GB2500288A - Shaft connector having a non-circular cross-section, the male shaft connector having a biased peg - Google Patents

Abstract

A shaft connector for connecting rotating shafts, the male connector 1 having a mating section 2 with a non-circular external cross-section, preferably a circle with a missing segment; a locking peg 5 moveable between protruding and flush positions and biased to the protruding position; and a shaft mounting section 8 attached to said male mating section 2. An angled portion 17 on the peg 5 causes the peg to be automatically depressed when male and female connectors are joined. Also provided is a corresponding female shaft connector 19, having a cavity to receive male mating section 2 from a corresponding male shaft connector 1, which also has a non-circular cross-section perpendicular to the axis of a shaft to be connected.

Description

C on fleet a

Field of the invention

The invention relates to connectors for conneetiir.g hafts or rods intended to be regularly and releasably coupled to each other and manually--or mechathcaflyth-iven to rotate. their conrtnon axis Such shafts -are typically used to tlean t-unblock conduits such as phimney drains flues and ducts *(eg. aircondftioning or ventilation ro ducts) by aitachthg an appropriate toot to the end of an array of (continuaIy coupledi hafts.Such shafts we usually flexible to enable them to be used in curving conduits, and to allow them to be introduced, into conduits. but they can also. he rigid, dependihg on the particular application of use.

to ackrndrjorArt USPatent6,6g8,8OQdese5 a coupling device fbr shafts of this nature. having a sprvwtased pi3nger in one pat of the coup'er that energes ft-or' &e su face of a male coupling part and that may be depressed by an operator to connect a con-esponding female coupling part Once connected, the plunger is biased by the spring to epgage with a corresponding hole located in the wail of the female coupling part. To disengage the connector; an opet-ator may again push the plunger against the action of its biasing spring, aflowing the two connector parts to be separated.

The rese.nt invention is an improvement on this type of connector and seeks to address some shortcoming of this known device. Firstly, it has been found that Connection of two shafts fitted with these couplers can be a little dIfficult because the plunger needs to be depressed by the on rator in order to allow the connection to be made. The shafts are ofteruesed in situations where the operator wears gloves, and the necu 10 depress the olu rgr n-th a g1oved hand ir orde' to naki a Connection can make it dIfficult to quickly add a further thaft onto-the shaft array. Also the shafts are often used in conditions of low light, a dirty envlrcm-nen{, and poor access.

Cdnnection of one shaft to another requires that, not only must the plunger he depressed to make the connection1 but the shafts must be correctly totationaily aligned

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such that the plunger mates wnh th.e cottcsijonding hole in. the female connector to cesure a secure.connection is made, There arc situations where the plunger might oflly Partially retu.nj toils b]ased poe-»=hon. with just one edge of the plunger engaged thu hne flic o)erItor nrght l2ear a Jick as fit part a] erigageniect oecur, and s be unaware that the connectiora has not been properly made. Once the shaft has been pushed into a conduit the connection is, Qfcourse, t longer visible and rotation of the shaft, or a change 01. direction o.fthe shaft rotation can cause the shafts to become disconnected. Sthe plunger disengages from the hole, This is a partieularI.y.difficuh situation to re.mccb and theopez'ator is left with.a disconnected array of shafts and ye associated tools connected to the shafts located vii thin an inaccessible due..t This often requires a drain to be excavated or ductwork to be dismantled to enable the shafts to be recovered.

Furthermore, the rotational forces that need to. be transmitted aJon,g the shaft si-ray are io transfened from shaft to shaft by the abutment of one face of the plunger to a corresponding face of its mahng hole. if and when the rotational direction is rev&s'ed.

force transfer occurs through the corresponding other face of the plunger. Repeated force transmission in this fashion can cause the edges of the plunger to wear to such an extent that rotational forces, conibined with flexing of the shaft array, can cause the plUnger to become disengaged from the hole in the conesponding connector leading to decoupling of the shafts. This again poses significant problems for recove-y of the disconnected shaft array and associated tools, Accordingly, theinvention provides, in a first aspect, a male shaft connector for connecting manually-ut mechanieailydriven (preferably m:echanicallydrjven) rotating shafts, said male connector comprising: amale mating Section having a non-so circular exter.al cross-section perpendicular to the axis of a shaft to be Oonnected; a locking peg located within said male mating section and moveahie between a first position wherein said peg protrudes from the surface of said mating section artd a second position wherein the outermost surface of-said peg is nthatantially flush with z the surface ef said male mating section; biasing means to bias said peg.towards. said first position; and a shaft mounting section attached to said male natiug section.

The provision ofa male connector (and as will be described below, a contoOnding female connector) having a non-circular cross-section is advantageous b.cause (he rotational forces that have hitherto been trnsferred between adjacent connected rods or shafts by means of the pIuoger an nw he transfrn-ed between adjacent shafts by the non-Circular, and therefore non-rotatable, connection between eon-esçonding male and f alt 0100ec'on 1 be <pungtr o peg is now no ioigi the only mechanism w -for transfer of rotational flutes between adjacent rods or shafts in a connected array.

Furthermore by choosing a rihaoe fbr the non--circular crossections that can orty be mated in one POS1L100 (ie. nave no totaoonal snm etry), a furtier.advantage is gan-ico in that the biased locking peg can he arranged to alwys be cpu'eotiy aligned with the corresponding peg-receiving aperture in the female matitig section. in this way, th secure locking of the connector is ensured.

Preferahh he protruding surface of said peg includes an angled portion ueh that the edge of the peg furthest from the shaft mounting section is substant.illy flush with, or recessed below, the surface of said male mating section such thatinsertion of the male mating section into the cavity of a corresponding female mounting section causes the peg to mqve towards its second position. in this way, the two connectors may be simply pushed together, and the lip of the cavity in the female connector will act against the angled,surface, therthy depressing the locking peg and allowing the connection to bc made.

it. is further preferred that the protruding surface of said peg includes a flat portion perpendicular to the axis of movement of said neg between its fIrst and second positions. This provides a fiat surface against which a user can push to move the peg into its second position in order to disconnect the connectors, It is also preferred that in the male. connector, the cross..section of said rnaie mating section perpendicular to the axis of a shaft to be connected comprises a circle with a o-ussi'g egreeru Ibis corfigukatior is t1ativeIy siraigh-forwaid manufacture, -j and provides the lack of non-rotatonal symmetry to ensure aiin1ent of the locking peg and aperture.

Ih this ease,. it s also preferred that said locking peg is located. on the flat portion of & said m&e.rnating section correspondipg to the dhord defining said missing segment, This eiisure that the peg passes th.roui tha thickest portion of the aperture in the corresponding ftrnale.cormeeor, thertby giving a stronger connection for rotational torque trarasmjssjor3 (so that te shafts do not nisconnect w*lttiout the operator depressing the locking peg), it is further preferred that the faces of said locking peg parallel to the axis of a shaft to be connected comprise fiat surfaces.. The use of flat faces eirsures a greater surfaoe area of contact for transmission of any rotational forces not transferred va the 11011-circularinating elements, in use, should there be some slack in the joint.

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it;5 also preferred that the face of said locking peg perpendicular to thu axis of a shaft to be connected, and finthest away from said shaft mounting section comprises a flat surface. By contrast to the device in US Patent 6,6SS8QOwhjc1, has a rounded.end plunger", this provides a larger surface area for axial force transmission when the iod array is moved into or out of a conduit.

in a second related aspect. the invention also provides a femaiesh.afl connector for connecting manuaI]y or rneehani.oaiiydriven (preferably mechanicalIydrivein) rotating shafts, said female connector comprising:, a shaft mounting section; a female matifig section comprising a cavity to receive a male mating section from a corresponding male shaft connector, said cavity having a noncircuiar erossseetion perpendicular to the axis of a shaft to he connected; an.d an aperture extending from the interior &f said cavity to the exterior of said female mating section to receive a locking peg fi-orn a corresponding male shaft connector.

Prtkrably, the nom-circuiar cross-section of said aperture comprises a circle with a missing Segment for t*easons corresponding to those fix the equvaiently-sh.aped male connector.

The invention also provides a shaft connection system %mpdsing a male shaft connector described herein and. a female shaft connector as dscdt ed herein, wherein each such cOnnector lIsa S conespondingly shaped mating section.

S Tlieinvenfion further provides a shafteomprising: an elongate shaft member; a male shall ConnectOr described herein affixed to one end; and a female shaft uontLector as desc:ribed herdin affixed to [he other end, Also included within the scope. of the invention is a shaft connector. shaft connection iv system or shaft substantially as described erein, with relerence to and as niustrated by any appropriate eornhiration of the accomnanving drawings.

Brief DescriptIon of the Figures

The invention will he described with reference to the accompanying drawings, in whch: Figure 1 shows an axial cross-sectional view of a male Oo1neOtoi-; Figures 2A. to 2.C' show detaii.s of a locking peg Figure 3 shows an axisi cross-sectional view of a female shaft connector; so Figure 4 shows a radial cross-sectional view of a female connector; FigureS shows a plan view of a female connector; Figure 6 shows a radial: cross-section of a female connector; Figures 7 and 8 show a radial cross--sectional view of connected male and female connectors; 2-5 Figure 9 shows a plan view of a male connector; Figure 10 shows a radial cross-section of a male connector; Figure II shows an. axial cross-section of a male and thrnale connector: Figure 12 shows an gial cross-section of a male connector; and Figures i3 to 15 show cross-sections of a selection of embodiments of female so connectors.

Descrptionof PrcthrrcdEmL'odimerus Figure.1 illustrates, in axial crosssectional view, a male shaft connector according to an aspect of the present invention, generally:fldlCcjd by I. The connector has a male mating section 2 that has a non.circuiar cmss-.section of the external surfaceS of the i ah ig & i this e rhc nunt, e çtcr su face 3 is ton-nan as a 4indncal surfnce with fiat face 4. The external cnisssectjrjn is thus. hi the tibrni of a circle with a missing segment (a 4Dsbaned" c.rosssection). The connecter i also has a locating peg 5 monnted in a hdie On the male mating section 2. There is a cavity 6 within the connecter rehouse a biasing e1nient, such as a spring (not illustrated) to bias the peg in an outw rad[ direction. PJefeJTed configtrations of the peg are described below: The cavity 6 is scaled with an end cap 7 to prevent ingress ofdirt that mIght cause maifimenon of the biasing elethent. The connector I also has a shaft mounting section 8 to enable the connector to h mounted onto a shaft in an essentially t5 permanent fashion. in this enbodirinent. the shaft mounting section 8 conprises a cylindrical hole 9 o sized as to receive the end of a shaft and an abutment region IL) against which the shaft can abut. The ithaft oan tkn be Thed to the connector by e.g. use of a pin driven through the side ii of the shaft mounting section, crimping the shaft mounting seotion or by the use of an apttoptiate adhesive. Typically the shaft connector I will be made of stcei, with an appropriate surface nman (spec as an electroplated finish) to prevent corresion, or be made of aluminium.

Figures 2A-2C illustrate in side elevation, end eleation and top plan view respectively, a locking peg 5 for use in the present invention. The pegS has the kmt a ofabutton portion 12.mountedon a flange 13. T.hebutton portion 12 protrudes througi, a correspondingly shaped. hole in the surface of the mate mating section:2, whilst the flange diement. 13 serves to keep the pegs captive in the male connector against the biasing force of' the biasing element. he button has generally rectangular plan cross-section with rounded oorhers.14 as seen in Figure 2C, The generally rectangular cross-section provides flat surfaces 15 parallel to the axis of a shaft to be connected, and also a flat.surfce 16 perpendicular to the axis ofa shaft to be connected and thrthest away from the shaft mounting section 8, once assembled into the cone ect.or, The top., or outermost (when assembled) surface of the peg 15 compises an angled portion 17 such that. when assembied the leading edge 18 of the peg (i.e.. the edge of the peg furthest from the shaft thounting section 8J is.'suhsanti'ally flush with, or even recessed below. the surface Oldie male mating section.. in this way, when the a-sale Li and female'poitions are pushed together, the female connector serves to'.depress the peg 5 against its hiosing ejement, allowing the two connectors to he mated, The non-cirefflar cross-section of the mating suriirces of the two connectors ensures that the peg and the corresponding hiie. in the' fei-x ale connector are lined-up and prevents relative iotalionai movement of connectors, Figure 3 illustr-ates in axial cross-sectional view, a fetnak shaft connector of the present invention, generally indicated by 12. The cOlineetor 19 has a female mating section 20 comprising'a cavity 21 having a non-circular mte.rtal cross-sectior: perpendicular to the axis of a shaft to he cornected. The matipg scct,ivn aso includes m an aperture 22 extending. through the wail of the mating.section between the cavity 21 and the exterior so sized and shaped to reccive the external portion of the kIcking peg c: -a correspondin " alt' cnn'vu'tcr 1. The external surface of the th$ing section is also provided with a cutout 23 surrounding the aperture 22 to enable the peg to be more easily depressed to. facilitate disengagement of connectors.

The internal surface 27 of the cavity 21 has anon-circular cross-section. h this embodiment, the cross-section has the for-rn essentially of a circle with a missing segment. There is, therefore,, a flat portion 28 that corresponds to the tiat surtace 4 on a corresponding male eormect-or. This is shown in radial cross--sectional view in Figure 4, in which corresponding features are numbered identically.

The female connector 19 is also provided with a shaft mounting section 24. This again comprises a shaf -receiving c'vity 25 and a shaft abutment region.26. In a corn sponding fashion as for the. mna].e connector 1, a shaft may be inserted into the ao cavity 25> abutting the abutment section 26 and be secured there, in an essentially permanent Thshion. using ineans such as a nm. erituping or a suItab]e adhesive.

Figure n showa. in pian view, a female sr,a1 connector 19 or the. pree invention connected to the end of a sh'ft 29. Figure 6 is a cross-section through the connector at position A ---A and has corespondingly_nunthered alements. Tiis view shows the aperture 22 between (he exterior of the comiector and the cavity 21. The aperture is shuped to receive a locking peg from a cnrrespon.ding male connector, and in pretbntd embodiments has a flat region 20 to abtu with a corresponding flat region l6 ofa Iockhg pegS, thereby reducing the noint loads on the connector in the face of axial letisron m a roe. or shaft array. Also iilirstrateci IS tue cutout 23. provaaed to fhcilitat depression ofa locking peg 5. It can be seen in Figure 6, that the cavity 21 of' the connector bath a non-cli-cular cross-sec.tjon. in thIs embodiment in the form of a flat face 2 in an othenvse circular cross-section.

Figure 7 illustrates.a cross-section through a female connector 19 at position A -.A in FigureS, when mated with a male connector I and with, the locking peg S biased to its first position hymens of a biasing clement in the form of a coil spring 3L ro Figure.8 shows the cross-section of Figut-e 7, but with the locking peg 5 depressed to a position against the biasing force such that tj male connector 1 may he inserted hub the female ce"cctor 19.

Fgare 9 shows, in. plan view, a male connector I connected to a shaft 29 by its shaft mounting section 8. The male mating section 2 is again of non-circular axtemal cmss-section, having the shape Ulustrated in FIgure 10 ofa circle with a missing segment., thereby leaving a flat face 4. Figure 10 is a cross-section through the line B -B of Figure 9. The locking neg5 is shown protruding througha hole located in the fiat face 4 of the male mating section 2. me peg n-as a generaily rectanguiar man view, with rounded corners but presenting flat faces 15 parallel to the axis of the shaft 29 and a flat face 16 perperdiudar to the axis of the thrafl 29. An angled portion 17 is also included on the top of the peg 5.

Figure Ii illustrates, in axial cross--sectional view, a male connector I and a female connector 19 lit a configuration read.y -for connection. The male mating part 2 of the male connector 1 is inserted-into the end of cavity 21 of e female mating part 20, The leading edge 18 oftht ptotruding button 12 of the locking pegS i.s located at, or just below, the surfaec of the ma mating pan such that when the two connectors are puthed together; tire edge of the cth'rty of the female connectormteracts with the s1oing portion 7 or the peg, and causing it to move down into tile body of the male corlnStor against the biasing force of the.spring 3.1, allowing the cOnnectOrs to be puhod together. Once the male connector 1 Is inserted into the femule. connector, the biasing element 31 urges the peg into engagement with the hole 22. in the female a COP oct thereby tedcasabie.ioclcing the two connectors ogether.

Figure 12 illuatiates. in axidi cTosssec±iona1 view, a male connector 1 according to the present invenhon, and illustrating the locking peg 5 in its driressed second position, blared against the spring 31.. and whore the oWer surface ofthe ea S is subrtuntiaily io flush with the surface 3 of the male mating sectien 2.

Figure 13 illustrates an alternative cross-section of the cavity 21 of a female connector 19 in whith the cavity 21 in the female mating section 20 is oftriengular cross-section. This shape, in combination with a corresnonding i:angrt1ar Section male mating section would also achieve thenon-rotatable connection desired.

Figure 14 illustrates a fUrther alternative non-circular cross-section of the Osvity 21 of afemale connector 19 in which thecavity 21 is essentially circular hut is ffitd ith an internal pin or ridge 32 that can mate with a corresponding groove on a male rnatingportion of a male connector thereby achieving the non-rotatable connection desired.

Figure 15 illustrates a yet further embodiment of a non-circular cavity 21. in a female mating portion.20 of a female connector. In this embodiment, two flat faces 28 are provided err an otherwise generally circular cavity. Again, however, this achieves the desired object of forming a non-rotatable cennechon it is clear that the shaft connectors provided by the invention can be used not only to couple shafts but also to attach a shaft (or a shaft array) to, at one end, a head device thnt is used to dean/unblock a conduit), wherein such a head device comprises a female connector, andtor to, at the other end, a component that facilitates the appijeation of rotational three (e.g. a drill hit, to he connected to a power drill), wherein such a component comprises a male connector.

Claims (9)

1. LL.MMS Amaleshaft cotinector for connecting manually--ormechantcafly-dliven rotating shafts, said male connector comprising: h a flW e mating scthon having a noti-cheular external cross-section perpendicular to the axis of a shatito he connected; a locking peg ioated within an aperture in said male mating section and moveabli-between a first position wherein said peg protrudes from the surface of said mating section and a second position wherein the outermost surface of iv said peg is substantially flush with the surface of said male mating section; biasing means to bias said pQg towards said first position; and a shaft mounting section attached to said male mating section.
2. 2. A male connector according to Claim: I wherein he protruding surface of said peg n includes an angled portion such that the edge of the peg furthtst from the shaft mounting section is substantially flush with, or recessed below, the surface of said male mating section such that insertion of the male mating section into the cavity of a corresponding female mounting section causes the peg to move towards-its second pOSItiOn.
3. 3.. A male connector according to either Ctaith I orClaim.2 wherein the protruding surface of said peg includes a flat portion perpendicular to the axis ofmovement of said peg between its first and second positions.
4. 4. A male connector according to any of Claims I to 3 Vhercin the cross-section of said male nating section peqendiculat to the axis of a shaft to be connected çximprses a circle with a missing segment.
5. 5. A male connector according to Claim 4 wherein said locking peg is located on the so fiat portion of said male mating section. corresponding to the chord defining said missing segment.
6. 6. A male connector according to any preceding Claim wherein the ihees of said locking peg parallel to the axi of a shaft to be connected eompnse flat surfaces.
7. 7. A male connector according tq anyprecedhig Claim wherein the face of said locking peg pcrpendicuiax to the axis, of a shaft to he. connected, and furthest away from said shaft mounting section comprises a flat surface.
8. 8. A Imak shaft connector for connecting manually-or mechanically-driven rotating shafts, said tèmale connector comprising: a shaft mounting section; a female mating Section comprising a cavity'to receive a male mating section from a corresponding male shall connector, said cavity having a non-circular cross-section perpendicular to the axis of a shaft to be connected; an aperture extending from the intcrior of said cavity to the exterior of said female mating section to receive a locking peg from a corresponding male shalt connector.
9. 9. A female connector according to Claim 7 wherein the non-circular cross-section of said aperture comprises a circle with a missing segment, I (LA.shaft.connection system comprising a male shaft connector according to any of claims Ito 6 and a female shaft connector according to either of Claims 7 and 8 wherein each such connector has a correspondingly shaped mating section.11. .A shaft comprising: an.eloilgate shaft member; a male shaft connector according to any of' Claims 1 to 7 affixed to one end'; and a female shaft connector according to either of Claims S and 9 affixed to the other end.12. A shaft connector, shaft connectior. system or shaft substantially as described herein, with reference to and as illustrated by any appropriate combination of the accompanying drawings. il