BAND SAW FOR CUTTING METAL WORKPIECES

TECHNICAL FIELD

The invention relates to a band saw apparatus particularly for cutting hardy metal workpieces, such as steel bars, wires or shafts, more particularly to a band saw having a continuous loop saw blade mounted on a pair of guide wheels which are mounted to a machine frame. The present invention provides an improved solution for cutting two or more independent workpieces simultaneously.

PRIOR ART

Various industrial uses for continuous loop band saws are known, and numerous band saw apparatus have been developed, some of them enabling to cut multiple workpieces simultaneously.

In US Pat. No. 4,893,533 a band saw apparatus is disclosed, having more than two blade guide assemblies formed for sliding engagement with a continuous loop saw blade to define at least two saw blade cutting stretches. The apparatus also comprises a vise assembly to separate multiple workpieces in two or more workpiece retaining channel. However, the apparatus is not suitable for cutting workpieces of rather large diameter, e.g. steel rods and shafts, etc. A further deficiency is that the apparatus has a relatively considerable length, due to the applicati- on of a series of longitudinally spaced saw blade guide assemblies and jaw members.

Another approach to the problem of multiple cutting is shown in US Pat. No.4,574,675. This patent teaches parallel simultaneous cutting, the suggested band saw apparatus comprising a pair of drums, one of them driven, arranged on a frame, and at least two saw-blades running over the drums beside each other, defining parallel cutting planes. One or more blade guiding units are also provided to achieve the proper cutting position of the saw blades. The apparatus is suitable for slicing relatively soft workpieces, particularly deepfrozen fish blocks, it does not enable, however, simultaneous cutting of hardy material, such as steel workpieces. It does not allow simple adjustment of dimensions, either, because of the fixed relative spacing of the parallel saw blades.

Accordingly, an object of the present invention is to provide a band saw apparatus for accurately cutting at least two workpieces simultaneously.

Another object of the present invention is to provide an apparatus which enables cutting multiple hardy workpieces, such as steel rods or other metal pieces to desired lenghts. It is a still further object of the present invention to provide a relatively simple apparatus with reasonable dimensions being realizable through minor alterations of existing constructions.

DISCLOSURE OF THE INVENTION

The band saw apparatus of the present invention comprises a frame, a pair of guide wheels rotatably mounted to said frame, a saw blade mounted on said guide wheels, a drive means driving at least one of said guide wheels, and a clamping device or gripping

jaw to grip a workpiece while cutting, and further comprises, a second pair of guide wheels with a second saw blade, said second pair of guide wheels rotatably mounted to said frame and driven by said drive means, and a second clamping device or gripping jaw to grip a second workpiece cut by said second saw blade.

According to a preferred embodiment of the band saw of the invention, said first pair and second pair of guide wheels are mounted to parallel sides of said frame, advantageously to parallel sidewalls of the motor case of said drive means, defining parallel cutting planes.

According to another possible embodiment, said first and second pairs of guide wheels are arranged in a vertically disposed position relative to each other.

The first and second pairs of guide wheels with their respective saw blades of the claimed apparatus may define vertical, horizontal or inclined cutting planes.

In a further preferred embodiment of the present invention there is provided a single outlet and workpiece conveying means attached thereto, common for both saw blade assemblies.

A still further embodiment of the apparatus of the present invention can comprise more than two saw blade assemblies, the guide wheel pairs of those saw blade assemblies being mounted to the same side or to different sides of the machine frame.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the invention will be described more in detail by way of example, with reference to the accompanying drawings, in which

FIG. 1 shows a schematic front view of a preferred embodiment of the band saw according to the invention;

FIG. 2 shows a top plan view of the band saw of FIG. 1; and

FIG. 3 shows a side view of the band saw of FIG.l.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Figs. 1 to illustrate the basic construction of the band saw apparatus of the present invention. As it is apparent from the figures, the apparatus comprises a support, generally designated machine frame 1, having support means 3 fixed on the top of frame l. Drive means 8 comprises an eletric motor having a motor case2, and a driving belt 9, mounted on drive support 13 pivotally attached to the main frame 1.

An operating device, such as lifting cylinder, a hydraulic cylinder e.g. is also mounted on the main frame 1, and connected to the drive support 13 or motor case 2.

The apparatus of the invention comprises a first pair of guide wheels 4;5, rotatably mounted to the right side of the motor case 2 and the support means 3, respectively. A continuous loop saw blade 6 is mounted to run over the guide wheels 4 and 5. In the present example the assembly of saw blade 6 and guide wheels 4 and 5 define a vertical cutting plane. The desired sawing position of saw blade 6 along the cutting stretch is achieved by means of blade guide member 12, mounted on the main frame 1. One of the guide wheels 4 and 5, e.g. guide wheel 4 is driven by the drive means 8.

The saw blade assembly is provided with a clamping device 11 or gripping jaw, carried by the main frame 1, to clamp one or more workpieces in a

suitable position relative to the saw blade cutting edge, while said workpiece/s/ being cut by the saw blade 6.

In order to increase the operative effectiveness of the apparatus, it is further provided with a second saw blade assembly arranged on the left side of the main frame 1. The second saw blade assembly comprises a second saw blade 19 mounted on a pair of guide wheels 15;16, defining a cutting plane which is parallel to the first one, i.e. vertical in the present example. Guide wheels 15 and 16 are rotatably mounted to the left side of the motor case 2 and support means 3. Guide wheel 15 is driven by said drive means 8, together with guide wheel 4 of the first saw blade assembly. The second saw blade 19 is provided with at least one blade guide member 18, insuring the correct sawing position along a given cutting stretch. Fitted relative to the cutting edge, there is a clamping device 17 or jaw, mounted on the main frame 1.

The apparatus of Fig.l comprises a discharging assembly with an outlet 20, conveying means such as roller assemblies 10, and guide means 14 directing the workpieces being cut by the first and second saw blade assemblies from the outlet 20 onto the roller assemblies 10. As illustrated in the drawings, the discharging system is common for both saw blade assemblies.

When operating the above band saw apparatus of the invention, it is advantageous to position the workpieces being simultaneously cut relative to each other in such a manner that one of the workpieces is finished some seconds earlier than the other one, so that discharging of the cut pieces through outlet 20 and guide means 14 can be carried out without hitch, fluently.

By use of the band saw apparatus of the invention two or more workpieces, even hardy metal workpieces of relatively large dimensions can simult¬ aneously cut, so that an increased efficiency will be achieved. The cutting parameters of the simultaneous¬ ly cut workpieces may be individually set, so that even different work steps can be carried out on different workpieces.

While in the foregoing description the invention has been described in relation to a preferred and rather simple embodiment, and many details have been set forth for purposes of illustration only, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments, and details described herein may be varied without departing from the basic principles of the invention.