QUICKLY-RELEASABLE CLUTCH

Abstract: A quickly-releaseable clutch (40), comprises a linearly-moveable member (32) with an external spiral thread (34) engageable by a ball (58) in an opening in an inner sleeve (54) secured to a rotatable member (38), the ball coupling the members (32, 38) when it is forced to engage the thread (34) by a small bore part (60a) of an axially moveable outer sleeve (60) which also has a larger bore part (60b) allowing the ball to disengage from the thread. The sleeve (60) may be moved against a spring (62) to its clutch-release position either manually by gripping its knurled outer surface, or by a collar (64) adjustably mounted on the member (32).

Description: The invention relates to a quickly-releasable clutch. The invention is particularly useful in liquid dispensing apparatus for dispensing predetermined doses of a liquid into individual tubes used for artifical insemination of poultry, and is therefore described below with respect to this application. In the artificial insemination of poultry, which is now a widely used technique, predetermined doses of semen are dispensed into small plastic tubes, which tubes are used for the artificial insemination. Apparatus is known for dispensing predetermined doses of the semen into the individual tubes, as described for example in U.S. Patents 3.593.761, 3.683.977 and 3.880.210. However, such known apparatus is generally of very complicated construction which is bulky and expensive to produce and to maintain. Furthermore, the document U.S.-A-3 546 930 discloses a releasable clutch according to the preamble of claim 1 and comprising a screw and a sleeve connectable through a ball. The sleeve is movable longitudinally by not in rotation. The ball can be engaged in the thread of the screw by a longitudinal moving plate mounted on the sleeve and maintained by a radial spring means. So, this apparatus constitues an elastic releasable clutch. Moreover, the manually moving of the plate is not easy. An object of the present invention is to provide a new and improved quickly-releasable clutch. Another object of the invention is to provide such a clutch in an apparatus for dispensing predetermined doses of liquid into individual tubes, particularly useful for filling tubes for the artificial insemination of poultry. Another object of the invention is to provide a releasable clutch easily operable manually and of simple construction. According to the present invention, there is provided a quickly-releasable clutch, comprising a first member formed with a spiral thread on its outer surface and a second member to be coupled to said first member for linear relative movement therebetween and formed by a sleeve overlying said first member formed with an opening theretrough receiving a ball; and operator means axially movable to a first position for forcing said ball into the spiral thread of the first member to couple the latter member to said second member, and to a second position to permit said ball to disengage from said spiral thread of the first member and thereby to decouple same from the second member; said operator means being formed with a first surface dimensioned to force the ball into the spiral thread of the spirally-threaded member in the first position of said operator means to couple said spirally threaded member to said sleeve, and with a second surface dimensioned to permit said ball to disengage from said spiral thread and thereby to decouple same from said sleeve in the second position of said operator means. More particularly, the invention discloses a quickly-release clutch in which said operator means comprises an outer sleeve surrounding said firstmentioned sleeve, contituting an inner sleeve, and axially and rotatably movable with respect thereto; said outer sleeve having a first inner annular surface forming the said first surface of said operator means and a second inner annnular surface forming the said second surface of said operator means and having a larger internal diameter than its first inner annular surface and in which a spring normally urges said outer sleeve to said first position wherein its inner annular surface engages said ball and thereby couples the inner sleeve to the spirallytheaded member. The invention is particularly useful with the above-cited liquid dispensing apparatus, and is therefore describes below in this type of apparatus. Further features and advantages of the invention will be apparent from the description below. The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is a top plan view illustrating one form of apparatus constructed in accordance with the present invention; Fig. 2 is a fragmentary view illustrating the actuated position of the manipulator included in the apparatus of Fig. 1; Fig. 3 is a side elevational view showing the tube feeder in its normal or return position; Fig. 4 is a view similar to that of Fig. 3 but showing the tube feeder in its actuated position; Fig. 5 is a side elevational view illustrating the structure for presetting the quantity of liquid dispensed with each actuation of the dispensing device; and Fig. 6 is a sectional view illustrating the structure of the quickly-releasable clutch used in the apparatus of Fig. 1; and Fig. 7 is a diagram of the pneumatic control system used in the apparatus of Figs. 1-6. DESCRIPTION OF A PREFERRED EMBODIMENT Broadly speaking, the apparatus illustrated in Fig. 1, includes a tube feeder, generally designated 2, for feeding a plurality of tubes T individually to a dispensing station; a dispensing device, generally designated 4, at the dispensing station for dispensing a predetermined dose of the liquid with each actuation of the dispensing device; and a manipulator, generally designated 6, at the dispensing station and movable from a home position (Fig. 1) for receiving a tube T, to an actuated position (Fig. 2) bringing the tube into dispensing position with respect to the dispensing device 4. The illustrated apparatus further includes a pneumatic control system, illustrated in Fig. 7, controlling the tube feeder 2, dispensing device 4, and manipulator 6 such that when the tube feeder 2 is in its actuated position and a tube T is present in the manipulator 6, the manipulator is actuated from its home position (Fig. 1) to its actuated position (Fig. 2) to bring the fed tube into dispensing position with respect to the dispensing device 4, and then to actuate the dispensing device 4 to dispense a predetermined quantity of the liquid (e.g., semen, in this example) into the end of the tube T held by the manipulator. The latter tube is then manually removed from the manipulator, whereupon a new tube is fed by the tube feeds 2, to the manipulator 6 for receiving another dose of the liquid from the dispensing device 4. More particularly, the tube feeder 2 comprises a container 10 for containing a supply of the tubes T to be fed to the manipulator 6 at the dispensing station and to receive a dose of the liquid from the dispensing device 4. As shown particularly in Figs. 3 and 4, the bottom of container 10 is closed by a wall 11 which is inclined so as to be at a lower elevation at its front than at its rear, and is formed with an elongated dispensing opening 11′ at its front end. A slide plate 12 underlies bottom wall 11, and its front end is formed with a recess 14 for receiving a tube T. Plate 12 is slidable by an actuator A₁ from a normal position (Fig. 3) to an actuated position (Fig. 4) to convey the tube T in its recess 14 out of container 10 to the manipulator device 6 at the dispensing station in alignement with the dispensing device 4. As shown in Figs. 1 and 2, the front end of the slidable bottom plate 12 is formed with a rectangular slot 16 in alignement with manipulator 6. The manipulator comprises a lower arm 18 and an upper arm 20 pivotable over the lower arm along a horizontal axis 19 (Figs. 3, 4). Both arms 18 and 20 are pivotable together about a vertical axis 21 from a normal position (Fig. 1) to an actuated position (Fig. 2) by a piston-cylinder actuator A₂. Slot 16 is sufficiently wide to accommodate this pivotal movement of the two arms. The apparatus further includes three sensors, namely: sensor S₁ (Figs. 3, 4) which is actuated by the tube-feeder actuator A₁ to sense the actuated position of the tube feeder; S₂ actuated by the tube feeder to sense the home or return position of the feeder; and sensor S₃ actuated by arm 20 of the manipulator 6 to sense when a tube is present and is clamped between the two arms 18, 20 of the manipulator. Sensor S₁ is actuated by the end of stem 22 of actuator A₁; sensor S₂ is actuated by an arm 24 carried by stem 22; and sensor S₃ is actuated by a threaded pin 25 carried by arm 20. These sensors are all of the pneumatic type and are used for controlling the actuators A₁, A₂, as well as a third actuator A₃ which actuates the dispensing device 4 as will be described more particularly below particularly with reference to Fig. 7. The dispensing device 4 is of the syringe type. It includes a container 26 adapted to contain a supply of the liquid to be dispensed, a plunger 28 which is actuated to dispense a predetermined dose of the liquid with each actuation of the dispensing device, and a discharge nozzle 30 through which the liquid is dispensed. As shown in Fig. 1, when a tube T is initially fed to the manipulator 6, the manipulator is in its normal position wherein the tube is spaced from discharge nozzle 30; and when the manipulator 6 is pivoted by its actuator A₂ to the position illustrated in Fig. 2, the tube T clamped between the two arms 18, 20 of the manipulator is moved to bring the end of the tube into dispensing position contact with respect to the discharge nozzle 30. Plunger 28 is actuated by a drive element 32 carried at the end of a feed screw 34 formed with an external spiral thread 36. Feed screw 34 is coupled to a ratchet wheel 38, via a clutch generally designated 40 in Fig. 6, such that when the clutch is engaged, the feed screw is moved linearly an increment of movement with each increment of rotation of the ratchet wheel. The ratchet wheel 38 is in turn rotated an increment of movement by a pawl 42 pivotably mounted by pin 44 to an arm 46 actuated by the pneumatic piston-cylinder actuator A₃. As shown particularly in Fig. 5, arm 46 is formed with a plurality of openings 48 spaced at different distances along its length from its pivotable axis. These openings are adapted to selectively receive a coupling element in the form of a pin 50 carried by the outer end of the piston stem 52 of actuator A₃ for presetting the increment of movement of arm 46, and thereby of ratchet wheel 38 and feed screw 34, with each actuation of actuator A₃. The structure of clutch 40 coupling ratchet wheel 38 to feed screw 34 is clearly seen in Fig. 6. It includes a first, inner sleeve 54 enclosing feed screw 34 and of larger internal diameter than the outer diameter of the feed screw so as to provide an annular clearance therebetween. Sleeve 54 is secured to ratchet wheel 38 so as to be rotated therewith. Sleeve 54 includes an extension in the form of a collar 56 to which it is secured by means of external threads formed at one end 56′ of the sleeve extension receivable within internal threads formed in sleeve 54. Sleeve extension 56 is also formed with an internal diameter larger than the external diameter of feed screw 34 so as to provide an annular clearance between the sleeve extension and the outer surface of the feed screw. Sleeve extension 56, however, is formed with a hole receiving a ball 58 of a diameter to be seatable within the groove of the spiral thread 36 formed on the outer surface of feed screw 34. Clutch 40 further includes a second, outer sleeve 60 overlying extension 56 of sleeve 54 and axially movable with respect to it. Sleeve 60 is formed with a first inner annular surface 60a dimensioned to engage the ball 58 and to force it into the groove of the spiral thread 36 formed on the outer face of feed screw 34 so as to couple the feed screw to ratchet wheel 38 via sleeve 54 and its extension 56. Sleeve 60 is formed with a second inner annular surface 60b, having a larger internal diameter than its annular surface 60a, so as to permit the ball 58 to disengage from the groove of the spiral thread 36 and thereby to decouple feed screw 34 from collar 56, of sleeve 54, and ratchet wheel 38. Sleeve 60 is normally urged to its coupling position illustrated in Fig. 6., i.e., with its annular surface 60a engaging ball 58, by means of a spring 62 interposed between sleeve 60 and ratchet wheel 38 carried by sleeve 54. Sleeve 60, however, is movable axially against the force of spring 62, i.e., rightwardly in Fig. 6, to bring its annular surface 60b over ball 58, to permit the ball to unseat from the spiral groove 36 of feed screw 34, and thereby to decouple the feed screw from sleeve 54 and ratchet wheel 38. Feed screw 34 carries a collar 64 at one end which engages sleeve 60 at a predetermined limit of travel of the feed screw to decouple the feed screw from ratchet 38. Collar 64 is presettable at the end of feed screw 34 by threads 66 to enable presetting this limit of travel of the feed screw. Sleeve 60 may also be moved manually against the force of spring 62 in order to decouple the feed screw 34 from sleeve 54 and ratchet wheel 38; for this purpose, the sleeve may be formed with an outer knurled surface as shown in Fig. 1. Thus, whenever it is desired to return feed screw 34 to its initial position, or to preset it to any desired position, it is only necessary to grasp sleeve 60 and to move it rightwardly against the force of spring 62, to bring the inner annular surface 60b of the sleeve into alignment with ball 58; this permits ball 58 to unseat from the spiral thread 36 formed in the outer face of feed screw 34, and allows the feed screw to be manually moved to any desired position. Fig. 7 illustrates the pneumatic circuit for operating the three actuators, namely: acuator A₁ of the tube feeder 2, actuator A₂ for the manipulator 6, and actuator A₃ for the dispensing device 4. This pneumatic circuit also includes the three sensors mentioned earlier, namely: sensor S₁ which senses the actuated position of the tube feeder slide plate 12, sensor S₂ which senses the normal or return position of the slide plate, and sensor S₃ which senses the presence of a tube T between the arms 18, 20 of the manipulator 6. These sensors control control actuators A₁, A₂, A₃ via two pneumatic controllers C₁, C₂. The illustrated apparatus operates as follows: Container 10 is first filled with a supply of tubes T to receive the liquid to be dispensed, and compartment 26 of the dispensing device 4 is filled with the liquid to be dispensed. Piston stem 52 of the dispensing device actuator A₃ (Fig. 5) is coupled to the appropriate opening 48 in arm 46 according to the predetermined quantity of liquid to be dispensed with each actuation of the dispensing device. Driving element 32 may be manually positioned to engage the end of plunger 28 of the dispensing device by manually gripping sleeve 60 of clutch 40, and moving it rightwardly (Fig. 6) against spring 62, whereupon the inner annular surface 60b of sleeve 60 is brought to overlie ball 58. This decouples feed screw 34 from ratchet wheel 38 by permitting ball 58 to unseat from the spiral thread 36 of the feed screw 34, whereby the feed screw may be manually positioned as desired. Actuator A₁ is actuated from its normal position (Fig. 3) to its actuated position (Fig. 4), thereby feeding a tube T between the two arms 18, 20 of the manipulator 6 in the dispensing station. Sensor S₁, actuated by piston stem 22 (Fig. 4) of actuator A₁, senses this actuated position of the tube feeder; and sensor S₃ actuated by arm 20 of manipulator 6 senses the presence of a tube clamped between the arms of the manipulator 6 in the dispensing station. As shown in the pneumatic diagram of Fig. 7, sensors S₁ and S₂ control pneumatic controller C₁ so as to produce an output in pneumatic line 70 to actuators A₂ and A₃. Actuator A₂ is first actuated to pivot the manipulator arms 18, 20 to their actuated position as illustrated in Fig. 2, bringing the end of the tube T, clamped between the arms, into dispensing position with respect to discharge nozzle 30 of the dispensing syringe 4; and then actuator A₃ is actuated to rotate ratchet wheel 38, via arm 46 and pawl 42, one increment of angular movement of sleeve 54. This angular movement of sleeve 54 is translated to an increment of linear movement of feed screw 34 by means of ball 58 seated within the spiral thread 36 of the feed screw 34. Accordingly, a predetermined quantity or dose of the liquid will be discharged via nozzle 30 into the tube T held by manipulator arms 18, 20. The so-filled tube T is then manually removed from between the two arms 18, 20 of the manipulator 6 and is used for inseminating the chicken. As soon as the tube T has been removed from between the manipulator arms 18, 20, this is sensed by sensor S₃, which controls actuator A₁ to return the tube feeder 2. The return of the tube feeder is sensed by sensor S₂, and when this has occurred, the two sensors S₂, S₃ control pneumatic controller C₂ to actuate actuator A₁ of the tube feeder in order to feed the next tube to the dispensing station between the manipulator arms 18, 20. While the invention has been described with respect to one preferred embodiment, it will be appreciated that many variations may be made. For example, the clutch mechanism 40 could include a plurality of balls 58, rather than a single ball, and could be used in many other applications.

Claims: 1. A quickly-releasable clutch (40), comprising a first member (34) formed with a spiral thread (36) on its outer surface and a second member (56) to be coupled to said first member for linear relative movement therebetween and formed by a sleeve (56) overlying said first member (34) formed with an opening theretrough receiving a ball (58); and operator means (60) axially movable to a first position for forcing said ball into the spiral thread of the first member to couple the latter member to said second member, and to a second position to permit said ball to disengage from said spiral thread of the first member and thereby to decouple same from the second member; said operator means be rig formed with a first surface dimensioned to force the ball (58) into the spiral thread (36) of the spirally-threaded member (34) in the first position of said operator means to couple said spirally-threaded member (34) to said sleeve (56), and with a second surface dimensioned to permit said ball (58) to disengage from said spiral thread (36) and thereby to decouple same from said sleeve (56) in the second position of said operator means, characterized in that said operator means comprises an outer sleeve (60) surrounding said first-mentioned sleeve (56), constituting an inner sleeve, and axially and rotatably movable with respect thereto; said outer sleeve having a first inner annular surface (60 a ) forming the said first surface of said operator means and a second inner annnular surface (60 b ) forming the said second surface of said operator means and having a larger internal diameter than its first inner annular surface (60 a ); and in that it includes spring (62) normally urging said outer sleeve to said first position wherein its inner annular surface (60 a ) engages said ball (58) and thereby couples the inner sleeve (56) to the spirally-theaded member (34). 2. The clutch according to claim 1, characterized in that said inner sleeve (56) is coupled to an angulary-movable member (38), which latter member is driven through an acurate stroke by a drive (42). 3. The clutch according to claim 2, characterized in that said angularly-movable member is a ratchet wheel (38) rotated by said drive (42). 4. The clutch according to claim 3, characterized in that said spirally-threaded member (34) is a feed screw which is driven one increment of movement each time the ratchet wheel (38) is rotated by said drive (42). 5. The clutch according to claim 4, characterized in that said feed screw (34) includes a limit (64) engageable by said outer sleeve (60) for moving said outer sleeve to its releasing condition at a predetermined limit of travel of the feed screw. 6. The clutch according to claim 5, characterized in that said limit is in the form of a collar (64) secured to the end of the feed screw (34) and also serving as a hand grip for manually moving the feed screw (34) with respect to both of said sleeves when the clutch has been disengaged by said outer sleeve (60). 7. The clutch according to one of the preceeding claims, characterized in that said outer sleeve (60) includes an outer surface exposed for manual gripping by the user to permit manual disengagement of the clutch.

Inventors: BERGER, MOSHE
Applicants: TRANSROL
Application year: 1988
Main classification: F16H25
IPC codes: F16H25, F16D1