GB2048420A

GB2048420A - Reciprocating drive

Info

Publication number: GB2048420A
Application number: GB7915311A
Authority: GB
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1979-05-02
Filing date: 1979-05-02
Publication date: 1980-12-10

Abstract

A reciprocating drive for a blade (1) comprises a drive motor (3) drivably connected via gearing (15, 16) to a cylindrical rotary member 4 defining an effectively endless scroll cam formation (20) extending angularly around and axially along the rotary member, a reciprocating slide mechanism (8) fixedly connectable to the blade has an abutment (21) for driveable cooperation with the endless scroll cam formation. <IMAGE>

Description

SPECIFICATION Reciprocating drive This invention relates to reciprocating drives.

In particular the present invention relates to reciprocating drives for blades.

An object of the present invention is to provide an improved reciprocating drive for a blade, the drive being simple, reliable and robust.

According to the present invention a reciprocating drive for a saw blade comprises a drive motor, a cylindrical rotary member driveably connected to the drive motor, an effectively endless scroll formation extending angularly around and axially along the rotary member, and a reciprocating slide mechanism fixedly connectable to the blade and having an abutment for driveable co-operation with the endless scroll formation.

Preferably, control means are provided for the drive motor.

Conveniently, the drive motor is fluid driven and the control means comprises a control valve.

Preferably, the control valve is activated into a drive mode against a resilient loading.

Advantageously, the control valve comprises throttle means for controlling the feed of pressure fluid to the motor and thereby controlling the drive speed of the motor.

Preferably, the control valve comprises a rotary handle having a spindle defining a helical formation engageable by an abutment on a valve closure member, rotation of the handle causing the abutment to move along the helical formation to urge the closure member against the resilient loading to open the valve.

Preferably, the valve closure member comprises a tapered portion.

Advantageously, gearing is provided intermediate the drive motor and the driven rotary member.

Conveniently, drive motor, the rotary member and the reciprocating slide mechanism are housed within a housing assembly.

Advantageously, a clamp is provided on the housing assembly.

By way of example only, one embodiment of the present invention will be described with reference to the accompanying drawings, in which: Figure 1 is a sectional view of a reciprocating drive constructed in accordance with the present invention, the section being taken along line I-I of Fig. 2; Figure 2 is a sectional view taken along line Il-Il of Fig. 1; and Figure 3 is a part sectional end view of Fig.

1.

The drawings show a reciprocating drive for a saw blade 1 (only one end portion of which is shown) to comprise a housing assembly 2 within which is mounted a hydraulic drive motor 3, a cylindrical rotary member 4 carried in bearings 6 and 7, and a reciprocating slide mechanism 8 having a slide member 10 fixedly connected to the saw blade 1 by two bolts 11 (not shown in Fig. 2). The drive motor 3 is driveably connected to the rotary member 4 via a coupling 5 and gearing comprising a train of two intermeshing gear wheels 15 and 16 driveably connected to the drive motor 3 and rotary member 4, respectively. The gear wheel 15 is mounted in bearings 1 7, 18 and the gear wheel 16 is driveably mounted on a stub shaft 19 of the rotary member 4.

An effectively endless scroll formation constituted by a continuous groove 20 extends angularly around and axially along the cylindrical rotary member 4, the groove reversing direction at both ends of the cylindrical member 4 and driveably co-operating with an abutment constituted by a peg 21 fixedly secured to the slide member 10 by a retainer bush 24 secured to the slide member by a key plate 25 and counter sunk screws 26.

The slide member 10, peg 21 and retainer bush 24 together with a guide rod 27 constitute the moving part of the reciprocating slide mechanism 8 which is reciprocated to and fro along a slideway 28 under the action of the rotating endless scroll formation 20 which driveably co-operates with the peg 21 to repeatedly urge the moving part of the reciprocating mechanism 8 first in one direction along the slideway 28 and then in the opposite direction, The slide member 10 and guide rod 27 being guided in wear resistant liner bush components 30.

Wiper seal 31 is provided at the mouth of the guideway 28 to prevent the ingress of dirt into the reciprocating slide mechanism 8.

The drive motor is activated by pressure fluid fed via a supply line (not shown) to an inlet union connector 34 which connects with a cross bore 35 leading to a valve chamber 36 provided with a closure member 37 of a control valve 38, the closure member 37 being slideable along the valve chamber from a closed-valve mode as shown in Fig. 2 towards an open-valve mode in which the tapered portion 40 of the valve closure member 37 is associated with the end of the bore 35 to permit flow of pressure fluid to the drive motor. The tapered portion of the closure member enables a valve operator to achieve a degree of control of motor speed ie the position of the tapered portion along the valve chamber determines the flow of pressure fluid through the control valve.

From the valve chamber 36 pressure fluid passes along a passage formed by a plurality of intersecting bores 41, 42, 43 and 44, the latter of which is provided in an inlet connector 45 to the drive motor. The pressure fluid return from the drive motor passes along an outlet connector 46 via a bore 47 within a tube 48 and along bore 49 and 51 to an outlet union connector 50 for connection to a fluid pressure return pipe (not shown).

A leakage drain passage 53 leading from a drain connector 54 on the motor housing to the return line is provided with a non-return valve 56.

Plugs 55 are provided to close various feed and return bores.

The control valve 38 comprises a rotary or twist-grip handle 60 rotatably mounted on an inner cylindrical valve housing 61 fixedly secured to the housing assembly 2 by bolts 64, a circlip 62 and coil spring 63 acting to retain the handle 60 in a closed-valve operational mode as shown in Fig. 2. The handle 60 is provided with an end cap 65 having a part circular groove 66 within which is engaged a dowel 67 fixedly mounted on the inner housing 61, the dowel 67 and the part circular groove 66 co-operating to limit rotational movement of the handle 60.The end cap 65 has a relatively outer circular projection 68 which guideably co-operates with the inner surface of the inner cylindrical housing 61 and an axial projection 69 which engages in a slot 70 defined between two prongs of a fork arrangement 71 provided on one end of a helix spindle 62 defining a helical formation constituted by a helical groove 73 (only one of which is shown) extending angularly around and axially along the spindle 72. The fork 71 and projection 69 is such that rotation of the handle 60 rotates the helix spindle 72 by an equal amount.

The helical groove 73 of the helix spindle 72 is driveably engaged by a peg 75 fixedly mounted on a bush 77 which in turn is fixedly secured to the valve closure member 37 by a bolt 78. The bush 77 is stopped from rotating by a dowel 80 fixedly mounted on the valve housing 61 which slideably engages in a longitudinally groove 81 on the bush 77.

To open the control valve 38 to feed pressure fluid to activate the drive motor 3, the handle is rotated causing the helix spindle 72 to rotate so that the peg 75 driveably engaging in the helical groove 73 is drawn to the right as seen in Fig. 2. Thereby, the valve closure member 37 is drawn to the right until the tapered portion 40 meets the cross bore 35 to open the valve slightly and allow a restricted flow of pressure fluid to activate the drive motor which rotates the rotary member 4 via the gearing 15, 16 causing the moveable part of the reciprocating slide mechanism to repeatedly reciprocate to and fro together with the saw blade 1.Upon further rotation of the handle 60 the closure member 37 is urged further to the right thereby opening the valve further to permit an increased flow of pressure fluid to the drive motor thereby increasing its speed and the speed of reciprocating of the saw blade.

Upon the operator releasing the handle 60 the spring 63 returns the handle and helix spindle 72 to the closed-valve mode with the closure member 37 closing off the bore 35, thereby cutting off the supply of pressure fluid to the motor and stopping reciprocation of the saw blade 1.

A handle 90 is fixedly mounted on the housing assembly 2 to enable the operator to hold the drive in position. Also a clamp 91 having a retaining screw 92 is provided to enable the drive to be supported in an operating position by a support.bracket (not shown).

From the above description it will be appreciated that the present invention provides a portable, simple, reliable and robust reciprocating drive for a saw blade.

Claims

1. A reciprocating drive for a blade, comprising a drive motor a cylindrical rotary member driveably connected to the drive motor, an effectively endless scroll formation extending angularly around and axially along the rotary member, and a reciprocating slide mechanism fixedly connectable to the blade and having an abutment for driveable co-operation with the endless scroll formation.

2. A reciprocating drive as claimed in claim 1, in which control means are provided for the drive motor.

3. A reciprocating drive as claimed in claim 2, in which the drive motor is fluid driven and the control means comprises a control valve.

4. A reciprocating drive as claimed in claim 3, in which the control valve is activated into a drive mode against a resilient loading.

5. A reciprocating drive as claimed in claim 3 or 4, in which the control valve comprises throttle means for controlling the feed of pressure fluid to the motor and thereby controlling the drive speed of the motor.

6. A reciprocating drive as claimed in claim 4 or 5, when dependent upon claim 4, in which the control valve comprises a rotary handle having a spindle defining a helical formation engageable by an abutment on a valve closure member, rotation of the handle causing the abutment to move along the helical formation to urge the closure member against the resilient loading to open the valve.

7. A reciprocating drive as claimed in claim 6, in which the valve closure member comprises a tapered portion.

8. A reciprocating drive as claimed in any one of the preceding claims, in which gearing is provided intermediate the drive motor and the driven rotary member.

9. A reciprocating drive as claimed in any one of the preceding claims, in which the drive motor, the rotary member and the reci procating slide mechanism are housed with a housing assembly.

10. A reciprocating drive as claimed in claim 1 of the preceding claims, in which a clamp is provided on the housing assembly.

11. A reciprocating drive for a saw blade, substantially as described herein and as shown in the accompanying drawings.

12. A saw in combination with a reciprocating drive as claimed in any one of the preceding claims.

CLAIMS (9 April 1980)

1. A reciprocating drive for an element, comprising a drive motor, a cylindrical rotary member mounted in bearings and driveably connected through gearing to the drive motor, an effectively endless scroll formation extending angularly around and axially along the rotary member, and a reciprocating slide mechanism fixedly connectable to the element and having an abutment for driveable cooperation with the endless scroll formation.