FR2489275A1 - CONVEYOR OF THE TYPE SAID "WALKING BEAM" - Google Patents

Abstract

THIS CARRIER INCLUDES 8 FIXED BEAMS BETWEEN WHICH ARE MOUNTED TRANSPORT BEAMS 1A, 1B PARALLEL TO THE FIXED BEAMS AND ANIMATED WITH CIRCULAR MOVEMENTS IN VERTICAL PLANS SO AS TO LIFT AN OBJECT PLACED ON THE FIXED BEAMS, MOVE IT TOWARDS THE AIR. 'A GIVEN DISTANCE THEN REFIT IT ON THE FIXED BEAMS, AT EACH CYCLE. THE BEAMS ARE DIVIDED, IN THE LONGITUDINAL SENSE, INTO N GROUPS WHICH CARRY OUT CIRCULAR MOVEMENTS IN THE SAME DIRECTION AND HAVING THE SAME PERIOD BUT ONE PHASE IN RELATION TO THE OTHERS OF 2PNRADIANS. IN THIS WAY, THE POTENTIAL ENERGY OF THE BELOWING BEAMS IS RECOVERED AND USED TO PROVIDE PART OF THE ENERGY NECESSARY TO LIFT THE RAISING BEAMS.

Description

The present invention relates to improvements made to a

  conveyor of the type known as "walking beam" which is used, for

  example, for transporting steel tubes, round bars and pro-

  similar products during their manufacturing and processing operations

is lying.

  When various types of steel products, such as a-

  cier, round bars and the like, must be transported aside

  that is to say in a direction transverse to their length, in part

  culier in the case of a heat treatment chain, constituted, for example, by an oven for heat treatment, case in which it is necessary

  Avoid damage such as scuff marks, use

  reads a walking beam to transport steel products placed transversely. This type of walking beam comprises a series of fixed beams and a series of transport beams which are arranged so as to extend parallel to each other, the beams of

  transport being driven by a circular movement controlled by mechanics

  links with links articulated in such a way that the operation which consists in lifting the product from below, in moving the product forward then in resting the product on the fixed beams is carried out repeatedly by the circular movement of the beams transport, thereby carrying out the transverse transport of the steel product. In the case of an ordinary walking beam, a series of transport beams are arranged, in combination with fixed beams, in one direction

  longitudinal to form a transverse transport chain of a long

  predetermined, the transport beams being coupled to a drive system in such a way that all the transport beams are moved with the same period and with the same phase ratio, the

  transport beams being raised and lowered simultaneously.

  In other words, the load applied to the engine of the fuel system

  dragging of the transport beams becomes maximum at the moment the transport beams are raised while, when the transport beams are lowered, the applied load becomes negative and the engine is caused to produce a braking action or a generator action. As a general rule, the characteristics of an engine must be determined according to the maximum load and, therefore, the nominal power of the engine used must be determined according to the power required to lift the transport beams whatever

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  that the power of the engine is during the braking action. So,

  there is a drawback that energy consumption is increased

  raw compared to, for example, that of a chain conveyor which

  transports steel tubes or the like horizontally.

  One of the main aims of the present invention is to achieve

  an advanced walking beam designed so that wasted

  the energy required to drive its transport beams

  following a circular motion is completely removed, that is

  say that the transport beams are divided into two groups so that when one group of transport beams is lifted, the other group of transport beams is lowered which means that each

  of the two groups absorbs the potential energy of the other group.

  Another object of the present invention is to provide an improved walking beam designed such that a small motor of a

  relatively low power can be used as a drive motor

transport beams.

  According to one embodiment of the invention, in a conveyor called a walking beam of the type according to which transport beams perform a circular movement in response to the rotation of drive shafts so that an object to be transported placed on fixed beams is lifted from below, moved forward and rested on the fixed beams by the transport beams, this operation being performed repeatedly to transport the object,

  transport beams are divided, relative to the longitu-

  dinal, in at least N groups (N being an integer equal to or greater than 2) and the transport beams are connected to the drive shafts

  by hinged link mechanisms such that the movements

  circular elements made by the transport beams of the N groups have the same direction and the same period but are out of phase with each other

to others 2 l / N radians.

  The integer N is chosen equal to or greater than 2 so that if N = 2, for example, the transport beams are divided into two groups

  and the phase difference becomes equal to nf radians. In this case,

  that the transport beams of a group are in their upward travel,

  the transport beams of the other group are in their downward travel

  dante. In accordance with a preferred embodiment of the invention, the 3 drive shafts and the transport beams are connected by

  hinged link mechanisms such that the rotational movement

  tif of the drive shafts is transformed into the circular movement of the transport beams by the articulated link mechanisms and that the radius of the circular movement is equal to the length of the link rods

  articulated link mechanisms. The phase shift of the circulatory movements

  of the two groups is preset by the initial mounting angle between the articulated link mechanisms and the transport beams in

each of the groups.

  In the walking beam of the present invention, when the transport beams of one group are raised, the transport beams of the other group are lowered so that the potential energy due

  the weight of the transport beams that are lowered is effectively used

  used as the driving energy for the transport beams which move upwards and are thus canceled. It follows that, considered from the point

  from view of the motive source, the charge becomes as small as the difference

  between the loads applied by the objects to the respective transport beams of each group and the frictional resistance of the shafts

  of the transport beam drive system that can be used

  as a motor constituting the driving source, a low power motor. Other characteristics of the invention will appear on reading

  of the description which follows and on examining the drawings appended in

  which: Fig. 1 is a side view which schematically represents the transport beams of a walking beam of a common type; Fig. 2 is a schematic front view of the walking beam shown in FIG. 1; the Figs. 3a, 3b and 3c are schematic views which are used to explain the operation of the walking beam shown in FIG. 1; Fig. 4 is a plan view showing the general arrangement of an embodiment of the present invention; Fig. 5 is a front view taken in the direction of the arrows V-V in FIG. 4; Fig. 6 is a schematic side view of the transport beams of the embodiment of the invention; Fig. 7 is a partial front view of the embodiment of the walking beam of the present invention; and

  Figs. 8a and 8b are schematic views used to explain

  quer the operation of the embodiment of the walking beam of the present invention. We will first describe the construction and operation of the

  conventional walking beam with reference to Figs. 1, 2, 3a, 3b and 3c.

  In the figures, the reference 1 designates transport beams assembled

  wired in a rigid structure having a length of 20 to 30 m, the reference

  rence 2 designates notches formed at regularly spaced locations in the upper surface of each of the transport beams

  1 so that a steel tube P which is to be transported can be posi-

  stably held on the beams 1 and the reference 2 designates arms rigidly fixed to the lower part of the transport beams 1, each of the arms 3 being provided with an axis 4. The reference 5 designates

  rotary shafts which are driven simultaneously by a motor (not re-

  presented) and each of the rods 6 has a first end rigidly

  fixed to one of the rotary shafts 5 and its other end rotatably mounted

  tion on the axis 4 of one of the arms 3. These elements form drive mechanisms 7 for the transport beams 1. The spacing between the

  notches 2 formed on the transport beams 1 is chosen equal to approx.

  twice the distance "l" between the rotating shaft 5 and the axis 4, that is

  say equal to "21". Reference 8 designates fixed beams mounted vertically

  securely in place and in the upper surfaces of which are

  mées of the notches 9 at positions which correspond to those of the

  notches 2 formed on the transport beams 1, the transport beams - 1 and the fixed beams 8 being arranged parallel to one another as

shown in Fig. 2.

  The operation of the walking beam will now be described.

  trout as described above with reference to Figs. 1, 2 and

3a to 3c.

  Initially, when the walking beam is in the represented state

  tee in Fig. 1, the axes 4 of the drive mechanisms are in horizontal positions to the right of the rotary shafts 5 so that the upper surfaces of the transport beams 1 and the fixed beams 8

  are practically in the same plane and that one of the notches 2a, is so-

  killed directly above one of the rotary shafts 5. Then, when the rotary shafts 5 are displaced by 11/4 radians in a clockwise direction, the axes 4 coupled to the rotary shafts 5 are

  moved to their lower position and are thus placed in the condi-

  tion shown in FIG. 3a. At this stage, the transport beams 1 have been placed in their low position and each of the notches 2a has been moved to the left by the distance "1" from the position

  of Fig. 1. When the rotary shafts 5 still rotate by 7r / 4 ra-

  dians clockwise, as shown in Fig. 3b, the axes 4 are brought into horizontal positions at the

  left of the rotating shafts 5 and the transport beams 1 are raised.

  It follows that the transport beams 1 are arranged practically in the same plane as the fixed beams 8 and that each of the notches 2a

  has been moved to the left by a distance "21" from the position

  tion tion so that it is aligned with one of the notches 9 of the fixed beam 8. The rotary shafts 5 continuing to rotate clockwise, the steel tube 10 placed in the notches

  9a of the fixed beams 8 is transferred to the notches 2a of the transfer beams

  port 1. When each of the rotary shafts has again rotated from TC / 4

  radians from the position shown in FIG. 3b to the point

  sition shown in FIG. 3c, each of the beams has been moved to

  that in its high position and each of the notches 2a which hold the steel tube 10 has been moved to the right by a distance "1" from the position shown in FIG. 3b. When the rotary shafts 5 rotate again TC / 4 radians clockwise

  shows, the transport beams 1 are reduced to the condition shown

  felt in FIG. 1 and the steel tube 10 is transferred to the notches 9 of the fixed beams 8. In other words, the steel tube 10 is moved

  by successive advances of a distance "21" at each turn of the red trees

  5 and in this way the steel tube is gradually moved

to the right of Fig. 1.

  When the walking beam is constructed in the manner described above, all the rotary shafts 5 are driven by a single motor or, alternatively, they are driven by several motors, one of which is provided for each of the various groups of rotary shafts. In this case, the load applied to the motor during each rotation of the rotary shafts reaches a maximum value during the upward movement of the transport beams 1 (during the period of 11/2 radians of position of Fig. 3a until at the position of Fig. 3c) and during

  the deceleration period of the downward movement (during the

  riode of Ir / 2 radians from the position of Fig. 3c to that of FIG. 3a passing through the position of FIG. 1) the load acts in a negative direction and the motor provides a braking action. Figs. 4 et seq. Show an embodiment of a walking beam according to the invention embodiment in which the

  integer N previously mentioned is equal to 2.

  Fig. 4 is a plan view which shows the general arrangement of the embodiment of the walking beam of the present invention and FIG. 5 is a front view taken looking in the direction of the arrows V-V of FIG. 4. In the figures, the reference 8 designates fixed beams, the references 1a and 1b designate transport beams which are divided into two groups in the longitudinal direction and are arranged between the fixed beams 8 and the references 5a and 5b designate rotary drive shafts which are respectively coupled by connecting rods (not shown) to the transport beams la and to the transport beams lb. The drive shafts 5a of the transport beams la which form one of the groups are coupled to a motor lla

  via gearboxes 12a and the drive shafts

  ment 5b of the transport beams lb which form the other group are ac-

  coupled to a motor llb via gear boxes 12b.

  The walking beam thus constructed has a width "W" which depends on the

  length of steel tubes 10 which are to be transported and is habi-

  in the order of 20 to 30 m and a length "L '' which depends on the

  transport distance and is usually around 20 to 50 m.

  Fig. 6 is a schematic side view of the transport beams 1a and 1b which constitute the main element of the embodiment of the invention and FIG. 7 is a front view of the beams shown in FIG. 6. Figs. 8a and 8b are schematic views used to explain the operation of this embodiment. We have designated in Figs. 4 to 8 with the same reference numbers as in FIG. 1,

  elements that perform the same functions as the corresponding elements

  of this figure and we will not describe them again. In the pasture-

  In one embodiment, the transport beams are divided into two groups 1a and 1b in the longitudinal direction and are mounted between the fixed beams 8. The transport beams 1a which form the first group are driven by drive mechanisms 7a while that the transport beams lb which form the other group are driven by drive mechanisms 7b. The transport beams la and lb are

  driven in such a way that they perform circular movements

  which are in the same direction and have the same period. In the present case, the drive mechanisms 7a drive the transport beams

  the in such a way that their circular motion is out of phase in ar-

  re of 7 'radians with respect to the circular movement of the transport beams lb driven by the drive mechanisms 7b. In other words, as shown in Figs. 8a and 8b, the initial mounting angle of the transport beams 1a on the connecting rods 6a is offset by it radians from the mounting angle of the transport beams 1b on the connecting rods 6b

  so that the transport beams lb are moved to their posi-

  high when the transport beams are moved to their low position, for example. When the transport beams 1a and 1b are in their neutral position, as shown in FIG. 6, the beams

  transport la and lb are arranged at almost the same height.

  On the other hand, when the transport beams are displaced towards their

  high position, the transport beams lb are moved to their posi-

low tion.

  In the embodiment of the present invention constructed from the

  above described manner, when the maximum load is applied to the mo-

  drive tor 11b when the transport beams lb are lifted

  raised, as shown in Figs. 8a and 8b, the other trans-

  port la are lowered under the action of their weight and their load, from which it follows that the motor lla provides braking action and operates as a generator recovering braking energy. As a result, from the point of view of energy consumption, the weights of the beams la and lb compensate each other and the load is represented only by the difference between the weight of the steel tubes carried by each of the two groups and by the friction resistance of the drive system

  transport beams. As a result, the overall consumption of

  energy required for the transport of steel tubes can be considered

  reduced and that small motors can be used

  low power as drive motors.

  Although, in the embodiment described above, the transport beams are arranged longitudinally in rows of two beams, the number of transport beams in each row can be increased if the transport distance is long. Furthermore, in this embodiment, the transport beams of each group are driven by a separate motor but it is possible to have all the transport beams driven by a single motor in such a way that the circular movements of the two groups transport beams are mechanically out of phase thanks to the use of articulated link mechanisms

  abutments. Furthermore, although the embodiment described above has been described

  above of the invention with reference to its application to the transport of -

  steel tubes, round bars and the like, it is understood that the apparatus of the present invention can be used to transport

  any other products and materials.

  We can thus see on reading the detailed description

  above that the walking beam of the present insertion can re-

  considerably reduce the power necessary to transport steel tubes and the like and that it also allows the use of small-sized moteuys thus reducing the production cost and ensuring

energy savings.

Claims (3)

  1 - A walking beam of the type according to which an object (10) to transport   ter is placed on fixed beams (8) and is transported by the repetitive process which consists in lifting the object from below, moving the object 5. forward and resting the object on the fixed beams by means a series of transport beams (1> arranged to execute a movement   circular in response to rotation of rotating drive shafts, ca-   characterized in that the series of transport beams is divided, with respect to the longitudinal direction, into N groups, N being an integer equal to or greater than 2, and in that the transport beams (la, lb) are coupled to the rotary drive shafts (5a, 5b) in such a way that the circular movements of the transport beams of the N groups have the same direction and the same period but are out of phase   relative to each other by 2 T / N radians.   2 - A walking beam according to claim 1, characterized in that the number N of groups is 2 and in that the phase difference between the circular movements of the transport beams (la, lb) of two groups is from a radians.   3 - A walking beam according to claim 3, characterized in that it further comprises link mechanisms for transforming the rotational movements of the rotary drive shafts (5a, 5b)   in circular movements of the transport beams and in that the difference   The phase rence of the circular movements of the groups is determined by the link mechanisms in accordance with the initial mounting angles.   connecting rods (6a, 6b) on the transport beams (la, lb).