FR2544438A1 - DEVICE FOR TRANSFORMING UNIFORM CIRCULAR MOVEMENT IN A VARIABLE SPEED CIRCULAR MOTION - Google Patents

Abstract

THE INVENTION REFERS TO THE TECHNICAL FIELD OF CINEMATIC MECHANISMS AND IT CONCERNS IN PARTICULAR A DEVICE OF THE TYPE ACTING AS A JOINT CAPABLE OF TRANSFORMING A UNIFORM CIRCULAR MOVEMENT INTO A CIRCULAR MOVEMENT AT VARIABLE SPEED ACCORDING TO A NON-HARMONIC LAW. THE DEVICE ACCORDING TO THE INVENTION IS INTRODUCED BETWEEN A DRIVE SHAFT 2, 3 TURNING AT A CONSTANT SPEED AND A DRIVEN SHAFT 3, 2 OFF-AXIS AND SENSITIVELY PARALLEL TO THE DRIVE SHAFT AND IT INCLUDES A ENGAGING 6 RIGIDLY FIXED IN POSITION ECCENTRIC TO ONE OF THE ENDS OF ONE OF THE TWO ABOVE TREES, AS WELL AS A GROOVE 8 ARRANGED ON THE END OF THE OTHER SHAFT AND EXTENDING PERPENDICULAR WITH THE AXIS OF THE LATTER, THE ORGAN OF ENGAGEMENT AND THE COOPERATING GROOVE THUS TRANSFORMING THE UNIFORM CIRCULAR MOVEMENT OF THE DRIVE SHAFT INTO VARIABLE MOVEMENT OF THE DRIVEN SHAFT.

Description

The present invention relates to a device for transforming a

  uniform circular motion in a circular motion at variable speed

  it refers to a device defined by an element

  seal function, particularly suitable for

  machines in which it is necessary to transport

  those that need to be subjected to specific work from a workstation to a next job, or between a workstation and a product storage

raw-or finished product.

  It is known that generally machines of the aforementioned type provide chains or other similar type of transport members provided with removal teeth.

  parts and having a substantially constant speed.

  In other types of machines the trans-

  carriers do not have chains and teeth

  removal, but sliders actuated by biellemanivelle systems In this case the movement of organs

  carriers is essentially harmonic type.

  In certain situations, however, both transporters with essentially

  the fact that the transporting bodies provided with

  variable harmonic frequency are not

  It might indeed be desirable to

  transporting organs at varying speeds in a non-harmonic manner. This need is verified by

  example when it is necessary to remove a piece at a speed

  in order to avoid damage or errors in

  positioning of the piece, and then increase the

  transport capacity so as to reduce as much as possible

  the dead time due to moving workpieces In addition, it may be necessary to reduce the speed also at the time of transfer of a part

  carrier bodies at a receiving station.

  In this situation, the technical task which is the basis of the present invention is to implement a device able to provide a movement for

  variable speed from a single circular motion

  form. As part of this technical task it is a

  purpose of the present invention to implement a

  acting as a joint able to transform

  a uniform circular motion in a circular motion

  variable speed, which can also be associated with means for transforming, when necessary, the circular motion at a speed

  variable in a linear motion at variable speed.

  Another object of the invention is to

  implement a joint function which can

  to be associated with means of the crank-handle type,

  in such a way as to obtain an alternating linear movement

  2 O tif of essentially non-uniform type.

  Another object of the invention is to

  a seal element which has particularly low manufacturing costs so as to make it inexpensive and advantageous to use

  in machines of any type.

  The technical task indicated above, the goals

  mentioned above and others which will emerge more clearly

  subsequently achieved by the device according to the invention, to be introduced between a motor shaft rotating at a constant speed and a parallel driven shaft and

  offset from said motor shaft, which is

  characterized in that it comprises a fixed engagement member

  rigidly in an eccentric position at one of the

  of one of those trees, opposite another

  fitted to the other shaft, and a groove provided on said other end of said second shaft and extending in a direction substantially perpendicular to the same shaft, said engagement member slidably penetrating said groove in a manner adapted to transform the circular motion uniform of said motor shaft in one movement

  variable circular of said driven shaft.

  Other features and advantages of the

  will become clearer from the description

  a preferred but not exclusive embodiment of the device, given by way of non-limiting example only, with reference to the accompanying drawings, in which: FIG. 1 is a side view, partly in section, of the device according to the invention;

  FIG. 2 is a view perpendicular to that shown

  shown in Figure 1, which shows schematically and from the point of view of the operation the trajectories of

  different elements of the device.

  Referring to FIG. 1, the device se-

  the invention is indicated generally in 1 It has a joint structure and consists-essentially of two

  shafts 2 and 3 arranged in such a way that their axes are

  parallel to each other but not aligned, existing between

  them a distance or eccentricity e.

  On the two opposite ends of the shafts 2 and 3 two elements are provided, for example two disks,

  one on each tree, indicated respectively in 4 and 5.

  Each of these disks is coaxial with its respective shaft and therefore offset from the other disk

  of the same size as trees 2 and 3 between them.

  On the face of the disk 4 facing the disc is fixed a roller-shaped engagement member 6, supported by a shank 7. The engagement member or roller 6

  is eccentric with respect to the disk 4 and its central axis

  tral is parallel to the axis of the shaft 2 to which the said

that 4 is fixed.

  On the other hand, a groove 8 is provided on the

  be indicated in 5, in this engaging groove

  slidably said roller 6.

  Figure 2 shows in

  the trajectory 9 of the roller 6, which maintains a constant radial distance equal to the radius R of the center of the

  disc 4 secured to and concentric with the shaft 2.

  The distance of the same roller 6 from the center of the disc 5 and the corresponding coaxial shaft 3 varies, on the contrary, between a minimum and a maximum, as represented in FIG. 2, for example, by the radius A close to the

  minimum radius, and the radius B near the maximum radius.

  In order to describe the functioning of the

  acting as a seal according to the invention,

  sounds first that the shaft 2 is the motor shaft and the shaft

3 the trained tree.

  When the motor shaft 2 is set in motion se-

  in a uniform circular motion by appropriate means

  already known and therefore not illustrated, the disc 4 and

  the pebble 6 which is attached to it rotate with him.

  The roller 6 executes the trajectory 9, concentric

  than at tree 2 and having, therefore, a radius of

  curvature R constant The movement of the roller 6 has a speed

  constant tangential, given the constancy of the

  radius R and the angular velocity of the shaft 2.

  On the other hand, the driven shaft 3 is rotated at a variable speed, because the roller 6 varies its position along the groove 8 and consequently its distance from

the axis of the driven shaft 3.

  As already mentioned, the tangential speed of

  let 6 is constant and therefore the radius variations that occur between the path 9 and the axis of the driven shaft 3 translate into variations in the angular velocity of the latter, given the known mathematical relationship V = ad R existing between the tangential velocity V and the angular velocity Do at the variation of the radius R.

  A link of this type may be particularly

  advantageous for machines provided with a system for transporting workpieces from a workstation to

  For example, it may be usefully

  bent into an automatic machine to form-weld metal containers, to remove the formed container

  at the exit of the grille and transport it to the

welding.

  In this case, as well as in similar cases, it suffices to fit on the shaft 3 a toothed pinion which actuates a chain or rack equipped with transporting teeth spaced apart from each other by a distance

  equal to the length of the original circumference of the

  In this way, after one turn of the tree 3, a next tooth comes to occupy the position that was occupied

by the previous tooth.

  In this case the movement of the chain and the teeth takes place at a variable speed and the device can

  be easily envisioned so that the tooth moves

  this at a lower speed at the time of the removal of

  the piece and then accelerate during its course towards the pos-

following you.

  Suppose now that tree 3 is used

  as a motor shaft operated at a constant speed

  aunt and that tree 2 is the tree driven at a speed

  is variable. In this second case the groove 8 rotates at a constant angular velocity and the roller 6 is forced to also move at an angular speed always constant with respect to the center of rotation of the shaft

engine.

  But its distance from this center of rotation varies

  continually with his movements along the path of

  8 and therefore the tangential speed of the roller

varies continuously.

  Because the pebble is integral, through

  the disk 4, of the driven shaft 2, these variations

  tangential velocity translates into

  angular velocity variations of the driven shaft 2.

  This type of device can be advantageously

  used in an automatic type press, to remove

  the strips coming out of the magazine and transfer them under the stamps: indeed the band can be moved by a particularly soft and advantageous movement when the

  press has to work at a high speed.

  The invention achieves the intended goals.

  Note that by appropriately varying the eccentricity between trees 2 and 3 and choosing one or the other as a motor shaft, one can obtain

  appropriate results for the most

paid.

  The device also has a very simple structure and is easily executable at a low cost. The invention thus conceived is capable of numerous modifications and variants without departing from

its protection framework.

  In particular, the illustrated applications are not

  indicative and should not be considered

  for this type of device that can be applied

  in a wide variety of modes.

  All details can be replaced by

  technically equivalent elements.

  In practice, the materials used, the

  mes and dimensions can be any following

the necessities.

Claims (4)

R E V E N D I C A T IO N S   1 Device for transforming a uniform circular motion into a circular motion at a speed   variable, to be inserted between a motor shaft 2 (3)   at a constant speed and a driven shaft 3 (2)   parallel and off-axis with respect to said motor shaft,   characterized in that it comprises an engagement member (6)   rigidly in an eccentric position to one of the ex-   trenches of one of said shafts, facing another end of the other shaft, and a groove (8) provided   on said other end of said second shaft and extends   in a direction substantially perpendicular to the axis of   the latter, this engagement organ (6) penetrating   slidably in said groove (8) suitably   transforming the uniform circular motion of said   motor in a variable circular movement of said trained.   2 Device according to claim 1, characterized   characterized in that said drive shaft and driven shaft are each provided at their ends facing each other with a disk-shaped element (4, 5) coaxial with the axis of its respective shaft and in that said engagement member (6) is eccentrically attached to one of said disk-shaped members, whereas said groove   (8) is provided on the other disc-shaped element.   3 Device according to claim 2, characterized   characterized in that said engagement member (6) is attached to a disk-shaped member integral with said drive shaft, and said groove (8) is provided on an element   disc-shaped integral with said driven shaft.   4 Device according to claim 2, characterized   in that said engagement member (6) is fixed S -   a disk-shaped element associated with said ar-   driven, and that said groove (8) is   swum on another related disk-shaped element with said motor shaft.