US3162765A

US3162765A - Length measuring device for automatic folders

Info

Publication number: US3162765A
Application number: US186450A
Authority: US
Inventors: Cran William Broadbent Gordon
Original assignee: Thomas Broadbent and Sons Ltd
Current assignee: Thomas Broadbent and Sons Ltd
Priority date: 1961-04-11
Filing date: 1962-04-10
Publication date: 1964-12-22
Anticipated expiration: 1981-12-22
Also published as: GB1016692A; FR1323138A

Description

22,-, w. B. G. CRAN 3,162,755

vmsumuc DEVICE FOR AUTOMATIC FOLDERS IUENGWEH tFilefl April 35%? 4 Sheets-Sheet l HINVEFIIOR;

WILL IAN 8.16. 0 WA u :sBY

Dec. 22, 1964 w. B. G. CRAN 3,162,765

LENGTH MEASURING DEVICE FOR AUTOMATIC FOLDERS 4 Sheets-Sheet 2 Filed April 10, 1962 INVENTORZ WILLIAM A GRAN A770? NE Y3 w. a 5. GRAN 3,162,765

LENGTH MEASURING DEVICE FOR AUTOMATIC FOLDERS Dec. 22, 1 964 4 Sheets-Sheet 5 Filed April 10, 1962 INVENTOR: /uunm CH N w. B. G. GRAN 3,162,765

LENG IZHZ MEASURING DEVICE FOR AUTOMATIC FOLDERS 4 Sheets-Sheet 4 Dec. 22, 1964 Filed April 10, 19623 INVENTORZ A/ILLIAM B -0 BY MJQM W 'W United States Patent Qfifice 3,162,7h Patented Dec. 22, 1964- 3,162,765 LENGTH MEASURING DEVICE FOR AUTOMATIC FGLDERS William Broadbent Gordon Cran, Den'oy Dale, near Huddersfield, England, assignor to Thomas Broadbent & Sons Limited, Huddersfield, Yorkshire, England Filed Apr. 1t), 1962, Ser. No. 186,450 Claims priority, application Great Britain, Apr. 11, 1961, 12,937/61; Feb. 14, 1962, 5,596/62 16 Claims. (Cl. 250-223) The present invention relates to timing devices for monitoring the progress of articles travelling in open form along a given path and each of which changes speed, earlier or later depending upon its length, at a time when its trailing end passes a given point in said path. The invention is particularly applicable to the monitoring of the progress of articles travelling from an ironing machine to a folding device for the purpose of ensuring that the article is folded by the folding device at a given locality with respect to its length.

According to the present invention a timing device for monitoring the progress of articles travelling in open form along a given path and each of which changes from a first speed to a second speed, earlier or later depending upon its length, at a time when its trailing end passes a given point in said path, comprises a controller adapted to initiate a signal when it has moved through a given amplitude of movement, means to drive the controller through an initial portion of said given amplitude at a speed in prescribed ratio to the first speed of the article during the period when the article moves past said given point, and means to drive the controller at a speed in given ratio, higher than said prescribed ratio, to the second speed of the article immediately after the trailing end of the article moves beyond said given point and until the controller completes its movement through the remainder of said given amplitude to achieve the result that irrespective of the length of the article a signal is initiated by the controller when a point on the article in advance of its trailing end by a distance equal to a fraction of its length represented by said prescribed ratio divided by said given ratio reaches a second given point in the path of the article beyond said given point by a distance equal to said amplitude of the controller divided by said given ratio.

According to another aspect of the invention a timing device for monitoring the progress of articles travelling in open form along a given path at speeds governed respectively by a first driving means and a second driving means and the speed of each of which becomes subject to the second driving means earlier or later depending upon its length when its trailing end leaves said first driving means comprises a controller adapted to initiate a signal when it has moved through a given amplitude of movement, means to drive the controller through an initial portion of said given amplitude of movement at a speed in prescribed ratio to the speed of the first driving means during the period that the article moves past a given point adjacent to the position Where the trailing end of the article leaves said first driving means, and means to drive the controller at a speed in given ratio, higher than said prescribed ratio, tothe speed of the second driving means immediately after the trailing end of the article leaves said first driving means and until the controller completes its movement through the remainder of said given amplitude to achieve the result that irrespective of the length of the article a signal is initiated by the controller when a point on the article in advance of its trailing end by a distance equal to a fraction of its length represented by said prescribed ratio divided by said given ratio reaches a second given point in the path of the article beyond said given point by a distance equal to said amplitude of the controller divided by said given ratio.

The controller may be driven through the said initial portion of its amplitude of movement by rotatable means in the path of the article positioned adjacent to said given point and adapted to be engaged and driven by the article.

In one form of construction of timing device according to the invention the distance between said given point and said second given point may be equal to the amplitude of movement of the controller in which case the controller should be driven through said initial portion of its amplitude of movement at a fraction of the speed of the article equal to the aforesaid fraction of the length of the article from its trailing end. The amplitude of the controller however may be different from but in a fixed proportion to the distance between said given point and said second given point in which case the speeds at which the controller is driven should be modified in accordance with said fixed proportion.

The controller may be driven through said initial portion of its amplitude of movement at a speed in prescribed ratio to or at said prescribed fraction of the speed of the article or of said first driving means through a mechanical power transmission means and through a releasable clutch. The controller may be driven through the remainder of said given amplitude of movement at the speed of the article or at a speed in said given ratio to the speed of the article or of said second driving means by an electric motor and through a clutch. Said clutches are preferably electro-magnetically operable. Alternatively electrical driving links may be provided for driving the controller through said initial portion and through said remainder of said given amplitude of movement. Thus the controller may be driven by an electric motor fed with pulses at rates proportional to the speeds of the article or of said first and second driving means.

The invention includes the combination of an ironing machine, a folding device and a conveyor extending from the ironing machine to the folding device and a timing device as above set forth for monitoring the progress of the article from the ironing machine to a predetermined position between the ironing machine and the folding device whereby to enable the folding device to be brought into operation on the article at a given production of its length from one end thereof by timing the operation of the folding device in relation to said signals to the speed of the conveyor.

In one form of construction of the invention a photoelectric receiver is arranged at one end of a folder conveyor immediately adjacent to the exit of an ironing machine. A controller in the form of a rotatable cam is arranged to operate a micro-switch on movement through a prescribed amplitude preferably 360 and is driven through gears by a roller which is arranged immediately above the extreme end of the folder conveyor adjacent to the ironing machine and which is driven by the article as it emerges from the ironing machine, the gear ratio between the roller and the cam being such that the cam is driven at a prescribed fraction, e.g. one half, of the speed of the article,

The photo-electric receiver controls a clutch for drivably connecting the cam to the roller. The cam is also drivable at the speed of the folder conveyor either by an electric motor which is synchronized with the speed of the conveyor, or through suitable transmission means by the folder conveyor itself. The driving of the cam at the speed of the folder conveyor is afiected by means of a clutch also under the control of the photo electric receiver, the arrangement being such that when light projected towards the photo electric receiver is obstructed by an article passing from the ironer to said roller the cam is driven by the roller through said first mentioned clutch but when the article has emerged from the ironer to enable the light beam to impinge on the photo electric receiver said first mentioned clutch is released and said second mentioned clutch engaged to cause the cam to be driven at the speed of the folder conveyor. Since the cam is driven by the roller for a period corresponding to the length of the article and since during this period the cam is driven at a fraction, e.g. half the speed of the article and since the cam is thereafter driven at the speed of the article it follows that irrespective of the length of the article the micro-switch will be operated when the midlength of the article has reached a given point spaced from the roller by a distance equal to the amplitude movement of the cam.

The controller may be driven from said rotatable means by an electrical link instead of a mechanical power transmission means as described above. The provision of an electrical link enables the clutch employed in the mechanical connection to be replaced by a switch and relay.

The invention will be further described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic side elevation of one embodiment of the invention,

FIG. 2 is a diagrammatic plan view of the embodiment shown in FIG. 1, 7

FIG. 3 is a diagrammatic side elevation of a second embodiment of the invention,

FIG. 4 is a schematic diagram illustrating the driving of the controller by electrical links,

FIG. 5 is a side view of a further embodiment of the invention, and

FIG. 6 is a fragmentary sectional view corresponding to FIG. 5.

Referring to the FIGS. 1 and 2 an article emerging from an ironer 1 passes along a folder conveyor 2 and drop between a fold blade 3 and nip rollers 4 situated beneath the delivery end of the folder conveyor. At a correct moment an air cylinder 5 or other suitable means actuates the fold blade 3 to push the article between the nip rollers. The folded article is then delivered out of the apparatus on a second conveyor 6 leading for example to a stacking device or to a delivery table or to a further folding mechanism.

The article moves at the speed of the ironer 1 until its trailing end clears the ironer and thentravels at the higher speed of the folder conveyor. Above the folder conveyor at the end adjacent to the ironer, is a roller 7 which drives a gear wheel 8 through a system of intermediate gears 9. A cam 10 coaxial with this gear wheel 8 18 connected or disconnected to the gear wheel 8 through an electromagnetic clutch 11 (FIG. 2). Also coaxial with the gear wheel 8 and the cam 10 is an electric motor 12 which may be connected or disconnected to the cam through a second electromagnetic clutch 13.

The electric motor 12 is of constant speed such that when it drives the cam 10, the peripheral speed of the latter 1s exactly the same as the speed of the folder conveyor 2. When the cam is driven through the gears by the roller 7 the peripheral speed of the cam is a certain fraction of the peripheral speed of the roller depending upon the diameters and numbers of gears 9 between the cam 10 and the roller 7. For the purpose of the present example, the peripheral speed of the cam 10 will be taken as half that of the roller 7.

Once every complete revolution the cam 10 operates a mlcro-switch 14. In line with the roller 7 is a switch re (FIG. 2), preferably a photo-electric receiver and light source so arranged that as an article reaches the conveyor 2 it cuts the light beam impinging on the receiver. The photo-electric receiver is adjustable longitudinally 1n the direction of travel of the article so that the point at whlch the leading end of the article cuts the beam (and When the trailing end leaves it) can be adusted.

Dimensions are arranged so that the length of the folder conveyor is approximately 60% Of the length of the longest article to be folded, and the circumference of the cam is approximately of the length of the longest article.

The operation of the device is as follows: When no article is passing, the roller 7 is driven by the folder conveyor 2 and the gear wheel 8 is disconnected from the cam which is at rest, with the micro-switch 14 inoperative. As an article emerges from the ironer 1 it is nipped between the roller 7 and the folder conveyor 2. As long as part of the article is in the ironer, the article moves at the speed of the ironer. On entering the nip, the leading end of the article interrupts the light beam striking the photo-electric receiver 15 and this causes energisation of the electromagnetic clutch 11 so that the cam 10 is now driven by the roller 7. This, in turn, operates the micro-switch 14 which starts the motor 12.

The roller 7 continues to drive the cam 10 until the trailing end of the article emerges from the ironer 1 and clears the photo-electric receiver 15. When this happens the roller will have rotated proportionally to the length of the article and the recess on the cam will have moved through a distance equal to one half of the length of the article. When the trailing end of the article clears the photo-electric receiver 15 the impingement of the light beam on the receiver causes the electromagnetic clutch 11 to be disengaged and the second electromagnetic clutch 13 to be engaged so that the cam 10 is now rotated by the motor 12 but at a speed equal to that of the folder conveyor. When the cam 16) has completed one revolution, the micro-switch 14 will again be operated and the midlength of the article to be folded will have reached a fixed point on the folder conveyor in advance of the switch 15 by a distance equal to the amplitude of the cam i.e. its peripheral length. This point is marked X on FIG. 1 and holds good for any length of article. When the cam 10 has completed one revolution the motor 12 stops and a time delay relay is operated to actuate the fold blade 3 after a preset time interval determined by the distance from the point X to the nip rollers 4 and the time taken by the article to travel this distance. The operation of the fold blade 3 (or alternatively the operation of the micro-switch 14) disconnects the electromagnetic clutch 13 and resets the device for the next cycle of operation.

As in practice, articles follow each other in rapid succession from the ironer, it will be apparent that at least two devices are needed with an automatic cycling switch so that succeeding articles are measured on different devices.

The example given is for folding articles in half but by suitable arrangement of the gear train 9 an article can be folded into a desired fraction of its length.

The embodiment illustrated in FIG. 3 operates in a similar manner to that already described. The cam 10, operating a micro-switch 14 and driven by gear wheels 9, has however been replaced by a disc 16 driven by a system of pulleys 17. A hole 18 is bored through the disc 16 at a point near its periphery and a photo-electric receiver 19 and a light source 20 are located on opposite sides of the disc 16. When the disc 16 is at rest, prior to the passing of an article beneath the roller 7, the light beam passes through hole 13 and impinges on the photoelectric receiver 19. As soon as the disc starts to rotate the beam is cut off, and is not restored until the disc has completed one revolution and the hole 18 has returned opposite to the light source. This photo-electric receiver 19 and light source 20 replaces and performs the same function as the micro-switch 14 of the previous embodiment. The relationship between the peripheral speeds of the disc 16 and the roller 7 are determined by their diameters and the pulley system used.

The device illustrated in FIG. 4 comprises an endless conveyor 31, a fold blade 32 and a nip roller 33. A roller 34 is situated adjacent the end of the conveyor 31 remote from fold blade 32. This roller is driven by the conveyor 31 or by an article to be folded passing between it and the conveyor 31. The roller 34 drives a tachogenerator which is preferably located inside the roller 34 and whose presence is indicated by the reference 35. A photo-electric unit 36 is also positioned adjacent the end of the conveyor 31 and the roller 34. The tacho-generator 35, which is preferably of the permanent magnet type, is electrically connected to a pulse shaping and amplifying circuit 37, which is connected in turn through a switch 38 to a synchronous motor 39 which drives a cam 40. The present invention thus provides a synchronous electrical link between the roller 34 and the cam 40 instead of a mechanical connection as described with reference to FIGS. 1, 2 and 3. The synchronous motor 39 is also connected electrically to a second supply source through a relay 4-1 and a switch 42. The cam 40 is arranged to actuate a micro-switch 43.

The device operates in the following manner. An article to be folded on entering between the conveyor and the roller 34 cuts across a light beam impinging on the photo-electric unit 36. The article moving between the conveyor 31 and the roller 34 directly drives the roller 34 and hence the tacho-generator 35. The tacho-generator produces voltage pulses at a rate proportional to a fraction of the speed of the article, and will produce on pulse per unit length of the articles independent of the speed of the article. For the sake of illustration voltage pulses are produced in the present example at a rate proportional to half of the speed of the article to result in the article being folded in half.

The photo-electric unit 36, on actuation by the leading edge of the article passing between the roller 34 and the conveyor 31 and cutting across the light beam, operates switch 38 so connecting the pulse shaping and amplifying circuit 37 to the synchronous motor 39. Thus the synchronous motor 39 is driven from the tacho-generator 35 while the article passes between the nip formed by the roller 34 and the conveyor 31. This causes the cam 40 to rotate at a peripheral speed equal to half of the speed of the article. As soon as the cam 40 starts to rotate, micro-switch 43 is actuated and this in turn closes relay 41 in the leads to the external supply circuit.

When the trailing edge of the article clears the nip between the roller 34 and the conveyor 31 the light beam re-impinges on the photo-electric unit 36. This causes the switch 33 to open and at the same time closes switch 42. The pulse shaping and amplifying circuit 37 is therefore cut off from the synchronous motor 39 which is now driven by the external power supply source as both the relay 41 and the switch 42 are closed. The external power supply source may be the same as that driving the conveyor 31. The cam 46 now rotates at a peripheral speed equal to the speed of the conveyor until it completes one full revolution. On completing the full revolution the microswitch 43 is again actuated by the cam 48 and this causes the relay 41 to be opened to disconnect the synchronous motor from the external supply source.

By the time the cam 40 has completed a full revolution, the mid length of the article to be folded will have reached a point X on the folder conveyor 31. The distance from the nip between the roller 34 and the conveyor 31 to the point X is equal to the circumference of the cam 40 and the mid point of an article will always coincide with the point X on the conveyor 31 irrespective of the length of the article to be folded. When the mid-point of the article has reached the point X a time relay is operated to actuate the fold blade 32 after pre-set interval determined by the distance from the point X to the nip rollers 33 and the time taken by the article to travel this distance. The operation of the fold blade 32 re-sets the device for the next cycle of operation. The folded article on emerging from the nip rollers 33 is carried away on a conveyor 44.

The above example refers to folding an article in half, but by suitable choice of tacho-generator to produce volt- 6 age pulses at a rate proportional to any fraction of the speed of the article the article can be folded at such a fraction of its length.

In the above example after the article has cleared roller 34, the synchronous motor 39 is supplied by a power supply having the same frequency as that delivered to the motor driving the conveyor 31. As an alternative to this method a second tacho-generator driven by the conveyor 31 may be used to provide the required pulse rate. This pulse rate has to be shaped and amplified by a circuit similar to the circuit 37 before being supplied to the synchronous motor 39.

Referring now to FIGS. 5 and 6 a roller 51 located on a conveyor 52 and drivable by an article passing therebetween is connected through a gear train 53 to a timing device 54.

As may be seen from FIG. 6 the timing device 54 comprises a pair of timers 55 arranged side by side. Each timer 55 comprises a shaft 56 having a cam disc 57 at one end. Three

sleeves

58, 59 and 60 are located on each shaft 56;

sleeves

58 and 60 are rotatably mounted on the shaft 56 whilst the centre sleeve 59 is rigidly fixed or splined to the shaft. A pair of electro-magnets 61 and 62 encircle the sleeves. The sleeve 58 carries a gear wheel 63 which is at the end of the gear train 53 linking the sleeve 58 to the roller 51. The sleeve 60 carries a gear wheel 64 which meshes with another gear wheel 65 mounted on a shaft 66 (FIG. 5). The shaft 66 is driven at a speed proportional to that of the conveyor 52, either by a separate motor (not shown) or by a drive taken from the conveyor 52 itself.

A pawl 67 (FIG. 5) engages in a notch 68 in the periphery of the cam disc 57. The pawl 67 is raised on energisation of a solenoid 69 to allow rotation of the disc 57.

In operation, when an article passes between the roller 51 and the conveyor 52 light falling on a photo-electric receiver 70 from a light source 71 is interrupted and electromagnet 61 and solenoid 69 are energised. Energisetion of the electro-m-agnet 61 causes sleeves 58 and 59 to be brought into engagement so causing rotation of the disc 57 as the pawl 67 is now lifted out of the notch 68. Disc 57 is therefore driven from the roller 51 through the gear train 53 such that the speed of rotation of the disc 57 is a certain fraction of the speed of rotation of disc 51. As before, this fraction will be taken as a half for the sake of example only.

When the trailing edge of the article clears the photoelectric receiver 70 and light source 71, electromagnet 61 and solenoid 69 are de-energised. Pawl 67 now drops on to the surface of the disc 57 and at the same time electromagnet 62 is energised. Energisation of electromagnet 62 causes sleeve 59 to be moved out of engagement with sleeve 58 and into engagement with sleeve 60. Disc 57 is now driven at the same speed as the conveyor 52 through the gear wheel 64, sleeve 60, and shaft 56.

Upon completion of a single revolution of the disc 57, the pawl 67 drops back into the notch 68. This causes the de-energisation of the electromagnet 62 and a time delay is actuated to operate a folder blade after a set time interval.

As articles generally follow one another in quick succession along the conveyor 52, it is necessary to have at least two timing devices in operation. This is achieved, as shown in FIG. 6, by duplicating the mechanism already described. Gear wheel 63 is mounted on sleeve 58 which in turn is rotatably mounted on shafts 56 and 72. The shafts are separated by a gap 73 so that the shafts can rotate independently of one another.

Although the invention has been particularly described in combination with an ironing machine it may of course be employed in other combinations. For example the conveyor 2 may receive articles from a feeding conveyor running at a slower speed than its own. Moreover the invention can be used in other combinations than with a folding device.

I claim:

1. A proportional length measuring device for monitoring the progress of articles travelling in open form along a given path and each of which changes from a first speed to a second speed during its monitored progress comprising a controller. adapted to initiate a signal when it is moved through a given amplitude of movement, rotatable means in the path of the article adapted to be engaged and driven by the article and to drive the controller through an initial portion of said given amplitude at a speed in prescribed ratio to the speed of the article and means to drive the controller at a speed in given ratio, higher than said prescribed ratio, to the second speed of the article immediately after the trailing end of the article moves out of contact with said rotatable means and until the controller completes its movement through the remainder of said given amplitude to achieve the result that irrespective of the length of the article the signal is initiated by the controller when a point on the article in advance of its trailing end by a distance equal to a fraction of its length represented by said prescribed ratio divided by said given ratio reaches a point in the path of the article beyond said rotatable means by a distance equal to said amplitude of the controller divided by said given ratio.

2. A proportional length measuring device according to claim 1 comprising mechanical power transmission means and releasable clutch means for transmitting drive to said controller through said initial portion of its amplitude of movement.

3. A proportional length measuring device according to claim 1 characterized by an electric motor and a releasable clutch for driving said controller through said remainder of its amplitude of movement.

4. A proportional length measuring device according to claim 1 comprising electrical links for transmitting drive to the controller through respectively said initial portion of its amplitude in said prescribed ratio to the speed of the article and through said remainder of its amplitude in said given ratio to the speed of the article.

5. A proportional length measuring device according to claim 1 comprising an electric motor for driving said controller fed with pulses at rates proportional to the speeds of the article.

6. A proportional length measuring device according to claim 1 comprising an electric motor for driving the controller, a tachogenerator adapted to feed pulses to said motor and rotatable means engageable by the article for driving the tachogenerator.

7. A proportional length measuring device according to claim 1 comprising switch means located substantially at said rotatable means to initiate the driving of the controller at one speed through said initial portion of said given amplitude when the leading end of the article reaches said rotatable means and subsequently to discontinue the driving of the controller at said one speed and to initiate the driving thereof at a different speed through the remainder of said given amplitude when the trailing end of the article moves beyond said rotatable means.

8. A proportional length measuring device according to claim 7 comprising switch means in the form of a light source and photo-electric receiver.

9. A proportional length measuring device according to claim 7 comprising a second switch operated by the controller when it completes its movement through said given amplitude.

10. A proportional length measuring device according to claim 1 comprising two controllers, switch means located substantially at said rotatable means to initiate be driving of said controllers alternately at one speed through said initial portion of the given amplitude and then at a different speed through the remainder of the given ampli-. tude, and individual switch means associated one with each of the controllers each adapted to be operated by its controller as the controller completes its movement through its given amplitude.

11. A proportional length measuring device for monitoring the progress of articles travelling in open form along a given path at speeds governed respectively by a first driving means and a second. driving means and the speed of each of which becomes subject to the second driving means earlier or later depending upon its length when its trailing end leaves said first driving means, comprising a controller adapted to initiate a signal when it has moved through a given amplitude of movement, rotatable means in the path of the article adapted to be engaged and driven by the article and to drive the controller through an initial portion of said amplitude at a speed in prescribed ratio to the speed of the driving means during the period that the article moves past a given point adjacent to the position where the trailing end of the article leaves said first driving means, and means to drive the controller at a speed in given ratio, higher than said prescribed ratio, to the speed of the second driving means immediately after the trailing end of the article leaves said rotatable means and until the controller completes its movement through the remainder of said given amplitude to achieve the result that irrespective of the length of the article a signal is initiated by the controller when a point on the article in advance of its trailing end by a distance equal to a fraction of its length represented by said prescribed ratio divided by said given ratio reaches a second given point in the path of the article beyond said given point by a distance equal to said amplitude of the controller divided by said given ratio.

12. A proportional length measuring device for monitoring the progress of articles travelling in open form along a given path and each of which changes from a first speed to a second speed earlier or later depending upon its length at a time when its trailing end passes a given point in said path, comprising a controller adapted to initiate a signal when it has moved through a given amplitude of movement, rotatable means in the path of the article positioned adjacent to said given point adapted to be engaged and driven by the article and to drive the controller through an initial portion of said given amplitude at a prescribed fraction of the speed of the article during the period that the article moves past said rotatable means and means for driving the controller at the second speed of the article immediately after the trailing end of the article moves beyond said rotatable means and until the controller completes its movement through the remainder of said given amplitude to achieve the result that irrespective of the length of the article a signal is initiated by the controller when a point on the article in advance of its trailing end by a distance equal to said prescribed fraction of its length reaches a second given point in the path of the article.

13. A proportional length measuring device according to claim 12 in which said second given point is located beyond said first given point by a distance equal to the amplitude of the controller.

14. A proportional length measuring device according to claim 13 in which the amplitude of the controller is different from but in a given proportion to the distance between said given point and said second given point and the speeds at which the controller is driven are modified in accordance with said fixed proportion.

15. A proportional length measuring device for monitoring the progress of articles travelling in open form along a given path each of which changes from a first speed to a second speed earlier or later depending upon its length when its trailing end passes a given point in said path comprising a controller adapted to initiate a signal when it has moved through a given amplitude of movement, rotatable means in the path of the article adapted to be engaged and driven by the article and to drive the controller through an initial portion of said given amplitude at a speed in prescribed ratio to the speed of the article during the period when the article moves past said given point, means to drive the controller at a speed in given ratio, higher than said prescribed ratio, to the speed of the article immediately after the trailing end of the article moves beyond said given point and until the controller completes its movement through the remainder of said given amplitude, switch means located substantially at said given point to initiate the driving of the controller at one speed through said initial portion of said given amplitude when the leading end of the article reaches said given point and subsequently to discontinue the driving of the controller at said one speed andto initiate the driving thereof at a dilferent speed through the remainder of said given amplitude when the trailing end of the article moves beyond said given point and a second switch operated by the controller when it completes its movement through said given amplitude.

16. The combination of an ironing machine for articles of laundry flatwork, a folding device, conveyor means between the ironing machine and folding device and a proportional length measuring device for monitoring the movement of articles from the ironing machine to the folding device, said measuring device having a controller adapted to initiate a signal when it has moved through a given amplitude of movement in which the conveyor means conveys the articles at a speed higher than that of the movement of the articles through the ironing machine so that the speed of each article changes from a first speed to a second higher speed at an instant when its trailing end leaves the ironing machine, which controller is driven by a rotatable means which is located near to where the article leaves the ironing machine and which is adapted to be engaged and driven by the article and thus to drive the controller through an initial portion of said given amplitude at a speed in prescribed ratio to the first speed of the article.

References Cited by the Examiner UNITED STATES PATENTS 2,743,920 5/56 Petre 27080 2,774,592 12/56 Kagan 270-81 2,858,129 10/58 Buss 27081 2,871,010 1/59 Likens 27081 2,942,874 6/60 Hajos 27083 RALPH G. NILSGN, Primary Examiner.

WALTER STOLWEIN, Examiner.

Claims

1. A PROPORTIONAL LENGTH MEASURING DEVICE FOR MONITORING THE PROGRESS OF ARTICLES TRAVELLING IN OPEN FORM ALONG A GIVEN PATH AND EACH OF WHICH CHANGES FROM A FIRST SPEED TO A SECOND SPEED DURING ITS MONITORED PROGRESS COMPRISING A CONTROLLER ADAPTED TO INITIATE A SIGNAL WHEN IT IS MOVED THROUGH A GIVEN AMPLITUDE OF MOVEMENT, ROTATABLE MEANS IN THE PATH OF THE ARTICLE ADAPTED TO BE ENGAGED AND DRIVEN BY THE ARTICLE AND TO DRIVE THE CONTROLLER THROUGH AN INITIAL PORTION OF SAID GIVEN AMPLITUDE AT A SPEED IN PRESCRIBED RATIO TO THE SPEED OF THE ARTICLE AND MEANS TO DRIVE THE CONTROLLER AT A SPEED IN GIVEN RATIO, HIGHER THAN SAID PRESCRIBED RATIO, TO THE SECOND SPEED OF THE ARTICLE IMMEDIATELY AFTER THE TRAILING END OF THE ARTICLE MOVES OUT OF CONTACT WITH SAID ROTATABLE MEANS AND UNTIL THE CONTROLLER COMPLETES ITS MOVEMENT THROUGH THE REMAINDER OF SAID GIVEN AMPLITUDE TO ACHIEVE THE RESULT THAT IRRESPECTIVE OF THE LENGTH OF THE ARTICLE THE SIGNAL IS INITIATED BY THE CONTROLLER WHEN A POINT ON THE ARTICLE IN ADVANCE OF ITS TRAILING END BY A DISTANCE EQUAL TO A FRACTION OF ITS LENGTH REPRESENTED BY SAID PRESCRIBED RATIO DIVIDED BY SAID GIVEN RATIO REACHES A POINT IN THE PATH OF THE ARTICLE BEYOND SAID ROTATABLE MEANS BY A DISTANCE EQUAL TO SAID AMPLITUDE OF THE CONTROLLER DIVIDED BY SAID GIVEN RATIO.