for the article, and in that it also comprises first and second control members which, by means of the control signals, control the rotation of the rotatable member and a device supporting an engraving member/engraving needle in coordination in such a way that an engraving corresponding to the input instructions/control signals is obtained on the bent/ curved surface.

The device which supports the engraving needle or the like can be controlled essentially at right angles to the plane of rotation of the article. The rotatable member can be designed with a central recess into which that part of the device which supports the engraving member projects in order to permit cooperation between the

engraving member and the surface of the article. The rotatable member can be rotated by means of a motor which, via first cooperating members (gear wheel, gear ring etc.) , gives the rotatable member its rotational movements, which in this respect can be forwards and backwards.

The device is preferably mounted or suspended on the one end of a first lever which can be actuated via its other end by means of a motor or the like, forming part of the second control members, via second cooperating members (for example toothed arc, gear wheel etc.) .

The said device is preferably adjustable to different article thicknesses by means of a unit (motor) which forms part of the second control members.

The application of the engraving needle or the like against the material of the article in order to permit engraving is effected in one embodiment by means of a spring force, which can be obtained for example from a mechanical tensile spring. The raising of the engraving member counter to the action of the said spring force is effected in one embodiment by means of an electromagnet.

The device is preferably designed as a second lever which is mounted at its centre on the first end of the said first lever. The said second lever (= the device) sup- ports the engraving member at its first end and can cooperate at its other end with the said spring force and the electromagnet.

In a further embodiment, the unit (motor) in the second control member can cooperate with a slide or similar member which can be adjusted by means of the unit to different displacement positions in relation to the device (the second lever). The slide or similar supports the electromagnet and, as a result of its displacement to different predetermined positions by means of the unit,

it is possible to carry out the adjustment to the dif¬ ferent article thicknesses. The effect of the unit on the slide can be achieved via a thread or the like which is screwed into and screwed out of a thread on a part coupled to the slide. The degree of screwing-in of the thread thus determines the longitudinal displacement position of the slide in relation to the device.

ADVANTAGES

By means of the invention the measurement instructions and engraving instructions can be sent to the central site, which makes use of some of the instructions in the engraving function. The engraving of different types, thicknesses and sizes of rings or the like can therefore be carried out. The rings or the like are produced or are selected from among articles already produced, after which the respective engraving can be carried out. The engraving machine operates with reliable functioning and with great speed. The engraving of a ring can be carried out in 20 seconds or in a shorter period, which is to be compared to manual engraving in which a very much longer period has to be spent on each ring.

DESCRIPTION OF FIGURES

A proposed embodiment of a method and an engraving machine according to the invention will be described below with reference to the attached drawings, in which

Figure 1 shows a skeleton diagram of the handling of rings or the like at a central site. Figure 2 shows a longitudinal section through the engraving machine, Figure 3 shows the engraving machine according to Figure

2 from one end, and Figure 4 shows a horizontal view of the engraving machine according to Figure 1.

PREFERRED EMBODIMENT

In Figure 1 a central site receiving orders is indicated by 1. The orders can come in by telephone, by order forms 2, 3 from different shops 4 and 5 which are served by the central site, etc. In-coming orders 2, 3 can contain instructions on the articles which are to be supplied centrally and instructions on the individual customer- adapted engravings with which the articles are to be provided. The central site thus comprises a production or storage unit 6 in which the articles are ordered or stored. After production or selection from the store of a particular article 7, for example in the form of a ring, the latter is conveyed to an engraving machine 8 which is controlled by computer equipment 9. The computer equipment is provided with a write-in member (terminal) 10. Some of the instructions, more specifically the instructions relating to the engraving of the article 7, are transmitted to the computer equipment 9 via the write-in member 10. These transmitted instructions have been symbolized in the Figure by 11. There is thus obtained for the shops 4, 5 a centralized production and engraving service which the shops can buy. The input instructions in the unit 10 lead to input signals iM to the computer equipment. The computer equipment can send adjustment and control signals is to the engraving machine 8.

For an effective handling service according to Figure 1, an effectively functioning engraving machine according to Figures 2-4 is required. The engraving machine comprises a frame with a base plate 12, a top plate 13 and corner pins (corner parts) 14, 15, 16 and 17 holding the plates together. The plate 12 has a multi-sided horizontal section and the plate 13 has an essentially round hori¬ zontal section. The plate 13 is provided with a central part 13a which is displaced parallel in the longitudinal section according to Figure 2 and on whose top side there is a depression 13b. On the top side of the plate 13

there is arranged a rotatable member 18 which is provided with a thickened central part 18a via which the member 18 is rotatably mounted in the said depression 13b. The bearing comprises a ball bearing 19 which is secured in a bushing 20 which in turn is secured in the part 13a. The member 18 is in turn applied on the bearing 19. The axis of rotation of the member is indicated by 21, and the member can be regarded as being essentially disc¬ shaped. The plate 13 and the member 18 are provided with central recesses 22 and 23 respectively. In the recess 23 there are attachment members 24, 25, 26, 27 and 28 for the said article 7' (cf. Figure 4). The said attachment consists of pegs or pins which are longitudinally dis- placeable in the plane of rotation and which are each provided with a cap 29 of a material which does not damage the article when the latter is secured in the attachment. The material of the cap can consist of rubber, non-rigid plastic etc.

The pins 24-28 can be locked in different longitudinal displacement positions by means of locking members comprising a guide pin 30 and locking disc 31, which is provided with recesses 31a for the guide pins 30. There is also a manually actuable manoeuvring part 32 which acts via a shaft 33 on a gear wheel 34 whose teeth are in engagement with teeth arranged in the outer edge of the locking disc in order to permit displacement of the locking disc 31 in the plane of rotation and, thus, longitudinal displacement of the pins 24-28 to different longitudinal displacement positions in which they can cooperate with outer surfaces of articles 7' of different external diameters. The ball bearing 19 is closed in by means of a bushing 35 and a radial seal 36. The member is provided with a cover 37 which has a central recess 37a.

The article/ring can be secured in the attachment 24-28 via the recess 37a and the recess 23. The member 18 is provided with an outer gear ring 18b. A first control member in the form of a motor (for example a stepping

motor) 38 acts on the member for the purpose of turning in both directions of rotation by means of a gear wheel 39 which cooperates with the gear ring 18b.

A device 40 is arranged so as to extend from below through the recesses 22 and 35a and into the recess 23. It supports an engraving head 40a with an engraving needle 41 which is held in place by means of a pin 42. The device can be tilted on the one hand about a bearing axis 43 at its central part, and on the other hand can be raised and lowered relative to the rotatable member 18. The movement of the device is essentially at right angles to the plane of rotation of the member 18. The raising and lowering are obtained by means of a part 44 which is designed as a first lever and is mounted on a bearing axle 45 which in turn is arranged on a part 46 which is secured (by screws) in the frame plate 19. The part 44 supports the device 40 at its first end 44a and is provided at its other end 44b with a toothed arc 44c. A control member in the form of a motor (for example a stepping motor) 47 is designed to rotate the part 44 about the axle 45 via a gear wheel 48 which cooperates with the toothed arc 44c and is therefore designed to produce the raising and lowering movements of the device 40.

The device 40 can also be regarded as being designed as a lever, here called the second lever, which supports the engraving head 40a at its first end and can cooperate at its other end on the one hand with a tensile spring 49 and on the other hand with an electromagnet 50. The latter is arranged on a displaceable slide 51. The displacement is achieved by means of a unit, for example a motor, whose shaft 52a supports a threaded end part 52b which cooperates with an internal thread 53a in a part 53 which is connected to the said slide 51. The slide is mounted in ball bearings in a known manner (not shown) . By means of the rotation of the motor 52, its end is threaded into or out of the internal thread 53a,

resulting in the slide with the electromagnet being displaced towards or from the other end 40b of the device 40. Different starting positions can be obtained in this way for the degree of tilting of the device 40 about the axis 43, resulting in the fact that the engraving needle or the like can be set in relation to the inner surfaces of articles with different ring thicknesses (ring material thicknesses).

The tensile spring 49 effects the application pressure of the needle 41 against the material of the article. The electromagnet lifts the needle when it is activated (= position according to Figure 2) counter to the action of the spring 49. The spring is tensioned between ah attachment 54 on the plate 12 and a stud 55 on the device 40. The electromagnet 50 is provided with an armature with projecting ends 50a and 50b. A link arm 56 connects the end 50a to the device 40. The bearing axles for the arm 56 are indicated by 56a and 56b. At the end 50b there is a bushing 57, determining the stroke length of the electromagnet, and nuts 58. The electromagnet is shown in the ^• activated state in which it acts on the device 40 counter to the action of the spring 49 in such a way that the needle 41 on the device takes up a position within the inner surface of the article. When the electromagnet is deactivated, the spring acts on the device in such a way that the needle 41 presses into the ring material with a force which in the present case is chosen at about 2 Kp.

The function of parts not described (retaining screws etc.) emerges clearly from the drawing and is not des¬ cribed here. The computer equipment can be set up by known techniques and can operate with known software and will therefore not be described in greater detail here.

The function of the engraving machine is as follows. Instructions on ring thickness, typeface etc. are fed into the input member 10 (see Figure 1). The article is

secured in the engraving machine. The computer equipment effects control signals iS which can consist on the one hand of signals for adjusting the machine to the indi¬ vidual article (its dimensions) and on the other hand control signals for the engraving which is to be carried out.

The adjustment signals act on the motor 52 which sets the slide 51 (the electromagnet 50) to the particular ring material thickness, i.e. the slide/electromagnet is set in a displacement position in relation to the end 40b of the device in such a way that the device is given an initial position for the particular ring material thick¬ ness in which the needle in the activated position of the electromagnet has the optimum height over the inner surface of the ring for the engraving. Thereafter (elec¬ tromagnet still activated) the motors 38 and 52 are given adjustment signals in which the needle is placed above the point on the inner surface of the ring where the engraving is to be started. The engraving can then be started, and this is brought about by the electromagnet 50 being deactivated. The tensile spring 49 then acts on the device 40 in such a way that the needle 41 is pressed into the article material at a force determined by the spring. The engraving is then carried out by means of the motors 38 and 47 and the electromagnet 50 being supplied with control signals depending on the design of the engraving. When the engraving is complete, the electro¬ magnet is held in the activated position (needle raised) and the article can be removed.

In the exemplary embodiment, an article has been shown with surfaces which are curved in one direction and straight in the direction at right angles to this direc¬ tion. Other bend or curve configurations are possible. The equipment can also be designed in such a way that engraving can be carried out on the outside of ring- shaped articles, etc.

The invention is not limited to the embodiment shown above by way of example, but can be subjected to modifi¬ cations within the scope of the following Patent Claims and the inventive concept.