GB2355639A - Scraper cleaning system - Google Patents

Abstract

The cleaning system uses a drive unit 10 to wind rope 38 on and off a capstan 26 whereby scrapers 42a,44a attached to the rope 38 are pulled up and down a floor of an animal housing. The drive unit can pull the rope in either direction. The rope 38 is pretensioned about an extendable pivot member 14. There are also means to detect slippage of the rope 38 on the capstan 26.

Description

2355639 SCRAPERS This invention relates to cleaning apparatus and

particularly scrapers. More particularly, though not exclusively, this invention relates to a scraper system for collecting and removing waste (muck) such as manure and/or slurry from an animal housing or the like.

Herein the term "animal housing" is intended to mean any research or agricultural establishment, abattoir, market premises, industrial premises or farm premises or the like, where animals are kept or pass through.

Collection and removal of manure and slurry from animal housings is essential to maintain the health of beasts. If, for example, cows are unwell, this adversely affects milk productivity. In a dairy herd mastitis is a major problem. Mastitis is an infection of the udder and leads to decreased milk yield, rejection of collected milk, additional vet costs, increased cell counts, higher cull rates and extra time to treat and cure infected animals.

Keeping the cow environment clean and dry is therefore an essential element in the control of mastitis. To prevent mastitis scrapers are used to clear the passageways in cow housings.

In the milking environment, the cubicle passages and feed stands should be scraped at each milking before the cows return from the milking parlour. As the teat sphincter takes twenty to thirty minutes to close after 2 mi Iking, h c-, s K' o _F i n f e c t i o n s h--gher during t h i s period.

Iner- 2-s therefore an e',;er greater need fcr a clean hoidirg area Immediately posi, Iq i k 4 - ng. Keeping cows clean- aft-er ml_;_king has the advar-,,4e that there is.--ess muck taken -in T-_ he -ubicle bed on hle cows feet Lamenes- further ma -j c i- cause of loss in productivi-cy cows. A clear - __nvironmenc, including clean access p_ssages for the cows, feduces the infectdous conditions in wl-lch lameness can oc":ur.

Regular scraping o.- passages t,, remove dung and urine is also essential-, to reduce the of animals slipping and injurinq -L---mselves. The clean passages are therefore safer, healt-ier, and are a more acc(ptable place for stock and stockmen.

Ait-ougl'n' trac--or mounted scrapi-s can be used and can be taken fr_= one cow shed to aiio-'Iher, they are not automatic and requ4re the use of a tractor. Few farmers can afford the -..ime to scrape pass;.ges more than twice a day.

f=---her d1sadvantage is -_.hat scraping witha tractor requ_'Ire'-S the cows to be exclAded from the passages.

There is also a -isk o_-" damage to cu.-)-,.cie divisions, gates, doors and other s--ructural componer-s with the movement of the tractor..Ianual scraping thereffore takes up precious time of the tal-mer which can bc, loetter used on other management du-_ies.

Three t',:ces ofL automatics sc--al:)ers are known.F-'L--st 3 of all there are chain systems which use two scraper blades linked by a chain circuit which run the length of passages passing round idler pulleys at the end of the passages and across the end of a unit. Secondly, there are hydraulic systems which use a ram in each passage to reciprocate a channel with drive teeth along the passage length.

Finally, there are rope scrapers which require a winch in each passage to pay on and pay off rope along the passage length using two winches, two motors and two gearboxes as well as a double controller.

A common problem with these known automated systems is that the chain or channel which is located in the middle of the passage presents a fairly rigid obstruction and is a danger to the stock. Chains and channels are therefore not cow-friendly. There are also worries concerning the effect of the chain or channel on cows feet, and in particular bruising. Tails, new-born calves or collapsed cows may also be injured by the rigid chain.

It is an object of at least one aspect of the present invention to obviate or at least mitigate one or more of the aforementioned problems.

It is a further object of at least one aspect of the present invention to provide a scraper mechanism using a single drive unit.

It is yet a further object of at least one aspect of the present invention to provide a scraper mechanism which 4 does not use n.

Accordlin:j -o a first, aspe Ct of the present --inventJLon, e there Js provaed a: cleaning system including a driv and an elon-g-----o member, the drive 11-init being capable of driving the I L e member si ibs tant iL al I y along a _=ga longitudi,nal of the elongate 't"-mber in either axLal direction.

Preferabiv, the cleaning syster[ is a scraper system.

Preferab_V, t. fie drive unit cj,---.-ps a portion of --he elongate member, i_n use, by friction.

Pre f era bi the elongate membea is a rope or cable.

-1, 4-he elongate membei- is a rope made from a Preferably synthetic f"ID--e. and preferential-ly polyester, e.g. oi: a diameter of I,'-__2=.

It is even,rore oreferred if' th( elongate member is an endless rope, e.q. in the form of a loop.

The drIve means may include:i motor operationa---ly connected, e.,-_. -,,-.,-a a gearbox, to a c:apstan.

Accordin_- --o a second asDect of the oresent invention, there is prov ---d-2d a, drive unit for U,;E in a cleaning sVstem such as a system, the driVE unit having means to drive an elonqat_e member substantial.--y along a longitudinal axis of the Iongate member in each of two axial directions.

Accordin_j to a third aspect of the present invention, there is prov_-,-,.-J a method of cleaning, e.g. scraping, a substantially planar surface comprising the steps of:

providing a scraper system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in either axial direction, the scraper system also including at least one scraper member attached to the elongate member; and driving the elongate member by means of the drive unit so as to cause the at least one scraper member to move.

In this way the at least one scraper member may be caused to move back and forth between first and second positions.

Preferably, the planar surface is a portion of floor.

Advantageously, the floor comprises at least a portion of an animal housing or the like.

Preferably, manure/slurry or the like scraped from the surface is clumped into a pit(s) formed in the surface.

According to a fourth aspect of the present invention there is provided a cleaning system including a drive unit capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided means for tensioning the elongate member.

The cleaning system may be a scraper system.

6 Advanta-e--)us-iy, -here are provided means to pretenzion or further tenslon tne elongate merrher.

The pretens-Loning means may b-', provided a-- or near _he/one of _--leaning -_lemen-s ana mav comprise a ratchet me c h a n i sm.

Pref erah1%,', -,_ne means for te--,sioning the eLongate member compr1ses a pi-uo.-ab_le m.ember.

Convenlen-,_ -I',/ drive u n i. includes means for driving the o n g a t e member suhtantiallv along the longitudinal axis Lhereot: in eithe-- axial direction.

Preferab'-,', tle pi Vo- membrr is substantially symmetrical abc-At a pivot point.

Preferablv, the pivotable member carries first and second guide ',T'Ileeis aL each of -'rst and second ends -thereof.

Preferabiv, -,-here are provided means to extend a length of the p_vot member.

It is fu_---her p-referred tha, --he pivotable member 1-n-ludes a firs-_ member resiliently b;ased. from a first end of a pivot body.

It is aisc fu_-ther preferred t'na-, t-he pivotable meml--)er includes a seco,_d member resilienti., biased from a sec(.-nd end of the pivoz_ body.

Preferabl,, the pivo--able member is provided below a caostan of th Unli.

Preferab-,.,V '--hE- capstar. and fi-st and secord gu_de 7 wheels are disposed at corners of an equi'ateral triangle.

According to a fifth aspect of the present invention, there is provided a drive unit for use in a cleaning system such as a scraper system capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided means for tensioning the elongate member.

According to a sixth aspect of the present invention is provided a method of cleaning, e. g. scraping, a substantially planar surface comprising the steps of:

providing a scraper system including a drive unit capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided is means for tensioning the elongate member, the scraper system also inc'Luding at least one scraper member attached to the elongate member; tensioning the elongate member by means of tensioning means; and driving the elongate member by means of the drive unit so as to cause the at least one scraper member to move.

According to a seventh aspect of the present invention there is provided a drive unit for use in a cleaning system such as a scraper system capable of driving an elongate member substantially along a longitudinal axis of the - i.- 1, and means -for e ongate mei-.Le- J_- at: leas-L one -1--rec-,ion, detecting silpuaae of the elongate member relat-,ve to the dri-ve unil c.

Preferall)P,2, E!-e drive unit _3 _'apable of selectively drIving the -_'Lcnqa-_e member i r t h e r of two a:,iai d-4--ections.

It is preferred that --,-e drive unit includes drive means %,;,ic_'h Mav 1--iclude a -_,_-pstan for driving 7he elongate membe_-.

Preferabl-, _-he capstan inclu-d.-; a helical path along which the elonq-a-L-e member may pass.

Preferab-'l-v, tle detecting means include means -for detecting movement of the elongate member and means for detecting rot-,-t-,_on of the capstan.

Advantaqec)._s'_,,,, there are pr,,D-.;-ded means to compare movement of roi:,e and the rotation, of the capstan, e.g.

suitable elect-r-)n1c means.

Preferablv tnere are provided means -o control rotation of caostan such tha-- Lhe direction and/or speed of ro-,auicr of the capstan may be changed if and wner) slippage is Accordinc. --c) an, eighth aspect o! the present inventLon there is pro-,,.-ir_ied a c1eaning sy,--;t-,n such as a scralper system includdri--1, a drive unit and a, elongate member, --he drlve unit be'_nq --apable of driv-n:j the elongate meml ber substantlally -i'=q a longitudinal axis of the elongate 9 member in at least one axial direction and the system includinQ means for detecting slippage of the elongate member relative to the drive unit.

According to a ninth aspect of the present invention there is provided a method of cleaning, --.g. scraping a substantially planar surface comprising:

providing a scraper system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in at least one axial direction, and the system including means for detecting slippage of the elongate member relative to the drive unit; driving the elongate member in the at least one axial direction by means of the drive unit; monitoring slippage occurring between the elongate member and the drive unit; and if slippage is detected, controlling the direction and /or speed of drive of the elongate member appropriately.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:

Figure I is a perspective view of a drive unit for a scraping system according to an embodiment of the present invention; Figure 2' j.H, -sectional side -,.,,i'-ew of the drive unit of Fiaure i; Figure _3 is a front view of -h-I drive unit of Figu--e 1; ana Fiqures zi.a, -4b and 4c show schemat'-Ic representatiDns 0 4z I L t h r e- I o 1- t s of scraper systems according to embodiments o- the present-- inVEntion.

Shown in -;gures 1, 2 and 3, tiiere is a single drive --ic-s gnated 10 accord-ng to an embodiment of unit, generall.,, the present e n i on and i n c I, u d i n g a rame 12; an automatic rope --ensioner 14; two rope guide wheels 16, L8; two tensioner return springs 20, 22; a motor 24; a capstan 26; a gearbox 2.-; a belt pulley 30 (and a rope s'Lip dri,,en wheel mechanism 32.

is All corrpoi--ents of the drive 10 are mounted on the frame 12. TjI--e -r-ame 12 is construc-E-ed from welded metal a wood stru, ---ture -ubing. (Alt; mav be used). As shown in Figure! although three verticai inclined portions are attached to two substantially 'horizontal portions on each side of t'-e frame 12, any suitabie construction may be used that pr(D,.-,j-de--, a top surface and a region for the automatic rope 14 to extei)d through. The frame 12 is bolted or s-ecured by any other -neans to a floor of an animal housing.

Extendin,--j the frame 12 L.1--iere is '-the automatic rope tens-ione-c The automatic rope tensioner 14 is a 11 longitudinal beam member which comprises a central box member 14a which has a member 14a' extending through the central box member 14a. Attached to member 14a' on either end there are two rope guide wheels 16, 18 each which are freely rotatable. The rope guide wheels 16, 18 each have a channel on an outer annular surface which is used to feed a rope 38 on and off the capstan 26. Attached on either end of member 14a' and the central section 14a, there are spring mechanisms 20, 22 which retain member 14a' within the central member 14a and bias member 14a' towards the central section 14a. A centre of the central member 14a is attached to an axle 34.

Below a top surface of the frame 12 there is a motor 24 The motor 24, for example a 0.37 kW motor which may be electric, diesel or petrol, is connected via a belt pulley mechanism 30 to a gearbox 28 which is situated on the top surface of the frame 12. The gearbox 28 is connected to the capstan 26. The capstan 26 is mounted on a horizontal axis connected to the gearbox 28. Around an annular surface of the capstan 26 there is provided a helical channel forming a guide member 36 which is used to wind a rope 38 on and off the capstan 26. This prevents the rope 38 from winding on top of itself leading to possible slippage.

After the rope 38 winds under the two rope guide wheels 16, 18, the rope runs under rope guides 40,42 on 12 the floor on either side of the drive unit 10.

As shown _Ln Figures 4a, 4b and there are a variety o layouts fr,r s=aping rnechanisms..,'he suf" fixes a, b and -e a--e used F-o de--o same part J-n a dLfferent schema---ic layou- for the s--raping mechanism) - The drivI-C)a, 10b, 10c is used to wind rope 38a, 38b, 38c in eA-'.er direction since ti-le, motor 24a, 24b, 21ic is bL-direct-,-Jna-l The rop('i8a,.38h, 38c is made from any synthe---ic -'ibre such a-c po'-yes--er and has a diameter of -1-4-22 mm.

As shown -in Figures 4a, 4b and -ic, the rope 38a, 38b, 38c may be used in substantially recLangular arrangemen-1--s.

Using these ar--angements allows the passageways of the animal house be scraped.

Tn '- a- -1 FigurE 4a th- Irive unit -0,.: is situated between two corner pulleys 48a-', 48a". Tw:) scraper blades 42a, 44a are shown a scraping cy-Ie starts with each scraper biade 2a, 4 4 a next to Pulley 48a, 48a'', respectively. '1--ids 46a, 4a are also shown which have a pit below them. 1-o co-I'lect collected Tanure and slurry.

An aterna----ive scraping mechanism is shown in Figure 4b where there -ire -four scraDer blades 42-b, 42b' 44b, 4zlb' which work -Ln -1-andem. Scraper blades 42b, 42b' scrape manure and onto grid, 416b ar-,(, scraper blades 44b, 44b' scrape --nan-Ilre or slurry onto grid 47b. When the manure or L's placed on gricis "6b,47b it Ialls into 13 a pit below.

in Figure 4c a further alternative is shown where the drive unit 10c is off-set- from the main scraper operating system.

The use of the scraper systems will now be discussed.

First of all the rope 38a, 38b, 38c is connected around the guide member 36a, 36b, 36c on the capstan 26a, 26b, 26c. As shown in Figures 4a to 4c the rope 38a, 38b, 38c is then connecued around four corner pulleys, 48a' 4 8 a 48a'' 4 8 a 48b' 48b'', 48b''', 48b f r r 48c', 48c' 48c' 48c' The rope 38a, 38b, 38c is then pre-tensioned by using a ratchet type pretensioner (not shown) either on the rope 38a, 38b, 38c or on one of the scraper blades 42a, 44a; 42b, 42b' 44b, 44b'; 42c, 44c which has two sets of jaws gripping the rope 38a, 38b, 38c. The first set of jaws pull the rope 38a, 38b, 38c through a drawbar and on release the second set of jaws then grip the tightened rope 38a, 38b, 38c. This procedure is repeated until a final tension of about 1,500 kgs load is obtained. At this stage the automatic rope tensioner 14 is substantially horizontal. This initial pre-tensioning is required, otherwise the rope will merely stretch. On rotation of the capstan 26a, 26b, 26c the automatic rope tensioner 14a, 14b, 14c tilts away from the horizontal as shown in Figure 3,with further tension being applied to the rope 38a, 38b, 14 r 38c by the puIL-1- cf the capstan 26a, '-b, 26c.

To move scraoers 42a, 44a; 42b, 42b' 44b, 44b; 42c, 44c the rr.ot-or _24a, 24b, 24c is __ed -o rotate the belt z p,u 1 _JI e y 3 0 a, 3 0 L, 3" 0 c h i c h i n -,-,i r n:-auses the gearingin the gear box 28a, 8 b, 28c to rol -,te and thereby a_-so rotate the capsl-ari 26a, 26b, 26c. _i shown in Figure 4a, on this rotat---or,, scraper blade 42a iioves towards grid 46a dragging alonc any manure or slurrv:-,n, the floor. ScraDer blade 44a is d.--laged along the othe side. Scraper blade 44a does not c-c-l-lect manure or slur--,,,, during this pass.

When the capstaii 26 is first)f all rotated in Lhe direction as shown in Figure 3, the automatic rope tensioner 14 -,)iwots on its axle 34 _iue to the extra!Dad being taken ip or, the rope 38. The automatic rope is tensioner 14 pi-vots in this embod-,ment by a maximum of around 30' frorn, thle horizontal. Up-)n this movement, --he member l4a' is --a-ised to move within, the central box member 14a so that on one side o-f member rope guide wheel 16 Eral box membei 14a and on the ot_er abuts againsiL t!-.e cenT side rope gUidE wnee-I 18 extends _c, its maximum dist-ance away from cenLr_-! box member 14a. '--his is shown by -:he T 1 dotted line. _ a u r e 3.

The caps-1:an 26 is usually rotatd so that the rope 38 T_ moves at a o3-3.5 metres:,er minute. When---he scraoer 42a hEts reached the end of passageway and is on Top of the arid 16--a, aria scraper 44;,. abuts against pul.Ley 48a' This leads to an increase in the tension in the rope 38a as the rope 38 can be pulled no further. Although the capstan 26a continues to rotate as before, the rope 38a can be pulled no further. This change in movement of the rope 38a is detected by an increase in motor amperage sensed by a current transformer via a printed circuit board located within the control panel (not shown). At this point if the scraper 42a is on a first (scraping) stroke then the rotation of the capstan 26a is reversed. However, at this point if the scraper 42a is on a second (return) stroke then the capstan 26a is caused to stop; the system will start again after a pre-determined time set by a control clock e.g. a number of hours.

On the change of the direction of the capstan 26a, the automatic rope tensioner 14a pivots in the opposite direction with member 14a' sliding in the other way. This procedure can be repeated as many times as necessary during any period, e.g. up to 24 times a day. The operation can be either started manually or pre-set into the control electronics to start at specific times in the day.

An advantage of the present invention is that if a cow stands in front of any of the scraper blades 42a, 44a; 42b, 42b', 44b, 44b'; 42c, 44c and impedes its travel, this will cause an increase in the tension in the rope 38a, 38b, 38c.

At this point the automatic rope tensioner 14a, 14b, 14c tilts down to increase the tension in the rope 38a, 38b, 38c. This will affect the rate of rotation of the capstan 26a, 26b, 26c which will be detected by an increase in motor amperage. This change of rotation will cause the control panel to either stop the rotation of the capstan 26a, 26b, 26c or actually change its direction to reverse back the scraper blade in contact with the cow.

A further feature of the machine is the motion sensor which consists of a rope slip driven wheel 32a within which is a magnet which pulses a reed switch. If the pulses stop, the machine detects via a printed circuit board that the rope 38a is slipping on capstan 26a. This will cause the control panel to either stop the rotation of the capstan 26a or actually reverse direction depending on which stroke the machine is on. On the first stroke, the capstan 26a reverses before proceeding any further. On the second (return) stroke, the capstan 26a merely stops until the next cycle starts.

A yet further advantage of the present invention is that it is possible to use a partially extensible rope, e.g. a polyester rope by pre-tensioning the rope. If the rope was not pre-tensioned, the rope would merely stretch when initial stretch was applied. A polyester rope will not damage animals feet as opposed to a hard metal chain driven device.

Claims (1)

1. -17CLAIMS

   1. A cleaning system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in either axial direction.

   2. A cleaning system according to claim 1 wherein the cleaning system is a scraper system. 3. A cleaning system according to any preceding claim wherein the drive unit grips a portion of the elongate member, in use, by friction. 10 4. A cleaning system according to any preceding claim wherein the elongate member is a rope or cable. S. A cleaning system according to any preceding claim wherein the elongate member is a rope made from a synthetic fibre such as polyester. 15 6. A cleaning system according to any preceding claim wherein the elongate member is an endless rope such as in the form of a loop.

   7. A cleaning system according to any preceding claim wherein the drive means includes a motor operationally connected such as via a gearbox, to a capstan.

   8. A drive unit for use in a cleaning system such as a scraper system, the drive unit having means to drive an elongate member substantially along a longitudinal axis of the elongate member in each of two axial directions.

   9. A method of cleaning such as scraping, a substantially planar surface comprising the steps of:

   providing a scraper system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in either axial direction, the scraper system also including at least one scraper member attached to the elongate member; and driving the elongate member by means of the drive unit so as to cause the at least one scraper member to move.

   10. A method according to claim 9 wherein the at least one scraper member is caused to move back and forth between first and second positions.

   -19 11. A method according to any of claims9 or 10 wherein the planar surface is a portion of floor.

   12. A method according to claim 11 wherein the floor comprises at least a portion of an animal housing or the like.

   13. A method according to any of claims 9 to 12 wherein manure/slurry or the like scraped from the surface is dumped into a pit(s) formed in the surface.

   14. A cleaning system including a drive unit capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided means for tensioning the elongate member.

   is 15. A cleaning system according to claim 14 wherein the cleaning system is a scraper system.

   16. A cleaning system according to any of claims 14 and 15 wherein there are provided means to pretension or further tension the elongate member.

   17.A cleaning system according to any of claims 14 to 16 wherein pretensioning means are provided at or near the/one of the cleaning elements and comprise a ratchet mechanism.

   18. A cleaning system according to any of claims 16 and 17 wherein the means for tensioning the elongate member comprises a pivotable member.

   19. A cleaning system according to any of the claims 14 to 18 wherein the drive unit includes means for driving the elongate member substantially along the longitudinal axis thereof in either axial direction.

   20. A cleaning system according to any of claims 18 and 19 wherein the pivot member is substantially symmetrical about a pivot point.

   21. A cleaning system according to any of claims 18 to 20 is wherein the pivotable member carries first and second guide wheels at each of first and second ends thereof.

   22. A cleaning system according to any of claims 14 to 21 wherein there are provided means to extend a length of the pivot member.

   23. A cleaning system according to any of claims 18 to 22 wherein the pivotable member includes a first member -21 resiliently biased from a first end of a pivotbody.

   24. A cleaning system according to any of claims 18 to 23 wherein the pivotable member includes a second member resiliently biased from a second end of the pivot body.

   25. A cleaning system according to any of claims 18 to 24 wherein the pivotable member is provided below a capstan of the drive unit.

   26. A cleaning system according to claim 25 wherein the capstan and first and second guide wheels are disposed at corners of an equilateral triangle.

   27. A drive unit for use in a cleaning system such as a scraper system capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided means for tensioning the elongate member.

   28. A method of cleaning, such as scraping, a substantially planar surface comprising the steps of:

   providing a scraper system including a drive unit capable of driving an elongate member in at least one direction substantially along a longitudinal axis of the elongate member, and wherein there is provided -22 means for tensioning the elongate member, the scraper system also including at least one scraper member attached to the elongate member; tensioning the elongate member by means of tensioning means; and driving the elongate member by means of the drive unit so as to cause the at least one scraper member to move.

   29. A drive unit for use in a cleaning system such as a scraper system capable of driving an elongate member substantially along a longitudinal axis of the elongate member in at least one direction, and means for detecting slippage of the elongate member relative to the drive unit.

   30. A drive unit according to claim 29 wherein the drive unit is capable of selectively driving the elongate member in either of two axial directions.

   31. A drive unit according to any of claims 29 and 30 wherein the drive unit includes drive means which include a capstan for driving the elongate member.

   32. A drive unit according to claim 31 wherein the capstan includes a helical path along which the elongate member passes.

   -23 33. A drive unit according to any of claims 29 to 32 wherein the detecting means include means for detecting movement of the elongate member and means for detecting rotation of the capstan.

   34. A drive unit according to any of claims 31 to 33 wherein there are provided means to compare movement of the elongate member and the rotation of the capstan such as suitable electronic means.

   35. A drive unit according to any of claims 31 to 34 wherein there are provided means to control rotation of the capstan such that the direction and/or speed of rotation of the capstan may be changed if and when slippage is detected. 15 36. A cleaning system such as a scraper system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in at least one axial direction and the system including means for 20 detecting slippage of the elongate member relative to the drive unit. 37. A method of cleaning, e.g. scraping a substantially planar surface comprising:

   providing a scraper system including a drive unit and an elongate member, the drive unit being capable of driving the elongate member substantially along a longitudinal axis of the elongate member in at least one axial direction, and the system including means for detecting slippage of the elongate member relative to the drive unit; driving the elongate member in the at least one axial direction by means of the drive unit; monitoring slippage occurring between the elongate member and the drive unit; and if slippage is detected, controlling the direction and /or speed of drive of the elongate member appropriately.

   38. A cleaning system substantially as hereinbefore described with reference to the accompanying drawings.

   39. A method of cleaning substantially as hereinbefore described with reference to the accompanying drawings.

   40. A drive unit substantially as hereinbefore described with reference to the accompanying drawings.

   41. A method of cleaning using a drive unit substantially as hereinbefore described with reference to the accompanying drawings.