GB2299772A

GB2299772A - Portable drilling system

Info

Publication number: GB2299772A
Application number: GB9507513A
Authority: GB
Inventors: Francis Donald Robins
Original assignee: UK Secretary of State for Defence
Current assignee: UK Secretary of State for Defence
Priority date: 1995-04-11
Filing date: 1995-04-11
Publication date: 1996-10-16
Also published as: GB9507513D0

Abstract

A portable power operated drilling system 2 that allows an operator to stand back whilst it is in operation includes a platform 6 on which is mounted a drill head 4 having an automatic feed means 102 to advance a cutter 104 in relation to a work surface 22. The platform 6 is attachable to the work surface 22 by one or more suction pads 16,18,20 arranged such that the platform 6 remains attached to the work surface 22 on engagement of the cutter 104 with the work surface 22.

Description

A PORTABLE SEMI-AUTOMATIC DRILLING SYSTEM The present invention relates to portable power operated drilling system that allows an operator to stand back from an area while the drilling system is in operation. Stand back operation provides safer working conditions for the operator when working for example in hazardous environments in which the time available to perform a task is limited. As may be the case when working under conditions of high ambient gamma radiation or high ambient temperature, or under water.

It is known to anchor a drill to a work surface with a magnetic base. However, these drills are invariably hand operated, that is the operator has to apply the cutting pressure, usually with a hand operated wheel or similar manually operated device. Consequently the operator must remain alongside the drill whilst it is in operation. In addition drills with a magnetic base are unable to adhere to non-magnetic materials such as non ferrous metals or plastic material.

Attempts to automate the feed of magnetic base drills, either mechanically or electrically, have resulted in high cost equipments, with a bulky gearboxes with a fixed gear ratio; alteration of the gear ratio entailing changing gear wheels after dis-assembly of the gearbox.

Another disadvantage of known equipments is the inability to match accurately feed rates to variation in cutting conditions, with the result that a reactive force is experienced which may overcome the attractive force detaching the magnetic base from the work surface.

In practice a small air gap between the magnetic base and the work surface significantly reduces the holding power of the magnetic base causing the attractive force to rapidly decay to zero. Thus the surface of the magnetic base and work surface must be kept scrupulously clean. Also both surfaces must be flat to the extent that even a coating of paint or a small piece of swarf can seriously impair the holding power of a magnetic base.

According to the present invention a drilling system is provided including a platform on which is mounted a drill head having an automatic feed means to advance a cutter in relation to a work surface, the platform being attachable to the work surface by one or more suction pads arranged such that the platform remains attached to the work surface on engagement of the cutter with the work surface.

The suction pads minimise the time taken for attachment of the drilling system to the work surface.

The suction pads will also attach the platform to most work surfaces particularly work surfaces that are not horizontal.

The drilling system may be operated whilst the operator is standing back from the drilling system because the attractive force between the suction pads and the work surface is greater than the reactive force tending to push the platform away from the work surface as the automatic feed means advances the cutter to engage with the work surface. The drilling system therefore reduces the time that an operator needs intervene in a drilling operation.

According to another aspect of the invention each suction pad may be attached to one end of a leg, and the other end of each leg may be attached to the platform by a first connecting means such that the legs may be moveable and lockable in relation to the platform and arranged such that the suction pads may be repositionable in a first direction substantially parallel to the work surface, to fit the configuration of the work surface.

According to another aspect of the invention the platform may include a spine and at least one arm, one end one end of each arm may be attached to the spine by a second connecting means such that each arm may be moveable and lockable in relation to the spine and arranged such that the suction pads may be repositionable in a second direction substantially parallel to the work surface and substantially at right angles to the first direction.

According to another aspect of the invention a third connecting means may be provided such that each suction pad is moveable and lockable in relation to each leg and arranged such that the suction pads may be repositionable in a third direction substantially perpendicular to the work surface, to accommodate a work surface with variance in height. Alternatively, a suction pads with a deep cup may be used on irregular work surfaces.

According to another aspect of the invention at least one arm may be positioned on one side of the spine and at least arm may be positioned on the other side of the spine, one leg may be positioned towards one end of the spine and the drill head may be mounted towards the other end of the spine.

According to another aspect of the invention the platform may attachable by two suction pads to the work surface.

According to another aspect of the invention the platform may attachable by three suction pads to the work surface.

The invention uses a suction pad to provide the attractive force between the drilling system and the work surface because the flexible nature of a suction pad allows it to conform, to a certain extent, to irregularities in the work surface. Added to which, axial movement is accommodated by flexure of the suction pad.

If one suction pad does not provide the rigidity required for a drilling operation two, three or more suction pads may be used.

According to another aspect of the invention a vacuum pump may be attachable to each suction pad.

According to another aspect of the invention the drill head may be powered by a compressed gas supply.

Pneumatic power is chosen for the drill head because of its ability to withstand a stall and not to be subject to overload. Self contained pneumatic drill heads also tend to be much more compact than their electric counterparts.

Also a compressed gas supply can advantageously be used to power the vacuum pump and the automatic feed means. Thus the drilling system requires just the one service, compressed gas.

According to another aspect of the invention an exhaust gas flow from the drill head or the vacuum pump or the automatic feed means is directed towards the cutter.

The compressed gas supply chosen will usually be a compressed air supply because it is readily available in workshop areas either as a piped system or in compressed air cylinders.

According to another aspect of the invention the automatic feed means includes: a first feed rate setting means such that an approach rate of the cutter towards the work surface is predeterminable, and a second feed rate setting means such that the rate of advance of the cutter below the work surface is predeterminable.

According to another aspect of the invention the automatic feed means includes reversing means engageable such that the cutter on completion of a forward stroke from an initial position, resumes the initial position.

According to another aspect of the invention a method of drilling using a drilling system including a platform on which is mounted a drill head having an automatic feed means to advance a cutter in relation to the work surface, the platform being attachable to the work surface by one or more suction pads, includes the steps of: attaching the platform to the work surface; checking that the cutter is fitted to the drill; starting the drill head; starting the automatic feed means to advance the cutter in relation to the work surface to drill the hole.

According to another aspect of the invention a method of drilling, using a drilling system wherein each suction pad is attached to one end of a leg, the other end of each leg being attached to the platform by a first connecting means such that the legs are moveable and lockable in relation to the platform, including the step of: adjusting and locking the legs in a relation to the platform to reposition the suction pads in a first direction substantially parallel to the work surface.

According to another aspect of the invention a method of drilling, using a drilling system wherein the platform includes a spine and at least one arm, one end of each arm being attached to the spine by a second connecting means such that each arm is moveable and lockable in relation to the spine including the step of: adjusting and locking the arms in a relation to the spine, to reposition the suction pads in a second direction substantially parallel to the work surface and substantially at right angles to the first direction.

According to another aspect of the invention a method of drilling, using a drilling system wherein third connecting means are provided such that each suction pad is moveable and lockable in relation to each leg, including the step of: adjusting and locking the suction pads in relation to each leg to reposition the suction pads in a third direction substantially perpendicular to the work surface.

According to another aspect of the invention a method of drilling may use a drilling system wherein at least one arm is positioned on one side of the spine and at least arm is positioned on the other side of the spine, one leg being positioned towards one end of the spine and the drill head mounted towards the other end of the spine.

According to another aspect of the invention a method of drilling may use a drilling system wherein the platform is attachable by two suction pads to the work surface.

According to another aspect of the invention a method of drilling may use a drilling system wherein the platform is attachable by three suction pads to the work surface.

According to another aspect of the invention a method of drilling, using a drilling system wherein a vacuum pump is attachable to each suction pad, may include the steps of: checking that the vacuum pump is attached to each suction pad; starting the vacuum pump.

According to another aspect of the invention a method of drilling, using a drilling system wherein the vacuum pump is powered by a compressed gas supply, may include the step of: checking that the vacuum pump is attached to the compressed gas supply.

According to another aspect of the invention a method of drilling, using a drilling system wherein the drill head is powered by a compressed gas supply, may include the step of: checking that the drill head is attached to the compressed gas supply.

According to another aspect of the invention a method of drilling, using a drilling system wherein the automatic feed means is operated by a compressed gas supply, may include the step of: checking that the automatic feed means is attached to the compressed gas supply.

According to another aspect of the invention a method of drilling may use a drilling system wherein the an exhaust gas flow from the drill head or the vacuum pump or the automatic feed means is directable towards the cutter.

According to another aspect of the invention a method of drilling, using a drilling system wherein the automatic feed means includes a first and a second feed rate setting means, and a reversing means, may include the steps of: adjusting the first feed rate setting means to predetermine an approach rate of the cutter towards the work surface; adjusting the second feed rate setting means to predetermine a rate of advance of the cutter below the work surface; engaging the reversing means such that the cutter on completion of a forward stroke from an initial position, resumes the initial position.

One specific embodiment of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings of which: Fig. 1 shows in schematic form: an end elevation, a part side elevation and a plan view of a drilling system according to the invention; Fig. 2 shows a diagram of air flows in a drilling system according to the invention Fig. 3 is an end elevation of a prototype drilling system according to the invention corresponding to Fig. 1; Fig. 4 is a view on Arrow C in Fig. 3; Fig. 5 is Arrow D in Fig. 4; Referring to Fig. 1, a drilling system 2 has a drill head 4 in the form of a power operated drill mounted on a platform 6 at one end 8 of a spine 10 using a mounting bracket 12 and fasteners 14.

Suction pads 16 18 and 20 capable of attaching the drilling system 2 to a work surface 22 are attached to one end 24 26 and 28 of legs 30 32 and 34.

The other ends 36 38 and 40 of the legs 30 32 and 34 are attached by a first connecting means 42 44 and 46 to arms 48 50 or the spine 10 forming the platform 6.

One leg 32 is attached near an end 9 of the spine 10 remote from the end 8 to which the drill head 4 is attached.

The first connecting means 42 44 46 include 'T' shaped projections 52 which are carried on the legs 30 32 34 and are slideable in 'T' shaped slots 54 which are formed in either the arms 48 50 or the spine 10. Rotation of clamping handles 56 58 to extend screw threaded portions 60 62 locks the 'T' shaped projections 52 in the 'T' shaped slots 54 clamping the legs 30 32 and 34 in position.

Conversely rotation of the clamping handles 56 58 to retract the screw threaded portions 60 62, unlocks the 'T' shaped projections 52 in the 'T' shaped slots 54 to permit movement of the legs 30 32 34 in relation to the arms 48 50 or the spine 10.

Thus retraction of the screw threaded portions 60 62 allows the suction pads 16 18 20 to be adjusted in directions 60 62 64 parallel to the work surface 22.

Ends 66 68 of the arms 48 58 are attached respectively to sides 70 72 of the spine 10 by a second connecting means 74 76.

The second connecting means 74 76 include 'T' shaped projections 78 which carried on the arms 48 50 and are slideable in 'T' shaped slots 80 which are formed in the sides 70 72 of the the spine 10. In practice operation of the second connecting means 74 76 is similar to the operation of the first connecting means 42 44 46 so that rotation of clamping handles 82 84 to extend screw threaded portions 86 88 locks the 'T' shaped projections 78 in the 'T' shaped slots 80 clamping the arms 48 50 in position. Conversely rotation of the clamping handles 82 84 to retract the screw threaded portions 86 88, unlocks the 'T' shaped projections 78 in the 'T' shaped slots 80 to permit movement of the arms 48 50 in relation to the spine 10.Thus retraction of the screw threaded portions 86 88 allows the suction pads 16 and 20 to be adjusted in directions 90 92 substantially at right angles to the directions 60 62 64 and parallel to the work surface 22.

A first envelope 91 in Fig 1 indicates the possible movement of a centre 15 of the suction pad 16. Similarly, an envelope 93 indicates the possible movement of a centre 19 of the suction pad 20.

The suction pads 16 18 and 20 are attached to the legs 30 32 34 by a third connecting means 94 96 98 in the form of a threaded spindle and a lock nut (not drawn).

The third connecting means 94 96 98 allows the suction pads 16 18 20 to be adjusted and locked in a direction 100 perpendicular to the work surface 22.

Alternatively, the third connecting means may be in a form similar to the first 42 44 46 or the second 74 76 connecting means.

The drill head 4 has an automatic feed means 102 in a form of a power operated mechanism that is commercially available. The automatic feed means 102 is capable of advancing a cutter 104 through a distance 106 above the work surface 22 and a distance 108 below the work surface 22. The automatic feed means 102 may be adjusted such that a feed rate (approach feed) over the distance 106 is faster than feed rate (cutting feed) over the distance 108. Preferably the cutting feed rate over the distance 108 should be matched to the cutting properties of a work piece 110.

The applicant has in trials of a drilling system according to the invention used an automatic feed means 102 with a fixed stoke of 150 mm corresponding to the distance 106 plus the distance 108. The distance 108 below the work surface 22 may be varied by repositioning the drill head 4 on the mounting bracket 12 using the fasteners 14; to vary an initial position 103 of a cutter 104. The cutter 104 may be in the form of a drill-bit for drilling masonry, metal or wood; or it may be in the form of a hole saw for cutting holes in plastics or composite materials.

The skilled reader will understand that the drill head 4 fitted with a standard Jacobs No 3 taper 101 will allow a choice between using a Morse taper or a Jacobs chuck (not drawn).

Referring to Fig. 2 detailing air flows in a drilling system according to the invention; a vacuum pump 112 is operated directly from a compressed gas supply 114 producing an exhaust gas flow 116. The suction pads 16 18 and 20 are individually connectable to the vacuum pump 112 by three, three way valves 118 120 122. A box 123 marked on Fig. 2 indicates the equipment working under vacuum.

The drill head 4 and automatic feed means 102 are connectable through an isolation valve 124 to same compressed gas supply 114 as the vacuum pump 112. The automatic feed means 102 is manually controllable from a five way valve 126.

Compressed air 114 is the preferred compressed gas source 114 and is supplied direct to the drill head 4 at 7 bar through a 10 mm diameter plastic tube 128. Compressed air 114 is also supplied from the five way valve 126 through two 4mm diameter tubes 130 132 at 7 bar pressure to the automatic feed means to control the drill head 4 start, stop and feed.

Referring to Fig. 5 a lever 127 is used to operate the five way valve 126. Moving the lever 127 downwards starts the drill head 4 and moves the cutter 104 towards the work surface 22. Moving the lever 127 upwards causes the cutter 104 to retract from the work surface 22, return to the initial position 103 and stop.

Preferably the automatic feed means 102 includes first and second feed rate setting means to adjust respectively the approach feed rate and the cutting feed rate of the cutter 104 such that during a drilling cycle there is a rapid approach of the cutter 104 through the distance 106 above the work surface 22 followed by a controlled feed of the cutter 104 to the distance 108 below the work surface 22.

The first feed setting means (not drawn) is in the form of an adjusting screw controlling the opening of a first simple taper needle valve to vary a bleed rate of air through a first orifice. Although air is compressible and may give an inconsistent rate of approach, (that is a spongy movement) it is of little consequence and is a cheaper option.

The second feed setting means is in the form of an adjusting screw controlling the opening of a second simple taper needle valve to vary a bleed rate of oil through a second orifice. Oil is preferred as it is non-compressible and therefore provides a controlled feed of the cutter 104 when cutting into the work piece 110.

In addition the automatic feed means 102 preferably includes a reversing means engageable after completion of a forward stroke equal to the distance above the work surface 106 plus the distance below the work surface 108, so that the cutter 104 returns automatically to initial position 103 for the drill head 4 to stop automatically.

The suction pads 16 18 and 20 have a diameter 140 equal to 150 mm or 100 mm with an inbuilt gauze filter (not drawn). The suction pads 16 18 and 20 have a flat cup portion 142 with cleats 144 for use with a flat work surface 22 where minimum movement of the drilling system 2 is required. The cleats 144 aid stability and prevent the diameter 140 reducing in size as the suction pads 16 18 and 20 are evacuated.

The suction pads 16 18 and 20 are easily changed when required because the third connecting means 94 96 98 allows them to be removed or assembled by hand. A mixture or pad diameters 144 may be used if desired.

Three suction pads 16 18 and 20 with the diameter 144 equal to 150 mm working together give a combined holding force of approx .5 Tonne, while three suction pads 16 18 and 20 with the diameter 144 equal to 100 mm give a holding force of approx .25 Tonne.

Clamping handles 56 58 82 84 are made of plastic, and can be set in any one of twenty positions (not drawn) to suit individual requirements where the clamping handles 56 58 82 84 cannot be turned fully through 360 degrees.

Three lifting eyes 146 may be screwed into the end 9 of the spine member 10 and an end 148 of the arm 48 and at an end 150 of the arm 50 to provide lifting points.

Alternatively as an aid to manoeuvreability lifting points 152 154 are provided to allow suspension of the drill system 2 from a lifting point close to its centre of gravity 156.

As an aid to portability a handle 158 is attached to each of the arms 48 50 and to the spine 10.

Fig. 4 shows the compressed gas supply 114, the isolation valve 124, the five way valve 126, the three way valve 122 connecting the vacuum pump 112 to the suction pad 20 in relation to the drill head 4, the platform 6 and the suction pads 16 18 and 20.

The vacuum pump 112 is sited out of the way on the spine 10 for safety. Also for safety the vacuum pump 112 is not connected through the isolation valve 124 to prevent the vacuum pump 112 being turned off inadvertently. The exhausted gas 116 is directed away by a flexible hose 160. The exhaust gas 116 is directed towards the cutter 104 to keep it cool in order to significantly extend its life.

The applicant has found that blocking the flexible hose 160 from the vacuum pump 112 provides an air cushion between each suction pad 116 18 20 and the work surface 22 this aids repositioning of the drilling system 2 especially when used on a work surface 22 that is substantially horizontal.

Fig. 5 shows the positions of the three way valves 118 120 and 122 in relation to the drill head 4, the platform 6 and the suction pads 16 18 and 20. The three way valves 118 120 122 are ergonomically positioned to relate to their suction pads 16 18 and 20.

In order to minimise the weight of the drilling system 2 extensive use is made of aluminium alloy and plastics in it construction.

The use first and second connecting means 42 44 46 and 74 76 in the form of clamps in the drilling system 2 and the use of plug-in pneumatic fittings for example 164 166 168 aids rapid set-up of the drilling system 2.

The drilling system 2 is able to adhere to most surfaces including metals, glass, plastics, mortar, bricks, concrete, wood and similar materials.

Claims

What is claimed is 1. A drilling system including a platform on which is mounted a drill head having an automatic feed means to advance a cutter in relation to a work surface, the platform being attachable to the work surface by one or more suction pads arranged such that the platform remains attached to the work surface on engagement of the cutter with the work surface.
2. A drilling system as claimed in Claim 1 wherein each suction pad is attached to one end of a leg, the other end of each leg being attached to the platform by a first connecting means such that the legs are moveable and lockable in relation to the platform and arranged such that the suction pads are repositionable in a first direction substantially parallel to the work surface.
3. A drilling system as claimed in Claims 2 wherein the platform includes a spine and at least one arm, one end of each arm being attached to the spine by a second connecting means such that each arm is moveable and lockable in relation to the spine and arranged such that the suction pads are repositionable in a second direction substantially parallel to the work surface and substantially at right angles to the first direction.
4. A drilling system as claimed in Claim 2 or Claim 3 wherein third connecting means are provided such that each suction pad is moveable and lockable in relation to each leg and arranged such that the suction pads are repositionable in a third direction substantially perpendicular to the work surface.
5. A drilling system as claimed in Claim 4 wherein at least one arm is positioned on one side of the spine and at least one arm is positioned on the other side of the spine, one leg being positioned towards one end of the spine and the drill head being mounted towards the other end of the spine.
6. A drilling system as claimed in any one of Claims 1 to 4 wherein the platform is attachable by two suction pads to the work surface.
7. A drilling system as claimed in any one of Claims 1 to 4 wherein the platform is attachable by three suction pads to the work surface.
8. A drilling system as claimed in any one of Claims 1 to 7, wherein a vacuum pump is attachable to each suction pad.
9. A drilling system as claimed in Claim 8, wherein the vacuum pump is powered by a compressed gas supply.
10. A drilling system as claimed in any one of Claims 1 to 9, wherein the drill head is powered by a compressed gas supply.
11. A drilling system as claimed in any one of Claims 1 to 10 wherein the automatic feed means is powered by a compressed gas supply.
12. A drilling system according to any one of Claims 9 to 11, wherein an exhaust gas flow from the drill head or the vacuum pump or the automatic feed means is directed towards the cutter.
13. A drilling system according to any one of Claims 1 to 12 wherein the automatic feed means includes: a first feed rate setting means such that an approach rate of the cutter towards the work surface is predeterminable, and a second feed rate setting means such that a rate of advance of the cutter below the work surface is predeterminable.
14. A drilling system according to any one of Claims 1 to 13 wherein the automatic feed means includes reversing means engageable such that the cutter on completion of a forward stroke from an initial position, resumes the initial position.
15. A method of drilling using a drilling system including a platform on which is mounted a drill head having an automatic feed means to advance a cutter in relation to the work surface, the platform being attachable to the work surface by one or more suction pads, including the steps of: attaching the platform to the work surface; checking that the cutter is fitted to the drill; starting the drill head; starting the automatic feed means to advance the cutter in relation to the work surface.
16. A method of drilling as claimed in Claim 15 wherein each suction pad is attached to one end of a leg, the other end of each leg being attached to the platform by a first connecting means such that the legs are moveable and lockable in relation to the platform, including the step of: adjusting and locking the legs in a relation to the platform to reposition the suction pads in a first direction substantially parallel to the work surface.
17. A method of drilling as claimed in Claim 16 wherein the platform includes a spine and at least one arm, one end of each arm being attached to the spine by a second connecting means such that each arm is moveable and lockable in relation to the spine including the step of: adjusting and locking the arms in a relation to the spine, to reposition the suction pads in a second direction substantially parallel to the work surface and substantially at right angles to the first direction.
18. A method of drilling as claimed in Claim 17 wherein third connecting means are provided such that each suction pad is moveable and lockable in relation to each leg, including the step of: adjusting and locking the suction pads in relation to each leg to reposition the suction pads in a third direction substantially perpendicular to the work surface.
19. A method of drilling as claimed in Claim 18 wherein at least one arm is positioned on one side of the spine and at least one arm is positioned on the other side of the spine, one leg being positioned towards one end of the spine and the drill head being mounted towards the other end of the spine.
20. A method of drilling as claimed in any one of Claims 15 to 19 wherein the platform is attachable by two suction pads to the work surface.
21. A method of drilling as claimed in any one of Claims 15 to 20 wherein the platform is attachable by three suction pads to the work surface.
22. A method of drilling as claimed in any one of Claims 15 to 21 wherein a vacuum pump is attachable to each suction pad, including the steps of: checking that the vacuum pump is attached to each suction pad; starting the vacuum pump.
23. A method of drilling as claimed in Claim 22 wherein the vacuum pump is powered by a compressed gas supply, including the step of: checking that the vacuum pump is attached to the compressed gas supply.
24. A method of drilling as claimed in any one of Claims 15 to 23 wherein the drill head is powered by a compressed gas supply, including the step of: checking that the drill head is attached to the compressed gas supply.
25. A method of drilling as claimed in any one of Claims 15 to 24 wherein the automatic feed means is operated by a compressed gas supply, including the step of: checking that the automatic feed means is attached to the compressed gas supply.
26. A method of drilling as claimed in any one of Claims 23 to 25 wherein an exhaust gas flow from the drill head or the vacuum pump or the automatic feed means is directable towards the cutter.
27. A method of drilling as claimed in any one of Claims 15 to 26 wherein the automatic feed means includes first and second feed rate setting means1 and reversing means, including the steps of: adjusting the first feed rate setting means to predetermine an approach rate of the cutter towards the work surface; adjusting the second feed rate setting means to predetermine a rate of advance of the cutter below the work surface; engaging the reversing means such that the cutter on completion of a forward stroke from an initial position, resumes the initial position.
28. A drilling system substantially as hereinbefore described with reference to the accompanying drawings Figures 1 to 5.