CA1068898A - Tape measure - Google Patents
Tape measureInfo
- Publication number
- CA1068898A CA1068898A CA306011A CA306011A CA1068898A CA 1068898 A CA1068898 A CA 1068898A CA 306011 A CA306011 A CA 306011A CA 306011 A CA306011 A CA 306011A CA 1068898 A CA1068898 A CA 1068898A
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- CA
- Canada
- Prior art keywords
- housing
- tape
- measuring tape
- sensing
- combination
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Abstract
ABSTRACT OF THE DISCLOSURE A tape measure comprising a tape housing with a tape exit opening and an internal take-up spindle for the tape is provided with an e.g. optical sensing device for sensing the length by which the tape has been extended. A counter and a display device are associated with the sensing device, the display being on the outside of the housing. -1-
Description
The present invention concerns a tape measure having a housing in which is arranged a take-up spindle for the measuring tape which can be extended from an exit opening in the housing.
In known tape measures of this type the measuring tape is pulled out from the housing by hand and may optionally be reeled into the housing again by means of a retraction spring. A scale is provided on the measuring tape to allow the magnitude of the length to be measured to be read off from the tape.
In contrast, by means of the invention there iq pro-vided a poc~et type tape measure with which the measurement result may be obtained more rapidly, more simply and more ~ accurately with simpler handling and which may readily be so further developed as to increase its versatility of use.
In particular in the pocket type tape measure accord-ing to the invention there is provided in the housing a sensing device for sensing the length of extension of the measuring ~ -tape from the housing, as well as a counter device and an indicating device co-ordinated with the sensing device, the indication field of the indicating device being visible on the outside of the housing.
In this way the measurèment result need no longer be read off from the measuring tape itself, although in the tape measure according to the invention a conventional scale on the measuring tape may additionally also be provided so that it may then be used also in the conventional manner.
As i~ usual in other contexts, the indication field may be r' ' `' illuminated or may be provided with luminous d1gits so that the tape measure according to the invention may also be used in unfavourable light conditions.
a ~ :
1~68898 The tape measure according to the invention provides that the measuring tape can be extended until it abuts e.g.
a wall the distance of which from the housing is to be measured, whereafter the measurement result can be read off in the indication field of the indication device. Conversely, the measuring tape may also be`extended to a preset length or section which is achieved when the associated measurement value can be read off from the indication field and then the preset section or length i9 measured by means of the extended length of the measuring tape.
The initial or starting value of the counter device may be related to a suitable fixed reference or datum point on the housing. Preferably, a locating surface is formed on the housing plane, so that such locating surface extends perpendicularly to the direction of extension of the measuring tape and forms a reference magnitude or value for the initial value of the counter device. This locating surface may be formed at the front side of the housing, i.e~, in the plane of the exit opening for the measuring tape, so that when the tape measure is used, it may be laid with this locating surface on a reference surface from which it i5 desired to measure.
Thus, the counter is in a null position when the front end of the measuring tape lies exactly in the plane of this locating surface.
It may also be advantageous to provide the locating surface as the reference magnitude for the initial value of ~`
the counter device at the rear side of the housing, i.e., the 9ide which is remote from the exit opening of the measuring tape, In this way one may for instance determine the spacing between two walls from one another by laying the tape measure with the rear side of its housing at one of the two walls and
In known tape measures of this type the measuring tape is pulled out from the housing by hand and may optionally be reeled into the housing again by means of a retraction spring. A scale is provided on the measuring tape to allow the magnitude of the length to be measured to be read off from the tape.
In contrast, by means of the invention there iq pro-vided a poc~et type tape measure with which the measurement result may be obtained more rapidly, more simply and more ~ accurately with simpler handling and which may readily be so further developed as to increase its versatility of use.
In particular in the pocket type tape measure accord-ing to the invention there is provided in the housing a sensing device for sensing the length of extension of the measuring ~ -tape from the housing, as well as a counter device and an indicating device co-ordinated with the sensing device, the indication field of the indicating device being visible on the outside of the housing.
In this way the measurèment result need no longer be read off from the measuring tape itself, although in the tape measure according to the invention a conventional scale on the measuring tape may additionally also be provided so that it may then be used also in the conventional manner.
As i~ usual in other contexts, the indication field may be r' ' `' illuminated or may be provided with luminous d1gits so that the tape measure according to the invention may also be used in unfavourable light conditions.
a ~ :
1~68898 The tape measure according to the invention provides that the measuring tape can be extended until it abuts e.g.
a wall the distance of which from the housing is to be measured, whereafter the measurement result can be read off in the indication field of the indication device. Conversely, the measuring tape may also be`extended to a preset length or section which is achieved when the associated measurement value can be read off from the indication field and then the preset section or length i9 measured by means of the extended length of the measuring tape.
The initial or starting value of the counter device may be related to a suitable fixed reference or datum point on the housing. Preferably, a locating surface is formed on the housing plane, so that such locating surface extends perpendicularly to the direction of extension of the measuring tape and forms a reference magnitude or value for the initial value of the counter device. This locating surface may be formed at the front side of the housing, i.e~, in the plane of the exit opening for the measuring tape, so that when the tape measure is used, it may be laid with this locating surface on a reference surface from which it i5 desired to measure.
Thus, the counter is in a null position when the front end of the measuring tape lies exactly in the plane of this locating surface.
It may also be advantageous to provide the locating surface as the reference magnitude for the initial value of ~`
the counter device at the rear side of the housing, i.e., the 9ide which is remote from the exit opening of the measuring tape, In this way one may for instance determine the spacing between two walls from one another by laying the tape measure with the rear side of its housing at one of the two walls and
2 -10~8898 then extending the measuring tape until it engages the opposite wall. Then the initial value of the counter device is so adjusted that when the free front end of the measuring tape lies in the plane of the exit opening, its spacing from the locating surface at the rear side of the housing appears in the indication field and the length of the housing correspond-ing to this spacing is compensated.
A tape measure according to the invention may also be constructed in a simple manner so that the initial value of the counter may selectively be set to several predetermined reference points and/or completely as desired. For instance, it is possible to make the counter adjustable so that either the front locating surface or the rear locating surface of the housing may be selected as the reference magnitude or value for the initial value of the counter. Correspondingly, in certain embodiments of the invention it is advantageous to make the counter settable to zero when the measuring tape has already been partially extended so that when a further -extension of the measuring tape to a second part, this new length appears on the indication field as a difference between the two partial lengths.
In a further development of the invention it is pro- ~-posed that the counter should be a forward-backward counter which can be adjusted accordingly so as to make it possible ~
to measure selectively when the measuring tape is extended ~ -and/or retracted.
Thus according to the invention there is provided in a pocket-type tape measure having a housing in which the take~
up spindle is arranged for a measuring tape extending with its free end through an exit opening at a front face of the housing ~' to be pulled out of the housing to allow a length to be meaRured ~long the pulled-out part of the measuring tape between :,:
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the free end thereof and the housing, the improvement comprising - in combination: a) a sensing means positioned within said housing for contactlessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corres-ponding series of sensing impulses for each passing marking element; b) an electronic counting means positioned within said housing and coupled with said sensing means to count said sensing impulses: c) an electronic digital display means positioned within said housing and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field; d)j a first locating surface at an outside front face of the housing and in the plane of the exit opening, said first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing, e) A second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing; f) a manually operatable zero switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of ..
: .. ...
the counting and display means to zero: and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure, It will be understood that the sensing means a) is in operating relation with said me~suring tape.
J ~ ~ 4 ~
The invention is suitable for making the possibilities ` of use of the tape measure more varied. In particular it is possible to accommodate in the housing additional electronic computing elements corresponding to those of a per se known electronic pocket calculator with a keyboard on the outside of the housing. In this case, separate indication fields may be provided for the computing elements and for the indicating/
di~play device so that a length measurement value can remain in the indication field associated with the counter device while a calculation is carried out with the aidlof the computing elements. Howevex, it is also possible to provide a common-indicating field for the computing elements and the counter device.
The calculator portion of such a tape measure may be indepe~dent from the measuring part of the latter. By including a calculator in the tape measure it becomes possible to analyse -or evaluate the previously measured measurement value with the aid of the calculating device. This is particularly favourable when the calculating portion is so coupled with the measuring portion that the count value of the counter device can be read into or entered into the calculator. Thus one may for instance further process the measurement value in a calculation without having to enter it or to key it manually into the calculator.
For such a construction it is advantageous to include at least i~' one memory means in the computing element into which memory means the count value of the counter device can be read in or entered so that the measurement value can be included in a calculation process at any desired position by recall from the store. A further advantageous possibility is to provide several memory means of this type thereby enabling several measurement values to be stored in them, for instance the two ;A - 5 - ~
- .: ~ . ... . . . . : .
length measurements of a rectangular surface whose area may then be calculated with the calculator.
Suitable electronic computing elements and associated circuits are known to a man skilled in the art so that they are not required to be described here in further detail.
Sensing devices suitable for the purposes of use of this invention are also known in themselves. In particular, contact-less sensing may be provided whereby the measuring tape may for instance contain a suitable pattern of light and dark areas as a series of perforations which are passed in a manner known per se by an optical sensing device so as to generate a corresponding train of electrical pulses to control the counter device. An electrically conductive filament may also be provided within the measuring tape which is sensed by a corresponding sensing device. The sensing may also take place directly at the measuring tape. However, indirect sensing is also possible, for instance by engaging the measuring tape within the housing by means of a roller which rotates to an extent corresponding to the length of extension of the measur-ing tape and which carries e.g. a perforated disc,monitored bya sensing device operating in a contact-less manner. A
mechanical counting mechanism may instead be directly driven by such a roller so that then the roller itself forms the sensing device.
The roller may be a pressure roller which co-operates with a counter roller while providing a gap for the passage of the measuring tape.' Another advantageous embodiment of the invention comprises: constructing the roller as a toothed roller which meshes with a row of teeth formed on the measuring tape.
J ~ - 6 -10~8898 - The counter device may be a per se known electrical or electronic counter device. As has already been mentioned above, the counter may however also be a mechanical counting mechanism which is switched or tripped by the tape itself via a drive means.
In the tape measure according to the invention the measuring tape may as usual be extended manually and optionally may be retracted again after releasing a suitable lock by means of a retraction spring which is tensioned on extension.
According to a further advantageous development of the invention, it is however preferred to arrange a battery-driven reversible electric motor in the housing for driving the measuring tape in extension and retraction. In this way the handling of the tape measure is further facilitated. The battery for the electric motor may be in the form of a com-mercially available torch battery (i.e. a conventional flash-light or dry battery), or the like, accommodated in the housing itself to which end a suitable battery space or chamber is formed. Additionally, an external connection may also be provided through which a connection to an external current source may be made. The battery associated with the ;
electric motor may cimultaneously also be used as the power source for an electric indicating/display and counting device and for an electronic calculator.
Preferably the drive is via a worm wheel drive driven from the motor which may for instance engage the take up spindle of the measuring tape, the spindle being constructed for this purpose so that one end disc thereof is in the form of a worm wheel. However, the worm wheel drive may drive a drive roller which drives the measuring tape directly. Finally, it is also possible to form the measuring tape with suitable helical teeth meshing with the worm wheel.
_ 7 ~
-In particular the measuring tape may be passed or guided hetween a drive roller driven by the motor and the pressure roller, as is usual for instance in tape recorders as a tape drive, Instead of a worm wheel drive another reduction gear may be used instead, for instance a suitable belt drive. In order to ensure that the measuring tape is sufficiently stiff to extend without bending, which is parti-cularly advantageous in the embodiment wherein the tape drive is via an electric motor, that the ~easuring tape be comprised of a resilient springy material of an arcuate cross-section which can be resiliently pressed flat. ~he tape is then passed through a squeeze guide in the housing which presses its arcuate cross-section to a flat shape for winding up the measuring tape. In this case, the measuring tape may, as with the usual tape measures, be arched on the side turned to the take up spindle so that a pressure roller engaging the periphery of the spindle can accomplish the pressing flat of the -tape cross-section.
In order to enhance the stiffness of the extended measuring tape, so that it may optionally be~ extensible i~ a self-supporting manner, in a further embodiment,of the measuring tape a measuring tape is provided having a hollow cross-section pressable fla-t by the squeeze guide. ~his hollow cross-section being obtained by using a double tape of which the individual tapes are connected with each other at their ends, with each individual tape being of arcuate section. In this way the measuring tape forms an approximately lenc shaped cross-section in its extended part and a strip or brand-shaped cross-section in its wound-up part.
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,~ ~ - 8 -.
10~8898 In order that in given cases a squeeze guide should be usable which is spaced in front of the take up spindle of the measuring tape without the measuring tape becoming arched up again due to its pretensioning obtained by the squeeze guide between the latter and the take-up guide, in a further develop~
ment of the invention the hollow cross-section of the measuring tape can be pressed flat so that it has the hollow cro`ss-section in a first stable position which is then pressable flat into a second stable position by means of the squeeze guide.
In thiQ connection, advantageously t-here is provided a lateral guide between the squeeze guide and the exit opening of the housing which presses the measuring tape from its second stable ~;
position into its first stable position to extend the measuring tape. To obtain a strip shape cross-section with two such stable positions in the embodiment wherein the measuring tape is constructed in the manner described above, a,double tape can be obtained for example by connecting the individual tapes at its side edges with a small spacing from each other so that the biconvex hollow cross-section can be pressed flat with the aid of a suitable ground roller of the squeeze guide to a biconcave hollow cross-section forming the second stable position.
The invention will hereafter be described with reference to the preferred embodiments shown schematically in the drawings wherein:
FIGURE 1 is a fragmentary sectional view of various elements operationally arranged within a tape housing in accordance with the invention, FIGURE 2 is a plan view of the housing of one preferred embodiment, including a calculator portion, _ g _ 10~8898 FIGURE 3 is a side view of the embodiment of Figure 2, FIGURE 4 is a schematic detail view to explain the tape drive and the sensing of the measuring tape in the embodiment according to Figures 2 and 3, and FIGURE 5 is a further detailed view of the tape drive of Figure 4.
Figure 1 shows schematically a housing 1 accommodating therein a takeup spindle 2 for a non-illustrated measuring tape which can be extended and retracted by means of a motor via a slit guide 3 at one of the longer sides of the housing through an exit opening 4 at the front of the housing. To this end the housing accommodates furthermore a small electric motor 5 with an associated battery 6, the shaft of the motor carrying a worm gear 7 which matches with a side disc of the takeup qpindle 2 formed as a worm wheel 8. -A sensing slit 9 is formed in one wall of the slit guide 3 adjacent to the takeup spindle 2 through which a suitable mark of the tape running past the slit is sensed by means of a schematically illustrated optical sensing element 10. The sensing element 10 is a component of a sensing device which is not shown further and which includes a counter which -counts the sensing pulses and converts them to a measurement value which is then displayed in an indication or display field on the outer side of the housing.
The front and/or rear side of the housing 1 forms a locating surface 11 or 12 extending at right angles to the direction of extension of the measuring tape. Such locating ~urfaces may be used as reference values for the initial value of the counter device. Further, a push-button switch 13 is provided at one side of the housing which may be depressed to switch the apparatus on. When depressed, two further switch ~A
iO~8898 contacts 14, 15 are closed which are then opened again when the push-button switch is released. The lower contact 15 is used for resetting the counter after a preceding measurement whereafter the upper contact 14 sets the initial value of the counter.
The counter may be released and set to zero as desired with the aid of the push-button switch 13. In addition, a separate motor switch 16 is alsQ provided for switching the motor on and off and to reverse the direction of the drive. It i~ also possible to include a separate programme part with the aid of which the motor and optionally also the counter can be controlled by means of a preset or keyed-in programme.
In the embodiment shown in Figures 2 and 3, the housing 1 includes an electronic calculator similar to the usual pocket calculators, the keyboard 17 of which is arranged on the outside of the housing 1. In addition to the display field 18 on which the sensed measurement value of the extended measuring tape 19 appears, there is provided a separate display field 20 for the calculator part. As can be seen from Figure
A tape measure according to the invention may also be constructed in a simple manner so that the initial value of the counter may selectively be set to several predetermined reference points and/or completely as desired. For instance, it is possible to make the counter adjustable so that either the front locating surface or the rear locating surface of the housing may be selected as the reference magnitude or value for the initial value of the counter. Correspondingly, in certain embodiments of the invention it is advantageous to make the counter settable to zero when the measuring tape has already been partially extended so that when a further -extension of the measuring tape to a second part, this new length appears on the indication field as a difference between the two partial lengths.
In a further development of the invention it is pro- ~-posed that the counter should be a forward-backward counter which can be adjusted accordingly so as to make it possible ~
to measure selectively when the measuring tape is extended ~ -and/or retracted.
Thus according to the invention there is provided in a pocket-type tape measure having a housing in which the take~
up spindle is arranged for a measuring tape extending with its free end through an exit opening at a front face of the housing ~' to be pulled out of the housing to allow a length to be meaRured ~long the pulled-out part of the measuring tape between :,:
i ~ - 3 ~
, ` '~
the free end thereof and the housing, the improvement comprising - in combination: a) a sensing means positioned within said housing for contactlessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corres-ponding series of sensing impulses for each passing marking element; b) an electronic counting means positioned within said housing and coupled with said sensing means to count said sensing impulses: c) an electronic digital display means positioned within said housing and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field; d)j a first locating surface at an outside front face of the housing and in the plane of the exit opening, said first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing, e) A second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing; f) a manually operatable zero switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of ..
: .. ...
the counting and display means to zero: and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure, It will be understood that the sensing means a) is in operating relation with said me~suring tape.
J ~ ~ 4 ~
The invention is suitable for making the possibilities ` of use of the tape measure more varied. In particular it is possible to accommodate in the housing additional electronic computing elements corresponding to those of a per se known electronic pocket calculator with a keyboard on the outside of the housing. In this case, separate indication fields may be provided for the computing elements and for the indicating/
di~play device so that a length measurement value can remain in the indication field associated with the counter device while a calculation is carried out with the aidlof the computing elements. Howevex, it is also possible to provide a common-indicating field for the computing elements and the counter device.
The calculator portion of such a tape measure may be indepe~dent from the measuring part of the latter. By including a calculator in the tape measure it becomes possible to analyse -or evaluate the previously measured measurement value with the aid of the calculating device. This is particularly favourable when the calculating portion is so coupled with the measuring portion that the count value of the counter device can be read into or entered into the calculator. Thus one may for instance further process the measurement value in a calculation without having to enter it or to key it manually into the calculator.
For such a construction it is advantageous to include at least i~' one memory means in the computing element into which memory means the count value of the counter device can be read in or entered so that the measurement value can be included in a calculation process at any desired position by recall from the store. A further advantageous possibility is to provide several memory means of this type thereby enabling several measurement values to be stored in them, for instance the two ;A - 5 - ~
- .: ~ . ... . . . . : .
length measurements of a rectangular surface whose area may then be calculated with the calculator.
Suitable electronic computing elements and associated circuits are known to a man skilled in the art so that they are not required to be described here in further detail.
Sensing devices suitable for the purposes of use of this invention are also known in themselves. In particular, contact-less sensing may be provided whereby the measuring tape may for instance contain a suitable pattern of light and dark areas as a series of perforations which are passed in a manner known per se by an optical sensing device so as to generate a corresponding train of electrical pulses to control the counter device. An electrically conductive filament may also be provided within the measuring tape which is sensed by a corresponding sensing device. The sensing may also take place directly at the measuring tape. However, indirect sensing is also possible, for instance by engaging the measuring tape within the housing by means of a roller which rotates to an extent corresponding to the length of extension of the measur-ing tape and which carries e.g. a perforated disc,monitored bya sensing device operating in a contact-less manner. A
mechanical counting mechanism may instead be directly driven by such a roller so that then the roller itself forms the sensing device.
The roller may be a pressure roller which co-operates with a counter roller while providing a gap for the passage of the measuring tape.' Another advantageous embodiment of the invention comprises: constructing the roller as a toothed roller which meshes with a row of teeth formed on the measuring tape.
J ~ - 6 -10~8898 - The counter device may be a per se known electrical or electronic counter device. As has already been mentioned above, the counter may however also be a mechanical counting mechanism which is switched or tripped by the tape itself via a drive means.
In the tape measure according to the invention the measuring tape may as usual be extended manually and optionally may be retracted again after releasing a suitable lock by means of a retraction spring which is tensioned on extension.
According to a further advantageous development of the invention, it is however preferred to arrange a battery-driven reversible electric motor in the housing for driving the measuring tape in extension and retraction. In this way the handling of the tape measure is further facilitated. The battery for the electric motor may be in the form of a com-mercially available torch battery (i.e. a conventional flash-light or dry battery), or the like, accommodated in the housing itself to which end a suitable battery space or chamber is formed. Additionally, an external connection may also be provided through which a connection to an external current source may be made. The battery associated with the ;
electric motor may cimultaneously also be used as the power source for an electric indicating/display and counting device and for an electronic calculator.
Preferably the drive is via a worm wheel drive driven from the motor which may for instance engage the take up spindle of the measuring tape, the spindle being constructed for this purpose so that one end disc thereof is in the form of a worm wheel. However, the worm wheel drive may drive a drive roller which drives the measuring tape directly. Finally, it is also possible to form the measuring tape with suitable helical teeth meshing with the worm wheel.
_ 7 ~
-In particular the measuring tape may be passed or guided hetween a drive roller driven by the motor and the pressure roller, as is usual for instance in tape recorders as a tape drive, Instead of a worm wheel drive another reduction gear may be used instead, for instance a suitable belt drive. In order to ensure that the measuring tape is sufficiently stiff to extend without bending, which is parti-cularly advantageous in the embodiment wherein the tape drive is via an electric motor, that the ~easuring tape be comprised of a resilient springy material of an arcuate cross-section which can be resiliently pressed flat. ~he tape is then passed through a squeeze guide in the housing which presses its arcuate cross-section to a flat shape for winding up the measuring tape. In this case, the measuring tape may, as with the usual tape measures, be arched on the side turned to the take up spindle so that a pressure roller engaging the periphery of the spindle can accomplish the pressing flat of the -tape cross-section.
In order to enhance the stiffness of the extended measuring tape, so that it may optionally be~ extensible i~ a self-supporting manner, in a further embodiment,of the measuring tape a measuring tape is provided having a hollow cross-section pressable fla-t by the squeeze guide. ~his hollow cross-section being obtained by using a double tape of which the individual tapes are connected with each other at their ends, with each individual tape being of arcuate section. In this way the measuring tape forms an approximately lenc shaped cross-section in its extended part and a strip or brand-shaped cross-section in its wound-up part.
.
,~ ~ - 8 -.
10~8898 In order that in given cases a squeeze guide should be usable which is spaced in front of the take up spindle of the measuring tape without the measuring tape becoming arched up again due to its pretensioning obtained by the squeeze guide between the latter and the take-up guide, in a further develop~
ment of the invention the hollow cross-section of the measuring tape can be pressed flat so that it has the hollow cro`ss-section in a first stable position which is then pressable flat into a second stable position by means of the squeeze guide.
In thiQ connection, advantageously t-here is provided a lateral guide between the squeeze guide and the exit opening of the housing which presses the measuring tape from its second stable ~;
position into its first stable position to extend the measuring tape. To obtain a strip shape cross-section with two such stable positions in the embodiment wherein the measuring tape is constructed in the manner described above, a,double tape can be obtained for example by connecting the individual tapes at its side edges with a small spacing from each other so that the biconvex hollow cross-section can be pressed flat with the aid of a suitable ground roller of the squeeze guide to a biconcave hollow cross-section forming the second stable position.
The invention will hereafter be described with reference to the preferred embodiments shown schematically in the drawings wherein:
FIGURE 1 is a fragmentary sectional view of various elements operationally arranged within a tape housing in accordance with the invention, FIGURE 2 is a plan view of the housing of one preferred embodiment, including a calculator portion, _ g _ 10~8898 FIGURE 3 is a side view of the embodiment of Figure 2, FIGURE 4 is a schematic detail view to explain the tape drive and the sensing of the measuring tape in the embodiment according to Figures 2 and 3, and FIGURE 5 is a further detailed view of the tape drive of Figure 4.
Figure 1 shows schematically a housing 1 accommodating therein a takeup spindle 2 for a non-illustrated measuring tape which can be extended and retracted by means of a motor via a slit guide 3 at one of the longer sides of the housing through an exit opening 4 at the front of the housing. To this end the housing accommodates furthermore a small electric motor 5 with an associated battery 6, the shaft of the motor carrying a worm gear 7 which matches with a side disc of the takeup qpindle 2 formed as a worm wheel 8. -A sensing slit 9 is formed in one wall of the slit guide 3 adjacent to the takeup spindle 2 through which a suitable mark of the tape running past the slit is sensed by means of a schematically illustrated optical sensing element 10. The sensing element 10 is a component of a sensing device which is not shown further and which includes a counter which -counts the sensing pulses and converts them to a measurement value which is then displayed in an indication or display field on the outer side of the housing.
The front and/or rear side of the housing 1 forms a locating surface 11 or 12 extending at right angles to the direction of extension of the measuring tape. Such locating ~urfaces may be used as reference values for the initial value of the counter device. Further, a push-button switch 13 is provided at one side of the housing which may be depressed to switch the apparatus on. When depressed, two further switch ~A
iO~8898 contacts 14, 15 are closed which are then opened again when the push-button switch is released. The lower contact 15 is used for resetting the counter after a preceding measurement whereafter the upper contact 14 sets the initial value of the counter.
The counter may be released and set to zero as desired with the aid of the push-button switch 13. In addition, a separate motor switch 16 is alsQ provided for switching the motor on and off and to reverse the direction of the drive. It i~ also possible to include a separate programme part with the aid of which the motor and optionally also the counter can be controlled by means of a preset or keyed-in programme.
In the embodiment shown in Figures 2 and 3, the housing 1 includes an electronic calculator similar to the usual pocket calculators, the keyboard 17 of which is arranged on the outside of the housing 1. In addition to the display field 18 on which the sensed measurement value of the extended measuring tape 19 appears, there is provided a separate display field 20 for the calculator part. As can be seen from Figure
3, the measuring tape 19 is rotated by a suitable tape guide within the housing 1 for taking it up on the tape spindle 2.
In this embodiment, the drive for the measuring tape 19 is similar to that of a recording tape in a tape recorder apparatus as can be seen schematically from Figures 4 and 5. A lower drive spindle 21 driven from the motor 5 by a suitable drive mechani~m co-operates with an upper pressure roller 22 which forms a through-gap or passage for the measuring tape 19.
The pressure roller 22 is pivotably mounted on an arm 23 and is pressed by means of a non~illustrated spring against the drive spindle 21 or the through-going tape so that the latter is entrained by the drive spindle 21.
10~i8898 A perforated disc 24 rigid with the drive spindle 21 has a series of perforations or holes 25 which are arranged at a predetermined spacing.
The perforations pass through a light barrier of a non-illustrated sensing device so that as the drive spindle 21 rotates corresponding to the movement of the tape, the length of extension of the measuring tape 19 can be measured.
The battery 6 also supplies power to the calculator which in this embodiment nevertheless operates independently from the measuring device. A measurement value appearing in the display field 18 can therefore be keyed via the keyboard 17 into the calculator in order to carry out a calculation.
After the calculation has been carried out the result appears in the normal manner at the display field 20 of the calculator.
' ~
In this embodiment, the drive for the measuring tape 19 is similar to that of a recording tape in a tape recorder apparatus as can be seen schematically from Figures 4 and 5. A lower drive spindle 21 driven from the motor 5 by a suitable drive mechani~m co-operates with an upper pressure roller 22 which forms a through-gap or passage for the measuring tape 19.
The pressure roller 22 is pivotably mounted on an arm 23 and is pressed by means of a non~illustrated spring against the drive spindle 21 or the through-going tape so that the latter is entrained by the drive spindle 21.
10~i8898 A perforated disc 24 rigid with the drive spindle 21 has a series of perforations or holes 25 which are arranged at a predetermined spacing.
The perforations pass through a light barrier of a non-illustrated sensing device so that as the drive spindle 21 rotates corresponding to the movement of the tape, the length of extension of the measuring tape 19 can be measured.
The battery 6 also supplies power to the calculator which in this embodiment nevertheless operates independently from the measuring device. A measurement value appearing in the display field 18 can therefore be keyed via the keyboard 17 into the calculator in order to carry out a calculation.
After the calculation has been carried out the result appears in the normal manner at the display field 20 of the calculator.
' ~
Claims (14)
1. In a pocket-type tape measure having a housing in which a take-up spindle is arranged for a measuring tape extending with its free end through an exit opening at a front face of the housing to be pulled out of the housing to allow a length to be measured along the pulled-out part of the measuring tape between the free end thereof and the housing, the improvement comprising, in combination:
a) a sensing means positioned within said housing and in operating relation with said measuring tape for contact-lessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corresponding series of sensing impulses for each passing marking element;
b) an electronic counting means positioned within said housing and coupled with said sensing means to count said sensing impulses;
c) an electronic digital display means positioned within said housing and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field;
d) a first locating surface at an outside front face of the housing and in the plane of the exit opening, said first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing;
e) a second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing, f) a manually operatable zero switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of the counting and display means to zero; and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure.
a) a sensing means positioned within said housing and in operating relation with said measuring tape for contact-lessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corresponding series of sensing impulses for each passing marking element;
b) an electronic counting means positioned within said housing and coupled with said sensing means to count said sensing impulses;
c) an electronic digital display means positioned within said housing and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field;
d) a first locating surface at an outside front face of the housing and in the plane of the exit opening, said first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing;
e) a second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing, f) a manually operatable zero switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of the counting and display means to zero; and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure.
2. The combination of claim 1, wherein said array of marking elements are on the measuring tape itself.
3. The combination of claim 1, wherein said marking elements are perforations in the measuring tape.
4. The combination of claim 1, wherein the measuring tape consists of a double tape of a spring material in which the individual tapes have an arched cross-section and are inter-connected at their edges to form the double tape with a sub-stantially lens-shaped biconvex cross-section, adapted to be resiliently pressed flat by a squeezing guide in the housing through which the tape is passed.
5. The combination of claim 1, further including an electronic computer means positioned within said housing and having a keyboard and a display field on an outside surface of the housing, the display of the computer means being separate of the display of the sensing means.
6. The combination of claim 5, wherein the computer means is coupled with the sensing means in such a way that the count value of the sensing means can be keyed into the computer means.
7. The combination of claim 1, wherein said manually operatable zero switching means is capable of selectively setting the initial value of the counting and display means to zero or to a number which corresponds to the distance between said first and second locating surfaces to allow, at choice, the counting value to be referenced to the first locating surface or the second locating surface.
8. In a pocket-type tape measure having a housing in which a take-up spindle is arranged for a steel measuring tape extending with its free end through an exit opening at a front face of the housing to be pulled out of the housing to allow a length to be measured along the pulled-out part of the measuring tape between the free end thereof and the housing, the improvement comprising, in combination:
a) a sensing means mounted within said housing for contactlessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corresponding series of sensing impulses for each passing marking element;
b) an electronic counting means of the forward-backward counting type mounted within said housing and coupled with said sensing means to count said sensing impulses;
c) an electronic digital display means positioned within said housing means and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field;
d) a first locating surface at an outside front face of the housing and in the plane of the exit opening, the first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing;
e) a second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing;
f) a manually operatable setting switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of the counting and display means to zero or to a number which corresponds to the distance between said first and second locating surfaces to allow, at choice, the counting value to be referenced to the first locating surface or the second locating surface; and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure.
a) a sensing means mounted within said housing for contactlessly sensing an array of marking elements passing the sensing means in response to the movement of the measuring tape relative to the housing and producing a corresponding series of sensing impulses for each passing marking element;
b) an electronic counting means of the forward-backward counting type mounted within said housing and coupled with said sensing means to count said sensing impulses;
c) an electronic digital display means positioned within said housing means and having a display field observable from the outside of said housing, said display means being connected to said counting means to display the number of sensing impulses counted by the counting means in said display field;
d) a first locating surface at an outside front face of the housing and in the plane of the exit opening, the first locating surface extending in a plane normal to the direction of extension of the measuring tape outside the housing;
e) a second locating surface at an outside rear face of the housing in spaced relation relative to the first locating surface and extending in a plane normal to the direction of extension of the measuring tape outside the housing;
f) a manually operatable setting switching means positioned on a surface of said housing remote from said locating surfaces for selectively setting an initial value of the counting and display means to zero or to a number which corresponds to the distance between said first and second locating surfaces to allow, at choice, the counting value to be referenced to the first locating surface or the second locating surface; and g) an electrical battery positioned within said housing and coupled to the electrical components of said combination to provide power thereto, said housing being common to all said elements of the tape measure.
9. The combination of claim 8, wherein said manually operatable zero switching means is capable of selectively setting the initial value of the counting and display means to zero.
10. The combination of claim 8, wherein said array of marking elements are on the measuring tape itself.
11. The combination of claim 10, wherein said marking elements are perforations in the measuring tape.
12. The combination of claim 8, wherein the measuring tape consists of a double tape of a spring material in which the individual tapes have an arched cross-section and are interconnected at their edges to form the double tape with a substantially lens-shaped biconvex cross-section, adapted to be resiliently pressed flat by a squeezing guide in the housing through which the tape is passed.
13. The combination of claim 8, further including an electronic computer means positioned within said housing and having a keyboard and a display field on an outside surface of the housing, the display of the computer means being separate of the display of the sensing means.
14. The combination of claim 13, wherein the computer means is coupled with the sensing means in such a way that the count value of the sensing means can be keyed into the computer means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA306011A CA1068898A (en) | 1978-06-22 | 1978-06-22 | Tape measure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA306011A CA1068898A (en) | 1978-06-22 | 1978-06-22 | Tape measure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068898A true CA1068898A (en) | 1980-01-01 |
Family
ID=4111745
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA306011A Expired CA1068898A (en) | 1978-06-22 | 1978-06-22 | Tape measure |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1068898A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5691923A (en) * | 1995-04-25 | 1997-11-25 | Levi Strauss & Co. | Digital measuring system |
-
1978
- 1978-06-22 CA CA306011A patent/CA1068898A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5691923A (en) * | 1995-04-25 | 1997-11-25 | Levi Strauss & Co. | Digital measuring system |
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| MKEX | Expiry |