AU2600388A

AU2600388A - Drive mechanism

Info

Publication number: AU2600388A
Application number: AU26003/88A
Authority: AU
Inventors: Kevin Barrett; Gosta Ingvald Hook
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-22
Filing date: 1988-10-21
Publication date: 1989-05-23
Anticipated expiration: 2008-10-21
Also published as: AU620055B2

Description

_ . _

TITLE DRIVE MECHANISM DESCRIPTION The present invention relates to a drive mechanism. FIELD OF THE INVENTION

The present invention provides a drive mechanism which enables rotary motion of a rotatable member to be converted to reciprocating motion of a working tool that may be connected to the drive mechanism. The drive mechanism of the present invention may be used for any application in which this type of motion is suitable.

SUMMARY OF THE INVENTION In accordance with one aspect of the present invention there is provided a drive mechanism characterised in that it comprises: a rotatable member comprising an end face arranged at an angle to the direction transverse of the axis of rotation of said rotatable member; bearing mounting means arranged to have a working tool connected thereto; rotatable bearing means mounted on said bearing mounting means and in contact with said end face; wherein rotation of said rotatable member causes said rotatable bearing means to rotate and said working tool to move in a reciprocating motion.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described,- by way of example, with reference to the accompanying drawings, in which :

Figure 1 is a perspective view of an embodiment of drive mechanism in accordance with one aspect of the present invention; Figure 2 is first plan view of the drive mechanism shown in Figure 1 with the bearing mounting at one of its extreme positions;

Figure 3 is a second plan view of the drive mechanism shown in Figure 1 with the bearing mounting at the other of its extreme positions;

Figure 4 is a perspective view of the rotatable member of the drive mechanism shown in Figure 1; Figure 5 is a partly cut-away perspective view of an embodiment of a first shearing device in accordance with a second aspect of the present invention;

Figure 6 is a longitudinal sectional sliver view of the shearing device shown in Figure 5, taken through the axis of rotation of the rotatable member of the drive mechanism; Figure 7 is a first partly cut-away plan view of the shearing device shown in Figure 5 with the fork assembly and cutting plate at one of their extreme positions; Figure 8 is a second partly cut-away plan view of the shearing device shown in Figure 5 with the fork assembly and cutting plate at the other of their extreme positions; Figure 9 is a first perspective view of an embodiment of a second shearing device in accordance with a third aspect of the present invention; and

Figure 10 is a second perspective view the shearing device shown in Figure 9 with the upper forward portion removed — *" ^*3 —— from the casing.

DESCRIPTION OF THE INVENTION In Figures 1 to 3, there is shown a drive mechanism 10 comprising a rotatable member 12 and a bearing mounting 14. The rotatable member 12 has an end face 16 arranged at an angle to the transverse direction of the axis of rotation 18 of the rotatable member 12 to form a face cam. The rotatable member 12 is shown separately in Figure 4. Bearings 20 are rotatably mounted on the bearing mounting 14, by pins 22. The bearings 20 are in contact with the end face 16 of the rotatable member 12.

The bearing mounting 14 has an upper extending portion 24 and a lower extending portion 26. In use, the upper and lower extending portions 24 and 26 are positioned in bearing sleeves (not shown) which are fixed to a suitable support (not shown) . The bearing mounting 14 is rotatable in these bearing sleeves. The axis of rotation 28 of the bearing mounting 14 is substantially at right angles to the axis of rotation 18 of the rotatable member 12. The bearing mounting 14 is provided with working tool receiving means. The working tool receiving means is arranged to receive the non-working portion 30 of a working tool i.e. the shank portion. Preferably, the working tool is releasably receivable in the working tool receiving means.

The working tool receiving means may comprise an opening 32 in the bearing mounting 14.

In use, a suitable drive actuator 34 (shown in phantom in Figures 1 to 3) is connected to the rotatable member _.12. The drive actuator 34 causes the rotatable member 12 to rotate about its axis of rotation 18, as shown by the encircling arrows in Figures 2 and 3. The drive actuator 34 may be of any suitable form, e.g. air motor, mechanical drive, electric motor, hydraulic motor, etc.

The non-working end 30 of a working tool is attached to the bearing mounting 14 via the working tool receiving means. When the drive actuator 34 is activated, it causes the rotatable member 12 to rotate as shown by the encircling arrows in Figures 2 and 3. Since the end face 16 of the rotatable member 12 is in contact with the bearings 20, the bearings 20 are also caused to rotate. Rotation of the end face 16 causes the bearings 20 to rotate in the respective directions shown by arrows in Figures 2 and 3. Due to the angle of the end face 16 and the rotation of the bearings 20, the bearing mounting 14 executes a- reciprocating motion in the bearing sleeves. This causes the working tool to execute a similar reciprocating motion, as shown by the heavy arrows in Figures 2 and 3. In Figure 2, the bearing mounting 14 is shown at one of the extreme positions of its reciprocating motion, just prior to its commencing movement in the direction opposed to the heavy arrow shown therein. Similarly, in Figure 3 the bearing mounting 14 is shown at its other extreme position, just prior to its commencing movement in the direction opposed to the heavy arrow shown therein.

A turn of 180° (half a full turn) of the rotatable member 12 is required to move the bearing mounting 14 and the working tool from the position shown in Figure 2 to that shown in Figure 3.

The reciprocating motion executed by the working tool is a side to side motion, as shewn by the heavy arrows in Figures 2 and 3. The direction of this reciprocating motion is substantially at right angles to the axis of rotation 18 of the rotatable member 12. The size of the sweep of this reciprocating motion is determined by the angle of the end face 16 to the transverse direction of the axis of rotation 18. As this angle of the end face 16 increases, then the size of the sweep of the reciprocating motion is also increased. Thus, the desired amount of sweep can be obtained by forming the end face 16 at the appropriate angle. The working tool used in the drive mechanism 10 may be a suitable tool to which it is desired to impart a reciprocating motion of the type hereinbefore described. The working tool may be a cutting blade, cutting blade assembly, or some member in machinery to which it is desired to impart a reciprocating motion, etc. To maintain optimum operation of the drive mechanism 10 it is desirable that the bearings 20 and end face 16 be adequately lubricated. This also applies to the upper and lower extending portions 24 and 26 and their respective bearing sleeves. In Figures 5 to 8 there is shown a shearing device 40 incorporating a drive mechanism as hereinbefore described. In the drive mechanism of the shearing device 40 shown in Figures 5 to 8 the same reference numerals will be used to denote the same parts as used in Figures 1 to 4. The shearing device 40 co-prises a drive mechanism 10 and a fork assembly 42.

The rotatable member 12 of the drive mechanism 10 is detachably mounted to an end of a shaft 44. The other end of the shaft 44 is connected to an air motor 46 which serves as the drive actuator. However, any suitable form of drive actuator may be used, as previously described. The shaft 44 is rotatably mounted in one or more bearings 48. The drive mechanism 10 and the drive actuator, i.e. the air motor 46 are contained in a casing 50 which forms a handle for a user. A lever 52 is pivotally connected to the casing 50. A pin (not shown) projects from the casing 50 and abuts the lever 52 in the vicinity of its proximal end. An adjustment screw 54 for the air motor 46 is provided in the upper portion of the casing 50. In use, an air feed line (not shown) is connected to the air motor 46 at the end 56 of the casing 50. When the casing 50 is grasped by a user the lever 52 may be simultaneously grasped and pivoted toward the casing 50. This causes the pin (previously referred to) to be depressed which activates the air motor 46.

With particular reference to Figure 6, the lower extending portion 26 of the bearing mounting 14 is rotatably held in a bearing sleeve 56. The bearing sleeve 56 is screw threadedly connected to an opening in the casing 50. The upper extending portion 24 of the bearing mounting 14 is rotatably held in a bearing sleeve 58. The bearing sleeve 58 is firmly connected to an outer sleeve 60. The^' outer sleeve 60 is screw threadedlv connected to an upright portion 62 of the casing 50. A cap 64 is screw threadedly connected to the upper portion of the outer sleeve 60. Alternatively, the cap 64 may be screw threadedly connected to the upright portion 62 of the casing 50.

The bearing sleeves 56 and 58 and the bearing mounting 14 have respective aligned bores therethrough. These aligned bores contain a pin 66. This is best seen in Figure 6. The upper end of the pin 66 abuts against the inner upper surface of the cap 64. The lower end of the pin 66 abuts against a comb mounting assembly 68.

The comb mounting 68 is substantially in the form of a plate and is pivotally mounted relative to the casing 50 by way of a pin 10 rotatable in a sleeve 72. The sleeve 72 is connected to the under surface of the casing 50, e.g. by welding. The pin 70 is rigidly held near its ends in supports 74 which are rigidly connected to the comb mounting assembly 68. The comb mounting assembly 68 is provided with a pair of screw threaded apertures such that a comb 76 may be attached thereto by way of screws 78 from underneath.

The comb 76 comprises teeth 80 and is provided with an arcuate groove 82. In the shearing device 40, the working tool comprises a fork assembly 84 and a cutting plate 106. The fork assembly has a shank portion 86 which fits into the opening 32 that forms the working tool receiving means. A slit is provided in the upper wall of the working tool receiving means and an "L" shaped clip 90 extends therethrough and engages i a slot formed in the upper part of the shank portion 86 of the form assembly 84. A screw 92 holds the clip 90 against the upper surface of the shank portion 86. The arrangement releasably retains the fork assembly 84 in the opening 32. The foregoing is best seen in Figure 6.

The fork arms 94 are each rotatably held in first and second sleeves 96 and 98. A clip 100 is secured to the fork assembly 84 by way of a screw 102. The clip 100 abuts against the fork arms 94 via slots (not shown) formed in the undersurfaces of the first sleeves 96. The clip 100 enables the amount of play of the fork arms 94 in the first sleeves 96 to be adjusted. The feet 104 of the fork arms 94 bear upon a cutting plate 106. The undersurface of the cutting plate 106 is provided with an arcuate tongue 108 which engages in the-arcuate groove 82. The cutting plate 106 is provided with four projections each having a pair of bevelled cutting edges 110. The shearing device 40 is particularly suitable for the shearing of sheep.

The manner of operation of the shearing device 40 will now be described. Air may be fed to the air motor 46 by the feed line (not shown) . The air motor 46 is activated by the operator simultaneously grasping the casing 50 and depressing the lever 52.

Activation of the air motor 46 causes the shaft 44 and the rotatable member 12 to rotate as shown by the encircling arrows in Figures 7 and 8.

Rotation of the end face Iβ of the rotatable member 12 causes the bearings 20 tc rotate as shown by arrows in Figures 7 and 8. Due to the angle of the end face 16 and the rotation of the bearings 20, the bearing mounting 14 executes a reciprocating motion in the bearing sleeves 56 and 58. This causes the fork assembly 84 to execute a similar reciprocating motion. The reciprocating motion of the fork assembly 84 is transferred to the cutting plate 106 by the feet 104 of the fork arms 94. The cutting plate 106 thus also moves in a reciprocating motion. In Figure 7 the fork assembly 84 and cutting plate 106 are shown at one of the extreme positions of their reciprocating motion, just prior to their commencing movement in the direction opposite to the heavy arrow shown therein. Similarly in Figure 8, the fork assembly 84 and the cutting plate 106 are shown at their other extreme position, just prior to their commencing movement in the direction opposite to the heavy arrows shown therein. A turn of 180° (Half a full turn) of the rotatable member 12 is required to move the fork assembly 84 and cutting plate 106 from the position shown in Figure 7 to that shown in Figure 8.

Thus, the cutting plate 106 moves in a side to side motion along the groove 82 of the comb 76, from one side of the comb 76 to the other. As the cutting plate 106 moves from side to side across the comb 76, fleece of the sheep (or other animal) being shorn comes between the teeth 80 of the comb 76 and the cutting edges 110 of the cutting plate 106, and is thereby cut or shorn from the animal. The direction of the side to side reciprocating motion executed by the cutting plate 106 and fork assembly 84 is shown by the heavy arrows in Figures 7 and 8. The direction of this reciprocating motion is substantially at right angles to the axis of rotation 18 of the rotatable member 12. The size of the sweep of this reciprocating motion is determined by the angle of the end face 16, as previously described with reference to Figures 1 to 4. The tension between the comb 76 and the cutting plate 106 may be adjusted by turning the cap 64 in the appropriate direction. Turning the cap 64 to increase the tension moves the cap downwardly. This causes the pin 66 to project further from the bearing sleeve 56. This movement of the pin 66 pushes downwardly on the comb mounting assembly causing it to pivot by way of the sleeve 72 and the pin 70. The forward portion of the comb 76 is thus caused to pivot upwardly against the cutting plate 106 thereby increasing the tension.

If the cap 64 is turned in the opposite direction, the reverse effect is achieved and the tension between the comb 76 and the cutting plate 106 is reduced.

Thus, the tension between the comb 76 and the cutting plate 106 may be adjusted to achieve the optimum tension for cutting in any given situation. In Figures 9 and 10, there is shown a shearing device 120, incorporating a drive mechanism as hereinbefore described. In the drive mechanism of the shearing device 120 shown in Figures 9 and 10, the same reference numerals will be used to denote the same parts as used in Figures 1 to 4. The shearing device 120 comprises a drive mechanism 10 and a working tool in the form of a projecting member 122 with an upturned end 124.

The rotatable member 12 may be connected to a drive actuator of the same type and in the same manner as in the shearing device 40 of Figures 5 to 8. Whilst the drive actuator is preferably an air motor any suitable form of drive actuator may be used, as previously described. The drive actuator is hidden by the casing 126 in Figures 9 and 10 but it will be understood that it may be the same as the drive actuator of the shearing device 40.

A spindle 128 is rigidly connected to the lower. inside surface of the casing 126. The bearing mounting 14a has a bore therethrough.

The bore of the bearing mounting accommodates the spindle 128 such that the bearings 20 are in contact with the end face 16 of the rotatable member 12 and the bearing mounting 14a is rotatable about the spindle 128. Washers 130 may be provided on the spindle 128 above and beneath the bearing mounting 14a. The upper forward portion 132 of the casing 126 is held in place by a hollow screw 134 which engages with the upper portion of the spindle 128. The front face 136 of the upper forward portion 132 is inclined as shown in Figure 9. Similarly the front face 138 of the lower part of the casing 126 is inclined as shown in Figure 9. Further, a small plate 140 is connected to the front face 138 such that it projects slightly above the upper edge of the front face 138, as best seen, in Figure 10. The shearing device is particularly suitable for shearing goats and rabbits.

In use, the shearing device 120 operates in a manner substantially the same as the shearing device 40. When the drive actuator is the shearing device 120 is activated the rotatable member 12 is caused to rotate. This causes the bearing mounting 14a and the projecting member 122 to execute a side to side reciprocating motion about the spindle 128 since the bearings 20 are in contact with the end face 16 of the rotatable member 12. The reciprocating motion of the bearing mounting 14a and the projecting member 122 is analogous to that of the bearing mounting 14, fork assembly 84 and cutting plate 106 described with reference to Figures 1 to 8, and is not here again repeated. The reciprocating motion of the bearing mounting 14a and the projecting member 122 is shown by the heavy arrow in Figure 10.

As the projecting member 122 moves in a side to side reciprocating motion the fur of the animal being shorn is cut therefrom. The size of the sweep of the side to side reciprocating motion is determined by the angle of the end face 16, as previously described with reference to Figures 1 to 4 and 5 to 8. Whilst the drive mechanism 10 has been described with particular reference to t c embodiments of shearing devices it is to be understood that it is of general applicability, as hereinbefore stated.

Modifications and variations such as would be apparent to a skilled addressee are deemed ^'within the scope of the present invention.

Claims

1. Drive mechanism characterised in that it comprises: a rotatable member comprising an end face arranged at an angle to the direction transverse to the axis of rotation of said rotatable member; bearing mounting means arranged to have a working tool connected thereto; rotatable bearing means mounted on said bearing mounting means and in contact with said end face; wherein rotation of said rotatable member causes said rotatable bearing means to rotate and said working tool to move in a reciprocating motion.

2. Drive mechanism according to claim 1, characterised in that said reciprocating motion is a side to side reciprocating motion about an axis that is substantially at a right angle to said axis of rotation of said rotatable member.

3. Drive mechanism according to claim 1 or 2, characterised in that said rotatable bearing means comprises a pair of bearings with one bearing being disposed on each side of said bearing mounting means.

4. Drive mechanism according to claim 2 or 3 characterised in that said bearing mounting means also moves in said reciprocating motion about said axis.

5. Drive mechanism according to any one of the preceding claims, characterised in that a drive actuator is connected to said rotatable member to cause said rotatable member to rotate about its said axis of rotation.

6. Drive mechanism according to any one of the preceding claims, characterised in that said working tool comprises a shearing device fork assembly and cutting plate and said drive mechanism in contained in a casing to form a shearing device and shearing comb mounting means is connected to said casing such that when a shearing comb is connected to said shearing comb mounting means said cutting plate is disposed between said fork assembly and said shearing comb and said bearing mounting means is rotatably held in upper and lower sleeve bearings.

7. Drive mechanism according to claim 6, characterised in that said shearing comb mounting means is pivotally connected to said casing such that said shearing comb is moveable toward or away from said cutting plate to thereby enable the tension between said cutting plate and said shearing comb to be adjusted.

8. Drive mechanism according to claim 7, characterised in that said bearing mounting means comprises a bore therethrough having pin means slidably retained therein and extending through said casing to engage said shearing comb mounting means and adjustment means to alter the length of said pin means extending through'said casing to engage said comb mounting means such that said tension between said cutting plate and said shearing comb is adjustable by altering said length of said pin means extending through said casing to engage said comb mounting means.

9. Drive mechanism according to claim 8, characterised in that said adjustment means comprises cap means screw threadedly connected to said upper sleeve bearing or a projecting portion of said casing and said pin means engages with said cap means such that said length of said pin means extending through said casing to engage said comb mounting means is alterable by turning said cap means.

10. Drive mechanism according to any one of the preceding claims, characterised in that said working tool comprises a projecting member having an upturned end and said drive mechanism is contained in a casing to form a shearing device wherein the lower and upper front parts of said casing slope away from said projecting member and said bearing mounting means is rotatably mounted on spindle means connected to said casing and said upper front part is releasably connected to said spindle means.