DE3315761C1 - Device for generating compressive or tensile loads on essentially flat models - Google Patents

Abstract

The invention relates to a device for generating compressive or tensile loads on flat, supported models by means of spindle rotation for optical visualisation of stresses with the aid of a polariscope. In order to achieve a more precise and finer force metering, to simplify the switch from compressive to tensile load, and to extend the possibilities for use, the support strip consists of an upper (14) and a lower (13) lever, between which the spindle (21) is arranged, a sliding member (22) pressing on the insides of the levers, which insides face one another and are partly inclined. <IMAGE>

Description

The invention relates to a device according to the preamble of claim 1.

Such a device is available from Gunt Gerätebau GmbH, Hamburg, as a FL 200 transmitted light polariscope in trade. With this device, the model is supported on a rigid frame. At a A spindle is mounted on the frame side. If pressure is to be exerted on the model, the model a spindle nut is screwed on facing the end of the spindle, which may be connected via intermediate pieces, presses on the model. In the event of tensile loads, the spindle nut must be removed from the ground, one end of the The model on top of it is connected to the end of the spindle facing the model and the spindle is rotated by means of appropriate devices at the other end.

A similar device is on one of the company Berthold Horstmann, Unna, Essen, provided overhead polariscope with a similar one Frame is arranged horizontally, with a spindle arranged on one side of the frame, optionally is connected to the model via intermediate pieces and exerts either a tensile or compressive force.

The term `` model '' is usually used here as a transparent one Understood flat workpiece with a generally smooth surface, generally made of plastic. The tension are usually viewed with the help of a polariscope that is not part of the device itself. Such Devices are used, for example, for teaching purposes in schools.

The device according to the prior art makes it difficult to apply the loads to the model precisely and in a finely dosed manner. Switching from pressure to tensile loads is cumbersome. The purposes of use are limited; in particular, only one model can be shown at a time.
The invention is based on the object of designing a device according to the preamble of claim 1 so that the disadvantages of the prior art are avoided, that a more precise and finer force metering is achieved, that the changeover from pressure to tensile loading is simplified and that the possible uses be expanded.

The object is achieved according to the invention by the features of the characterizing part of claim 1.

Further developments of the invention are presented in the subclaims.

The basic principle of the invention is that the support bar for the spindle consists of an outer and consists of an inner lever, each rotatable by means of bolts or the like on opposite side strips are stored, with a support point of the model or models on the opposite side of the inside Counter bar is arranged. Between the inner and the outer lever is a spindle on the opposite side strips rotatably mounted and rotatable via an externally arranged rotary crank. the In its central area, the spindle preferably has a smooth non-spindle area with a smaller diameter on.

On the spindle is a spindle nut in the form of a: Sliding member provided, which is substantially on the inner surfaces of the outer and inner levers when Turning the spindle crank slides. In the middle area of the lockers! a load transfer part is provided which either with the outer lever or the inner lever is connected, and its facing the counter bar End, if necessary via intermediate pieces, is connected to the model, is in contact with it or is in a rotatable bearing.

On one side of the load transfer part, one lever has a lever facing the other

45 'inclined surface on the other side of the load transfer part the other lever has an inclined plane facing the one lever, a gradual one Increase from the inside out.

As a rule, the inside of the outer lever has a first incline that rises continuously outwards Level up to generate a continuous tensile force and that on the other side of the load transfer part arranged inner lever has in the direction of the outer lever a rising from the inside to the outside second inclined plane in order to generate a continuous pressure on the model or models.

In a particular embodiment, one is releasable to the lower end of the load transfer member connected bridge member pivotably mounted, at both ends of which a model can be attached, for example is rotatably mountable. The other end of the two models can then be supported on the counter bar.

In a further embodiment of the invention, the bridge part is rigid by two, but detachable

h5 extension links connected to both ends connectable, the lower ends of which from above onto the model, for example onto a side edge of the model, while pressing the opposite side on two

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lateral supports arranged below. While the two previously described embodiments essentially allow compressive and tensile loads, but with very different model shapes and clamping or support points, enables the explained in this embodiment The procedure is to generate a pure bending moment, d. H. without support force component.

Finally, a further development of the aforementioned exemplary embodiments enables a direct one visual comparison of two different models, on each of which a pure bending moment is exerted will. This is done by means of an additional link, in which, on the one hand, the aforementioned bridge part is used finds that, for example, presses on the upper edges of the upper model, the lower edges of the attack the upper models as well as the upper edges of the lower model on two further swivel supports, while the lower edge of the lower model in the same places as the supports of the bridge parts rest on lower counter bearings.

For the measurement of larger models, for example wall openings, there are two detachable ones Lower supports are provided on which the lower edge of the workpiece can rest, the center of the Upper edge of the workpiece takes place with the help of the lower end of the load transfer member.

The side supports and the lower supports and the pivot supports can preferably be combined in one single component can be provided, expediently each such component by the two side strips forming a side part of the device can be pushed in and locked in this position.

You connect the lower or inner lever with one that runs between the two side strips Printing part, a model can be clamped on the opposite side edge in such a way that the free end of the model lies between the first-mentioned sidebars, so that the lower free end the same exerts a pressure on the free end of the model. In this way, with a cantilever arm occurring stresses are simulated and visually displayed.

Finally, a further embodiment enables the visualization of the on a screw, for example a hexagon screw and stresses occurring on the attacking wrench. to For this purpose, a first model is clamped between the two side strips of a side edge The end tapers in the manner of a hexagonal screw. The model of a suitable wrench engages on this end piece of the first model. The free end of the wrench takes the position of the previously described model, such that the lower end of the pressure part pressure on the free end of the second Model in the form of a wrench.

Embodiments of the invention are explained below with reference to the drawing. It shows

Fig. 1 is a front view of an embodiment,

F i g. 2 shows a side view of an exemplary embodiment,

3 shows a detail of a further embodiment of the embodiment shown in Fig. 1 and Fig. 2,

F i g. 4 another special embodiment,

Fig.5 also shows a certain embodiment of the illustrated embodiment, F i g. 6 shows a detail of the in FIG. 4 shown embodiment,

7 shows a further application example of the invention Dung,

F i g. 8 shows another specific application example of the invention.

In Fig. 1, the front view of an embodiment of the invention is shown. In this embodiment, the frame is arranged upright. It will pointed out that the frame in the same way in another position, for example lying, can be executed.

According to Fig. 1, a base frame 1 is shown, consisting from two substantially identically constructed side parts with two side strips 2,3 respectively 4.5. In the illustration of FIG. 1, however, only the sidebars 2 and 4 are visible. The (lower) ends of these Sidebars are fixedly connected to a (lower) counter bearing 6, albeit preferably releasably.

The counter bearing contains various, generally releasably arranged (lower) supports 7, 8, 9, respectively the special measurement purpose. Often the upward facing free ends of these supports have a Bearing pin on, with the help of which the lower free end of the model to be examined 10,11,12, rotatable is stored. As a fourth side part opposite the lower counter bearing 6 are a lower or inner lever 13 and an outer or upper lever 14 is provided, which is detachable with the upper part of the side strips 2, 3, 4 and 5 and are connected to pivot at times. Each of the four connecting bolts can be easily removed will. The resulting unstable storage is compensated for by a load transfer member 15, which can either be pivoted with the upper lever 14 or rigidly, but detachably, connected to the lower lever 13 is.

The left underside of the upper lever 14 has a first inclined plane 16 that goes from the inside to the outside as well as increasing downwards. Likewise, the lower lever 13 has a second oblique on the right side Level 17, which increases from the inside outwards and upwards. The pivotable connection of the load transfer member 15 with the upper lever 14 is with the help of a bearing pin 18, the rigid connection the load transfer member 15 with the lower lever 13 is carried out with the aid of the fixed bolts 19,20.

A spindle 21 is arranged between the upper lever 14 and the lower lever 13, which on the side parts 2,3 and 4, 5 is rotatably mounted. In the right-hand area, a sliding member 22 is shown in solid lines, whereas in FIG so left section the identical sliding member 22 'is shown in dashed lines. This is intended to indicate that it is the same part that is in either the right or left pane. The same is true for the rest for the model 12, which is also shown in dashed lines, since it is usually not used when the two. Models 10 and 11 can be used.

On the right outside the base frame of the exemplary embodiment, a rotary crank 23 is provided which the spindle 21 drives and thereby the sliding member 22,22 'in the direction of the arrow along the threaded sections 24 and respectively 25 moves. Between the two threaded sections 24 and 25 is a thread-free section 26Ü; ings of which the sliding member 22, 22 'move freely leaves.

ft ^r ) The reason for this is simply to simplify and accelerate the conversion of the member from the right area to the left area and vice versa.

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The sliding member 22, 22 'always contacts the inside of the upper lever 14 as well as the inside during use of the lower lever 13 and is designed so that it relative to the spindle 21 is not rotatable.

The lower lever 13 is by means of a left bearing pin 27 and a releasable right bearing pin 28 with the left side strips 2, 3 and the right side strips 4.5 of the two side panels connected. In the same way, the upper lever 14 is detachable by means of a upper left bearing pin 29 and by means of an upper right bearing pin 30, optionally pivotable, connected to the left side parts 2, 3 and the right side parts 4, 5.

The lower end of the load transmission member 15 carries in the illustration of FIG. 1 a load transfer pin 31, to which, in the present case symmetrically, a bridge part 32 is rotatably mounted, its Ends of pivot pins 36 and 37 for the rotatable and detachable fastening of the models 10 to be examined and 11, while partially upwardly projecting cylindrical supports 33 and 34 symmetrically thereto are arranged.

The device is used to transfer compressive or tensile forces to models 10 and 11. Target pressure are transmitted, the crank 23 is rotated so that the slide member 22 moves to the right. To The three remaining fastening points for the lower lever 13 are on the lower right bearing pin 28 and the upper lever 14 is present. The lower fixed bolts 19, 20 also form a connection to the lower one Lever 13 with the load transferring member 15, while the upper bearing pin 18 is removed to a required To allow pivoting movement. The one moving outwards along the right second inclined plane 17 Sliding member 22 presses in the right area around the lower left bearing pin 27 as the axis of rotation right end of the lower lever 13 down and exercises in this way over the load transfer member 15 and the two ends of the bridge part 32 exert a pressure on the two models 10 and 11.

Looking at the optically active models 10 and 11 between devices of measuring instruments, in particular between the two mutually twisted around Polarization filter of a polariscope, then the lines of equal voltage differences, the so-called Isochromates, visible as alternating colored lines and figures.

If, on the other hand, models 10 and 11 are to be subjected to tensile loads the sliding part 22 'is pushed into the left-hand area, all bearing or fastening bolts except for the upper left bolt 29 and the lower fixed bolts 19, 20 are present. That I when the rotary crank 23 is rotated to the left along the first inclined plane 16 sliding member 22 'moving pushes the upper left end of the upper lever 14 upwards, pivoting it about one through the right upper bearing pin 30 formed axis of rotation. Due to this pivoting movement of the upper lever 14 after above is via the load transfer member 15 and the bridge part 32 on the symmetrically arranged models 10 and 11 exerted the same tensile force. This can be done in the same way as above for loading can be made visible with compressive forces.

F i g. 2 shows a schematic representation of a side view the device 1 shown in Fig. 1 from the left, the lower counter bearing 6, the right side strips 4.5 and the lower or inner lever 13 and the upper or outer lever 14 are shown. aside from that the rotatable mounting of these levers by means of bearing bolts 28 and 30 is shown. Between these two The spindle 21 is shown levering, which can be rotated in the direction of the arrow by means of the rotary crank 23. Additionally is in Figure 2 a connected to the lower lever 13 pressure member 35 is shown, the function of which is below described in connection with Fig.7 and Fig.8 will.

F i g. 3 shows an enlarged illustration of an embodiment of the example according to FIG. 1. Here are the load transferring members 15 and the bridge member 32 pivotally connected therewith are shown, but with the Bridge member 32 is hung rotated by 180 °, so that the left support 33 and the right support 34 are directed downwards, whereas the left pivot pin 36 and the right pivot bearing pin 37, on which the upper ends of the Models 10 and 11 are rotatably mounted, facing upwards.

As additional structurally identical parts are shown in Fig.3 left extension link 38 and a right extension link 39 shown, which is connected to the two ends of the Bridge part 32 are rigidly, but releasably connected and a left or a on its underside have right pressure support 40 and 41, respectively. As shown in FIG. 3, the extension links exist 38,39 from two legs of a U-profile, the upper (narrower) in a corresponding side Recess with a U-profile at the ends of the bridge part 32 can be pushed in and fastened by means of bearing bolts is, while the top of the lower (wider) leg notches 42 and 43, respectively with which the left or 'das. right support 33 and 34 is engaged. The rigid Determination of the extension members 38 and 39 is done via the pivot pins 36, 37, which in corresponding Openings in the upper section of the extension members 38, 39 and of the bridge member 32 can be pushed in are.

The left and right lower pressure supports 40 and 41 of the extension members 38 and 39, respectively, press from above onto the edge of a model 44, while in the outer area of the lower edge of the model 44 a Press another left or right pressure member 45 or 46 on the lower edge of the model 44. The pressure supports 45 and 46 are provided on identical bearing parts 47 and 48, which have bearing bolts between the side parts 2 and 3 or 4 and 5 are rigid, but releasably attached.

4 shows a further embodiment of the invention, the sidebars 2 and 4 are visible. While the at the lower edge of the bridge pontic 32 arranged supports 33 and 34 press on the upper edge of a first model 44, are further out arranged on the lower edges of the upper model 44 engaging pressure members 49.50. These compression links are arranged at the ends of arms, which can be pivoted on the upper via bearing bolts (not designated) Section of the identical bearing parts 47, 48 are mounted.

The pressure members 49 and 50 simultaneously serve to exert one pressure on the upper edge of a second Model 51, which is arranged below the first model 44. Opposite the upper supports 33 and 34 on the bridge part 32 grip lower supports 52,53 which are detachable via corresponding holders 54, 55 but are fixedly arranged on the counter bearing 6. By the arrangement of Figure 4 is a direct comparison

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two models with different shapes or different materials in terms of tension possible, whereby these models (in mirror image) are exposed to exactly the same pressure loads and where in the middle of each model there is a pure bending line.

F i g. 5 shows in a very schematic form a large-area model 56, which is attached to the load transfer member 15 in upper central part is rotatably mounted, while the middle supports 45,46 of the bearing parts 47 respectively 48 press from below onto the outer edge area of the large-area model 56.

F i g. 6 shows in detail a bearing part 47 with an upper pivotable support 49, a central support 45 and a lower support 59 for adaptation to different models, measuring points and measuring methods. Furthermore, the pivot bearing for the support 49 and two bearing bores (not designated) shown.

F i g. 7 shows a further embodiment of the invention, a clamping piece 61 for the end of the model 44 being provided on a side strip 2. The clamping piece 61 is mounted pivotably on the side strips 2, 3 on a pivot bearing 62 arranged in the upper region. The lower leg of the approximately U-shaped clamping piece 61 can be adjusted via an adjusting screw 63, which is also arranged on the side strips 2 and 3.

The second end of the model 44 hangs freely in the space between the opposing side strips 4 and 5 in. This already expresses itself in this area in connection with FIG. 2 mentioned, with the lower one Lever 13 connected pressure member 35 into it. The lower free end of the pressure member 35 exercises from above when actuating the rotary crank 23 and moving the sliding member 22 on the inclined plane 17 a Pressure on the upper edge of the free end of the model 44.

In this way, the forces and stresses occurring in a cantilever can be simulated.

F i g. 8 shows a further embodiment of the invention, wherein a screw model 64 and a screw or open-end wrench model 65 cooperate. While the screw model 64 with hexagonal End 66 is firmly clamped on the right side strips 2 and 3, engages the key part of the wrench model 65 at the helical end 66, while the free end of the wrench model 65 comes to lie between the opposite side strips 4 and 5 that in the above mentioned actuation of the rotary crank 23, the lower free end of the pressure member 35 on the upper edge of the Model 65 wrench pushes. In this way the forces can be simulated when tightening hexagon head screw occur in each area of the screw and the wrench.

In addition 6 sheets of drawings

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Claims (11)

Patent claims: 1. Device for generating compressive or tensile loads on essentially flat models for visualizing stresses with the help of a polariscope, consisting of a frame (1) with side strips (2,3; 4,5), a counter strip (6) and one of the counter strip arranged opposite Support bar (13, 14) with which a rotatable, force-transmitting spindle (21) is connected, marked by a) one consisting of an upper (outer) lever (14) and a lower (inner) lever (13) Support bar, b) a detachable and temporarily pivotable mounting of at least two diagonally opposite one another Ends of these levers (13, 14) on the upper section of the side strips (2,3; 4,5), preferably via pull-out bearing bolts, c) a rotatable mounting of the spindle (21) on the side strips (2, 3; 4, 5) in the area between upper (14) and lower lever (13), d) a through the spindle rotation along the thread section (s) (24, 25) of the spindle (21) in the direction of the side strips (2, 3; 4, 5) which can be displaced Sliding member (22), the top of which with the lower (inner) side of the upper (outer) Lever (14) and its underside with the upper (outer) side of the lower (inner) lever (13) is in contact, e) a through arrangement, training and functional interaction of the spindle (21), upper (14) and lower lever (13) and sliding member (22) resulting gradual change in distance between the lever (14) fixed on the two side strips (2, 3; 4, 5) and the lever (14) that is temporarily pivoted on a side strip (2, 3) mounted lever (13), f) one with the upper pivotably mounted lever (14) pivotable or the lower one pivotably mounted lever (13) rigidly connectable load transfer member (15), whose free end into the interior of the frame (1) in the direction of the counter bearing (6) for the bracket of the models (10, 11; 12) - directly or via intermediate links - or for exerting pressure protrudes onto this. 2. Device according to claim 1, characterized in that that the spindle (21) is arranged in the center line between the two levers (13, 14), can be driven via a rotary crank (23) arranged on the side of the frame (1) and from a left-hand one (24) and a right threaded section (25) and a thread-free section arranged in between (26) for the free displacement of the sliding member (22). 3. Device according to one of claims 1 or 2, characterized in that the gradual change in distance via a first (left) inclined plane (16) on the left underside of the upper lever (14) as well as a second (right) inclined plane (17) on the right upper side of the lower lever (13) with both inclined planes gradually rising towards the sides from the center. 4. Device according to one or more of claims 1-3, characterized in that the Sliding member (22) is designed in the shape of a wheel that there is a threaded hole for the threaded sections transversely to the axis (24,25) of the spindle (21), and that the upper or lower wheel circumferential surface with the underside of the upper lever (14) or the first inclined plane (16), and its Bottom with the top of the lower lever (13) or the second inclined plane (17) are in contact. 5. Device according to one of claims 1-4, characterized in that the load transfer member (15) consists of two strips, which are located on both sides in the middle area of the two levers (13, 14) as well as the unthreaded portion (26) of the spindle (21) extend downward, with a rotatable Connection to the upper lever (14) via a pull-out bearing pin (18), a rigid (detachable) Connection to the lower lever (13) takes place via two pull-out bolts, and the into the interior of the frame (1) protruding end of the load transmission member (15) has a bore that engages both strips for receiving a bearing pin (31), which is also the fastening of models (12) under tensile load, the direct exertion of pressure by the bearing pin (31) an edge of a model arranged below, as well as the rotatable mounting of intermediate links (32) is used. 6. Device according to one of claims 1-5, characterized by a through the bearing pin (31) of the load transfer member (15) rotatably mounted, preferably symmetrical, intermediate member in the form of a bridge member (32) with bores (36,37) at both ends and in the region of the ends the longitudinal edge, preferably at the same height as the bores (36, 37), extending outwards Supports (33, 34) preferably in the form of cylindrical ones oriented transversely to the frame (1) Has metal parts, half of which are fixedly arranged in corresponding recesses in the bridge member (32) are. 7. Device according to one of claims 1-6, characterized by lower supports (7,8, 9) which are releasably connected to the counter bearing (6) and corresponding releasable, rotatable brackets or supports, preferably in the form of cylindrical ones extending transversely to the (imaginary) frame surface Parts, about half of which are sunk into corresponding recesses in the counter bearing are, have. 8. Device according to one of claims 1-7, characterized in that the side strips each consist of two strips (2,3; 4,5), between which various insert parts in the form of bearing parts (47, 48), clamping parts (61), locking and adjusting parts (63), pressure members (35) and the like can be pushed in and mounted rigidly or pivotably, preferably via the two in each case associated side strips (2, 3; 4, 5) comprehensive holes, corresponding, in the insert parts (47, 48, 61) provided holes as well as corresponding, detachable, preferably pull-out, bearing bolts. 9. Apparatus according to claim 8, characterized by two on the opposite two-part Rope boxes (2, 3; 4, 5) retractable, essentially COPY chcn identical, bearing parts (47, 48). Consists of an outer strip, on the upper linden tree an ins Inside the frame protruding and pivotable arm with a pivot support (49, 50) on its free End, a middle support (45,46) on a wider one Middle section, and a lower support (59 * 60) are arranged on an even more widened lower "section. 10. Device according to claims, characterized in that that between two side strips (4, 5) a pressure part (35) with the (pivotable) lower Lever (13) is firmly connected, protrudes down to the free end of one of the opposite Sidebars (2,3) clamped (44) or a model attacking another model (64) (65) To apply pressure. 11. Device according to one of claims 6 to 10, characterized by two, preferably symmetrically arranged, according to the inside of the frame downwardly extending extension members (38, 39) which are essentially U-shaped, the (narrower) upper leg in corresponding lateral, essentially U-shaped recesses of the bridge member (32) engages and held by the bearing bolts (36, 37) provided there can be, wherein the top of the lower (larger) leg of the extension links (38, 39) has a recess, which with the (in this case) downwardly protruding supports (33, 34) the bridge member (32) for a rigid, but easily detachable connection between the bridge member (32) and Extension members (38, 39) can be brought into engagement, and that the counter strip (6) facing Ends of the extension members (38, 39) supports (40, 41) for engagement with the upper edge of a to having the investigating model.