NZ205851A - Shearing hand piece with means for sensing loss of grip whereby drive thereto is stopped - Google Patents

Description

2 05851 | Priority Date(s): U\ 3J.I.£?.

Complete Specification Filed: .?f!i Class: . £<f.

Publication Date: P.O. Journal, No: 2 3 JAN 1987 v. \ <*L? ■ I* •"* 1 Patents Form No. 5 Number PATENTS ACT 1953 Dated COMPLETE SPECIFICATION IMPROVEMENTS RELATING TO SHEARING MACHINES //We COLIN WTT.TJAMS TTT.T.EY of Williainstown Road, Gumeracha, South Australia, and MICHAEL GUTHRIE of Birdwood Road, Gumeracha, South Australia, both Australian citizens do hereby declare the invention for which //we pray that a Patent may be granted to nfoe'us. and the method by which it is to be performed, to be particularly described in and by the following statement: 205851 2.

This invention relates to shearing and particularly to improvements pertaining to shearing machines.

It is conventional to use a power driven comb and cutter for most shearing of sheep.

It is conventional that such a comb and cutter is a part of a hand-piece which is coupled through a mechanical linkage to an overhead drive mechanism which can be coupled or disengaged with respect to the drive by a rope hanging usually in a location behind the shearers shearing location.

It has also been accepted as conventional wisdom that if for any reason the shearer loses control of his sheep or otherwise loses control of the hand-piece for any reason, that it can generally only be hoped that this will not cause injury either to the sheep or to the shearer or to the equipment.

Such a position has been accepted for probably as long as most shearers presently shearing can remember and it is therefore accepted generally as the norm within the industry.

The mechanism by which the drive is coupled to the hand-piece is mechanical and because there is firstly an inherent delay for a shearer to reach behind and find the rope and then pull this to effect the disengagement, it has been accepted that any damage will well and truly have resulted before the machine can be disconnected.

It is a very significant factor in considering any alteration to equipment of this type that it is not only that the apparatus should work but that it also will I Z. M TEST Of r-ICE ! t 2 NOV i9S6 RECEIVED 205851 3. be preferred by a shearer who must operate the equipment in a highly intensive work situation over long hours for many days.

The problem to which this invention is directed it to provide means by which there will be a higher potential safety for a shearing hand piece during its operation which, considering the highly conservative character of shearing and the shearer, will be acceptable and effective for continuous operation to and by the shearer during normal operation but which will also enable very rapid detection of a dangerous situation existing to enable a stop signal and a stopping of the drive connection to be connected.

The invention in one form can be said to reside in equipment for shearing of a type including a hand piece with a comb and cutter, and drive means to effect a reciprocal cutting action between the comb and cutter, and a housing for the hand piece having a member or members providing an outer surface of a shape appropriate for a user to hold and use the hand piece, the equipment being characterised in that there is a first portion of the said outer surface and second portion of the outer surface, said second portion defining a different portion from the first portion of the outer surface, the location and shape of the said first portion with respect to the remaining portion of the outer surface of the handpiece being such that during conventional use of a hand piece a portion of the hand of a user can be continuously kept comfortably against some part of the first portion, but such portion v of the hand of a user can be voluntarily lifted from such contact at any time during such use, and means adapted to be responsive to the status of such N.Z. PATENT OFFICE 12 MOV 1936 RECEIVED 2-057S 4. contact so as to provide a stop signal when such contact is broken and a drive signal when such contact is being maintained.

Preferably, said second portion is in such a position that the hand of a user will maintain contact with such outer surface of the second portion during all conventional usage.

Preferably the stop and drive signals are a selected change of resistance between the said first portion and the said second portion of the outer surface of the hand piece.

Preferably the said second portion of the outer surface of the hand piece comprises substantially all that outer surface of the housing not otherwise comprised in the first portion.

Preferably there are provided detector means whereby the stop and drive signals are used to provide an output comprising an electrical voltage which in the case of the stop signal is a voltage significantly differing from the voltage in the case of the drive signal.

Preferably the said detector means are located with the hand piece and electrical conductors convey the output as a voltage to means responsive to such output to effect a stopping or interconnecting of drive to the handpiece.

Preferably the said first portion of the said outer surface has a location and covers an area comprising that which will be conventionally contacted by the thumb of a right-handed user during conventional use of the hand piece for shearing purposes. *_. '"-Mgr.",- 205851 .

Preferably such area is further extended to a position below the housing and extending to an area appropriate for contact by the index finger of a right-handed user in some positions of use of the hand piece.

Preferably the detector means comprise a pair of transistors coupled as a Darlington pair biased to change from having a substantially non-conducting output to a conducting output upon a drive signal resistance being coupled across emitter to base of the input of said Darlington pair.

It can be said perhaps that what has been discovered is that the hand piece is arranged so that it is sensitive to the contact thereon of an appropriate portion of the shearer's hand which can be applied or lifted as appropriate then the shape of such portion can conform to the conventional shape of a hand piece, negligible additional weight or change in balance will be necessary to the hand piece and it is therefore possible to provide a hand piece that is to all intents and purposes substantially the same with respect to physical characteristics as a conventional hand piece as presently used.

However, when such appropriate signals are connected to a stop or drive responsive connection, the shearer can either voluntarily stop the drive to the hand piece by lifting the appropriate portion of the hand relative to a remainder portion or where the appropriate portion of the hand is the thumb, lift such thumb as compared to the remainder of the hand and this will effect a stopping of the drive to the hand piece.

It will be apparent that such an arrangement is appropriate not only for the conventional overv"J — 205851 6. coupling assembled for shearing hand pieces but it can also be used for electrically driven portable hand pieces or for drives effected by a flexible shaft.

Where such sensitivity to the position of a shearer's thumb is achieved by reference to electrical conductivity changes, it is a surprising discovery that in the conditions applying in the shearing of sheep, including a substantial quantity of perspiration which can be considered as relatively conductive, and many other materials including debris arising from the fleece of a sheep, but even in this situation, the use of two relatively insulated members having the relative resistance therebetween changed significantly by contact or otherwise of the hand of a user still provides an effective signal for effecting a stop or drive connection.

This perhaps is especially the case where it is considered that perspiration might stay in contact with the relative members and cross between the respective members but it has been found surprisingly inpractice perhaps because of the constant wiping of one's surface by the perhaps thumb of the shearer that such shorting out of the relative surfaces does not seem to occur.

The invention in another form therefore could be said to reside in equipment useful for shearing purposes having a hand piece for the control of a comb and cutter the equipment being characterised in that there are provided means adapted to co-operate with the hands of the shearer holding the hand piece to provide, upon a change of position of at least a portion of the shearer's hand an electrically significant change, and electrical conductors with the hand piece to connect such electrically significant change to control apparatus to effect a stop or drive signal. 205851 7.

Preferably equipment of the type described is further of the type wherein a flexible shaft within a first down tube is provided, a second tube and shaft between the first tube and shaft and the hand piece is further provided, the equipment then being characterized in that there is further provided electrical connection means between the hand piece housing and the first down tube, and a solenoid adapted to, in response to a stop or drive signal initiation conveyed through said electrical connection means, to disconnect or connect said interconnecting shafts to a rotating drive.

Preferably in such an arrangement the interconnection includes mutually engagable wheels adapted when interconnecting to be held together effecting a rotational drive by friction between the respective wheels.

The invention in another form can be said to reside in a touch sensing type switch located on the hand piece to effect a mechanical engagement of a drive mechanism when the switch is touched.

For a better understanding the invention will now be described with relation to a preferred embodiment which shall be described with the assistance of drawings in which FIG. 1 is a perspective view of a shearing hand piece according to the preferred embodiment, FIG. 2 is a perspective view of the hand piece as is shown in FIG. 1 in this case with a hand of a user showing an appropriate holding position for the right hand of a user, FIG. 3 is a underneath perspective view of the same hand piece as is shown in FIGS. 1 and 2 shown however from a view which is below the hand piece but shows an alternate holding position for the right han4.;^0;f^-ja:.;U^er1CE with respect to the hand piece, 3 1 OCT 1986 , 4^ ' received 205851 8.

FIG. 4 is a side view of the same hand piece as is shown in FIGS. 1, 2 and 3 showing a shape of a first portion of the outer surface of the housing of the hand piece and there is also shown in dotted outline an electrically conducting wire connection, FIG. 5 is an enlargement of the connecting joint at the rear of the hand piece in FIG. 4 especially showing engaging annular rings to effect with rotational freedom transfer of electrical voltage, FIG. 6 is a cross-sectional view of a portion of the outer end of the second tube as shown in FIG. 4 at the furthermost right hand side, FIG. 7 is a slightly schematic view of the circuit being used according to the preferred embodiment, and FIG. 8 is a side elevation of a complete equipment assembly according to the preferred embodiment.

Referring in detail to the drawings and especially to FIGS. 1 through 4, there is shown equipment for shearing especially sheep but not exclusively so which includes a hand piece 1 which in a conventional manner includes a housing 2, a canb 3 and a cutter 4 which is caused to rotate in oscillatory manner. A rotational drive for the cutter 4 is effected through interconnecting gears at 5.

The housing 2 is shaped as is shown including a central bulbous portion 6, a rearward less bulbous portion at 7 and a forward less bulbous portion at 8.

The shape is conventional and is appropriate for comfortable support- by the hand of a user for shearing purposes.

The external surface of the housing 2 is generally covered by a fibrous material called felt.

N.Z. iV-TENT orrscs 1 2 MOv' 1986 RECEIVED 2058 9.

The housing 2 is comprised in the main of metal which is electrically conductive.

The shape is further such especially by reason of the bulbous central portion 6 that a most comfortable position for a holder is to have the hand having the more bulbous portion central most and therefore especially with a right handed user holding the hand piece with the right hand, the thumb as shown at 9 will most readily be located at a forwardmost left hand side of the housing 2.

According to this embodiment then, there is provided a first portion 10 of the outer surface of the housing 2 which is electrically insulated from the remainder of the housing the location and shape of such said portion is generally of oval shape with an extension extending below the forward portion of the hand piece to a position almost mid-way below the hand piece especially as shown in dotted outline in FIG. 3.

The first portion 10 is comprised in the preferred embodiment of a sheet of metal especially brass which is supported with respect to the housing by an expoxy bed thereby effectively insuring such insulation.

The shape and location is generally such as is shown in the drawings which is such also that in most cases of use by a right handed user, the thumb 9 can be voluntarily lifted or reapplied to make contact with the outer surface of the portion 10 during all such time otherwise being able to comfortably support the hand piece by the remaining fingers and palm of the hand and otherwise providing continuous contact between such other portions of the hand and at least the outer surface of the remainder of the housing 2. " 205351 .

Electrical connections are provided in positions not shown in the drawings, there being located behind the metal sheet of portion 10, two transistors connected as a Darlington pair in the arrangement as is shown in FIG. 7, the transistors being shown as conventional NPN type as shown in the embodiment these being each of a type DS 548 and there being provided additional base to emitter series resistance of 10,000 ohms.

With an appropriate voltage supplied in accord with the rating of such transistors, it has been found that the difference in resistance between the portion 10 in the hand piece and the housing when a hand connects across these as compared to when the hand does not connect across these is sufficient to effect a substantial difference in output conducting status of transistor 2.

The result is to provide an adequate change in current through relay coil 11 which in turn is coupled in a manner not shown to connect through contactors a major current supply through a solenoid to effect a drawing in of rod 12.

In the circuit there is an appropriate direct current supply 13 and a diode protection across the relay coil 11 shown at 14.

In the embodiment, the two transistors T1 and "il as shown in FIG. 7 are embedded behind the metallic sheet 10 so that the electrical connections from the hand piece carry the amplified voltage or current appropriate to activate relay coil 11 and of course effect a holding in of the solenoid effecting control rod 12. 2058 ii.

The hand piece 2 is rotatable about its own lengthwise axis and to enable a connection at least for one side of the electrical connection to pass effectively from the hand piece to at least the second down tube at 14 there are provided two brass annular rings at 15 and 16, the ring 15 being of convoluted shape so as to provide maintenance of pressure against the planar shape of ring 16.

In this way these two members act as contacting slip rings to convey the electric signal across the rotating joint.

Flexible wire 17 conveys the signal from slip ring 16 through to a next rotatable joint at 18 which is in the same arrangement including two slip rings as at FIG.

. In FIG. 8 showing the joint, this is not shown in detail the drawing here being somewhat schematic but the arrangement is the same as at FIG. 5.

As is conventional in arrangements of this type, the hand piece has an interconnecting slide portion at 19 which has electrical connections by reason of a first tongue on the member 19 sliding across and being in electrical contact with a second contact at 20.

The first down tube is likewise arranged at 21 and has a similar electrical contact so that there is electrical communication between an upper part of the down tube 22 and the lower removable portion 21.

The drive means for the comb and cutter of the hand piece 2 is effected by a drive motor 24 driving a first 205851 12. friction wheel 2 5 which is engaged by a friction take off wheel 26 which in turn drives a shaft 27 which passes through the appropriate down tubes 22 and hence through the other tube to the hand piece.

The friction take off wheel 26 is supported by a frame 28 which is supported in such a way under spring pressure such that by reason of the rotational position of a cam 2 9 the frictional take off wheel 26 will either be held away from making contact with the friction surface of wheel 25 or it will be allowed under spring pressure to maintain such frictional engagement.

The position of the cam with respect to its rotational relationship at 29 is governed by level 30 which in turn is governed by push rod 12 which is in turn governed by a solenoid, which is not shown, activated by reason of the conducting character or otherwise available through the respective electrical conductors and especially the conductors operated through influence of the relay coil 11.

A factor of relevance in relation to a conventional arrangement includes the fact that the drive to the hand piece when viewed from behind the hand piece is clockwise so that relative turning reaction caused to the hand piece if left on a supporting surface is such that the hand piece will turn to lie once again when viewed from behind on its right hand side.

The positioning of the first portion 10 therefore on the left hand side reduces the possibility of accidental electrical connection occurring where for instance there is wet sheep wool onto which the hand piece might rest and be thrown by reason of reaction.

N.Z. PATENT OFFICE 12 NOV 1986 RECEIVED 13.

The advantage of the arrangement described is that the hand piece 2 is substantially unaltered in either weight or shape from a conventional hand piece and is therefore equally generally balanced for best use by a shearer.

However, the shearer can at any time by voluntarily lifting his thumb stop the drive connection to the hand piece or if he discards the hand piece at all, this is then no longer obtaining a drive connection.

A feature of such arrangement is also the fact that the hand piece will therefore not heat as much.

The touch control switch has been described with relation to a mechanically driven shearing hand piece.

In a further embodiment, the same contact portion is provided where the connection is to an appropriate electronic switch effecting a stopping or starting of the electric drive where the electric drive is either with the shearing hand piece or is connected thereto by a flexible cable.

It is not intended in the broader concept of this invention to limit the invention to simply that case where there is electrical communication caused by relative contact between conducting surfaces.

It is envisaged that an important aspect relates to the appropriate location of a surface which does not hinder the use of the shearing hand piece while at the same time provides significant safety and control. 20585 i4.

Such techniques as providing a pneumatic flow through apertures associated with a similar locality to the said first portion has been considered according to a broader concept of this invention.

There are generally therefore to be seen tremendous advantage in safety while maintaining an apparatus that is effective in the conventional way for use.

N.Z. PATENT OTFsCF 20S851 .

Claims (13)

WHAT WE CLAIM IS:

1. Equipment for shearing of a type including a hand piece with a comb and cutter, and drive means to effect a reciprocal cutting action between the comb and cutter, a housing for the hand piece having a member or members providing an outer surface of a shape appropriate for a user to hold and use the hand piece, the equipment being characterized in that there is a first portion of the said outer surface of the hand piece and a second portion of the outer surface of the hand piece defining a different portion from the first portion of the outer surface, the location and shape of the said first portion with respect to the remaining portion of the outer surface of the hand piece being such that during conventional use of the hand piece, a portion of the hand of the user can be continuously kept comfortably against some part of the first portion, but such portion of the hand of a user can be voluntarily lifted from such contact at any time during such use, and means adapted to be responsive to the status of such contact so as to provide an electrical stop signal when such contact is broken and an electrical drive signal while such contact is being maintained.

2. Equipment for shearing as in claim 1 further characterized in that the second said portion is in such a position that the hand of a user will maintain contact with such outer surface of the second portion during all conventional usage.

3. Equipment for shearing as in either of claims 1 or two wherein the stop and drive signals are a selected change of resistance between the said first portions and the said second portions of the outer surface of hand piece. N.2. PATENT OFFICE 12 MOV 1936 RECEIVED 205851

16. A. Equipment for shearing as in any one of the preceding claims further characterized in that the said second portion of the outer surface of the hand piece comprises substantially all that outer surface of the housing not otherwise comprised in the first portion.

5. Equipment for shearing as in any one of the preceding claims further characterized in that there are detector means included whereby the stop and drive signals are used to provide an output as an electrical voltage in the case of the stop signal which has a voltage significantly differing from the voltage in the case of the drive signal.

6. Equipment for shearing as in the last preceding , claim further characterized in that the detector means are located with the hand piece, and electrical conductors convey the output to means responsive to such output to effect a starting or stopping of drive to the hand piece.

7. Equipment for shearing as in any one of the preceding claims wherein the first portion contains a member having an outermost conductive surface insulated from the remainder of the housing.

8. Equipment for shearing as in any one of the preceding claims further characterized in that the first portion has a location and covers an area conventionally contacted by the thumb of a right handed user.

9. Equipment for shearing as in the last preceding claim wherein a further area is covered by the first portion which area extends below the housing appropriate for contact by the index finger of a right handed user in some positions of use of the hand piece. 17.

10. Equipment for shearing as in claim 5 further characterized in that the detector means comprise a pair of transistors coupled as a Darlington pair biased to change from having a substantially non-conducting output to a conducting output upon a drive signal resistance being coupled across emitter to base of the input.

11. Equipment for shearing as in any one of the preceding claims further characterized in that the drive means for the comb and cutter is of a type including a flexible shaft within a first down tube, a second tube and shaft between the first down tube and shaft and the hand piece, the further characterization being that there are provided electrical connection means between the hand piece housing and the first down tube, and a solenoid adapted to, in response to a stop or drive signal initiation conveyed through said electrical connection means, to disconnect or connect said interconnecting shafts to a rotating

12. Equipment for shearing as in the last preceding claim further characterized in that the interconnection includes mutually engaged wheels adapted when interconnecting to be held together effecting a rotational drive by frictional engagement.

13. Equipment for shearing substantially as described in the specification with reference to and as illustrated by the accompanying drawings. drive. WEST-WALKER, McCABE N_Z.FATL-fv- pcr: ATTORNEYS FOR THE APPLICANT