RU2104129C1 - Multiple-row scissors - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: this relates to cutting equipment and can be used for cutting thin-sheet material, primarily copper foil. Multiple-row scissors have upper and lower shafts with sets of round blades and extractors alternately located on shafts. Extractors of one shaft are located against blades of other shaft, and their outer diameter is equal to diameter of blades or larger by value of $$$, where $$$ - value of deformation of extractors. EFFECT: high efficiency. 5 dwg

Description

 The invention relates to cutting equipment and can be used for cutting into several parts of sheet material, for example, steel, copper foil, paronite, paper, etc.

 Known multi-disc scissors containing upper and lower shafts on which circular knives are arranged with a set with an interval equal to the width of the cut strips, interchangeable curved strips are installed in the interval between the knives, the ends of which are fixed on the brackets, and the strips are arranged so that their convex part directed towards each other [1].

 Multi-disc scissors are also known, containing cutting disks mounted on parallel drive shafts; ejectors are made between the disks made in the form of bushings bearing freely rotating bronze rings mounted between the rubber rings. These bushings are belt conveyor pulleys that feed and remove material from the cutting zone. Rubber rings are placed in the area of the cutting edges of the discs and press the material to the conveyor belt [2].

 The disadvantage of these scissors is the inability to obtain a stable width of cut tapes, the edges are torn, wavy with burrs and have a crescent shape in length because the cut sheet of material sags and lengthens in width at the time of cutting. In this case, the strip width is beyond the tolerance and exceeds the width of the curved plates that are located between the knives. As a result, when the strip leaves the cutting zone, it straightens and abuts against the side surfaces of the knives. The tension increases, the foil is pulled and torn. Therefore, the cutting process is difficult, is accompanied by frequent stops, is carried out at low speeds and therefore low productivity and unreliable during operation. In addition, there is a need to install additional mechanisms for transporting material, which complicates the design of scissors.

 The purpose of the invention is to increase labor productivity by ensuring uninterrupted guaranteed removal of strips from the recesses of the interknife space.

The goal is achieved in that in multi-row scissors containing upper and lower shafts, with a set of round knives and pushers placed on shafts alternating through one, while the pushers of one shaft are located opposite the knives of the other shaft, and the outer diameter of the pushers is equal to the diameter of the knives or more by the value determined by the formula
D _to = D _n + Δh
where D _k is the outer diameter of the elastic part of the ejectors;
D _h is the outer diameter of the knives;
Δh is the strain of the elastic part.

где K = 0,15-0,4 - коэффициент упругости выталкивателей;
α_p = угол резки материала;
τ_ср - допустимые напряжения материала на срез;
h - толщина упругой части выталкивателей;
S - толщина разрезаемого материала;
H - модуль упругости;
B - ширина ленты.

where K = 0.15-0.4 is the coefficient of elasticity of the ejectors;
α _p = cutting angle of the material;
τ _cf - allowable stresses of the material per shear;
h is the thickness of the elastic part of the ejectors;
S is the thickness of the material being cut;
H is the modulus of elasticity;
B is the width of the tape.

 In FIG. 1-5 are the proposed scissors.

They contain a housing 1 in which shafts 2 and 3 are installed that rotate around their longitudinal axes. A set of knives 4 and pushers 5 is mounted on the shafts 2 and 3. The knives 4 with a diameter of (D _h ) are made in the form of a continuous metal ring, and the pushers 5 are external the diameter is provided with an elastic ring 6 with a diameter (D _k ), the condition always being satisfied that (D _k > D _h ), the width of the ejectors 5 is equal to the width (B) of the strip. On the edges of the knives 4 and the pushers 5 on the axes 2 and 3, end knives 7 are installed. The width of the knives 4 is less than the width of the pushers 5 and they are installed in such a way that a gap (a) is formed, which ensures cutting of the material 8 into strips 9.

 Assembly of scissors is as follows.

 Shafts 2 and 3 are removed from the housing 1. Then, knives 4 and pushers 5 are mounted on them, alternating through one, over the entire width of the sheet. At the ends, knives 7 are installed, which serve to trim the ends of the sheet 8. Then the shafts are installed in the housing 1, while the order that the knives 4 of the shaft 2 are paired with the ejectors 5 of the shaft 3.

 The work of the proposed scissors is as follows.

 The assembled scissors set in motion, while including a drive that rotates the shafts 2 and 3 around its axes in opposite directions. Between them set the cut sheet 8. By the force of rotation and pressing of the shafts 2 and 3 to each other, the sheet 8 begins to pass between the shafts, and the edges of the knives 4 are cut. In this case, the knives 4, rolling on the pullers 5, compress the elastic rings 6, which, being deformed, are located at the moment of cutting below the knives 4, thereby allowing the destruction of the foil in the gap zone (a). At the same time, the rest of the outer surface of the knives 4 and ring 6 is tightly pressed against the sheet 8, which eliminates the formation of a gap and sagging of the foil in the puller 5 at the time of cutting. After cutting the sheet 8 to the width of the tape 9, the edges of the knives 4 move away from the foil in different directions, and the tape itself moves due to the friction force on the shafts 2 and 3. At the same time, due to the elasticity of the compressed ring 6, its reverse deformation occurs along its entire width and together with the expulsion of the split tape 9 from the cavity of the pullers 5 and wound on a drum.

 The coefficient of elasticity of the ring is established experimentally.

 If K <0.15, then the elastic ring 6 becomes "soft" and its compressive force at the time of cutting does not ensure the ejection of the tape after cutting. In this case, as a rule, the width of the tape is greater than the width of the cavity and it "gets stuck" in it when released.

 If R> 0.4, then the elastic ring becomes non-elastic, a large effort is required to compress it, and the amount of compression is insignificant and does not provide free exit of the foil from the cavity, which leads to its freezing in the cavity and, as a result, to breakage.

 The use of the invention allows to ensure the process of cutting foil reliable and high quality. At the same time, the number of equipment stops due to clipping of the foil is reduced and labor productivity is increased in comparison with the known scissors for cutting copper foil.

Claims (1)

Multi-row scissors containing upper and lower shafts with a set of round knives and pushers placed on shafts alternating through one, while the pushers of one shaft are located opposite the knives of the other shaft, characterized in that the outer diameter of the pushers is equal to the diameter of the knives or more by an amount determined according to the formula
D _to = D _n + Δh,
where D _{to the} outer diameter of the ejectors;
D _{n the} outer diameter of the knives;
Δh the magnitude of the deformation of the ejectors, determined by the formula

where K 0.15 0.4 the coefficient of elasticity of the ejectors;
α _p is the cutting angle;
H ejector thickness;
τ _cf - allowable material stress per shear;
S is the thickness of the material;
E is the elastic modulus of the ejector ring;
B is the width of the material.

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