GB2029738A - Cutting machine - Google Patents

Abstract

A machine suitable for cutting a leather strip 30 to a desired profile includes a pair of cutting wheels 3A, 3B mounted on relatively movable respective frame parts whereby the wheels can be moved towards and away from each other so as to accommodate leather strips of varying thickness. At least one of the frame parts is movable along a rotatable shaft for guiding and supporting the frame part while transmitting motion to a feed roller for the strip. A pair of burnishing wheels 4A, 4B are arranged downstream of the cutting wheels. The cutting wheels are diamond tipped and profiled so as to effect a radiusing of the strip. The wheels 3B, 4B are mounted at opposite ends of an arm 5 pivotally mounted on the machine frame and adjustable by a strip width preset mechanism 7. <IMAGE>

Description

SPECIFICATION Improvements in machine tools This invention relates to machine tools and, specially but not exclusively, leather working machinery.

In the manufacture of leather products such as horse harnesses and saddles it is highly desirable when producing a high quality product to provide a radiused edge on the pieces of leather so as to improve the aesthetic appeal of the product while minimising the effects of scuffing of the product against the animal and the rider's skin. Previously such radiused edges were produced manually which had the disadvantage of substantially increasing the production cost of the product.

Further, it is often necessary in machine tools to support, guide and provide a bearing surface for relatively heavy members. Conventional linear bearings suffer from the disadvantages of being susceptible to initial sticking and to uneven wear of the bearing surface.

According to the present invention there is provided a leather edge radiusing machine comprising at least one pair of work wheels between which a leather workpiece may be fed, in which said wheels are driven by underslung motors arranged in stepped formation and in which the axis of at least one of said wheels is movable away from and towards the axis of the other wheel.

Preferably, two pairs of wheels are provided and the movable wheels of each pair are mounted at opposite ends of a pivotal arm.

Preferably also, one of said two pairs of work wheels comprises cutting wheels and the other pair comprises burnishing wheels.

Preferably also, individual cutting and burnishing wheels are provided.

Preferably also, feed rollers are provided on each side of each pair of work wheels.

Preferably also, said cutting wheels are diamond tipped.

Further according to the present invention there is provided a machine tool including two or more frame parts and in which one of said parts is movable relative to the other along a plurality of rotating shafts which serve to guide and support the frame part while transmitting motion.

Preferably, said machine tool is a leather, working machine and said shafts are used to drive feed rollers thereof.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a leather edge radiusing machine according to the present invention; Fig. 2 is a detail view of a pair of work wheels; Fig. 3 is a view from underneath of the frame of the machine of Fig. 1; Fig. 4 is a side view corresponding to Fig. 3; Fig. 5 is a sectional end view corresponding to Fig. 4; and Fig. 6 is a detail view of a width preset mechanism.

Referring now to the drawings, a machine for radiusing and burnishing leatherworkpieces is indicated generally at 1 and comprises a frame 2 on which is mounted a pair of rotatable diamond tipped cutting wheels 3 having a cross-section as shown in Fig. 2 and a pair of similar burnishing wheels 4. The wheels 3A and 4A of each pair are axially fixed relative to the frame 2. However, the wheels 3B and 4B are mounted at opposite ends of an arm 5 pivotally mounted on the frame at 6 and are axially movable towards and away from the fixed wheels 3A and 4A by means of a strip width preset mechanism indicated generally at 7 in Fig. 1 and shown in detail in Fig. 6.

To allow axial movement of the wheels 3B and 4B the frame 1 is formed with three parts, a fixed part 8 and two movable parts 9 and 10 as shown in Fig. 3. The movable frame parts 9 and 10 are supported by shafts 11, 12 and 13 journalled in the fixed frame parts 8 and in lugs 14 on the parts 9 and 10 and the heads 3B and 4B are driven by shafts 1 5 and 16, respectively, journalled in the frame parts 9 and 10 at 17 and 18, the arrangement being such that the parts 9 and 10 can move relative to the frame part 8 and to each other by sliding on the shafts 11 to 13.Movement of the wheels 3B and 4B is achieved by means of pivoting of the arm 5 and by means of the preset mechanism which comprises a cam surface 1 9 secured to the arm 5 and a rotatable shaft 20 journalled in and secured against sliding in the fixed frame part 8 and having a cam follower 21 thereon so that rotation of the shaft will bias the arm 5 in the direction of arrow A in Figs. 1 and 6.

A dead weight loading is applied at all times to the arm 5 to bias it in the opposite direction to the arrow A and thereby providing the correct cutting and burnishing forces.

The fixed wheels 3A and 4A are driven through shafts 22 and 23 and are driven by motors 24, 25, 26 and 27 which are located in the frame in stepped formation as shown in Fig. 5 so as to save space while allowing direct drive. Thus, the arrangement is such that the motors 24 and 25 move with their associated wheels.

Strip guides 28 and 29 are provided to guide the leather strip 30 being radiused through the machine. In Fig. 1 the extreme positions of the wheels are shown to illustrate the different widths of strip which can be machined, in this example, between 9.5 and 3.5 mm. Moreover, driven soft rubber rollers (not shown) are provided on the shafts 11, 12 and 13 below the strip and idler rollers (not shown) are provided above the strip to form a nip to feed the strip into and out of the wheels. Drive to the shafts 11, 12 and 1 3 is provided by a motor 3 (and a chain and sprocket drive indicated generally at 32). Thus, it will be appreciated that the shafts 11, 1 2 and 13 perform the function of supporting and guiding the frame parts 9 and 10 while rotating.

The cutting wheels 3 are shaped as shown in Fig. 2 so as to provide the desirable radii on the strip and the wheel 3B is provided with limited vertical "float" to ensure symmetrical shaping while accommodating strips of thickness varying between 3 mm and 4 mm.

A clear plastic shatterproof safety guard 33 is provided over the machine and, if desired, individual cutting and bumishing wheels 34, 35 are provided on the machine for radiusing odd shaped workpieces 36. Quartz halogen lamps can be provided on the machine and vacuum suction heads are provided adjacent to the cutting heads to carry away waste.

Claims (9)

1. A leather working machine having pair of cutting wheels for receiving between them a leather strip, the wheels being mounted on respective frame parts movable relative to one another to adjust the distance between the wheels, at least one of the frame parts being movable along a rotatable shaft for guiding and supporting the frame part while transmitting motion.

2. A machine according to Claim 1, wherein the shaft drives a feed roller for feeding a leather strip between the wheels.

3. A machine according to Claim 1 or2, wherein the cutting wheels are driven by underslung motors arranged in stepped formation.

4. A machine according to Claim 1, 2 or 3, wherein a pair of burnishing wheels are also provided.

5. A machine according to Claim 4, wherein one wheel of each pair is mounted at a respective end of a common pivotal arm so that on pivoting of the arm the wheels of each pair approach or recede from each other.

6. A machine according to Claim 4 or 5, wherein feed rollers are provided on each side of each pair of wheels.

7. A machine according to any one of the preceding Claims, wherein the cutting wheels have diamond cutting portions.

8. A machine according to Claim 7, wherein the cutting wheels are diamond tipped.

9. A leather working machine substantially as hereinbefore described with reference to and as shown in the accompanying drawings.