BACKGROUND OF THE INVENTION
This invention relates to a tape measure.
1. Field of the Invention
In particular, the invention relates to a tape measure containing a magnifying lens, a light and a marker for making a mark on a workpiece when taking a measurement.
2. Description of Related Art
There are many patents and applications relating to tape measures including some form of marker, magnifying lens and/or light. Examples of such patents and applications are CA 1,287,972, issued to M. Legare on Aug. 27, 1991, CA 2,234,942, issued to M. D. Potter et al on Nov. 21, 2006, U.S. Pat. No. 2,992,487, issued to O. A. Miller on Jul. 18, 1961, U.S. Pat. No. 3,205,584, issued to C. H. Overaa on Sep. 14, 1965, U.S. Pat. No. 4,015,337, issued to J. A. Taylor on Apr. 5, 1977, U.S. Pat. No. 4,296,554, issued to E. A. Hammerstrom on Oct. 27, 1981, U.S. Pat. No. 4,462,160, issued to H. Cohen et al on Jul. 31, 1984, U.S. Pat. No. 4,580,347, issued to F. H. McKnight on Apr. 8, 1986, U.S. Pat. No. 4,630,376, issued to R. L. Pentecost on Dec. 23, 1986, U.S. Pat. No. 4,760,648, issued to S. W. Doak et al on Aug. 2, 1988, U.S. Pat. No. 5,671,543, issued to T. A. Sears on Sep. 30, 1997, U.S. Pat. No. 6,030,091, issued to C. L. Li on Feb. 29, 2000, U.S. Pat. No. 6,178,655, issued to M. D. Potter et al on Jan. 30, 2001, U.S. Pat. No. 6,209,219, issued to D. I. Wakefield et al on Apr. 3, 2001, U.S. Pat. No. 6,434,854, issued to I. C. MacColl et al on Aug. 20, 2002, U.S. Pat. No. 6,574,881, issued to R. E. Cole III on Jun. 10, 2003, U.S. Pat. No. 6,892,469, issued to B. D. Tufts et al on May 17, 2005, U.S. Pat. No. 7,174,655, issued to L. A. Gibbons et al on Feb. 13, 2007 and US 2007/0101600 (T. L. Alders), published May 10, 2007.
The devices disclosed by the patent literature include a magnifying lens, a light and/or a marker. However, many of the devices incorporating a light are designed merely to illuminate an area in the general vicinity of a tape, i.e. they do not concentrate light in the area where a measurement is being made. For the most part, the measuring tapes with markers are somewhat rudimentary and include a pencil, which, unless sharp, would not make a fine line or mark on a workpiece at the desired location. Many of the devices require two hands to operate and/or are structurally complicated and consequently would be expensive to manufacture
BRIEF SUMMARY OF THE INVENTION
The present invention provides a relatively simple, streamline tape measure incorporating a magnifying lens, a light and a marker, all of which are in close proximity to each other and to the tape, enabling accurate marking of a workpiece.
Accordingly, the present invention relates to a tape measure comprising:
a casing;
a tape in said casing with indicia thereon, said tape being adapted to be extended from said casing for making a measurement and retractable into said casing to a storage, non-use position;
a magnifying lens mounted in a front end of said casing above an outer free end of said tape when the tape is in the non-use position;
a light in said casing for illuminating said lens and the tape therebeneath;
an indicator line associated with said lens immediately above and extending transversely of said tape in vertical alignment with said indicia during measurements;
a marker slidable in said lens between a retracted position in said casing and an extended position exterior to said casing for making a mark on a workpiece at one end of said indicator line during measurement;
a switch in said casing for actuating said light; and
a slider movable on said casing for sequentially operating said switch and said marker when the tape has been extended to a desired length indicated by said indicator line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are isometric views of a tape measure in accordance with the invention;
FIG. 3 is a top view of the tape measure of FIGS. 1 and 2;
FIG. 4 is a front view of the tape measure of FIGS. 1 to 3;
FIG. 5 is a bottom view of the tape measure of FIGS. 1 to 4;
FIG. 6 is a schematic side view of an electrical circuit used in the tape measure of FIGS. 1 to 5, and
FIGS. 7 and 8 are schematic, longitudinal section views of the tape measure of FIGS. 1 to 5 in the non-use and use conditions, respectively.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1 to 5, a tape measure in accordance with the invention includes a casing indicated generally at 1 containing a conventional coiled tape 2 (FIG. 3), a return spring (not shown), and a hook 3 on the outer free end of the tape 2. The casing 1 is defined by a convex top wall 4, a bottom wall 5, side walls 6 and 7, a front wall defined by a removable cover 8 attached to the remainder of the casing by a screw 9, and a rear wall 10. A thumb operated, slidable button 11 on the front of the top wall 4 is used to operate a conventional brake (not shown) for releasably locking the tape (not shown) in an extended position. Straight extensions 12 and 13 project forwardly from the sides of the casing 1. The extensions 12 and 13 define a well 14 (FIG. 1) with the bottom wall 5 and the front of the casing 1. A clear plastic, magnifying lens 15 is mounted in the well 14 between the front ends of the extensions 12 and 13 above the front end of the tape 2 and the rear end of the hook 3 when the tape is in the retracted position shown in the drawings. The lens 15 has a convex top surface. Thus, the tape 2 is magnified when viewed from above. A black line 16 (FIG. 3) is provided on the bottom of the lens 15. The line 16 extends between the ends of the lens 16 perpendicular to the longitudinal axis of the tape i.e. transversely of the casing 1. While the line 16 could be incorporated in the lens 15, it is preferable that the line is located on the bottom of the lens to avoid parallax errors. Light from an LED 17 shines through the lens and lights up the area beneath the lens 15 including the line 16 and the tape 2, making it easier to read the indicia on the tape and providing a line across the tape indicating the length of tape extending from the casing 1. The LED 17 is mounted in a semi-cylindrical projection 18 on the extension 11. A small hole (not shown) in the extension 11 admits light to the lens 15.
The LED 17 extends slightly out of the bottom end of the housing 18 (FIGS. 4 and 5) so that the LED provides light to an area beneath a triangular alignment pointer 21. The pointer 21 is aligned with the line 16 through the lens 15.
Power for the LED 17 is supplied by a battery 23 (FIGS. 2 and 6) mounted in a compartment 24 (FIG. 2) behind the cover 8. Wires 25 and 26 connect the LED 17 to the battery 23 and to a switch 27, respectively. The switch 27 is mounted in the top front of the casing 1 for activation by a slider 28. Another wire 30 connects the switch 27 to the battery 23.
As best shown in FIGS. 1, 2, 7 and 8, the slider 28, which is slidable on a ramp 31 defined by the inclined top edge of the extension 13, includes a plastic push bottom 32 at its top end and an elongated, stainless steel bottom end 33. The slider 28 is biased upwardly to a rest position (FIG. 6) on the ramp 31 by a helical spring 35, one end of which is connected to the end 32 of the slider and the other end of which is connected to the casing 1 by a pin 36 (FIGS. 6 and 7). The slider 28 can be operated by a user's thumb, i.e. the tape measure can be operated using one hand.
Downward movement of the slider 28 activates a marker assembly indicated generally at 38 in FIGS. 7 and 8. The marker assembly includes a steel, nail-shaped marker 39 slidable in the lens 15. The marker 39 has an elongated body 41 with a disc-shaped head 42 on the top end thereof and a pointed bottom end 43. The marker 39 is located close to the tape 2, and the pointed bottom end 43 is aligned with the line 16. A helical spring 45 coaxial with the body 41 is sandwiched between the head 42 and the top of the lens 15.
In operation, the button 32 is pushed using a thumb or finger. When the slider 28 moves downwardly on the ramp 31 (FIGS. 2, 7 and 8) defined by the inclined top edge of the arm 13, the slider button closes the switch 27 to turn on the LED 17. When the line 16 on the bottom of the lens 15 is vertically aligned with the proper indicia on the tape 2, i.e. if the desired measurement has been made, the slider 28 is pushed further down along the ramp 31. At the same time, the button 11 is contacted with the user's thumb or a finger to actuate the tape brake. Because the tape brake-operating button 11 is located in side-by-side and slightly below the button 32 at the top end of the slider 28, a thumb can be used to push both buttons at the same time or sequentially. The bottom end of the slider 28 bears against the head 42 of the marker 39, pushing the marker downwardly through an opening 47 in the bottom wall 5 of the casing 1 (FIG. 8) to leave a mark in or on a surface abutting the bottom wall 5. The spring 45 is compressed between the head 42 of the marker 39 and the top of the lens 15. When the slider 28 is released, the spring 35 returns the slider to the rest position (FIG. 7) turning off the LED 17, and the spring 45 returns the marker 39 to the rest position.
Patent Application
20110239479
