GB1594258A - Pressure fluid operated tool - Google Patents

Description

PATENT SPECIFICATION

( 11) 1594258 ( 21) ( 23) ( 44) Application No 27793/77 ( 22) Filed 2 July 1977

Complete Specification filed 26 May 1978

Complete Specification published 30 July 1981 ( 19) ( 51) INT CL 3 B 21 D 28/34 ( 52) Index at acceptance B 3 W 43 9 A 4 C 9 AY ( 72) Inventor JOSEPH RONALD BENTLEY ( 54) PRESSURE FLUID OPERATED TOOL ( 71) We, GULLICK DOBSON LIMITED, a British Company, of Ince, Wigan, Lancashire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-

The invention relates to tools, for example, punches.

In underground mine workings, perhaps particularly coal mines, the use of powered tools for maintenance, repair and other engineering activities presents problems by reason of the setting of intrinsic safety standards and/or the necessity to take along bulky power sources It is, of course, usually the case that power-operated equipment already present on the face, typically mineroof supports, is of pressure-fluid-operated.

normally hydraulic type so as not to give rise to the sort of intrinsic safety requirements associated with electrical power sources Although such available pressure-fluid power is normally accessible for test purposes it is not usually at a pressure adequate to operate a tool such as a punch.

It is an object of this invention to facilitate the use of power tools from pressure-fluid equipment or systems.

According to the invention there is provided a pressure-fluid-operated tool having a portable frame or body having a pressurefluid-operated tool drive system and coupling means whereby the drive system is operatively coupled on-site to receive pressure-fluid from or for other equipment normally operated by that pressure fluid Preferably the coupling means is to or includes pressure-intensifier means to deliver high pressure pulses to the tool, typically to the A suitable system will have a differential piston type pressure intensifier associated with a control valve receiving pressurised fluid from a pump typically associated with a mine-roof support or system and supplying it alternatively according to setting to the small and large piston area sides of the intensifier, with a high pressure output there() from connected to the drive side of' the tool.

The control valve may automatically couple pump pressure fluid to the retract side of the tool at the same time as to the small piston area side of the intensifier or at any other convenient time different from high pressure 55 pulsing of the tool Normally, of course, high pressure output from and low pressure supply to the small piston side of the intensifier will be connected in common but via oneway valves to protect the valve gear from 60 high pressure pulses and to avoid loss of relatively low pump pressure fluid to the drive side of the tool.

Embodiments of this invention are particularly well suited to application within a 65 mine working in which intrinsic safety standards are applied, but may be equally well applicable to other environments where pressure-fluid-powered systems are employed, especially if there are objections to the use of 70 an electrically powered tool In most cases, pressure-fluid will be available at least via standard system test points and, if there should be an existing intensifier arrangements for test purposes, the invention may be 75 implemented with a minimum of modification to control valve gear therefor, typically the provision of an additional position.

One embodiment of the invention will now be described, by way of example, with 80 reference to the accompanying drawing in which:

Figure I is a part-sectional view through a hydraulic punch:

Figure 2 is a part-spherical exploded view 85 of the punch of Figure l; and Figure 3 is a schematic diagram of' a complete system embodying the invention.

Referring first to Figures I and 2 a hydraulic punch 10 comprises a generally C' 90 shaped punch body 11 having a plateaccommodating slot 12 extending between aligned bores 13 and 14 housing respectively a die 15 and a piston rod 16 carrying a punch 17 secured in a central end-recess 18 95 by a screwed-on retaining plate 16 a.

The bore 14 extends through, and is enlarged at 19 in, an extension 20) of the punch body 11 The bore enlargement 19 slidably accommodates a drive piston 21 for 100 1.594258 the rod 16 with a piston seal to its cylinder at 22 and a piston rod scal to the bore 14 at 23.

A low pressure inlet passage to the lower side of tic piston 21 is shown at 24 a commrunicating with a coupling port 24 A high pressure fluid teed to the other side of the piston 21 is via a passage 25 through a sealed end stop 26 for the bore enlargenient 19.

In Figure 3 punch 10 is shown coupled to high and low pressure fced lines 30 and 31.

Low pressure line 31 is shown connected directly to one outlet port of a control valve 32 which is of a conventional type with a hiandle-operated fluid steering disc 33 for coupling a pressure fluid inlet port to any ofa plurality specifically three outlet ports 34 according to the position of the disc 33 with all unselected ports connected to drain, as described for example in our patent specifi2 () cation No 1261129 A fluid pressure connection from a local on-site fluid-pressure operated system such as a mine-roof support installation is indicated at 37 in a valve body and central disc port 36 is associated with return or drain Thus, in the handle position indicated in full ( 39) locally available hydraulic fluid pressure, say from a mine-roof support supply pump will be connected to retract the tool piston over line 31.

The other two selectable output ports of the control valve are shown connected via first and second lines 41 and 40, respectively.

to opposite ends of a pressure intensifier 43.

the line 40 via a one-way valve 44 preventing flow from the intensifier to the control valve.

The high pressure tool supply line 30 is shown branched from line 40 between the one-way valve 44 and the intensifier 43 via a one-way valve 45 accepting high pressure output from the intensifier but ideally biasse O to remain closed under pump pressure in line 40.

The intensifier 43 is shown as being of the differential piston type with a large area piston 46 slidable in large bore cylinder 48 and connected by rod 47 to a small area piston 49 slidable in a much smaller bore cylinder 50 Both of the pistons 46 and 49 are driven by pumped pressure fluid in the lines 41 and 40, respectively, but selectively, usually alternately according to the setting of the control valve 32 Thus, the intensifier 43 is primed by setting the control valve 32 to pass pump-pressure over line 40 to the small area piston 49 in order to fully retract the piston 47 Subsequent selection of the line 41 by the control valve 32 will apply pump-pressure fluid to the large piston 46 and thus produce a high pressure pulse on line 30 via one-way valve 45.

In order to permit retraction of the punch piston a release device 52 is shown branched from the line 30 This should be automatically operable only on punch retract and may conveniently be biassed to a closed position and opened only by the presence of pressure in line 31 as indicated by the dotted interconnection 53.

If desired, the operating pressure for the punch may be varied either by having a 70 variable intensifier or a variable by-passing device in the line 40 and it then may be convenient to connect a pressure gauge to the line 30 so as readily to be able to control punch operating pressures 75 It will be appreciated that other forms of intensifier may be used, for example a device hydraulically driven on a retract or priming stroke to compress a trapped volume of compressible fluid, normally gas operative 80 thereafter to impart a high pressure stroke.

Also, the overall control arrangement may be varied perhaps particularly in relation to the handle controlled valve, say to give a desired rate of automatic punching 85

Claims (1)

1. WHAT WE CLAIM IS:

   1 A pressure-fluid-operated tool having a portable frame or body having a pressurefluid-operated tool drive system and cou 90 pling means whereby the drive system is operatively coupled on-site to receive pressure-fluid from or for other equipment normally operated by that pressure fluid.

   2 A pressure-fluid-operated tool accord 95 ing to claim 1, wherein the tool is a punch.

   3 A pressure-fluid-operated tool according to claim I or claim 2, wherein the coupling means is to or includes pressure intensifier means for delivering high pressure 100 pulses to the tool.

   4 A pressure-fluid-operated tool according to claim 3, wherein the pressure intensifier requires priming between high pressure delivery operations 105 A pressure-fluid-operated tool according to claim 3 or claim 4, wherein the pressure intensifier is of a differential piston type with high pressure delivery from its smaller area piston side when pressure fluid 110 is applied to its larger area piston side.

   6 A pressure-fluid-operated tool according to claim 5 with claim 4, wherein, for priming, pressure fluid is applied to the smaller area piston side with the larger area 115 piston side at a lower pressure.

   7 A pressure-fluid-operated tool according to any one of claims 3 to 6, wherein the coupling means includes a control valve selectively operable to couple said pressure 120 fluid over a first line to the pressure intensifier means to feed the tool drive system.

   8 A pressure-fluid-operated tool according to claim 7, wherein the pressure intensifier means is primed over a second line via 125 which it otherwise serves to give output to the tool drive system.

   9 A pressure-fluid-operated tool according to claim 8, comprising one-way valve means in said second line to prevent flow 130 1,594,258 from the intensifier means to the control valve.

   A pressure-fluid-operated tool according to claim 8 or 9, comprising one-way valve means in a tool drive feed branch of said second line to release flow to the tool drive system only at pressures above priming feed pressure.

   11 A pressure-fluid-operated tool according to any one of claims 8 to 10, wherein the first and second lines are coupled to different alternatively selectable feed ports of the control valve.

   12 A pressure-fluid-operated tool according to claim 11, wherein a further feed line for tool retraction is coupled via another alternatively selectable feed port of the control valve.

   13 A pressure-fluid-operated tool arranged and adapted to operate substantially as herein described with reference to and as shown in the accompanying drawings.

   ROYSTONS, Agents for Applicants, Tower Building, Water Street, Liverpool L 3 IBA.

   Chartered Patent Agents.

   Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd -1981 Published at The Patent Office, Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.