GB1574343A

GB1574343A - Hydraulic drive arrangement

Info

Publication number: GB1574343A
Application number: GB3772377A
Authority: GB
Original assignee: Smit & Sons Diamond Tools
Current assignee: Smit & Sons Diamond Tools
Priority date: 1978-05-26
Filing date: 1978-05-26
Publication date: 1980-09-03

Description

(54) HYDRAULIC DRIVE ARRANGEMENT (71) We, J.K. SMIT & SONS DIAMOND TOOLS LIMITED, a British Company, of Conwy Road, Mochdre, Colwyn Bay, North Wales, LL28 5HE, 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 bc performed, to be particularly described in and by the following statement:- This invention relates to a hydraulic drive arrangement for moving one or morc mcm bers along a path and is particularly suitable for raising and lowering a drill head.The invention will be described hereinafter with reference to up and down movement of a drill head of a drilling machine but it will be appreciatcd that it could have many other uscs. such as. for example, for controlling the up and down movement of a clamping device or for moving a prcss tool up and down, or for controlling a moulding operation.

Normally. drills are moved into and out of thcir operative position by means of one or more hydraulic cylinders acting bctwccn a stationary frame and a head slidablc on the frame and by means of which prcssure is applied to the drilling bit. While such drils operate quite satisfactorily, the or each hydraulic cylinder mechanism has a stroke of several feet and when the piston within the cylinder is at the commencement of its stroke, the length of the hydraulic cylinder is approximately twice that of its stroke, meaning that the drill needs a considerable amount of head room within which to operate. While this may be acceptable in some machine shops and on most drill sites, it is not always acceptable when the drill is to be used in a confined space.

Furthermore, if the drilling machine is of the portable type used for mineral or oil exploration, it is obviously desirable for the drill mechanism to be as light as possible and hence as compact as possible. In this way, transport costs can be kept to a minimum.

We have now developed a hydraulic drive arrangement for moving the head of a drilling machine to and fro which is compact in that it does not require any more space than that necessary due to the stroke of the drilling head and yet which is little or no more expensive than the cost of the traditional hydraulic machanism.

According to the present invention, we provide a hydraulic drive arrangement for moving one or more members along a path, said drive arrangement comprising a pair of hydraulic piston and cylinder devices, a sprocket mountcd on the end of a shaft and locatcd within a housing. said housing being in fluid communication with an open end of the cylinder of each device. cntrainment means entrained around said sprocket and having one end connected to the piston of one of said devices, and its other end connected to the piston of one of said devices, the housing, the open ends of said cylinders and thc pistons thcrcin defining a pressure chamber adapted to be supplied with hydraulic fluid so as to maintain the cntrainmcnt means undcr tension at all times. and hydraulic supply lines to the closed end of each cylinder whereby the pistons can be moved to and fro within their cylinders, said movement causing the sprocket to be rotated clockwise or anti-clockwise so as to rotate the shaft. the shaft being adapted to move one or more members along a path.

Also according to the present invention, we provide a drilling machine including a frame, a drilling head movable to and fro relative to the frame, and ahydraulic drive arrangement for causing said movement, the drive arrangement including a pair of hydraulic piston and cylinder devices located to one side of the frame, a shaft extending across an end of the frame and proecting to one side thereof, a sprocket mounted on the proecting end of the shaft and located within a housing, said housing being in fluid com munication with an open end of the cylinder of each device, entrainment means entrained around said sprocket and having one end connected to the piston of one of the said devices and its other end connected to the piston of the other device, the housing, the open ends of said cylinders and to pistons therein defining a pressure chamber within which hydraulic fluid is maintained under pressure to keep the entrainment means under tension at all times, hydraulic supply lines to the closed end of each cylinder so that application of hydraulic fluid to one or other of the cylinders will move the pistons therein to and fro, a pair of drive sprockcts mounted on said shaft, a pair of idler sprockets supported on the frame of the drilling machine and entrainmcnt means entrained around the respective oncs of said drive and idler sprockcts and having its cnds secured to the drill head, the arrangement being such that the drilling head can be moved to and fro as a rcsult of rotation of said shaft due to fluid pressure being applied to the closed end of one or other of said cylinders.

A preferred cmbodiment of the invention is now described by way of example with reference to the accompanying drawings, in which:- FIGURE 1 is a side elevation of a hydraulic drive arrangement applied to a drilling machine, and FIGURE 2 is a front elevation of the machine arrangement only and looking in the direction of the arrow B of Figure 1.

Referring to Figure 2 of the drawings, the drilling machine has a frame 1 having a pair of upstanding guide rods 3, 5 on which a drilling head 7 is slideably supported by means of sleeve guides 9. The drilling head has a drive motor 11 for rotating the drilling bit (not shown).

Extending across the top of the drilling machine and ournalled in suitable supports 13 is a shaft 15 adapted to be rotated by a hydraulic drive arrangement illustrated in Figure 1 and the left-hand part of Figure 2.

One end of the shaft projccts bcyond the side of the machine at 17 and is located within a fluid tight housing 19 forming part of the hydraulic drive arrangement which also includes a sprocket 21, is keyed to the pro ecting end 17 of the shaft and has entrainment means 23, e.g. a chain or toothed belt or the equivalent, entrained around it.

Depending from the housing 19 is a pair of piston and cylinder devices 25, 27, these being shown side by side (although this is not essential) and extending vertically alongside the driling machine. The open end of the eylinders of the devices 25 and 27 open into the housing 19. One end of the entrainment means 23 is connected to piston 29 of the device 25, whereas the other end of the entrainment means 23 is connected to the piston 31 of the device 27. The walls of the cylinders of the devices 25 and 27 together with the pistons 29 and 31 and the housing 19 define a pressure chamber 33 which is filled with hydraulic fluid under pressure through a port 35. The cylinders 25 and 27 are provided with inlet/outlet ports 37, 39 for hydraulic control fluid for moving the pistons 29 and 31 to and fro.The pressure of the fluid within the chamber 33 is always in excess of that for moving the pistons so that the entrainment means 23 is always maintained in tension. It will thus be appreciated that when fluid is applied to the cylinder 25 through the port 37, the piston 29 will move upwardly, whereas the piston 31 will move downwardly. Likewise, the pistons will move in the opposite direction when the fluid is applied to the piston 37 through the port 39 and the piston 29 is ventcd. It will thus be appreciated that the sprocket 21 and hence the shaft 15 can be made to rotate conscquint upon lincar movement of pistons 29 and 31.

The hydraulic drive arrangement causes movement of the drilling head 7 by use of sprockets 41, 43 keyed to the shaft 15 for rotation therewith and roller chains 45 entrained around the sprockets 41, 43.

(Altcrnative entrainment means could be uscd). The chains 45 each have one end con nected to the drilling head 7 at 47 whereas the opposite end extends around an idler sprocket 49 supported on the frame 1 and is then connected to the drill head 7 at 51. It is will thus be appreciated that as the shaft 15 is rotated to and fro. so the drill head will move up and down as shown in the drawings.

The drilling machine described above is of light weight and has the ability of providing relatively long strokes to the drill head in a restricted space. Furthermore, the whole machine is readily dismantled and broken down into small units for easy transportation.

Although the invention has been particularly described with reference to a drilling machine, it will be apprcciated that the hydraulic drive arrangement illustrated in Figure 1 and the left-hand part of Figure 2, which rotates the shaft 15 can be used for many other purposes.

WHAT WE CLAIM IS: 1. A hydraulic drive arrangement for moving one or more members along a path, said drive arrangement comprising a pair of hydraulic piston and cylinder devices, a sprocket mounted on the end of a shaft and located within a hiusing, said housing being in fluid communication with an open end of the cylinder of each device, entrainment means entrained around said sprocket and having one end connected to the piston of one of said devices, and its other end connected to the piston of the other device, the housing, the open ends of said cylinders and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. munication with an open end of the cylinder of each device, entrainment means entrained around said sprocket and having one end connected to the piston of one of the said devices and its other end connected to the piston of the other device, the housing, the open ends of said cylinders and to pistons therein defining a pressure chamber within which hydraulic fluid is maintained under pressure to keep the entrainment means under tension at all times, hydraulic supply lines to the closed end of each cylinder so that application of hydraulic fluid to one or other of the cylinders will move the pistons therein to and fro, a pair of drive sprockcts mounted on said shaft, a pair of idler sprockets supported on the frame of the drilling machine and entrainmcnt means entrained around the respective oncs of said drive and idler sprockcts and having its cnds secured to the drill head, the arrangement being such that the drilling head can be moved to and fro as a rcsult of rotation of said shaft due to fluid pressure being applied to the closed end of one or other of said cylinders. A preferred cmbodiment of the invention is now described by way of example with reference to the accompanying drawings, in which:- FIGURE 1 is a side elevation of a hydraulic drive arrangement applied to a drilling machine, and FIGURE 2 is a front elevation of the machine arrangement only and looking in the direction of the arrow B of Figure 1. Referring to Figure 2 of the drawings, the drilling machine has a frame 1 having a pair of upstanding guide rods 3, 5 on which a drilling head 7 is slideably supported by means of sleeve guides 9. The drilling head has a drive motor 11 for rotating the drilling bit (not shown). Extending across the top of the drilling machine and ournalled in suitable supports 13 is a shaft 15 adapted to be rotated by a hydraulic drive arrangement illustrated in Figure 1 and the left-hand part of Figure 2. One end of the shaft projccts bcyond the side of the machine at 17 and is located within a fluid tight housing 19 forming part of the hydraulic drive arrangement which also includes a sprocket 21, is keyed to the pro ecting end 17 of the shaft and has entrainment means 23, e.g. a chain or toothed belt or the equivalent, entrained around it. Depending from the housing 19 is a pair of piston and cylinder devices 25, 27, these being shown side by side (although this is not essential) and extending vertically alongside the driling machine. The open end of the eylinders of the devices 25 and 27 open into the housing 19. One end of the entrainment means 23 is connected to piston 29 of the device 25, whereas the other end of the entrainment means 23 is connected to the piston 31 of the device 27. The walls of the cylinders of the devices 25 and 27 together with the pistons 29 and 31 and the housing 19 define a pressure chamber 33 which is filled with hydraulic fluid under pressure through a port 35. The cylinders 25 and 27 are provided with inlet/outlet ports 37, 39 for hydraulic control fluid for moving the pistons 29 and 31 to and fro.The pressure of the fluid within the chamber 33 is always in excess of that for moving the pistons so that the entrainment means 23 is always maintained in tension. It will thus be appreciated that when fluid is applied to the cylinder 25 through the port 37, the piston 29 will move upwardly, whereas the piston 31 will move downwardly. Likewise, the pistons will move in the opposite direction when the fluid is applied to the piston 37 through the port 39 and the piston 29 is ventcd. It will thus be appreciated that the sprocket 21 and hence the shaft 15 can be made to rotate conscquint upon lincar movement of pistons 29 and 31. The hydraulic drive arrangement causes movement of the drilling head 7 by use of sprockets 41, 43 keyed to the shaft 15 for rotation therewith and roller chains 45 entrained around the sprockets 41, 43. (Altcrnative entrainment means could be uscd). The chains 45 each have one end con nected to the drilling head 7 at 47 whereas the opposite end extends around an idler sprocket 49 supported on the frame 1 and is then connected to the drill head 7 at 51. It is will thus be appreciated that as the shaft 15 is rotated to and fro. so the drill head will move up and down as shown in the drawings. The drilling machine described above is of light weight and has the ability of providing relatively long strokes to the drill head in a restricted space. Furthermore, the whole machine is readily dismantled and broken down into small units for easy transportation. Although the invention has been particularly described with reference to a drilling machine, it will be apprcciated that the hydraulic drive arrangement illustrated in Figure 1 and the left-hand part of Figure 2, which rotates the shaft 15 can be used for many other purposes. WHAT WE CLAIM IS:

1. A hydraulic drive arrangement for moving one or more members along a path, said drive arrangement comprising a pair of hydraulic piston and cylinder devices, a sprocket mounted on the end of a shaft and located within a hiusing, said housing being in fluid communication with an open end of the cylinder of each device, entrainment means entrained around said sprocket and having one end connected to the piston of one of said devices, and its other end connected to the piston of the other device, the housing, the open ends of said cylinders and

the pistons therein defining a pressure chamber adapted to be supplied with hydraulic fluid so as to maintain the entrainment means under tension at all times, and hydraulic supply lines to the closed end of each cylinder whereby the pistons can be moved to and fro within their cylinders, said movement causing the sprocket to be rotated clockwise or anti-clockwise so as to rotate the shaft, rotation of the shaft being adapted to move one or more members along a path.

2. A hydraulic drive arrangement according to claim 1 applied to a drilling machine having a drilling head which can be moved to and fro by means of further entrainment means secured at its ends to the drilling head and entrained around an idler sprocket on the drilling machine and a drive sprocket on the shaft of the hydraulic drive arrangement.

3. A hydraulic drive arrangement substantially as hereinbefore described with refcrence to Figure 1 and the left-hand portion of Figure 2 of the accompanying drawings.

4. A drilling machine including a frame, a drilling head movable to and fro rclative to the frame. and a hydraulic drive arrangement for causing said movement, the drive arrangement including a pair of hydraulic piston and cylinder devices located to one side of the framc, a shaft extending across an end of the frame and protecting to one side thereof, a sprocket mounted on the pro::ect- ing end of the shaft and located within a housing. said housing being in fluid communication with an open end of the cylinder of each device, entrainment means entrained around said sprocket and having one end connected to the piston of one of the said devices and its other end connected to the piston of the other device, the housing, the open cnds of said cylinders and the pistons therein defining a pressure chamber within which hydraulic fluid is maintained under pressure to kccp the entrainmcnt means under tension at all times, hydraulic supply lincs to the closcd end of each cylinder so that application of hydraulic fluid to one or other of the cylinders will move the pistons therein to and fro, a pair of drive sprockets mounted on said shaft, a pair of idler sprockets supported on the frame of the drilling machine and cntrainmcnt means entrained around the respective ones of said drive and idler sprockcts and having its ends secured to the drill head, the arrangement being such that the drilling head can be moved to and fro as a result of rotation of said shaft duc to fluid pressure being applied to the dosed end of one or other of said cylinders.

. A drilling machine substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.