GB2097940A

GB2097940A - Rotary viscometer

Info

Publication number: GB2097940A
Application number: GB8212998A
Authority: GB
Original assignee: VISCOMETERS UK Ltd
Current assignee: VISCOMETERS UK Ltd
Priority date: 1981-05-05
Filing date: 1982-05-05
Publication date: 1982-11-10

Abstract

The rotary driving shaft (7) of a viscometer is connected to a measuring spindle (1) by easy of a quick release adapter (4-6). The quick release adapter (4-6) can be connected to the spindle (1) or a second adapter secured to the measuring spindle (1) by way of a spring clip (6) engaging a circumferential groove (2) on the spindle (1) or second adapter, a flat (3) on the spindle or second adapter cooperating with a rivet (5) extending radially inwardly of the sleeve (4) to provide the rotary connection. The quick release adapter may comprise an O-ring in the inner wall of sleeve (4) which grips the measuring spindle (1) to provide the rotary coupling. <IMAGE>

Description

SPECIFICATION Improvements in or relating to viscometers and releasable connectors According to one aspect of the present invention, there is provided a viscometer, comprising a measuring member, a rotary driving member, and connecting means releasably connecting said measuring member to said driving member in such a manner that said measuring member is supported and rotatable by said driving member, the connection of the measuring and driving members to each other involving a relative motion therebetween which is at least mainly linear.

According to another aspect of the present invention, there is,provided an adapter for connecting a rotary driving member of a viscometer to a measuring member thereof, comprising an internally threaded bore at an axial end of the adapter for screwing onto an internally threaded stub of the driving member, and a- quick- connection and-release connecting means for connecting the measuring member to the driving member in such a manner that the measuring member is supported and rotatable by the driving member.

According to a further aspect of the present invention, there is provided in combination, a sleeve, a spindle which is received co-axially in said sleeve and is formed with a cutaway at one side thereof and with a detent, a clip mounted on said sleeve and arranged to engage releasably said detent to restrain the sleeve and the spindle against axial movement relative to each other, and a fastening element mounting said clip on said sleeve and extending through the wall of said sleeve into the interior thereof to protrude into said cut-away to restrain the sleeve and the spindle against rotary movement relative to each other.

In order that the invention may be clearly understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a fragmentary sectional side elevation of a rotary driving shaft, an adapter, and a measuring spindle of a viscometer, Figure 2 shows an underneath plan view taken on the line Il-Il of Figure 1, Figure 3 shows a fragmentary side elevation of an adapting spindle and a measuring spindle usable in place of the measuring spindle of Figure 1,and Figure 4 shows a fragmentary sectional side elevation of a modified version of the adapter and measuring spindle of Figure 1.

Referring to Figures 1 and 2, the viscometer is of a conventional kind with a rotary driving shaft 7 of which the output end is formed with an externally threaded stub 7' onto which can be screwed an adapter sleeve 4 formed at its upper end with an internal screwthread 4' to co-operate with the stub 7'. A spring clip 6 formed with a circular hole 6' can have its lower end displaced radially and resiliently to bring the hole 6' into a position coaxial with the sleeve 4. A fastening rivet 5 attaches the clip 6 at its upper end to the outside of the sleeve 4, the rivet 5 extending through the wall of the sleeve 4 into the interior of the sleeve. The shank of the rivet 5 terminates short of the axis of the sleeve 4. A measuring spindle 1 is provided, having at its upper end zone a machined peripheral groove 2, and a machined cut-away 3 at the uppermost extremity of the spindle 1.The cut-away does not need to be formed by removal of material, but could be formed in some other way. However, it leaves a flat, diametral axial surface. Just below the groove 2, the spindle 1 carries a collar 1' fixed thereto.

Referring to Figure 3, a conventional measuring spindle 10 is formed at its upper end with an internally threaded bore (not shown) into which can be screwed an externally threaded stud 9' at the lower end of a spindle 9, or the stub 7'.

The upper end of the spindle 9 is formed with a cut-away 3, while the middle of the spindle 9 is formed with a peripheral groove 2, there extending between the groove 2 and the stub 9' a collar 8 fixed to the spindle 9.

In the conventional viscometer, various conventional measuring spindles, such as the spindle 10, can be screwed to the driving shaft 7.

However, this has the disadvantage that the connection of the two together takes a relatively long period of time and meanwhile the conditions, particularly the temperature, of the fluid the viscosity of which is to be measured, can undergo a significant change. Similarly, if it is required to keep the spindle in a vessel containing the fluid to be measured and to fit the spindle to the driving shaft without removing the spindle from the fluid, the screwing of the two parts together can be a relatively clumsy and time-consuming operation owing to the bulk of the parts associated with the spindle and with the driving shaft.

According to the present invention of the invention, there is provided the adapter 4 to 6.

This adapter is screwed to the output shaft 7 in good time before the measuring operation needs to be carried out. When the measuring operation needs to be carried out, the clip 6 is displaced resiliently to bring the hole 6' into line with the internal bore of the sleeve 4 and the spindle 1 is inserted into the lower end of the sleeve, the clip 6 is released, and the spindle 1 continues to be inserted into the sleeve until the clip 6 engages in the groove 2 to prevent further axial movement of the spindle 1 relative to the sleeve 4. In this condition, the rivet 5 protrudes into the cut-away 3 to restrain the spindle 1 and the sleeve 4 against rotation relative to each other.It will be appreciated that, before the clip 6 engages in the groove 2, a small amount of turning of the spindle 1 about its own axis relative to the sleeve 4 may be necessary to bring the cut-away 3 to a position to receive the rivet 5. The collar 1' is provided to prevent excessive insertion of the spindle 1 into the sleeve 4 and to control the linear position of the spindle when it is resting in a sample container.

It may in some cases be desired to continue to employ the conventional measuring spindles, such as 10. In that case, before it becomes necessary to carry out the measuring operation, the adapter spindle 9 is screwed onto the measuring spindle 10. When the measuring operation becomes necessary, the measuring unit 9, 10 so formed has the upper end of its spindle 9 inserted into the adapter 4--6 on the driving shaft 7. The collar 8 limits the extent of insertion of the spindle 9 into the sleeve 4 and also the extent of screwing of the spindle 9 onto the spindle 10.

When it is desired to release the spindle 1 or 9, the spring clip 6 is simply displaced to bring its hole 6' to a co-axial condition, whereupon the spindle 1 or 9 will withdrawn immediately.

In the modified version shown in Figure 4, the adapter 1 2 again comprises a sleeve which is internally screw-threaded at its upper end to cooperate with the screw-threaded stub 7'. In its lower end zone it is internally provided with a peripheral O-ring 13. The measuring spindle 11 has fixed thereto a collar 1 1'. On axial insertion of the spindle 11 into the closely fitting adapter 12, the spindle 11 is peripherally resiliently gripped by the O-ring 13 to such an extent as to prevent the spindle 11 from falling under its own weight from the adapter 12 during normal use and to prevent the adaptor 12 from turning relative to the spindle 11 during normal use.The collar 11' prevents excessive insertion of the spindle 11 into the adapter 12 and controls the linear position of the spindle when it is resting in a sample container. The spindle 11 has an angled lead-in 14 at its upper end. In an alternative design, the adapter 12 can be made of a suitable elastic material, e.g. Tufnol or nylon, and have an internal diameter to grip frictionally the spindle 11 (or the spindle 9 is desired), so that the O-ring 13 can be dispensed with.

To release the spindle 11 from the adapter 12, it is simply necessary to pull the spindle 11 down axially relative to the adapter 12.

In the examples 6f the invention described with reference to the drawings, a conventional driving shaft 7 of a viscometer is employed. It is nevertheless feasible for the viscometer output shaft to be re-designed to take the form of the lower part of the adapter 4 to 6 or 12, so that the adapter itself can be dispensed with.

The examples according to the invention described above have the advantage of enabling the measuring spindle to be connected quickly and accurately to the driving shaft of a viscometer. The invention is particularly applicable in cases where certain conditions, for example a high risk of temperature change, make it necessary to take the minimum time from beginning to fit the spindle to actually taking the viscosity measurement. It is also applicable where it is necessary or desirable to keep the spindle in the vessel containing the fluid of which the viscosity is to be measured and to fit the spindle to the driving shaft without removing the spindle from the fluid.

Claims

1. A viscometer, comprising a measuring member, a rotary driving member, and connecting means releasably connecting said measuring member to said driving member in such a manner that said measuring member is supported and rotatable by said driving member, the connection of the measuring and driving members to each other involving a relative motion therebetween which is at least mainly linear.

2. A viscometer according to claim 1, wherein said connecting means comprises an element displaceable transversely of said motion and a groove arranged transversely of said motion for receiving said element.

3. A viscometer according to claim 2, wherein said element is resiliently displaceable as aforesaid.

4. A viscometer according to claim 3, wherein said element forms part of a spring clip.

5. A viscometer according to claim 4, wherein said connecting means comprises an adapter sleeve on which said spring clip is mounted, said element is situated just beyond one end of said sleeve, and said sleeve is formed at its other end with internal screwthreading for co-operation with external screwthreading of said rotary driving member.

6. A viscometer according to any one of claims 2 to 5, wherein said measuring member is formed with said groove.

7. A viscometer according to claim 6, wherein said measuring member is formed with a flat arranged to co-operate with a protrusion of said connecting means to deter rotation of said connecting means relative to said measuring member.

8. A viscometer according to any one of claims 2 to 5, wherein said connecting means comprises an adapting member formed with said groove.

9. A viscometer according to claim 8, wherein said adapting member is formed with a flat arranged to co-operate with a protrusion of said connecting means to deter rotation of said connecting means relative to said adapting member.

10. A viscometer according to claim 7 or 9 as appended to claim 5, wherein said protrusion comprises a pin whereby said clip is attached to said sleeve.

11. A viscometer according to any one of claims 6 to 10, wherein the member formed with said groove has an abutment fixed thereto just beyond said groove in the longitudinal direction of said motion away from said driving member.

12. A viscometer according to claim 1, wherein said connecting means comprises an adapter sleeve formed at one end thereof with internal screwthreading for co-operating with external screwthreading of said driving member.

13. A viscometer according to claim 1 or 12, wherein said connecting means comprises a friction fit connection.

14. A viscometer according to claim 13 as appended to claim 12, wherein said sleeve has mounted internally thereof an elastic ring in which said measuring member fits frictionally.

1 5. A viscometer according to claim 13 as appended to claim 12, wherein said sleeve comprises elastic material and said measuring member fits frictionally therein.

1 6. A viscometer according to claim 14 or 15, wherein said measuring member is provided with an abutment limiting the degree of insertion of said measuring member into said sleeve.

1 7. An adapter for connecting a rotary driving member of a viscometer to a measuring member thereof, comprisin,g an internally threaded bore at an axial end of the adapter for screwing onto an internally threaded stub of the driving member, and a quick-connection and-release connecting means for connecting the measuring member to the driving member in such a manner that the measuring member is supported and rotatable by the driving member.

1 8. A sleeve, a spindle which is received coaxially in said sleeve and is formed with a cutaway at one side thereof and with a detent, a clip mounted on said sleeve and arranged to engage releasably said detent to restrain the sleeve and the spindle against axial movement relative to each other, and a fastening element mounting said clip on said sleeve and extending through the wall of said sleeve into the interior thereof to protrude into said cut-away to restrain the sleeve and the spindle against rotary movement relative to each other.

1 9. A viscometer, substantially as hereinbefore described with reference to Figs. 1 and 2, or Fig. 3 or 4, of the accompanying drawings.