US2123619A - Stone cutting wire saw - Google Patents

Description

July 12, 1938. A. E. WIENHOLZ STONE CUTTING WIRE SAW Filed June 22, 1937 m H mm m m I T m B L A pm, I

BY 21,1 f. (aka/v YA TTORNEYS.

Patented July 12, 1938 UNITED STATEfi ATENT OFFIQE 6 Claims.

My invention relates to stone cutting wire saws and has particular reference to multiple strand wires used for cutting blocks. of stone or rock.

Twisted multiple strand wires have been found very effective for cutting stone with suitable abrasives, such as sand, emery, steel shot and steel chips, depending on the hardness of the rock. Usually three strands of steel round wire are used, the wire being sufficiently flexible to be wound on pulleys, and there being certain space between the wires for the abrasive material.

The round wire, however, has also certain disadvantages. Each individual strand occupies a relatively large space, leaving but little room for the abrasive, and this disadvantage rapidly increases with the wear of the wire, when the latter acquires a progressively larger rubbing surface at the expense of the spaces between the ad- 'acent wires, leaving correspondingly less room for the abrasive. It is very important therefore that the wire should have sharp edges not only for actual cutting of the stone but also for effective working of the abrasive along the out. One solution of thisproblem is found in the rectangular sharp-edged wire with sharp transverse grooves as described in my Patent No. 1,876,480. I have found, however, that the best results are obtained with a multiple strand wire cable, the individual wires being of an angular section and having sharp edges.

The object of my invention is therefore to provide a multiple strand stone cutting wire having sharp edges and being of such a shape that the maximum of space is provided for the abrasive.

Another object of my invention is to provide a multiple strand cutting or sawing wire having sharp edges and being of such a shape that the edges retain their sharpness even when the wires become considerably worn out in use. I have found that triangular wires well answer this requirement, when the wires wound into a cable by abutting their sharp edges in the center so that each wire has two sharp edges on the periphery of the cable.

The triangular wires have an added advantage that the space between the wires for emery etc. retains its relative volume or sectional area in comparison to the sectional area of the wires themselves even when the latter become more or less worn out.

Another object of my invention is to provide a multiple strand stone cutting wire twisted into a cable of a relatively steep pitch in order to provide a substantially round projectional area of the wires and to move the abrasive spirally with the wire. I also provide a secondary twist of a relatively long pitch by progressively advancing the turns, thissecondary twist providing further means for spirally moving the abrasive and for progressively changing the cutting edges of the wires.

Another object of my invention is to provide a stone cutting wire made of a magnetic mate- I rial so that it can be magnetized for entraining '10 steel shot and'chips into the cut, as described in my Patent No. 1,743,057.

Another object of my invention is to provide a stone cutting wire having sharp edges and con- I sisting of a relatively soft core and cutting edges '15 welded on the core, the edges being of a hard steel or an alloysuch as Stellite, carboloy etc.

Still another object of my invention is to provide a stone cutting wire having a plurality of relatively small inserts on its periphery, pref- .20 erably arranged in spirals along the wire, the insert providing cutting edges and being made of a harder material than the core of the wire.

My inventionis more fully described in the ac-' companying specification and drawing in whicha Fig. 1 is a view of'a portion of my multiple strand wire.

Fig.- 2 is a sectional View of the same on a larger scale.

Fig. 3 is a sectional view of a wire having welded cutting edges.

Fig. 4 is a similar view of a modified wire with welded cutting edges.

Fig. 5 is a similar view of a wire of a different shape.

Fig. 6 is a sectional view of another modification.

Fig. 7 is a sectional view of still another modification.

Fig. 8 is a sectional view of a single strand with cutting inserts.

Fig. 9 is a view of a portion of the wire with inserts.

Fig. 10 is a diagrammatic sectional view of a cable formed of round wires.

My stone cutting wire represents a cable twisted of several, preferably three strands of a wire I having sharp cutting edges. I prefer to use this wire of a triangular cross section, or formed of equilateral triangles as shown in Fig. 2. The wires are twisted so that they abut each other in the center of the cable by their sharp edges so that their sides extend radially toward the periphery of the cable. Spaces 2 between the radial sides form cavities for holding an of the wires Seven before any wear becomes noticeable, so that a relatively small quantity of an abrasive can be used with round wires. The cavities 4 become still further reduced in volume when the wires begin to wear as shown by a smaller circle in Fig. 10. Moreover, the cutting edges of the round wires remain very dull under all conditions, while the cutting edges in Fig. 2 remain sharp even when the wires become more or less Worn out.

The wires I are given a sharp twist of a more or less steep or short pitch as shown in Fig. 1 in order to provide a substantially round projectional section for the wire and to have a large number of spirally extending cutting edges. The twist also helps to carry the abrasive material along the wire into the cut in a stone.

In addition to this sharp twist, which may be called primary twist, there is also a secondary twist of a very long pitch, this secondary twist being formedby slightly advancing each turn of the primary twist in relation to the preceding turn. The secondary twist is shown in Fig. 1 and it improves still further the cutting properties of the wires, the latter resembling a twist drill in their shape. The secondary twist also facilitates the entraining of the abrasive along the wires in the cut and continuous changing of the cutting edges along the wires.

The wires I are preferably made of a carbon steel so that they can be hardened to increase their cutting action and to reduce their wear.

It is possible, however, to make the core 5 of the wires of a relatively soft metal, welding cutting outer portions 6 made of a carbon steel which is hardened while the core remains relatively soft if it is made, for instance, of a low carbonsteel. The edges 6 can be made of a special alloy such as stellite or carboloy in order to increase their durability for cutting very hard rock or stones.

When expensive alloy is used for cutting edges, their volume may be still further reduced by welding the corners 8 only to the cores 1 as shown in Fig. 4.

Modified sections of the wires are shown in Figs. 5, 6, and '7. Wires 9 in Fig. 5 have concave sides in order to render the cutting edges sharper and to increase the volume of spaces between the wires. Diamond shaped wires ID are shown in Fig. 6, such wires providing but a single cutting edge each, but spaces between the wires being relatively large.

The wires may be also formed of flat rectangular strips ll shown in Fig. 7 in order to still further increase the volume of the spaces between the wires.

Another modification is shown in Figs. 8 and 9. A single strand of a round wire I2 made of a relatively soft metal, is provided with a plurality of inserts l3 made of a relatively hard steel or alloy. These inserts can be welded or brazed in their places and may be round or sharp-pointed. They are preferably arranged in spiral directions in order to provide a more or less uniform cutting surface.

I claim as my invention: I

l. A stone cutting wire saw consisting of several strands of a sharp-edged wire twisted together into a cable and abutting by their sharp edges in the central portion of the cable thereby forming spaces between the sides of the strands extending to the axis of the cable.

2. A stone cutting wire saw consisting of several strands of a sharp edged wire formed of a relatively soft metal and having cutting edges of a relatively hard material.

3. A stone cutting wire saw consisting of several strands of a sharp edged wire forming a cable and having a primary twist of arelatively short pitch and a secondary twist of a relatively long pitch.

4. A stone cutting wire saw consisting of several strands of a sharp edged wire twisted into a cable of a short primary twist, the turns of the twist progressively advancing thereby forming a secondary twist of a longpitch.

5. A stone cutting wire saw consisting of three strands of a triangular wire twisted together into a cable, the wires abutting by their edges in the central portion of the cable.

6. A stone cutting wire saw consisting of three strands of wire twisted together to form a cable, each strand having the cross-sectional form of an equilateral triangle.

ALBERT E. WIENHOLZ.

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