FR2538364A1 - Device for handling containers in an installation for the deep-freezing of products. - Google Patents

Abstract

Device for handling containers in an installation for the deep-freezing of products, comprising a freezing tunnel in which the products are loaded into containers which have a number of shelves and are passed by a series of pushes around a closed circuit comprising at least two rows situated at different levels A and B. The mobile part of each elevator 9, 10 is provided with a rule 33 having indices I1 to I22 which interrupt an infrared beam that is guided by a pair of optical fibres 34, 34a and 35, 35a connected on one side to an emitter and on the other side to a receiver belonging to a photoelectric detecting element 36, 37 situated outside the tunnel 1. The invention is used for the deep-freezing of products.

Description

Container handling device in a product freezing installation.

 The present invention relates to a container handling device in a product freezing installation.

 There are known installations for freezing products which comprise a freezing tunnel in which the products are loaded into containers having several shelves and which are transferred by successive pushes in a closed circuit comprising at least two rows of containers located at different levels.

 Letuanel also contains two elevators located at the two ends of the rows of containers, one of which ensures the step-by-step rise of the containers opposite means of loading of products to be frozen and evacuation of frozen products and of which the other ensures the descent containers for transferring a container from the top row to the bottom row.

However, in known devices, it is not possible to obtain a very precise positioning of the containers, which can cause incidents causing the deterioration of the products to be frozen,
Furthermore, these devices often have the disadvantage of using jacks whose movement causes jolts of the container causing the displacement of the products on the shelves and thus risking deterioration of the products.

 The container handling device according to the invention is intended to overcome these drawbacks.

 In accordance with the invention3 the moving part of each breeder is provided with a rule comprising indexes I1 to I22 capable of interrupting an infrared ray which is guided by a pair of optical fibers connected on one side to a transmitter and to the on the other hand to a receiver of a photoelectric detector member located outside the tunnel and connected to a programmable controller which, depending on the cycle and the position of the elevator, sends signals to an electronic device for regulating flow, said regulating device countering a proportional solenoid valve supplying hydraulic fluid to a control jack of each elevator.

In the device according to the invention, the photoelectric detector bodies with infrared ray guided by optical fibers provide a small footprint of the fiber tips, a high signal accuracy, an insensitivity to temperature variations by heating the tips, a device control electronics located outside the refrigeration tunnel and insensitivity to daylight
This arrangement therefore allows great precision in the positioning of the containers, which avoids incidents during which the deterioration of the products may possibly occur. The programmable controller advantageously replaces components of more or less certain reliability. I1 assimilates the information and triggers the sequences with greater finesse.

 The proportional control solenoid device allows movements to be obtained without the usual jolts which move the products on the shelves and which risk damaging said products.

 Finally, the hydraulic cylinders are arranged so that their rods are in the retracted position when they are at rest, in order to avoid the deposition of ice which can damage the seals.

Other characteristics and advantages of the invention will be better understood on reading the following description of an embodiment and with reference to the accompanying drawings, in which
FIG. 1 is a view in longitudinal section of the tunnel showing the container handling device according to the invention in side elevation,
FIG. 2 is a cross-sectional view of the tunnel showing the handling device in transverse elevation,
FIG. 3 is a diagram of the means for controlling the jacks actuating the elevators,
- Figure 4 is a diagram of the means for detecting the passage of an index secured to the lift;
- Figure 5 is a diagram showing the rule with index and the corresponding movement of the lifting and lowering cylinders.

 Figures 1, 2 and 3, there is shown a product freezing installation which comprises a freezing tunnel in which is disposed a handling device comprising a structure consisting of two rows of posts 2, 2a resting on the floor of the tunnel and on which are fixed two pairs of rails 3, 3a and 4, 4a carried by support members 5 and arranged in two levels A and B corresponding to two rows A and B of containers 6 which have bosses 7, 7a on each side by which they rest and slide on each pair of rails 3, 3a and 4, 4a.

 Each container 6 has several shelves El to E8, on which are arranged. products to be frozen 8 which are in this case arranged in packages or cardboard boxes.

 The containers 6 move on the rails 3, 3a and 4, 4a in a closed circuit by successive pushes and according to the arrows F1, F2, F3, F4. At each end of the rows of containers 6 or of the structure 2, 3, 4 are arranged in the tunnel 1, two elevators 9, 10 resting on the ground of the said tunnel and one of which 9 is intended for the descent of the containers, then that the other 10 is intended for the step-by-step rise of the containers. Each elevator consists (Figures 2 and 3) of a frame ll having a yoke 12 on which is articulated around an axis 13 one of the ends of a beam 14 consisting of two parallel elements, which is articulated in its central part with another identical beam 16 around an axis 15 to form an XA at its other end, the beam 14 comprises a roller 17 which moves on a raceway 18 secured to a support member 19 of the elevator which comprises two candles 20, 20a on which rests by its bosses 7, 7a a container 6.

 The other beam 16 comprises at one of its ends a roller 21 which moves on a raceway 22 secured to the frame 11 and at its other end the beam 16 is articulated around an axis 23 on a body 24 d 'a hydraulic cylinder whose rod 25 is articulated around the axis .13 of articulation of the beam 14 on the frame 11.

 When the jack 24 is supplied at its upper part with hydraulic fluid and the piston being fixed, it is the body 24 of the jack which rises causing the opening between the two beams 14 and 16 and consequently the elevation of the support 19 carrying the container 6. By supplying the actuator to the lower part of the body 24, on the contrary, the body and the container support are lowered.

 At one end of the row of containers located at level B on the side of the descent elevator 9 is arranged a jack 26 whose rod 27 is capable of transferring a container 6 from the elevator 9 to row B by pushing the containers 6 of said row to bring a container 6 onto the elevator 10.

 Between the rows A and B is arranged a jack 28 for output of the products 8 to transfer these from one of the shelves El to E8 from a container to a conveyor belt 29 for the evacuation of the products.

 Above the conveyor 29 is mounted another conveyor belt 30 for supplying products 8 which are transferred from the conveyor to a shelf El to E8 of the container by a hydraulic cylinder 31. At one end of the upper row of containers located at level A and on the side of the step-up elevator 10 is there a cylinder 3? ensuring the transfer of a container 6 placed on the elevator 10 to the row A thus pushing all the containers 6 of said row to bring a container on the elevator 9. in the high position.

 On each elevator 9 and 10, is mounted a rule 33 which moves in height with the support member 19 of the elevator (FIGS. 3 and 5), said rule bearing indexes I1 to 122 for the rule of the elevator. ascent 10 and I1 to I4, for the descent riser 9. The indexes (FIG. 4) move opposite two infrared rays which they are likely to come to cut, said infrared rays being each guided by an optical fiber 34 , 35 connected to a transmitter and said spokes being recovered from the other block of the index I1 to I22 and brought back to receivers 36, 37 by optical fibers 34a, 35a. The ends of optical fibers 34, 35. and 34a , 35a are heated to prevent the deposition of ice which can interrupt the infrared beam.

 These light signals are then transformed by the detectors into an electrical signal sent to an input of a programmable controller.

 The two optical detectors 34, 35 are vertically offset by half a diameter of the indexes (FIG. 4). Each time an index I1 passes, there are two electrical signals offset by a few milliseconds.

These two signals Eo and El are processed as follows
On each rising edge of the electrical signal of Eo, if
Eo Q + El = 1 (# or exclusive), we increment (add 1) a counter.

On each falling edge of the electrical signal of Eo, if
Eo Q + El = 0 we decrease (remove 1) this counter.

 The counter is set to zero when the elevator is in the low position and, when it goes up, it increments by 1 each time it passes an index3 on the other hand when it goes down it decrements by 1 each time it passes an index.

 This device therefore makes it possible to know the position of the elevator at any time.

 The indexes II to I22 of rule 33 have two different functions. The first is the positioning of the elevator and the second gives the order to decelerate the movement before the elevator stops.

 The indexes I3, 5, 7, 9, 11, 13, 15, 17, 19, 21 mentioned in FIG. 5 give the climb deceleration orders for the elevator 10.

 The indexes I4, 6, 8, 10, 12, 14, 16, 18, 20 give the stop climb orders. The index I2 gives the order of deceleration of the descent of the elevator.

 The index gives authorization to stop the descent.

The stop is controlled by a pressure switch 38 which detects a pressure drop in the upper chamber of the jack 24, which means that the elevator is at rest on its mechanical stop.

The index 122 gives the authorization to err the rise of the elevator after a small delay, It allows the elevator 10 to slightly exceed its high position so as to allow the output of the pure locking cylinder 39 to come rest on its mechanical stop,
In principle, the rise of the elevator 9 is identical to the rise of the elevator 10.

However, the elevator 9 only stops on two high and low levels. For this purpose, the scale 33 has only 4 indexes
- the index I1 for the low level,
- index 12 for the deceleration of the descent of the elevator,
- index I3 for decelerating the rise of the elevator,
- the index I4 for the high level.

 The central device of the elevators 9 and 10 comprises a programmable automaton 41 which by means of an electronic flow regulation device 42 controls a proportional solenoid valve 43 supplying hydraulic fluid to a control cylinder 24 of each elevator. The programmable controller comprises a central unit 44, a programmable memory 45 and a data memory 46. The inputs 47 of the controller are connected to the photoelectric detectors 36, 37 and to the pressure switch 38 while the outputs 48 are connected by two conductors to the electronic flow control device 42.

 This device 42 includes a unit 49 for flow setpoints making it possible to preselect a constant flow rate and a unit 50 for integration time setpoints, said units being connected to an integrator 51 which via signals 52 sends signals electric to the coils 53, 53a of the proportional valve 43 which is connected to a hydraulic fluid center 54 comprising a fluid flow and a return tank, The valve 43 is connected by non-return valves 55, 55a and conduits 56 , 56a to one of the jacks 24 of an elevator.

 This proportional valve which makes it possible to reverse the supply to the jack 24 increases or decreases, as a function of the signals it receives from the device 42, the flow of fluid supplying the jack 24.

 The piloted non-return valves 55, 55a prevent the jack 24 from going back down> when the valve 43 is de-energized.

The handling device works as follows
At the start of the cycle the elevators 9 and 10 are in the low position and a container 6a full of products is located on the elevator 9, the elevator 10 being empty. At this moment the jack 26 pushes the container 6a, which causes it to be transferred into the row at level B and drives all the containers in the row along the arrow F1, so that a container 6b located at the opposite end is loaded on the elevator 10.

Then, the elevator 10 is actuated in the direction of ascent along the arrow F2, so that the upper shelf
El of the container 6b comes to a stop at the level of the unloading conveyor 29 and the actuation of the unloading cylinder 28 ensures the transfer of the products 8 from the shelf El onto the unloading conveyor 29 which discharges the products outside of tunnel 1.

The jack 28 then returns to its initial position.

 During the next phase the elevator 10 rises one step, that is to say the space between two shelves or between the loading and unloading belts.

 At the same time, the jack 28 unloads the product on the shelf E2 to the unloading conveyor 29 and, the jack 31 being actuated, it transfers the product 8 on the loading conveyor 30 to the shelf El previously emptied. The cylinders 28 and 31 then return to their initial position.

 These operations are thus repeated until the last shelf of the container 6b is loaded. However, since the difference between the shelves E4 and E5 is greater than one step and the shelf E5 is not opposite the jack 28, it is necessary to carry out an additional lifting operation of the elevator 10 to bring the shelf in front of the unloading conveyor.

After the unloading of the last shelf E8 and the loading of the shelf E7, as described above by means of the jacks 28 and 31, the elevator 10 rises with a pitch increased by a small height and the locking cylinder 39 comes in positive position. The elevator 10-then descends on the locking member which positions it on a mechanical reference and actuates the jack 31 which ensures the loading of the product on the last shelf
E8, said cylinder then being returned to its initial position. Iron elsewhere, the elevator 9 which is empty of container is actuated in the direction of ascent to the highest level increased by a small height and the locking cylinder 40 is actuated in the output position, so that the elevator descends on the locking member which positions it on a mechanical reference. the container being in the high position 6c, the actuator 32 is actuated which transfers the container from the elevator 10 to the row of containers at level A, so that all the containers move according to the arrow
F3 and that the last container in the row is loaded in position 6d on the elevator 9.

 Then, the elevators 9 and 10 rise from a low height in order to allow the retraction of the locking jacks 39, 40. When the jacks 39, 40 are retracted, the elevators 9 and 10 are actuated in the direction of the arrow F4, that is to say for the descent to rest on their low mechanical stops.

 The elevators 9 and 10 are then in the initial phase and a new cycle can start again. the transfer cylinders 26 and 32 operate on the same principle as the elevators 9, 10, that is to say with maximum acceleration and speed at the start of the output and re-entry of the cylinder, and a deceleration and a minimum speed at the end of the cylinder exit and re-entry.

 For this purpose, a proportional valve, an electronic flow regulation device and a programmable automaton of the type described above for elevators are used for the control of these jacks. However, the detection is different and it uses four magnetic detectors.

 Of course, the invention is not limiting and those skilled in the art may make modifications to it without departing from the scope of the invention.

Claims (8)

 B E V E N D i C A T i O s  1 Device for handling containers in a product freezing installation, comprising a freezing tunnel in which the products are loaded into containers having several shelves and which are transferred by successive pushes in a closed circuit comprising at least two rows located at different levels A and B, said tunnel also containing two elevators situated at the two ends of said rows of containers, one of which ensures the step-by-step rise of the containers opposite the means of loading of products to be frozen and deviation of products frozen and the other of which ensures the descent of the containers for the transfer of a container from the upper row to the lower row characterized in that the movable part of each lift- (9, 10) is provided with a rule (33) comprising indices (I1 to I22) capable of interrupting an infrared ray which is guided by a pair of optical fibers (34, 34a) and (35, 35a) connected on one side to a transmitter and on the other side to a receiver of a photoelectric detector (36, 37) located outside the tunnel (1) and connected to a programmable controller (41) which, depending on the cycle and the position of the elevator (9 10) sends signals to an electronic device (42) for regulating flow, said regulating device controlling a solenoid valve (43) supplying hydraulic fluid to a jack (24) control of each elevator (9, 10). 2. Device according to claim 1, characterized in that for each position of the elevator (9, 10) there are provided two infrared beams cooperating with the indexes of the rule (33) and which are detected vertically, said beams being guided by two pairs of optical fibers (34, 34a) and (35, 35a) connected to two photoelectric detectors (36, 37) which control a pulse counter giving the position of the elevator. 3. Device according to claims 1 or 2, characterized in that, for each position of the elevator (9, 10)> the rule (33) comprises two indexes (I1 to I22) offset vertically, one of which gives the ascending deceleration order, the other of which gives the elevator stop order and the descent two indexes give the deceleration and stop order. 4. Device according to claim 1, characterized in that the programmable controller (41) comprises a central unit (44), a programmable memory - (45), a data memory (46), several inputs (47) through which said apparatus is connected to photoelectric detectors (36, 37) and to a pressure switch (38) itself connected to the upper chamber of the elevator cylinder (24) and two outputs connected to the electronic device (42) for regulating flow . 5. Device according to claim 1, characterized in that the electronic device (42) for regulating the flow rate comprises a flow rate set point unit (49) and a unit of integration time set points t50) which are connected to the input of the device and which send signals to an integrator (51) connected via an amplifier (-52) to two coils (53, 53a) for controlling the proportional valve (43) supplying the cylinder of an elevator. 6. Device according to claim 1, characterized in that each elevator comprises two beams (14, 16) crossed and articulated one on the other in their middle part, one of the beams (14) being articulated to the one of its ends on the rod (25) of a jack and on a frame (11) and the other end carrying a roller (17) which moves on a raceway (18) provided on the support member (19) of the elevator3 the other beam (16) being articulated at one of its ends on the support member (19) and on the body (24) of the jack and the other end carrying a roller (21) which moves on a raceway (22) provided on the frame (11). 7. Device according to claim 1, characterized in that the transfer cylinders (26, 32) are controlled by a proportional valve, a flow control device and a programmable controller receiving 'pulses of magnetic position detectors. 8. Device according to claim 1, characterized in  that the tips of the optical fibers are heated to avoid  the deposit of ice which can interrupt the infrared beam.