DE3835609A1 - Length-measuring device (instrument) - Google Patents

Abstract

The invention relates to a length-measuring device, in particular for determining the body height of persons, consisting of a guide rail, provided with a scale, and of a measuring carriage (slide) which can be displaced along the guide rail. The scale has a bar code, and there is arranged opposite it an optoelectric measuring device which is coupled to the measuring carriage and to which an evaluation unit and display are connected. The measured value is preferably detected via an incremental tape and a light barrier. The measuring method permits very precise length measurement, and can be performed in a way which is largely free from noise and wear.

Description

The invention relates to a length measuring device, in particular especially for determining the body length of people, be standing from a guide provided with a scale rail and a slidable along the guide rail Measuring slide.

The determination is particularly in the field of medicine the body length of people of interest because of the Body length can be found in conjunction with others Sizes or data conclusions on the development, the Nutritional status etc. of a person. With increasingly improved diagnostic and therapeutic treatment options are the requirements special to the accuracy of these measuring instruments increasingly ge rose. For example, in the treatment of stunted growth It is extremely important to take as soon as possible after taking growth-promoting or inhibiting medications speak to determine any adverse effects or quickly determine the absence of any effect and take further therapeutic measures accordingly to be able to.

Length measuring devices for determining the body length of people consist in the simplest embodiment of one at the Wall mounted scale or tape measure to which the examining person is provided. The body length will determined by approximately horizontal and tangential to the head end the corresponding scale value is read. Such one Length measuring device is extremely inexpensive, has ever but the disadvantage that the length measurement is very imprecise.

Length measuring devices with a scale are widely used or measuring tape provided with sliding profiles Calipers, either directly on the wall or on Perso  scales are attached. The length measurement is done by the caliper from above on the head of each person is pushed and then the corresponding Kör on the scale per length is read. As a result of the simple structure these known length measuring devices inexpensively and require little space. However, since these devices are very light, undesirable deflections and consequently occur easily its too inaccurate measurements. In addition, it is on and very easy to use, not very comfortable bel.

Another known length measuring device comprises a teles copular tube profile on which a measuring arm is attached and ver with a scale or tape measure see is. This arrangement also takes up little space and is quite inexpensive. The length measurement is also in this Case pretty imprecise.

It is also known a length measuring device, the one at a Wall mounted flat guide rail includes. In this A measuring slide is guided in the guide rail. The measuring sled displacement corresponding distance is over a rack and a gear train on one turn transfer meter. The meter reading becomes the Body length determined. The measurement and reading accuracy are pretty good with this device. Extremely disadvantageous however, is the one with the rack and pinion gear assembly associated strong noise. Another disadvantage this known length measuring device is that single Lich unguided counterweights are provided and it due to the roller engine arrangement therefore in the course of Time comes to heavy wear.

As can be seen from the above description, they work known devices for measuring the length of people in general fairly imprecise and their handling is not special  expedient. Jerky adjustment movements usually occur and the constructions are often far too easy, what to unwanted deflections and an inaccurate reading caused by parallax errors etc. It is also common strong noise when moving the measuring slide tens, etc.

More length measuring devices developed for other purposes have been, for. B. Telescopic measuring rods (width measuring devices). Scales are attached to the individual telescope pieces or there is a measuring tape in the telescopic tube profile. To Length measurement can also with such a construction an incremental band and a light barrier can be provided. There are also drawing machines with a digital display have been struck, in which the measured value acquisition also carried out via an incremental belt and a light barrier becomes. The force applied during displacement is transverse to Guide rail. Length measuring devices have a similar structure Machine tools with digital display.

For the determination of short lengths in industrial applications sensor transducers and sensors, some of them inductive and partly via grinding resistors (potenti meters) record the corresponding lengths. More known Arrangements for length measurement are e.g. B. level gauges or pulse-echo measuring devices that are optical or ultrasonic work.

The invention has for its object a length measurement device, in particular for determining the body length of People to create a good display and measurement accuracy and at the same time good operating and loading has driving properties.

This object is according to the invention in a length measuring device solved with the features of claim 1. Favorable Wei  ter designs of the length measuring device according to the invention Subject of the subclaims.

One especially for determining the body length of people The proposed length measuring device according to the invention thus exists from a guide rail provided with a scale and a measuring slide that can be moved along the guide rail. The scale has a bar code and with the measurement sled is an opto arranged opposite the scale coupled electronic measuring device with which an off value unit and display are connected.

This measuring arrangement enables an extremely accurate Measurement, because by using an optoelectronic Measuring device is the inaccuracy of a naked eye reading has been turned off and the Meßge accuracy now depends among other things on the design of the Bar coding itself. So z. B. in an execution Example of the invention a measurement accuracy of ± 0.5 mm over a 2 m measuring distance can be realized inexpensively. Furthermore, the reading of the measurement result is provided a display much easier, the display of course for reading at an appropriate height and Size can be attached. In this way, the An show be designed so that measured values from larger Distance can be read without errors. This is the functional and handling properties of the Length measuring device according to the invention significantly improved. Another advantage of the length measuring device according to the invention is that it is largely noise and wear can be freely constructed.

The measuring device according to the invention works as follows. The optoelectronic measuring device detects the lines of the Bar coding by ent when moving the measuring carriage Talking light pulses received and sent to the evaluation  tronics are forwarded. This counts the received Light pulses and gives one converted into a length Measured value on the display.

An incremental band is preferred as a scale and as optoelectronic measuring device featured a light barrier see. The incremental band can be transparent or opaque appropriate stroke design, z. B. a through visible polyester tape with black lines.

The scale advantageously has one or more references markings, each with reference values in the off value unit are permanently assigned. When driving through this One reference mark is made by the measuring head Correction of the values recorded for these markings to the Reference values, d. H. a readjustment of the measuring system. This ensures that the measuring system is always measures correctly, even if it is due to aging or otherwise contingent changes to the system is coming.

The scale is appropriate in the guide rail arranges. This has the consequence that the risk of contamination is extremely small, and the whole unit can be made more compact.

The display is preferably a digital display, which makes it can be of any size. An An is cheap Bring the display to the measuring slide, which reduces the number of parts can be kept small and a direct reading at Place the measuring slide on the person's head can be. The digitally converted measurement data can also if necessary to a computer for forwarding or storage be performed.

According to a preferred embodiment of the invention are the evaluation unit and an accumulator or battery  Riesatz arranged in the measuring slide. This is for one thing allows a very compact arrangement and on the other hand there is no need to use cables. This enables the length measuring device according to the invention to be wide to operate independently of a supply source and also use it in outpatient measuring stations. Purpose the measuring slide has moderate in this embodiment a lid on top so that easy access to the Evaluation unit and the accumulator or battery pack can be held.

The guide rail is preferably provided with at least one upper stop. Another lower stop can also be provided. This will excessive Ver Avoid driving the measuring carriage, which in the case of Otherwise, up to a disassembly of the arrangement could lead.

In a preferred embodiment of the invention in the area of the upper stop and / or the rest position the measuring slide on the guide rail a contact for the Arranged on / off the measuring device. Through this Measure can greatly reduce energy consumption will.

It is also advantageous in the area of the upper part impact and / or the rest position of the measuring slide on the Guide rail charging contacts for the battery pack and on Arrange a charge indicator on the measuring slide. The accumulator sentence can be used in the case of a stationary use if not use of the measuring device are constantly reloaded, so that the measuring device according to the invention for measurement purposes largely is available regardless of a supply source. The charge indicator makes it possible to always see whether the Battery pack ready charged and the length measuring device is operational or not.  

The measuring slide is preferably roller-guided, whereby according to an advantageous embodiment ball bearing art rolls of fabric are provided as guide rollers. Such a stored or guided measuring slide is extraordinary smooth and quiet. It can also be a backlash-free Leadership can be achieved. One is favorable for this purpose Arrangement of the guide rollers in a set of three, whereby two fixed and one movable guide roller each Form role set. Usually there are four fixed ones and two movably mounted ball bearing guides roll, staggered, arranged. A pre-setting Direction expediently enables the alignment of the measurement slide and the roller guide in the guide rail, see above that the measuring slide is precisely aligned in its inclination can be. A particularly good storage results if the guide rollers, gripped by the rail legs, in the guide rail are stored.

In the area of the rest position of the measuring slide, d. H. purpose moderate in the area of the top stop, is one of the top mentioned reference marks arranged. In this way takes place with each pass or when the rest position is reached a zero setting so that the lengths according to the invention measuring device always according to the respective operating conditions updated works.

In the guide rail is preferably a compensating ge weight guided by means of a along the guide rail by means of pulleys revolving pull rope with the measuring sledge is connected. This will make a automatic return of the measuring slide to the upper end position achieved. This makes handling extraordinary Lich relieved, because it is always the resting position enough. This also ensures that that an update by the evaluation device is carried out. Also can be provided if appropriate  Set up the evaluation device during rest position should always be switched off and any accumulations Door sets can be charged regularly. When actuated the length measuring device, d. H. when the slide is down is moved, the charging contacts are then disconnected again and the evaluation unit and measuring device as well as the display switched on again.

An improved function of the counterweight with umlau The pulling rope results when there is a tension on the pulling rope Compensating spring is provided. In this way, the Upward movement of the measuring slide when a Measurement process are damped. Another dampening direction can be provided at the upper stop. Furthermore is e.g. B. a viscous damping for the measuring slide return appropriate, d. H. in this case a propeller will run floated in viscous material.

The resetting of the measuring slide is not, however imperative. For example, if the Füh rail to a counterweight without further ado to be waived. Such an arrangement is e.g. B. conceivable if Infants to be measured for this purpose in a bowl with a protruding head and feet are.

The correct attitude of a person to be measured results almost inevitably if the guide rail is a convex Has profile. This leads to an alignment of the person in the longitudinal axis, because the upper body is over the school centered leaves. This allows individual measurements be compared with each other.

Preferably, is fixed to the side of the guide rail distance below and with the measuring slide coupled a transparent, vertically aligned plate  arranged with markings. This plate can also shape or function of a ruler and makes it possible to hand of fixed points into the head of the person to be measured to bring the right position. Such an alignment is also used as an orientation towards the so-called Frankfurt Designated axis. This configuration also enables better comparability of the individual measurements.

The invention is based on an embodiment example described in more detail, with further fiction essential features in connection with the drawing he to be refined. In the drawing shows

Fig. 1 is a perspective view of a length measuring apparatus according to the Invention,

Fig. 2 in an enlarged scale a detail side view of the length measuring apparatus shown in Fig. 1, but the "Frankfurter ruler" is mounted on the other side of the measuring carriage,

Fig. 3 is a detailed front view of the length measuring apparatus of Fig. 1, showing the measuring slide in more detail,

Fig. 4 is a longitudinal sectional view of the length measuring apparatus of Fig. 1,

Fig. 5 is a partial cross-sectional view through the guide rail in the region of the measuring carriage,

Fig. 6 is a broken away partial plan view of the guide rail and the measuring slide,

Fig. 7 is a vertical partial sectional view of the guide rail, and

Fig. 8 is an explanatory diagram of the three-point bearing of the guide rollers.

First, the general structure of a length measuring device according to the invention is explained with reference to FIG. 1. A guide rail 2 made of extruded aluminum profile is mounted vertically on a wall 4 by means of wall brackets contained in the guide rail. If desired, a base plate can be arranged under the length measuring device. A longitudinally displaceable measuring slide 6 sits on the guide rail 2 . The measuring slide comprises sliding parts 8 on both sides and a measuring plate 10 which is intended to rest on the head of a person to be measured. With the sliding jaw parts connected at a distance is a two-legged additional handle 12 , which is used to handle the measuring slide 6 . Below the measuring plate 10 and above the additional handle 12 is a so-called Frankfurt ruler 14 is arranged. This Frankfurt ruler represents a transparent, vertically aligned plate with markings 16 , which can be moved together with the measuring slide 6 , and it enables a precise alignment of the head of a person to be measured.

Fig. 2 shows an enlarged partial view of the length measuring device of Fig. 1 in the area of the measuring slide 6 , but the Frankfurt ruler 14 is attached to the other side of the guide rail 2 . The Frankfurt ruler 14 is attached to a be on the back of the guide rail 2 be sensitive plate 18 which is screwed onto a back plate 20 firmly connected to the measuring slide 6 .

Fig. 3 shows a partial view of the measuring device of Fig. 1, similar to Fig. 2, the Frankfurt ruler 14 is attached upside down. The measuring carriage 6 has on the front of the measuring plate 10 as a digital display designed from display 22 , which is an example of an LED display in the illustrated embodiment. An area is left open in the top left of the display, in which a loading display 24 z. B. is in the form of a green light-emitting diode, which is seen before for a battery set to be explained later.

The internal structure of the measuring plate 10 of the measuring slide 6 can be seen in detail from the sectional view of FIG. 4, which is divided on the inside by a plurality of webs 28 . This web arrangement makes the measuring plate extremely robust. The display 22 already mentioned is located at the front end of the measuring plate 10 . Behind the evaluation unit 26 is arranged in the interior in the foremost chamber formed by the webs 28 . In a chamber 34 near the guide rail there is an accumulator set 30 on a mounting support 32 . On the upper side, the measuring plate 10 has a removable or hinged cover 36 , which allows easy access to the components contained in the measuring plate 10 .

As already mentioned, the measuring slide 6 can be moved along the guide rail 2 , the measuring plate 10 being arranged at a distance from the convexly curved front outer wall 52 of the guide rail 2 and the sliding jaw parts 8 firmly connected to the measuring plate, the guide rail 2 laterally to the rear thereof reach around and are firmly connected to the back plate 20 . The measuring slide 6 and the parts firmly connected to it are guided by means of a three-point bearing in the form of ball-bearing guide rollers 54, 82 inside the guide rail 2 and can be moved along this, a total of two sets of two guide rollers 54 and one guide roller 82 being provided. With the back plate 20 of the measuring slide 6 , a U-profile 56 is firmly connected by screwing, the central web 58 adjacent to the back plate 20 extending away from it with a slight inclination upwards. In the lower region, the central web 58 and the back plate 20 are fastened to one another by means of a screw connection 64 . Just below the screw connection 64 , the back plate 20 is bent forward in the direction of the outer wall 52 to a bottom edge 40 in the central region. Slightly above the position shown in Fig. 4 guide roller 82 is here a set screw carried out 86 whose end face 88 bears against the central web 58 from the rear side of the back plate 20, wherein an adjustment of the adjusting screw 86 58 has a more or less pronounced inclination of the central web result.

Side webs 60 of the U-profile 56 are bent forward in the direction of the outer wall 52 of the guide rail 2 . In each of the side webs 60 there is a bearing 62 and 84 designed as a ball roller, and a guide roller 54 and 82 . More specifically, as Fig. 5 shows, the back plate of the measuring carriage 6 is formed in two parts 20, wherein each weils a part of one of Gleitbackenteile 8 inwardly he stretches and terminates in a forwardly extending toward the outer wall 52 folded web 38. The web 38 and the respectively adjacent side web 60 of the U-profile 56 each form the bearing 62 or 84 of a guide roller 54 or 82 . The guide rollers 54, 82 are, as can clearly be seen from FIG. 5, guided in two guide edges 66, 68 of the guide rail 2 in the lateral region thereof. The guide rail 2 is reinforced in this area by a transversely extending transverse web 70 and two perpendicular transverse webs 72 with connecting webs 74, 80 to the curved front wall 76 and side wall 78 . This results in excellent stability of the guide rail 2 .

At the upper end, the guide rail 2 is covered by an end plate 102 , which at the front end has downwardly bent sections 104 , which are firmly connected to the front wall 76 and are in turn connected to a channel-shaped section 106 with a short leg bent backwards . The end plate 102 and the section from 106 are designed as mounting elements, the end plate 102 can also take over the function of an upper impact for the back plate 20 of the measuring slide 6 . In the lower region of the guide rail 2 there is a lower stop 108 for the bottom edge 40 of the measuring slide 6 on the rear side thereof. A scale 120 designed as an incremental band is fastened in the guide rail 2 on the front wall, as can be seen from FIG. 7. In the exemplary embodiment shown, the incremental band is transparent and has black bar coding. Compared to the incremental band one of these is arranged by luminous light barrier 122 which, when a line is detected on the incremental band when the measuring slide is moved by means of phototransistors, receives light pulses and outputs them in the form of electrical pulses which are fed to the electronic evaluation unit 26 . Contacts 124, 126 are provided for the light barrier 122 . Contacts 128 and 130 on the opposite side are a line to the battery pack 30 for connection. A ramp 132 for a contact guide wheel 134 is used to achieve a defined contact state.

The light barrier 122 is adjustable in height, so that it can be precisely adjusted after assembly on site. For applications in which such a high measuring accuracy is not required, the length measuring device can already be adjusted in the factory and attached precisely on site using an assembly template. On the front side of the front wall 76 of the guide rail 2 there is a counterweight 136 which can be pushed along the front and is covered by the outer wall 52 . On the front of the balance weight ben 138 spring tongues 140 are attached by means of screws, which abut the inside of the outer wall 52 and, when the balance is displaced longitudinally, grind along it. On the screws 138 , one end of a traction cable 142 is fastened, which extends between the outer wall 52 and the front wall 76 in the vertical direction and is deflected at the upper and lower ends to order pulleys 144 . The upper end of the pull cable 142 is attached to the upper end of the back plate 20 , whereby it runs around a further deflection roller. The lower end of the train rope 142 is attached by means of an intermediate compensation spring 146 to the bottom edge 40 of the back plate 20 .

The three-point bearing principle is illustrated schematically in FIG . Two of the guide rollers 54 each rest on one side 66 of the guide rail 2 , while the third guide roller 82 rests on the other side 68 . By adjusting the pressure on the third guide roller 82 , the plate 58, the three guide rollers of a guide set, can be adjusted in their inclination so that the sliding properties and adjustment can be adjusted in the desired manner. There are two pairs of roller sets nested in each other, as can also be seen from the partial sectional view of FIG. 5, where the left guide roller rests on the guide edge 68 and the right guide roller rests on the guide edge 66 .

The invention is based on a preferred embodiment Example and selected features described and been shown. The invention is self-evident not limited to this representation, but rather can all features alone or in any combination nation, regardless of their summary in the Claims can be used.

Claims (18)

1. Length measuring device, in particular for determining the body length of people, consisting of a guide rail provided with a scale and a sliding slide along the guide rail, characterized in that

• - the scale ( 120 ) has bar coding,
• - With the measuring carriage ( 6 ) an optoelectric Meßein direction ( 122 ) is coupled, which is arranged opposite the scale, and
• - An evaluation unit ( 26 ) and display ( 22 ) are connected to the measuring device.

2. Length measuring device according to claim 1, characterized in that a light barrier is provided as a scale ( 120 ) and an incremental band and as an optoelectric measuring device ( 122 ). 3. Length measuring device according to claim 1 or 2, characterized in that the scale ( 120 ) has one or more reference markings, each of which reference values in the evaluation unit ( 26 ) are permanently assigned. 4. Length measuring device according to one of claims 1 to 3, characterized in that the scale ( 120 ) is arranged in the guide rail ( 2 ). 5. Length measuring device according to one of claims 1 to 4, characterized in that the display ( 22 ) is a di gitalanzeige. 6. Length measuring device according to claim 5, characterized in that the display ( 22 ) on the measuring carriage ( 6 ) is attached. 7. Length measuring device according to one of claims 1 to 6, characterized in that the evaluation unit ( 26 ) and an accumulator or a battery pack ( 30 ) in the measuring carriage ( 6 ) are arranged. 8. Length measuring device according to one of claims 1 to 7, characterized in that the guide rail is provided with at least one upper stop ( 104 ). 9. Length measuring device according to claim 8, characterized in that in the area of the upper stop ( 104 ) and / or the rest position of the measuring slide on the guide rail ( 2 ) a contact ( 124, 126 ) for switching the measuring device on / off ( 122 ) is arranged. 10. Length measuring device according to claim 8 or 9, characterized in that in the area of the upper stop ( 104 ) and / or the rest position of the measuring slide ( 6 ) on the guide rail ( 2 ) charging contacts ( 128, 130 ) for the battery set ( 30 ) and on the measuring slide ( 6 ) a loading display ( 24 ) are arranged. 11. Length measuring device according to claim 1 to 10, characterized in that the measuring slide ( 6 ) is guided to roll. 12. Length measuring device according to claim 11, characterized in that ball-bearing plastic rolls ( 54, 82 ) are provided as a guide. 13. Length measuring device according to claim 11 or 12, characterized in that two fixed ( 54 ) and one movable ( 82 ) guide rollers form a roller set. 14. Length measuring device according to one of claims 11 to 13, characterized in that an adjusting device ( 86 ) for the alignment of the measuring slide ( 6 ) and the guide rollers ( 54, 82 ) is provided in the measuring slide. 15. Length measuring device according to one of claims 1 to 14, characterized in that in the guide rail ( 2 ) a counterweight ( 136 ) is guided by means of a along the guide rail ( 2 ) by means of guide rollers ( 144 ) revolving traction cable ( 142 ) is connected to the measuring slide ( 6 ). 16. Length measuring device according to claim 15, characterized in that a tension cable ( 142 ) is provided from equalizing spring ( 146 ). 17. Length measuring device according to one of claims 1 to 16, characterized in that the guide rail ( 2 ) has a convex profile. 18. Length measuring device according to one of claims 1 to 17, characterized in that a transparent, vertically aligned plate ( 14 ) with markings ( 16 ) laterally and coupled to the guide rail ( 2 ) at a fixed distance below the measuring carriage ( 6 ). is arranged.