IES20000669A2

IES20000669A2 - Movement device

Info

Publication number: IES20000669A2
Application number: IE20000669A
Authority: IE
Inventors: Gerald Neads
Original assignee: Fintan Kelly
Priority date: 2000-08-24
Filing date: 2000-08-24
Publication date: 2002-03-20
Also published as: AU2001282407A1; EP1313592A1; US20040007128A1; WO2002016074A1

Abstract

A device for moving an object relative to a surface, for example for pushing a bar in a bar feed mechanism, comprises a piston mounted for reciprocation within a chamber, and a piston rod extending from one end of the chamber. Front and rear looking devices respectively associated with the piston rod and chamber are activated alternatively in synchronism with the movement of the piston in opposite directions respectively in the chamber.

Description

MOVEMENT DEVICE The present invention relates to a movement device and, in particular, to a device for moving, for example, pushing, pulling, feeding, moving over or lifting an object.

Bar feed machines are used to feed metal bars to turning machines in the engineering 'industry. In known bar feed machines, a bar is placed inside a length of tubular steel, which is the bar feed and is fixed to the turning machine. A small piston pusher is placed at the back of the bar feed and energy, such as pneumatic, hydraulic or electric, is transferred into the bar feed to force the pusher to move along the bar feed. The pusher in turn pushes the bar forward towards the turning machine where the metal is processed.

However, there are several disadvantages associated with such known bar feed mechanisms. Known mechanisms are expensive and pneumatic or hydraulic mechanisms in particular require the same amount of energy to be constantly fed into the bar feed. Thus, as the bar gets smaller and lighter it is pushed at a quicker rate against the turret of the turning machine. This can cause the turret to go off line.

Known pneumatic and hydraulic bar feeds are wasteful since the whole bar feed must be filled with air or oil. In addition, the distance through which the bar can be moved is limited by limitations on the movement of The known systems are prone to the inherent physical the hydraulic cylinder. wc«ar 'and LbJb which can j OPEN TO PUBLIC INSPECTION UMDER SECTION 28 AND RUU lead to leakage of air or oil which is wasteful and undesirable. Some of the known mechanisms are slow.

The present invention has been made from a consideration of the disadvantages associated with known feeding mechanisms and, in particular, in order to provide a movement device which overcomes one or more of those disadvantages.

According to the present invention there is provided a movement device for moving an object relative to a surface comprising piston means mounted for relative movement within a chamber, a first locking device associated with said chamber and a second locking device associated with said piston means, wherein such locking devices can be selectively activated or deactivated to selectively lock said chamber or said piston means relative to said surface.

Preferably, the device comprises first means for moving said piston relative to said chamber when said first locking device is in the activated state and said second locking device is in the deactivated state. Preferably such first means comprises means for applying pressure to said chamber and may include a pressure input port. Preferably, the device comprises second means for moving said chamber relative to said piston when said second locking device is in the activated state and said first locking device is in the deactivated state. Preferably, such second means comprises a spring mounted on a rod of said piston and located within said chamber. Preferably, such spring is compressed as said piston moves relative to said chamber.

Preferably, the piston means comprises a piston head and a piston rod, said rod being mounted within said chamber. Preferably, said chamber comprises an elongate tube. Preferably, a second chamber is connected to said first chamber and houses said first locking device. Preferably, said piston head is located within a third chamber which moves with the piston head and houses said second locking device. Alternatively, the first and second locking devices may be provided on respective first and second clamp means associated with said first chamber and said piston means respectively.

Preferably, the first and/or second locking device comprise one or more apertures and one or more corresponding projection means wherein the locking device is activated by protrusion of a projection means through the corresponding aperture and the locking device is deactivated by retraction of a projection means from the corresponding aperture. Preferably, such apertures are provided in the walls of the second and third chambers. Alternatively, such apertures may be provided on an internal wall of a clamp means. Preferably, the projection means comprise spheres. Preferably, the direction of movement of a projection means relative to the corresponding aperture is transverse to the longitudinal dimension of the device or the longitudinal direction of movement of the piston relative to the chamber. ΙΕ ϋ ΰ ο ύ δ 9 The invention further provides a method of using a movement device of the invention for moving an object relative to a surface.

The device of the present invention avoids the constant energy requirement of known systems by only feeding the amount of energy required to move the bar forward at any given time. In addition, the device of the invention only requires energy to move the ram in the central chamber in order to move a bar forward. Thus, the device of the invention has a much lower energy requirement than the conventional hydraulic ram mechanism. The device is not as prone to wear and tear or leakage and the device has a fast response, for example it can be controlled to feed bars within microseconds of the chuck opening.

The invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a side view of an embodiment of a device of the invention in the unextended, pressure off configuration; Fig. 2 is a side view of the device of figure 1 in the part extended, pressure on configuration; Fig. 3 is a side view of the device of figure 1 in the fully extended, pressure on configuration; Fig. 4 is a side view of the device of figure 1 in the fully extended, pressure off configuration; ΙΕ ο o q g θ θ .

Fig. 5 is a side view of the device of figure 1 in the part extended, air exhaust configuration; Fig. 6 is a view showing the internal components of the device of figure 1 in the figure 4 configuration with the pressure on; Fig. 7 is a view showing an example of a device of the invention in use; Fig. 8 is a series of schematic views of alternative bore/bearing configurations suitable for use on a device of the invention; Fig. 9 is a side view of an embodiment of the device of the invention adapted for pulling an obj ect; Fig. 10 is a side view of an embodiment of the device of the invention adapted for lifting an object; and Fig. 11 is a schematic side view of a multi-jointed embodiment of a device of the invention.

Referring to Figures 1 and 2, a movement device 1 according to one embodiment of the invention comprises three chambers; a central chamber 2, a rear chamber 4 and a front chamber 6. The central chamber 2 holds a main piston ram 8. The device is adapted to move relative to a surface such as linearly along a tube or the like, for example as shown in Figure 7, either IE D 0 0 6 6 9 internally or externally. The embodiment described with reference to Figures 1 to 7 is intended to move internally along a circular cross-section tube. However, it will be appreciated that the shape and dimension of .the device may be chosen as desired to suit the particular application or tube.

The rear chamber 4 is connected to the central chamber 2 and comprises a locking device 10 for locking the rear chamber relative to the tube within which the device travels. The front chamber 6 is connected to the central chamber piston ram 8 and comprises a locking device 12 for locking the front chamber relative to the tube within which the device travels. A side port 14 and a back port 16 are provided on the device and either port may be used to supply pressure to the chambers .

In the embodiment of Figure 1, the three chambers are generally defined by cylindrical segments. The front and rear chambers have a substantially similar dimension and the central chamber is longer and has a similar diameter. The outer cylindrical wall of the front chamber comprises a plurality of circular apertures 18 arranged around the circumference of the chamber wall. The outer cylindrical wall of the rear chamber also comprises a plurality of circular apertures 19 arranged around the circumference of the chamber wall. Typically the apertures 18,19 are evenly spaced and centrally located along the longitudinal dimension of the corresponding wall.

IE 0 0 0 6 s 9 A corresponding series of ball bearings 20, 21 is provided inside each of the front and rear chambers respectively. Each bearing is movable between a recessed position, as shown in Figure 1, wherein it lies below its corresponding aperture and a protruded position, as shown on the rear chamber of Figure 2, wherein the bearing at least partly protrudes out of its corresponding aperture. The series of apertures and corresponding bearings on each of the rear and front chambers are the respective locking devices 10, 12 of said chambers. The protruded bearings abut against the inside of the tube within which the device travels thereby holding the chamber relative to the tube.

The operation of the device of the invention will now be described with reference to Figures 1 to 5. Referring to Figure 1, the device is shown in the unextended configuration with no pressure applied to the side or rear ports 14, 16. This is the neutral or off state in which the device is inserted into an appropriate tube. For the pneumatically operated device, a compression gap 15 is located between the front chamber 6 and the central chamber 2. As pressure is applied to the central chamber via the side port or the rear port, the main ram 8 moves forward relative to the central chamber thereby moving the front chamber forward. The device is shown in Figure 2 with the front chamber thus partly extended or at half travel and in Figure 3 with the front chamber fully extended or at full travel. In both the Figure 2 and the Figure 3 cases the pressure continues to be supplied through the side or rear port.

IE 0 0 0 6 6 9 The pressure applied via the port also results in pressure on the bearings 21 in the rear chamber 4 so that the bearings 21 are caused to protrude through their corresponding apertures 19. Such action causes the rear chamber locking device 10 to hold the central and rear chambers in place in the tube whilst the front chamber travels forward a predetermined distance as shown in Figure 3. Although, the pressure to activate the front chamber and the rear locking device is applied at the same time, the rear locking device will in practice lock first before the front chamber starts to move .

The pressure is then released from the central and rear chambers thereby actuating the locking device 12 in the front chamber 6 and deactivating the locking device 10 in the rear chamber 4. Thus, as shown in Figure 4, the bearings 21 in the rear chamber are retracted and the bearings 20 in the front chamber are protruded or forced outward against their apertures so that the front chamber is held in place in the tube whilst the central and rear chambers are free to travel forward in the tube to meet the front chamber. Thus, Figure 4 represents the state when the pressure is removed. The front chamber 6 tries to move back towards the central and rear chambers, due to compressed spring 56 described below with reference to Figure 6, but it cannot due to the locking device 12. As shown in Figure 5, the central and rear chambers can only move forward to meet the front chamber via the spring return as described with reference to Figure 6. A.ir can exhaust as necessary through side port 14 or back port 16.

IE 0 006 6 9 The device then reverts to the neutral or off configuration shown in Figure 1 with the pressure removed and both locking devices 10, 12 deactivated so that the bearings 20, 21 are below the apertures 18, 19. However, at this stage the device has travelled forward within the tube from its original Figure 1 longitudinal position.

The device can be operated successively as described above to move the device along the tube for any desired distance. Thus, with the device of the invention, there is no limitation on the maximum extent of travel along the tube. A forward movement of the device is obtained every time the device is activated and deactivated. The device of the invention has the power to push forward an object in its path or pull and carry objects horizontally, vertically or in a non-linear manner if required.

Figure 6 shows the internal components of the device 1. The piston comprises the main piston ram 8, the rear piston body 50 and the piston head 52. The piston is slidable within the central chamber 2 and the piston head 52 is located in the front chamber 6. The bearings 20 are mounted around the piston head 52 and the head is. connected to the front chamber by a front spring 54. A spring 56 is mounted on the piston ram 8 between the front wall of the central chamber and the rear piston body. The spring 56 compresses as the piston moves forward through the central chamber. The front chamber 6 is thereby biased to return towards the central chamber when the pressure is turned off but is prevented from doing so by the locking means 12. ΙΕΟ 0 0 6 8 9 Instead, the central and rear chambers are biased to move towards the front chamber as described with reference to Figure 5.

The central and rear chambers are secured together by suitable means. The bearings 21 are mounted around a spring loaded support 58. In use, the pressure, such as compressed air, is applied to the side and/or rear port 14, 16 and causes pressure within the rear chamber 4 to force the bearings 21 against the apertures 19 thereby locking the rear chamber against relative longitudinal movement and causes pressure within the central chamber 2 which pushes the piston and front chamber forward. Although in the embodiment shown in Figure 6, the front locking means 12 works mechanically, it will be appreciated that the front chamber and locking means could be made active by incorporating means, for applying pressure to the front chamber similar to the rear chamber mechanism.

The rear and front locking devices 10, 12 as described respectively comprise a tapered support 58 and a tapered piston head 52 around the periphery of which the bearings are mounted. Such a tapered head and ball bearing arrangement provides simple mechanical locking devices 10, 12. However, it will readily be appreciated that any other suitable locking device may be used.

Figure 7 shows the application of a device of the invention to a bar feed machine. Referring to Figure 7, the device 1 of the invention is shown by the cut away detail A located within a bar tube 30. The device is controlled by a control unit 32 which includes a 24V solenoid 34, an oil reservoir 36, an air inlet 38 and an exhaust outlet 40. The control unit 32 is connected to the side entry port 14 or the back entry port 16 of the device. The control unit successively actuates the device 1 so that the device proceeds forwardly along the tube 30 pushing feed bar 42 out the remote end of the tube. Each signal from the control unit may give, for example, approximately 25mm of travel.

Sample programme operations of the device may be as follows: Programme (1) to obtain a single travel distance movement:- Chuck open; Feeder on with dwell if required; Chuck close; Feeder off.

Programme (2) to obtain a three times travel distance movement:- Chuck open; Feeder on; Feeder off; Feeder on; Feeder off; Feeder on; Chuck close; Feeder off.

Referring to Figure 8, (a) to (d) show variations of ball bearing and aperture configurations which may be used on the front and/or rear chambers. Thus, for example, the bearings and apertures may be provided on IE 0 0 0 6 6 9 a chamber having an hexagonal, square, circular or triangular transverse cross-section.

Figure 8 (e) shows an alternative arrangement wherein the device can be secured with clamp 44 to the outside of a tube and the required grip is provided by bearings 46 protruding through apertures provided on the internal wall of the clamp. Again, the clamp and configuration of the apertures may have any crosssectional shape. Figure 8(f) shows a linear grip arrangement for an alternative external arrangement wherein grip means 48 can protrude and retract through apertures provided linearly along an external surface. It will be appreciated that any other suitable locking means may be provided.

Referring to Figure 9, the device of the invention is adapted for pulling an object by extending the main ram back through the rear of the rear chamber 4. The device comprises chambers 2, 4, 6 as previously described. In addition, the device comprises a repositioned side port 60 and the ram 8 extends through the rear of the rear chamber 4 as extended ram portion 8'. Suitable pulling connections 62 are provided on a pulling support 64 which incorporates a rear port 66. In use, the object to be pulled is attached to the pulling connections 62 and the device is activated.

Referring to Figure 10, the device of the invention is adapted for lifting an object by extending the main ram forwardly through the front of the front chamber 6, by means of an end button or the like. The device comprises chambers 2, 4, 6 as previously described. In ΐΕοο g addition, the device comprises an extension means or button 70 connected to the main ram 8. The extension means, which is shown more clearly in Figure 10(b), comprises a platform 72 supported by a shaft 74, a threaded portion 76 of which engages with a corresponding threaded aperture provided in the front end of the piston 8. In use, an object can be lifted upwardly by the platform 72.

Thus, it will be seen that the device of the invention has the ability to lock, move, lock and move itself again to a new start position. The device is a mobile ram that can push, pull, lift or carry objects to a predetermined distance by successively locking itself, activating and locking and then moving to meet itself to restart. This action enables the device to bodily move itself along objects of various shapes.

The device has several advantages. The device can interface internally or externally with an object to move over surfaces. When the device is powered, it is capable of moving itself forward at a rate and speed predetermined by the size of the shafts and frequency at which the device is powered. The device will push forward any objects that are placed in its path or will pull or carry objects that are connected to it.

It will be appreciated that the device of the invention can be used in a variety of applications other than as described with reference to bar feed machines. For example, the device could be used to unblock drains or could be used on the outside of a lamp post or the like. The device can crawl forward without being 0 6 6 9 attached to an object and can travel unlimited distances . The device can move vertically or horizontally and is not confined to linear movement. For example, the device may be in the form of a curved device or a multi-jointed device which can go around a curve or bend or in any desired direction. Tin example of such a general· arrangement is shown schematically in Figure 11 wherein the device is defined by a series of interengaged tapered joints 80 which allow the device to negotiate bends and generally to move non-linearly.

The device may be made from any suitable material and may have any suitable shape and size for the desired application. It can be designed to travel specific distances, for example 10 mm, as required. The device is cost effective and easy to manufacture and requires little maintenance. If desired for a particular application, the device can be operated remotely. The device may be operated or actuated by any suitable means, such as pneumatic, hydraulic or electronic means. The use of a side power port allows the power cable to be fed through a slot in the tube which avoids the use of a long cable on the back going up the tube in use.

The device can readily be made to travel in reverse by powering the device from the opposite end. For example, front ports may be provided to facilitate applying pressure to the front end, or both front and rear ports may be provided so that the device can be driven in either direction or me made to change direction as desired. It will be appreciated that the device can be self-powering. For example, a compressed air container ΙΕ Ο Ο η 6 Β 9 or other power source may be incorporated into the device and a remote control unit may be used to activate the power source.

It will be appreciated that the present invention is not intended to be restricted to the details of the above embodiments which are described by way of example only.

Claims

1. A device for moving an object relative to a surface, the device comprising a piston mounted for reciprocation within a chamber, a piston rod extending from one end of the chamber, a first locking device associated with the chamber for locking the chamber relative to the surface, a second locking device associated with the piston rod for locking the piston rod relative to the surface, drive means for effecting reciprocating movement of the piston in the chamber, and means for activating alternate locking devices in synchronism with the movement of the piston in opposite directions respectively in the chamber.

2. A device as claimed in claim 1, wherein the drive means comprises means for applying fluid pressure intermittently to the chamber on one side of the piston, the fluid pressure forcing the piston along the chamber from an initial position, the drive means further including means to return the piston to its initial position upon removal of the fluid pressure.

3. A device as claimed in claim 1, wherein the drive means comprises means for applying fluid pressure intermittently to the chamber on one side of the piston, the fluid pressure forcing the piston along the chamber from an initial position, the drive means further including means to return the piston to its initial position upon removal of the fluid pressure, and wherein the first locking device which comprises at least one locking element is forced laterally outwardly by the IE Ο Ο ο 6 6 9 ι-ρ fluid pressure applied to the chamber, relative to the axis of the piston rod into engagement with the surface.

4. A device as claimed in claim 3, wherein the at least 5. One locking element is forced laterally outwardly by at least one wedge member which is moved against a resilient bias by the fluid pressure.

5. A device as claimed in claim 4, wherein there are a

6. 10 plurality of locking elements disposed around the axis of the piston rod, and wherein the wedge member has a conical surface which is substantially coaxial with the axis of the piston rod, the wedge member being moved substantially along its own axis by the fluid pressure to

7. 15 force the locking elements simultaneously laterally outwardly relative to the piston rod axis and wherein the wedge member is contained within a housing, and wherein the locking elements are balls which are forced outwardly through respective apertures in the wall of the housing.