DE487681C - Automatic feed of the slidably arranged scissor knives in exchangeable knife frames for cast iron shears - Google Patents

Description

In the case of the scissors with an exchangeable knife frame according to patent 349 876, wider knives must be used to reduce the cutting opening if weaker shapes are to be cut without being deformed. The deformation occurs because the tips of the knives located in the housing part B of said patent protrude too far out of the angle of the shaped iron inserted for cutting and the knives cut the limbs of the shaped iron too far outside when the knives are fixed and therefore forced to the arc of a circle to follow, which describes the rotating parts with the knife frame B around the bolt e during its movement.

The subject of the present invention is a device which prevents the knife d and / by its own movement, caused by resilient push rods, in the exchangeable knife frame c , at the initial idling of the rotating part b, which can also be designed as a support, from the angle of the to Cutting out of the inserted shaped iron, whereby the deformation of the iron without having to change the knife is prevented.

In the drawing is the schematic embodiment of the invention shown.

Fig. Ι shows the side view of a cutting machine with the push rods k and I for the movable knife in the knife frame c used.

Fig. 2 shows the inner surface of the knife frame c (knife open).

Fig. 3 shows the inner surface of the knife frame c, knife d and / to e closed by hand or by the action of the push rods k and I.

Figure 3a is an end view of knife frame c.

Fig. 4 gives the external view of the knife frame c with the push rods k and /, knife in readiness position, and

Fig. 5 shows the external view of the knife frame c with the push rods k and '/ and with inserted T-iron, knife in the closed end position after the cut, again.

Fig. 6 shows a view and section of the push rod /.

When the lever Λ (Fig. 1) is pressed down by hand - the machine can also be set up for motorized drive - the S rather ent part b with the knife frame c seated in it performs a rotary movement around the pin g in Fig. 1 indicated care direction. If a weaker form iron has been inserted into the cutting opening for cutting, which does not completely fill the cutting opening, the push rods k and I set the knives d and / at the beginning of the rotary movement of the rotating part b in the knife frame c inevitably in motion, in such a way that

that the tips of the knives d and / follow a resulting movement, composed of the rotary movement around the pin g (Fig. 4) and the parallel displacement of the knives in their embedding by the push rods k and I , until the knives hit the iron cut sharply at an angle. As a result of this inevitable self-movement of the knives d and /, the knives attack the forging iron with their tips in every position of the knife frame c , whether strong or weak, at a sharp angle at the beginning of the cutting and thus bring about a clean cut.

The bearing pins ν and w of the push rods k and L are on the one hand firmly seated in the scissors body a, on the other hand the bearing pins m and n are firmly connected to the knives d and / (Fig. 3a, 4 and 5).

As soon as the knife and / or the cutting material take hold of the feed movement of the knives d and f, caused by the push rods k and L ₁ . The pressure acting on the push rods when cutting is absorbed by the spiral springs ρ (Fig. 6) in the push rods k and £, and the deflection is limited by the bolt guided in a slot. During the cutting, the knives then perform a pure rotary movement around the pin g . After completion of the cut, the push rods k and L come into action again and guide the knives d and / back into their starting position as soon as the scissor lever / i is brought back into its initial position.

For certain cutting operations, e.g. B. when cutting angle iron, it is necessary that the partial knife d and / and e close against each other from the start. To achieve this, the connection between the knives and the push rods is released and the knives are mutually adjusted in the knife frame by hand. The knives are then held in place by the screws t and α . Likewise, the knives in the opposite knife frame part can be adjusted by hand, for the purpose of producing the necessary cutting openings for the most varied cutting of angle and T-irons at right angles and with a miter, without the partial knives, as according to the patent mentioned, still being replaced have to.

In order to make it easy to detach the push rods k and I with the nozzles m and η of Figs. 3a, 4 and 5 screwed into the knives d and / , the push rods are pivotable around the rivet pin 0 of Fig. 6. This also ensures that the push rods are not a hindrance when the knife frame parts are inserted into the scissors and when they are removed from it, and the changing of the knife frame, which is important on such scissors, is not made more difficult.

For the sake of safe guidance, the partial knives d and / have a guide strip / · or s (Figs. 3a, 4 and 5) on their sliding surfaces, which guide well in a corresponding groove in the frame. -

Claims (1)

Claim: Automatic feed of the displaceably arranged scissors knives in the exchangeable knife frame for shaped iron shears, characterized in that the resilient push rods (k and /) causing the feed can be both switched in and out and pivoted away. 1 sheet of drawings