GB1590616A

GB1590616A - Folding rule

Info

Publication number: GB1590616A
Application number: GB25530/78A
Authority: GB
Original assignee: ULLRICH STABILA MESSGERAETE
Current assignee: ULLRICH STABILA MESSGERAETE
Priority date: 1977-09-22
Filing date: 1978-05-31
Publication date: 1981-06-03
Also published as: BE870624R; FR2404195B2; SE7809594L; ES238249Y; FR2404195A2; DE2742738C2; ES238249U; DE2742738A1; IT1160668B; CH631545A5; IT7869180A0

Abstract

In this folding rule, the elastic element, by means of which two adjacent members (1, 2; 4, 5) connected by a bolt (3) are held together secure against rotation in their latched tight position, is arranged in the interior of one member (1, 2), instead of on the outside thereof, as previously. Consequently, only the head (7) of the bolt (3) remains visible on this outside or scale side, with the result that the pattern of the scale is much less impaired. The resilient element can be a leaf spring (6) which is situated in a groove-shaped recess (9) now provided on the inside of the outer cross-sectional part (1); however, it can also be formed by the outer cross-sectional part (1) itself, which is pressed into a cavity (8) when the two members are pivoted by means of the head (7) of the bolt (3). An arrangement with resilient tongues is also conceivable. <IMAGE>

Description

(54) FOLDING RULE (71) We, STABILA-MESSGERATE GUS TAV ULLRICH GmbH & Co. KG., a German Company of Postfach 1340, 6747 Annweiler am Trifels, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: The invention relates to a folding rule comprising a plurality of elongate rule sections articulated one to another by ajoint pin or pins, each rule section comprising an inner part and an outer part assembled together, each articulated pair of sections comprising one or more projections on one of the sections engageable with one or more respective recesses in the other section for maintaining the two sections in parallel alignment and which are resiliently disengageable from the recesses when the rule is folded by rotating one section relative to the other about the pin.

The disengagement of the projections from the recesses as well as the engagement with the recesses is effected in a folding rule of the above type typically by means of a spring that sits in a recess provided for this purpose on the outside of one of the two rule sections that are connected to one another by means of the joint pin. The joint pin is supported against this spring in the axial direction.

Since the spring permits a 'relaxation' of the axial pin support when the two connected sections are rotated from their engagement position, it is directly possible to effect disengagement of the projections on the said one rule section from the recesses in the other section. However, on account of the wire or leaf-shaped spring located on the outside of the said one rule section, the scale divisions of the rule located on the surface of this section are considerably interfered with.

The object of the invention is accordingly to eliminate this disadvantage in a folding rule of the type mentioned at the beginning, i.e. to avoid as far as possible any interference in the scale divisions on the surface of the rule section.

In accordance with the invention this object is achieved by forming a hollow space between the inner and outer parts of at least one of the rule sections in the vicinity of the pin into which space a portion of one of the parts or a member associated therewith can be resiliently deflected.

In this way it is possible for the joint pin to be axially supported directly against the component part defining the hollow space. In this case a wire or leaf spring as referred to for the spring-loaded axial support of the joint pin can be replaced by the hollow space-defining wall of one of the two parts of the rule section serving for the spring-loaded axial support of the joint pin. An embodiment is, however, also possible in which the joint pin is supported axially as before against a wire- or leaf-shaped spring. but with the difference that the spring may in this case be arranged not on the upper side of the rule section but between the two component parts of the section.It is also possible to arrange and form the hollow space in such a way that, on rotating the rule sections connected to one another from their locking position, the rule parts carrying the engagement projections engage in a spring-loaded manner in the hollow space and their projections disengage from the recesses in the neighbouring section. To this end, in the case of a folding rule in which the rule sections are assembled in the axial direction of the joint pins, these projections may be formed by one-piece, spring-loaded tongue members on the inner cross-section part facing in each case the neighbouring section, the said tongue members engaging in the hollow space between the two cross-section parts.

Obviously, still other embodiments are possible in which, in the case of a folding rule whose sections consists of assembled component parts, the axially acting spring-loaded support of the joint pin for connecting two neighbouring rule sections is formed so that it does not interfere with the scale divisions on the upper side of the rule sections, or in which such a spring-loaded support of the joint pins is not necessary as a result of the spring-loaded arrangement of the engagement projections.

By way of further illustrations of the invention some particularly advantageous embodiments will now be described in more detail with reference to the accompanying drawings, in which Fig. I is a longitudinal section through the articulated ends of two neighbouring plastics rule sections of one embodiment of a folding rule according to the invention: Fig. 2 is a section along the line lI-Il in Fig. I; Fig. 3 is a view similar to Fig. I of a further embodiment of folding rule according to the invention; Fig. 4 is a section along the line IV IV in Fig. 3; Fig. 5 is a view similar to Fig.I of a third embodiment of folding rule according to the invention; Fig. 6 is a section along the line VI--VI in Fig. 5; and Fig. 7 is a section through the two neighbouring sections along the line VIZ VIZ in Fig. 5.

In the embodiment illustrated in Figs. I and 2, a leaf spring 6, clearly visible in Fig. 2, is inserted between the two profiled component parts 1, 2 of one rule section, which is rotatably connected by means of ajoint pin 3 to the other rule section, similarly consisting of two profiled component parts 4, 5. The head 7 of the joint pin 3, formed as a rivet, bears axially against the leaf spring 6. Beneath the leaf spring 6 in the inner profiled part 2 of the rule section accommodating the leaf spring 6 is located a hollow space 8 formed as a recess in the part 2. The leaf spring 6 lies in a groove or recess 9 in the outer part 1 of the upper rule section in Fig. 1 and its ends bear on the inner part 2 at the edge of the hollow space 8.The head 7 of the joint pin 3 bearing against the leaf spring 6 sits in a bore 10 in the outer part 1 so that it does not project beyond the surface of the rule section. In the same way, the foot 11 of this joint pin is received in a recess 12 in the outer part 5 of the other rule section.

The two profiled parts 1, 2 and 4, 5 of each rule section are stuck or welded to one another and are provided with oppositely facing recesses 13 in the region outside the joint pin connection, hollow spaces thereby being formed that reduce the weight of the rule sections.

In order to maintain the rule sections in parallel alignment, projections 14 are provided on both sides of the joint pin in the upper rule section in Fig. 1, and are directed towards the other rule section so that in the parallel alignment position of the two rule sections the projections 14 engage in recesses 15 of said other rule section. In the engagement position the leaf spring 8 is essentially not under tension. If the rule sections are rotated about the axis of the joint pin 3 from their mutual parallel position, the projections 14 must be raised from the recesses 15. This is possible since the head 7 of the joint pin 3 bears axially against the spring 6 and the latter can bend into the hollow space 8 during the aforementioned rotational movement.

As can be seen clearly from Fig. 1, in this embodiment the leaf spring 6 is located not on the outer top surface of the upper rule section in Fig. I but inside this rule section between its two parts 1, 2, so that it does not interfere with the scale divisions on the top of the section. The scale divisions are spoilt only by the head 7 of the joint pin 3 in the bore 10, for which allowances can be made.

In the embodiment shown in Figs. 3 and 4, the same reference numerals as in Figs. 1 and 2 are used for the same parts of the folding rule. In this embodiment a hollow space 16, similar to hollow space 8, is formed in the inner part 4 of the lower rule section. The head 7 of the joint pin 3, again formed as a rivet, bears through a washer directly against the outer part 1 of the upper rule section and the rivet foot 11 directly against the outer part 5 of the lower rule section. In this embodiment the outer parts 1 and 5 themselves act as springs.

If the two rule sections connected to one another by means of the joint pin 3 are rotated and disengage from their mutually parallel position, then to disengage the projections 14 from the recesses 15 the two inner cross-section parts 2, 4 are required to move apart. The necessary freedom for this movement is provided by the two outer parts 1, 5 which deflect or bend inwardly into the hollow spaces 8, 16.

The outer cross-section parts 1, 5 thus act in this embodiment as a spring-loaded axial support for the joint pin 3, which permits the release of the projections from the recesses.

By a suitable arrangement and depth of the aforementioned hollow spaces 8, 16, the spring action can be adjusted corresponding to the requirements of satisfactory engagement of the projections 14 in the recesses 15.

The spring elasticity of the axial support of the joint pin 3 on the two rule sections connected to one another by means of the said pin is determined by the thickness of the outer parts 1, 5 serving to support the joint pin. Weakened grooves may also be provided for this purpose in these cross-section parts.

In the Figs. 5 to 7 the same reference numerals are used to denote the same parts as in Figs. 1 to 4. In the embodiment of Figs.

5 to 7 the head 7 through washer 17 and the rivet foot 11 of the joint pin 3 again bear directly on the two outer parts 1, 5 of the two rule sections connected to one another. The inner part 2 of the upper rule section in Fig. 5 is likewise provided with projections 18 that engage in recesses 19 of the inner part 4 of the other rule section. These projections are however formed on tongue members 20 formed from the part 2 by substantially horse-shoe-shaped slits 21, the tongue members being connected to the part 2 only at their root portions 22.

The tongue members 20 are situated opposite hollow spaces 23 in the other part 1 of the upper rule section in Fig. 5. The tongue members can be pressed into the spaces 23 in a resilient manner by the inner part 4 of the other rule section on rotating the rule sections from their parallel position. In order to facilitate this procedure further, transverse grooves 24 are provided in the root portions 22 of the tongue members 20. The necessary rotational force for lifting the projections 18 from the recesses 19 on rotating the rule sections can be adjusted by the depth of the transverse grooves 24.

It is also possible, instead of providing the hollow spaces 23 in the outer part 1 of the upper rule section in Fig. 5, to provide a hollow space in the part 2 of this rule section in such a way that the upper boundary surface of the tongue members 20 in Fig. 5 runs from the joint pin 3 in an inclined manner to the rear.

The assembly of the articulated connection of two adjoining rule sections is just as simple with the folding rule according to the invention as in the case of a rule not designed according to the invention. The two parts 1, 2 and 4, 5 of each rule section are prefabricated so that upon assembling and bonding or welding the hollow spaces 8, 15 are formed by the assembling of the parts per se. In the embodiment illustrated in Figs. 1 and 2, when assembling the two parts 1, 2 containing the leaf spring 6, the latter together with the bolt 3 passing therethrough simply has to be inserted in the groove 9 in the part 1, following which the two parts can be assembled and joined to one another.

In addition to the embodiments illustrated in the drawings, other embodiments of the invention are also possible. Thus, for example, instead of the leaf spring 6 illustrated in Figs. I and 2, a wire- or plate-shaped spring or a similar spring member for the axial support of the joint pin can be provided between the two parts 1, 2. Furthermore, it is possible in the embodiment illustrated in Figs. I and 2 to provide a hollow space also in the lower rule section in Fig. 1, in which the part 5 of this lower rule section can bend.

Conversely, in the embodiment illustrated in Figs. 3 and 4 a variant is possible in which a hollow space is provided between the parts of the section not in both but only in one of the rule sections connected to one another. In this connection, the hollow space can be formed not as in the illustrated embodiment by one recess in the timer part, but by a recess in the outer part.

WHAT WE CLAIM IS: 1. A folding rule comprising a plurality of elongate rule sections articulated one to another by a joint pin or pins, each rule section comprising an inner part and an outer part assembled together, each articulated pair of sections comprising one or more projections on one of the sections engageable with one or more respective recesses in the other section for maintaining the two sections in parallel alignment and which are resiliently disengageable from the recesses when the rule is folded by rotating one section relative to the other about the pin, and a hollow space formed between the inner and outer parts of at least one of the rule sections in the vicinity of the pin into which space a portion of one of the parts or a member associated therewith can be resiliently deflected.

2. A folding rule according to Claim 1, wherein the joint pin bears axially against a portion of one of the parts of the rule section defining the hollow space which portion can be deflected into said hollow space.

3. A folding rule according to Claim 2, wherein the portion of the said one rule section against which the joint pin bears axially is a wire- or plate-like spring arranged in the rule section between its two component parts.

4. A folding rule according to Claim 1, wherein the hollow space is formed by a recess in at least one of the respective assembled inner and outer parts.

5. A folding rule according to Claim 4, in which the hollow space is formed by a recess or depression in the inner part of said respective rule section.

6. A folding rule according to Claim 3, wherein the spring is mounted in a groove in the outer part of the said one rule section and the ends of the spring bear on the inner part.

7. A folding rule according to Claim 1, wherein the projections on the said one rule section are formed by one-piece, springloaded tongue members on the inner part facing the adjacent section, and the tongue members are deflectable into the hollow space between the two component parts of this rule section.

8. A folding rule according to Claim 7, wherein the hollow space is bounded on the one side by the tongue members and on the other side by the outer part opposite the said tongue members.

9. A folding rule according to Claim 7, wherein the hollow space is formed by a recess in the outer part of the said one rule section opposite the tongue members.

10. A folding rule according to Claim 8, wherein the hollow space is formed by the inclined orientation of the tongue members of the inner part of the said one section and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the other rule section. These projections are however formed on tongue members 20 formed from the part 2 by substantially horse-shoe-shaped slits 21, the tongue members being connected to the part 2 only at their root portions 22. The tongue members 20 are situated opposite hollow spaces 23 in the other part 1 of the upper rule section in Fig. 5. The tongue members can be pressed into the spaces 23 in a resilient manner by the inner part 4 of the other rule section on rotating the rule sections from their parallel position. In order to facilitate this procedure further, transverse grooves 24 are provided in the root portions 22 of the tongue members 20. The necessary rotational force for lifting the projections 18 from the recesses 19 on rotating the rule sections can be adjusted by the depth of the transverse grooves 24. It is also possible, instead of providing the hollow spaces 23 in the outer part 1 of the upper rule section in Fig. 5, to provide a hollow space in the part 2 of this rule section in such a way that the upper boundary surface of the tongue members 20 in Fig. 5 runs from the joint pin 3 in an inclined manner to the rear. The assembly of the articulated connection of two adjoining rule sections is just as simple with the folding rule according to the invention as in the case of a rule not designed according to the invention. The two parts 1, 2 and 4, 5 of each rule section are prefabricated so that upon assembling and bonding or welding the hollow spaces 8, 15 are formed by the assembling of the parts per se. In the embodiment illustrated in Figs. 1 and 2, when assembling the two parts 1, 2 containing the leaf spring 6, the latter together with the bolt 3 passing therethrough simply has to be inserted in the groove 9 in the part 1, following which the two parts can be assembled and joined to one another. In addition to the embodiments illustrated in the drawings, other embodiments of the invention are also possible. Thus, for example, instead of the leaf spring 6 illustrated in Figs. I and 2, a wire- or plate-shaped spring or a similar spring member for the axial support of the joint pin can be provided between the two parts 1, 2. Furthermore, it is possible in the embodiment illustrated in Figs. I and 2 to provide a hollow space also in the lower rule section in Fig. 1, in which the part 5 of this lower rule section can bend. Conversely, in the embodiment illustrated in Figs. 3 and 4 a variant is possible in which a hollow space is provided between the parts of the section not in both but only in one of the rule sections connected to one another. In this connection, the hollow space can be formed not as in the illustrated embodiment by one recess in the timer part, but by a recess in the outer part. WHAT WE CLAIM IS:

1. A folding rule comprising a plurality of elongate rule sections articulated one to another by a joint pin or pins, each rule section comprising an inner part and an outer part assembled together, each articulated pair of sections comprising one or more projections on one of the sections engageable with one or more respective recesses in the other section for maintaining the two sections in parallel alignment and which are resiliently disengageable from the recesses when the rule is folded by rotating one section relative to the other about the pin, and a hollow space formed between the inner and outer parts of at least one of the rule sections in the vicinity of the pin into which space a portion of one of the parts or a member associated therewith can be resiliently deflected.

by the projections with respect to the outer part of said one section.

11. A folding rule substantially as hereinbefore described with reference to Figures I and 2, or Figures 3 and 4, or Figures 5 to 7, of the accompanying drawings.