CA2189556A1 - Turning device and cam guide mechanism included therein - Google Patents

Abstract

A device for turning an object through a predetermined angle about an axis (1) is disclosed. A means (5) for supporting this object is reciprocatingly movable, in particular in the vertical direction, in relation to a frame (16) along the axis (1) as well as turnable about the latter. A driving means (2) is connected to the supporting means (5) in order to produce the reciprocating movement thereof. A cam guide mechanism (11, 28), which is disposed between and connected to the frame (16) and the supporting means (5), is so designed that a linear force generated by the driving means (2) in order to produce the reciprocating movement of the supporting means (5) is partly converted to a turning force acting on the supporting means, such that the latter is turned through the predetermined angle during a cycle of reciprocating movement. The cam guide mechanism itself is also covered by the invention.

Description

WO95/3061~ 21 8q~6 r~ L ~

TURNING DEVICE AND CAM GUIDE MECHANISM INCLUDED TE~EREIN
Fleld of the Invention This invention relates to a device for turning an ob~ect, and more sp~ f~ y cnn- -~rnC a turning device as set forth in the preamble to ~L~ claim l. The 5 invention further relates to a cam guide ---hF~n~
intended for use in the turning device.
8~ Luulld o the Invention Various ~;UIIV~yUL~i, p~k~ln!T r~~h~n~c and the like 10 are used for conveying and h;ln~ll 1n~ ob~ects, and fre-quently require that the objects can be turned through a predet~ n~d angle. The reason for this may be that the ob~ ect is to be oriented in another direction and subse-quently be further c;u--v~y~d by the same ~;UIIV~yUl, or that 15 the object is to be LLal~:~rt:LL~d to another ~UIIVC:yUL and thus has to be turned through a predet~rrf n~l angle, for instance an angle of 90.
In both cases, the object at issue is frequently conveyed by some sort of ~;UIlvl:yuL, for instance a belt 20 Cullvl::yu~, up to a turning site or ~unction, where the object is LaLlly stopped and first is lifted a cer-tain distance in the vertical direction by one and the same turning device so as to be released f rom the con-veyor and be lU~ OL l.~dd by the turning device. The object 25 is then turned through the predet~ npd angle and is flnally lowered so as to rest on the ~ IIVe:yUL in the turned positlon. Thus, the turning operation often involves a lifting operation.
US-3, 100,039 teaches a conventional method of 30 achieving the, I n~l lifting and turning operation ~l~c~ h~ above. The US d~ describes a turning device intended for use in association with a ~;ullv~yul.
This turning device comprises a turntable which, with the aid of a first pneumatic piston and cylinder unit, is 35 movable in the vertical direction along an axis between a Wo 95/30612 ~ 2 1 8 9 5 5 6 ~ . J~ --lower posltion on a level with an ad~ oining ~;u-lvey~l belt and an upper positlon above the e~-lvey~L belt. Further-more, the turntable is, with the aid of a second pneuma-tic piston and cylinder unit, reciprocatingly turnable 5 about the axis within a restricted angular range.
l~owever, this prior-art ~ xLLueLlon suffers from a numher of IL~r/ba~hs~ Thus, the linear lifting and lower-ing ,~ t of the turntable, as well as the turning ~. L thereof, is brought about with the aid of 10 various driving means. This constitutes a ~ ted solution, since the relative ~ Lx of the driving means thus have to be :~y~;llL~Ilised. In addition, the turning ~ L i of the turntable are reciprocating, the forward v. L actively causing an object to turn, 15 whereas the ba-_}.wc-Ld v~ L merely rêturns the turn-table to a suitable position in view of a subsesluent forward v. L for turning the object. As a result, only every other turning v L of the turntable is an elctive . L, i.e. causes the Xu~oL L~d object to 20 turn. Also, this conventlonal construction is disadvan-tageous in that the ~ , , Lx involved in the turning operation are subJected to a cnnc1rl~rable load when heavy objects are to be lifted and turned.
There is thus a demand for a better solution than 25 the one offered by the prior-art ,;ol~xLLu~,Llon described above .
One ob~ect of the invention is to provide a device which is adapted to turn an ob~ect while the latter undergoes a linear reciprocating ~ L, ~Rr~n1~lly in 30 the vertical direction, and which obviates the rlr~wh~r-kR
mentioned above.
Another object of the invention is to provide a turning device which is sub~ected to less torsional stress than prior-art devices.

wo 95130612 2 ~ 8 ~ 5 -5 6 r~l Sum.mary of the Invention According to the invention, these and other objects are attained by a turning device having the distinctive features recited in ;~ '1 claim l, ~ GLeLLGd embodi-5 ments of the turning device being defined in cl~r~n~ntclaims 2-lO.
The invention further provides a cam guide ~h~n~ cm having the distinctive features recited in i n~ r.onA~nt claim ll, preferred '-'1 L~i of the cam guide mecha-nism belng defined in ~r~n(1~nt claims 12-14.
The present invention has several adva~lLauGs over the prior art. The fact that a single driving means, which may be of simple and conventional design, achieves not only the lifting and lowering ~ L but also the turning v L results in a uu.1~LLu.;Llon which, gene-rally cp~Flk; ng, iS less expensive than prior-art turning devices. In addition, the use of a single driving means of simple design increases the service life of the turn-ing device, since there are but a few ^h~nir~l compo-nents running the risk of being exposed to wear. Further-more, there is no need of :,y11u11Lvl~ising several sG~JaLaLG
driving means during the turning cycle.
The inventive ~ul.~LLu~Llon, in which the turning ,~. L is achieved by ~u11vGL l,lng a ~ , ~ of a linear force to a torsional force, further entails that the - lr~l L~ involved in the turning opera-tion are not exposed to torsional stress of any signif i-cance. This means that the device is able to take up a greater load and that the ~ , L parts are not much worn.
The invention further enables the prior-art, inac-tive, backward turning .VG L to be ~1~ cr~nc~rl with, since the turning ,-,. L according to the invention can be achieved contin1~n1Cly in the same direction.
It should further be G ~ C~ that the linear ,~ L of the turning device and the cam guide mecha-nism according to the invention may be vertical, as will 2 1 8 q 5 5 6 F~1 ~ 5'1 ' be described below in connection with the ~ fall~d emho-diment of the invention, as well as non-vertical, for instance horizontal. Thus, the ~rpDn~lD~l claims are meant to ~ all conceivable directions of the axis of ~. 1 of the device, and all references in the fore-going as well as in the following to a lifting and lower-ing Y L, as well as to a ~ ~ in the vertical direction, are to be i.l~ d accordingly.
Brief Description of the Drawings A L,l~=fellad: -'1 L of the inventive turning device in the form ~f a turntahle, as well as an inven-tive cam guide ^h~n1~ nrl u~9PA therein, will now be rlD~I-r~ hD-l in more detail with lt:Lt:Lc:.-u~: to the Rl _ y~
ing drawings, in which Fig. l is a side view of the turntable, which is ~11 qpo1 Dfl in a roller .u11vt:yol and shown when occupying a lower initial position, Fig. 2 is a top view of the turntable and the con-veyor in Fig. l, Fig. 3 is a side view of a ~rame forming part of the turntable, Fig . 4 is a top plan view of a ~ acket for the frame in Fig. 3 when in flat state, Fig. 5 is a section taken along the line A-A in Fig. 3, Fig. 6 is a side view of a lifting piston forming part of the turntable, Fig. 7 i9 a section taken along the line B-B in Fig. 6, and Fig. 8 is a side view of a cam follower adapted to be mounted in the lifting piston shown in Fig. 6.
Description of a Preferred ~m~o~
In Figs l and 2, the turntable is ~i~ qpo~Dd in a horizontal roller ~:UIIV~:yUl with rollers lO0 mounted in a stand llO, the turntable being here adapted to turn some 1-- wo 95130612 2 ~ 8 9 5 5 6 r~ 5 ~

gort of object, for instance a carton (not shown), about a vertical axis 1 through an angle of 90 in the direc-tion indicated by the arrow a.
As appears rom Flg. 1, the turntable comprises a driving means in the form of a vertical piston and cylin-der unit 2 ~nnlll~11n~ a cylinder 3 and a piston rod 4 which is reciprocatingly movable along the axis 1, as well as freely turnable about the latter. The turntable further comprises a ~:iUyyUL Ling means 5, which is intended to support the ob~ect and 1 n~ q an elongate lifting piston 6, which is centred round and extends vertically along the axis 1 and which, at its lower end, is rigidly connected to the piston rod 4 by means of a screw joint 8. The ~UyyUL Ling means 5 is thus vertically adjustable along the axis 1, as well as tllrnAhle about the latter.
It appears from Figs 6-8 that the lifting piston 6 at its lower end has four L~utz~ses 7, which are directed radial-ly inwards and each are adapted to ~- ' Lt: a cam fol-lower 11 in the form of a roller bearing which, with its inner rlng, is r~L~:I-ed by screws ln the Lc:~ye.;Llve recesses 7.
The :~UyyUL Llng means 5 further comprlses two ortho-gonal ~uyyuLLlng plates 12, 13 whlch, by the lllt ~1~ry of a spacer 10, are connected to the upper end of the llftlng piston 6 and which Lu~t:LlleL form the shape of a cross perp~n~1c~ r to the axls 1.
As appears from Flg. 1, the supportlng plates 12, 13 are, ln the initial position of the turntable, located on a level beneath the upper periphery of the rollers 100.
It i8 further evident from Figs 1 and 3-5 that the turntable comprises a frame 16, whlch ls statlonary ln relatlon to the stand 110 of the uullve:yvI and which ~nf ~ q an elongate, cyllndrlcal ~acket 18, whlch ls centred round and extends vertlcally along the axls 1 so as to surround essentlally the entire lifting piston 6.
The lnslde r~ e~ of the jacket 18 ~;uLL~2:iyul~ds to the ~i; L~L of the llftlng plston 6. The jacket 18 ls clamp-. . . _ _ . _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ WO95/30612 ~ 1 89556 F~1__ 5 ' ed in, and XU~JIJUl L~d by, a ~iU~l~)Ul Llng element 20 of the frame 16, this elenent being aLlally~d above the piston and cylinder unit 2 and having an opening for receiving the latter. The ~acket 18 is made up of two Yub,,La--Llally 5 identical parts, namely an upper part 22 and a lower part 24, which are rigidly illLt:l~;ullllected with the aid of four vertical connecting rods 26.
The jacket parts 22, 24 are shown in flat state in Fig. 4, from which it appears that the ~acket-part ends 10 facing one another are provided with recesses in such a manner that there is formed, between the two lacket parts 22, 24, an undulated, LhLu~ Jv1n~ guiding groove 28 run-ning ~nrll ~IRl y in the ci ~:ul~Ler~:llLlal direction and being adapted to ~ ' L~: the cam fol 1 x 11. The guiding 15 groove 28 has a width corrp~pnnrl~n~ to, but being slight-ly larger than, the rli Ler of the cam followers 11.
The guiding groove 28 comprises vertical lower por-tions 30, forming the troughs of the guiding groove, and vertical upper portions 32, forming the crests of the 20 guiding groove. A vertical~ axis 34 extends through each vertical portion 30, 32 and is horizontally centred therein .
Ful i ~, the guiding groove 28 comprises upward-ly ;nr.l ~n~-l portions 36, each having an upper cam surface 25 38, as well as ~ lly ;nr.l ;n~ portions 40, each hav-ing a lower cam surface 42. Each upper cam surface 38 extends from a du dly-directed narrow end 44, which consists of the transition between one of the d. dly 1 nrl; n~A portions 40 and one of the upwardly ~ nrl i nP~l 30 portions 36, to the point where the guiding groove 28 pâsses from the upwardly; nrl; nP~l portion 36 to an upper vertical portion 32. Each lower cam surface 42 extends from an upwardly-directed narrow end 46, which consists of the transition between one of the upwardly I nrl ~ nF~
35 portions 36 and one of the ,' - - dly lnrl ;n~ portions 40, to the point where the guiding groove 28 passes from WO 95/30612 2 1 8 9 5 5 6 P~
the ~n~ ~. dly 1 n~ l ~ n~cl portion 40 to a lower vertical portion 30.
Each ~ - dly-directed narrow end 44 and each upwardly-directed narrow end 46 are offset in the late-5 ral direction ( to the lef t in Fig . 4 ) in relation torespective axes 34, i . e . in relation to the centre of respectively the lower and the upper vertical portions 30, 32 of the guiding groove 28.
The turntable operates as follows. In a lower ini-10 tial position, the piston rod 4 of the piston and cylin-der unit 2 occ~ri ~c a retracted position, ln which the ZiUlll.)UL Ling plates 12, 13 are located on a lower level than the upper periphery of the rollers 100, and in which each cam follower 11 o--r--rl ~c a startlng position Pl 15 ( shown in Fig . 4 ) and rests on the bottom of one of the lower vertical portions 30 of the groove 28, the cam fol-lower 11 thus taking up the dead weight of the supporting means 5.
Initially, the ob~ect to be turned ls ~_u-lv~5yGd to a 20 position above the supporting plates 12, 13 by means of the C;UIIVG-~YU1. The plston and cylinder unit 2 is then ~_LuaLG-d, causing the piston rod 4 to perform a linear lifting ~ L along the axis 1. As a result of the upward linear ~ L of the piston rod 4, the lifting 25 piston 6 is likewise moved upwards, each cam follower 11 received in the guiding groove 28 being, owing to this linear ~ L, caused to follow the lower vertical por-tion 30 of the groove 28 up to a lower inL ~ te posi-tion P2. Having reached this lower illl '1~te position 30 P2, the cam follower 11 ellcùu--LGLr the upper cam surface 38 and is thus forcibly applied against the latter as the lifting .VG L continues. The linear force y'Gn'GLClLed by the piston and cylinder unit 2 is, as a result, partly C;UIIVGL LGd to a torsional force, such that the piston rod 35 4 and the supporting means 5 will, in addition to the lifting ~ L, be subjected to a turning ~ L. The cam follower 11 travels in contact wlth the upper cam WO9~/30612 21 89 55 6 8 r~
surface 38 along the entire length thereof, up to an upper turning position P3, where the cam follower 11 is located in the upper vertical portion 32 of the guiding groove 28. In the turning position P3, the piston rod 4 5 and the supporting means 5 have, as seen in Fig. 2, been turned ant~ rl Qrkwi qe through a part angle of 45 in rela-tlon to the starting position.
When the cam follower has reached the turning posi-tion P3, the supporting means 5 is thus completely up-10 lifted. As a result of a subsequent linear lowering move-ment of the piston rod 4, the cam follower 11 is moved vertically flc~:- ds from the turning position P3 to an upper i~ Ate position P4, where the cam follower 11 instead cllUUUll~.cL` the lower cam surface 42. As the 15 lowering v 1, continues, the cam follower 11 travels in contact with the lower cam surf ace 42 along the entire length thereof to a lower ill~ '~Ate position P5, the supporting means 5 and the piston rod 4 being thus com-pelled to turn anticlockwise, as seen in Fig. 2, through 20 a second part angle of 45 . Finally, the supporting means 5 is lowered in the vertical direction without turning, such that the cam follower 11 reaches an end position P6, which corresponds to the starting position P1, the only difference being that the end position P6 is located in 25 a sl~rr~cq~ve trough of the guiding groove 28, as ~ cd with the trough where the starting position P1 is locat-ed. The supporting plates 12, 13 will thus again be located on a level beneath the upper periphery of the roller8 100, thus r~lPAqin~ the object from the support-30 ing plates. The piston and cylinder unit 2 has thus com-pleted a cycle consisting of a lifting and a lowering vc ~, while the supporting means 5 simul~An~ qly has been turned through 90 . It will be appreciated that the end position P6 constitutes the starting position P1 of 35 the subsequent cycle of v, 1,.
ûwing to the special design of the groove with lower and upper narrow ends 4~, 46 offset in~ the lateral direc-~ WO 95/30612 2 1 8 9 5 5 ~

tion in relation to the axis 34, the cam follower 11 will be brought into direct application against the respective upper and lower cam surfaces 38, 42.
Thus, the object to be turned is first located on the `UJ)IJUl Llng rollers 100 above the turntable at a dis-tance therefrom. When the driving means 2 is actuated, the ob~ect is first lifted a small distance, such that the `'U~y~L Llng plates 12, 13 come to occupy a level above the upper periphery of the rollers 100 in order not to be i.-LcLrelc~ with during the :iub~e~uc~.L turning ~ L.
As the lifting ~ L continues, the ob~ect is gradual-ly turned through 45 in a Ç~LcdclP~ nP~l direction. ~hen, the driving means 2 is actuated ln the opposite direc-tion, such that the object is lowered and thus simulta-neously is turned through another 45 in the same direc-tion. Finally, the turntable is lowered beneath the sup-porting rollers 100, and the ob~ect thus turned through 90 again rests on the supporting rollers to be further ~ --vcycd thereby.
It will be appreciated that all the cam followers 11 simultaneously perform a ~ LL-~L~ ng ~c L in thelr c~e~Llve parts of the endless undulated guiding groove 28. It is also to be u-,deL~Luod that the ~'UL,IJ~JL Llng means will be turned through another 90 in the same direction during the subsc~uc--t cycle of ~. L of the piston and cylinder unit 2.
Conceivable Modifications of the Invention It goes without saying that the invention is by no means restricted to the preferred _]1 L described above, but can be '1f1P~l in many ways within the scope of the appended claims. For instance, the vertical por-tions 30 and/or the vertical portions 32 may be dispensed with. Also, the 1nr~ nPcl portions need not be straight but may, for example, have the shape of half a parabola.
In addition, the ~ acket parts 22, 24 may be mutually turnable about the axis 1, thus Pn;qhl lng turning in both , _ _ _ _ _ _ _ _ _ _ _ _ _ . _ . .... .. . .

WO 95/30612 2 1 8 9 5 5 6 I ~ C: ~

directions. There may be provided one cam follower 11 only. r5J~ v~:r, the guiding groove 28 and the cam fol-lowers 11 may change places, i.e. the guiding groove 28 may be provided in the lifting piston 6, while the cam 5 followers 11 are stationarily ::iU~ )Ul L~d by the frame 16 .
Finally, it should once more be ~mrh~ ed that the use of the turning device need not be focused on the vertical direction, for which reason the expressions "up" and "down" as well as "upper" and "lower" Lh-~Juyll~uL are to 10 be illLc~ dLed in the broad sense, as referring to oppo-site directions in relation to the ori entation of the main axis.

Claims (14)

1. A device for turning an object through a prede-termined angle about an axis (1), comprising a frame (16), a supporting means (5) which is adapted to support said object and which, in relation to the frame (16), is reciprocatingly movable, in particular in the vertical direction, along said axis (1) as well as turnable about the latter, and a driving means (2) which is connected to the sup-porting means (5) in order to produce the reciprocating movement thereof, c h a r a c t e r i s e d by a cam guide mechanism (11, 28) which is arranged between and connected to the frame (16) and the support-ing means (5) and which is so designed that a linear force generated by the driving means (2) in order to pro-duce the reciprocating movement of the supporting means (5) is partly converted to a turning force acting on the supporting means, such that the latter is turned through said predetermined angle during a cycle of reciprocating movement.

2. A device as set forth in claim 1, c h a r a c -t e r i s e d in that the cam guide mechanism comprises an undulated guiding groove (28) running endlessly about the axis (1) at a radial distance therefrom, and at least one cam follower (11) accommodated in and travelling along the guiding groove (28), one of the guiding groove (28) and the cam follower (11) being connected to said frame (16), while the other of the guiding groove (28) and the cam follower (11) is connected to the supporting means (5).

3. A device as set forth in claim 2, c h a r a c -t e r i s e d in that, during a cycle of reciprocating movement of the supporting means (5), the cam follower (11) first travels along an upper cam surface (38) of the undulated guiding groove (28) from a starting position (P1) in a trough to a turning position (P3) on a crest, and then travels along a lower cam surface (42) of the undulated guiding groove (28) to an end position (P6) in a trough, an upper end (46) of the lower cam surface (42) being so offset in the circumferential direction in rela-tion to the turning position (P3) that the cam follower (11) encounters the lower cam surface (42) when a linear return movement is begun, and said end position (P6) con-stituting a new starting position (P1) for a subsequent cycle of movement.

4. A device as set forth in claim 3, c h a r a c -t e r i s e d in that the cam guide mechanism is so designed that the supporting means (5) is turned through a first part angle in a predetermined turning direction when the cam follower (11) is moving from the starting position (P1) to the turning position (P3), and through a second part angle in the same turning direction when the cam follower (11) is moving from the turning position (P3) to the end position (P6), said part angles together forming said predetermined angle.

5. A device as set forth in any one of claims 2-4, c h a r a c t e r i s e d in that the endless, undulated guiding groove (28) comprises at least two troughs (30) and at least two crests (32).

6. A device as set forth in claim 5, c h a r a c -t e r i s e d in that the distance between two successive troughs (30) is the same along the entire circumference of the guiding groove (28).

7. A device as set forth in any one of claims 2-6, c h a r a c t e r i s e d in that the guiding groove (28) is provided in the frame (16), and that the cam follower (11) is connected to the supporting means (5) in order to move jointly therewith.

8. A device as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that the driving means (2) consists of a piston and cylinder unit (2) extending along said axis and compris-ing a stationary element which, at its upper end, is rigidly connected to the frame (16), and the supporting means (5) comprises an elongate lift-ing piston (6) which is centred round and extends along said axis (1), a lower end of the lifting piston (6) being rigidly connected to an upper piston end of the piston and cylinder unit (2), and an upper end of the lifting piston (6) being rigidly connected to a support-ing element (12, 13) of the supporting means (5) extend-ing transversely of said axis.

9. A device as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that the cam fol-lower (11) is in the form of a roller bearing, which is supported by the lifting piston (6) and projects radially therefrom.

10. A device as set forth in any one of the preced-ing claims, c h a r a c t e r i s e d in that the frame (16) has a cylindrical jacket (18).

11. A cam guide mechanism, c h a r a c t e r i s e d in that it comprises a first member (18, 22, 24) and a second member (6, 11) which are rotatable in relation to each other about an axis (1), as well as reciprocatingly movable in relation to each other along the same axis (1), the first member (18, 22, 24) comprising an undu-lated guiding groove (28) running endlessly round said axis (1) at a radial distance therefrom, and the second member (6, 11) comprising at least one cam follower (11) which is accommodated in and travels along the guiding groove (28), and that the cam guide mechanism is so designed that, during a reciprocating, linear relative movement of the first and the second member, the cam fol-lower (11) first travels along a front cam surface (38) of the undulated guiding groove (28) from a starting position (P1) in a trough to a turning position (P3) on a crest, and then travels along a rear cam surface (42) of the undulated guiding groove (28) to an end position (P6) in a trough, a front end (46) of the rear cam sur-face (42) being so offset in the circumferential direc-tion in relation to the turning position (P3) that the cam follower (11) encounters the rear cam surface (42) when a linear return movement is begun, and said end position (P6) constituting a new starting position (P1) for the subsequent cycle of movement.

12. A cam guide mechanism as set forth in claim 11, c h a r a c t e r i s e d in that it is so designed that the first member (18, 22, 24) and the second member (6, 11) are turned in relation to each other through a first part angle in a predetermined turning direction when the cam follower (11) is moving from the starting position (P1) to the turning position (P3), and through a second part angle in the same turning direction when the cam follower (11) is moving from the turning position (P3) to the end position (P6), said part angles together forming a predetermined angle.

13. A cam guide mechanism as set forth in claim 11 or 12, c h a r a c t e r i s e d in that the endless, undulated guiding groove (28) comprises at least two troughs (30) and at least two crests (32).

14. A cam guide mechanism as set forth in claim 13, c h a r a c t e r i s e d in that the distance between two successive troughs (13) is the same along the entire cir-cumference of the guiding groove (28).