Patent Publication Number: US-8117762-B2

Title: Tape rule and end hook therefor

Description:
This application relies on the benefit of priority from U.S. Provisional Application No. 61/299,224, filed on Jan. 28, 2010, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to rule assemblies. 
     A typical tape rule assembly includes an elongated thin metal rule blade that is mounted on a reel rotatably disposed within a housing. The rule blade is retracted into the housing for storage by coiling it about the reel. To measure a work-piece, a length of the rule blade is pulled out of the housing to span the distance to be measured and the blade is held against the work-piece so that gradation lines and numbers printed on the blade can be read against a point on the work-piece. To measure a distance between two objects or surfaces, the blade hook at the free end of the blade may be temporarily secured or placed against an object or surface. 
     The present invention provides improvements over the prior art tape rules and blade hooks. 
     SUMMARY 
     One aspect of the invention relates to a rule assembly that includes a housing, a reel rotatably mounted in the housing, and an elongated blade having an end hook member on a free end thereof. The end hook member includes a mounting portion and a generally hook portion extending from an end of the mounting portion. The end hook member comprises a pair of generally upwardly extending side edges, a generally laterally extending lower edge. The end hook member comprises recessed edge corner portions disposed between the upwardly extending side edges and the laterally extending lower edge. 
     Another aspect of the invention relates to a rule assembly that includes a housing, a reel rotatably mounted in the housing, an elongated blade arranged to be wound on the reel and to be extendable through an opening in the housing, the elongated blade having an end hook member on a free end thereof. The end hook member comprises a burred portion disposed on at least a portion of the end hook that is position above the elongated blade. 
     Another aspect of the invention relates to a rule assembly that includes a housing, a reel rotatably mounted in the housing, and an elongated blade having an end hook member on a free end thereof. The end hook member includes a mounting portion and a hook portion extending from an end of the mounting portion. The end hook member comprises a pair of generally upwardly extending side edges and a generally laterally extending lower edge. The end hook member comprises recessed edge corner portions disposed between the upwardly extending side edges and the laterally extending lower edge. Lower corner portions of the housing are constructed and arranged to extend beyond the recessed edge corner portions of the end hook member. 
     These and other aspects of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. In one example of the invention, the structural components illustrated herein can be considered drawn to scale. It is to be expressly understood, however, that many other configurations are possible and that the drawings are for the purpose of example, illustration and description only and are not intended as a definition or to limit the scope of the invention. It shall also be appreciated that the features of one embodiment disclosed herein can be used in other embodiments disclosed herein. As used in the specification and in the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a rule assembly in accordance with an embodiment of the present invention; 
         FIG. 2  shows a front of elevational view of the rule assembly in accordance with an embodiment of the present invention; 
         FIG. 3  shows a side of elevational view of the rule assembly in accordance with an embodiment of the present invention; 
         FIG. 4  shows a cross-sectional view of the tape rule assembly taken through the line  4 - 4  in  FIG. 2  showing a blade thereof in a fully retracted configuration in accordance with an embodiment of the present invention; 
         FIG. 5  is a view similar to  FIG. 4  except showing the blade in a fully extended configuration in accordance with an embodiment of the present invention; 
         FIG. 6  is a cross-sectional view taken through the line  6 - 6  in  FIG. 3 ; 
         FIG. 7  shows a front view of an end hook in accordance with an embodiment of the present invention; 
         FIG. 8  shows a perspective view of the end hook in accordance with an embodiment of the present invention; 
         FIG. 9  shows another perspective view of the end hook in accordance with an embodiment of the present invention; 
         FIG. 10  shows a side perspective view of the end hook in accordance with an embodiment of the present invention; 
         FIG. 11  shows a top view of the end hook in accordance with an embodiment of the present invention; 
         FIG. 12  shows a rear perspective view of the end hook in accordance with an embodiment of the present invention; 
         FIGS. 13A-C  show the procedures involved while the end hook engages with a work-piece having a large radius in accordance with an embodiment of the present invention; 
         FIG. 14  shows a front view of the end hook, where two-thirds of the mass of hook portion of the end hook lies outside a center section that comprises one-third of the hook portion&#39;s width in accordance with an embodiment of the present invention; 
         FIG. 15A  shows a perspective view of the rule assembly prior to a corner impact in accordance with an embodiment of the present invention; 
         FIG. 15B  shows a perspective view of the rule assembly, where lower corner portions of the housing extend beyond recessed surface portions of the hook portion in accordance with an embodiment of the present invention; 
         FIG. 16A-B  shows a corner impact drop orientation and a side impact drop orientation for the rule assembly in accordance with an embodiment of the present invention; 
         FIG. 17  shows a bottom plan view of the rule assembly, where a gap is located behind upwardly extending side edges of the hook portion of the end hook in accordance with an embodiment of the present invention; and 
         FIGS. 18-22  show portions and dimensions of various parts of an exemplary end hook in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-4  show a rule assembly  10  in accordance with an embodiment of the present invention. The rule assembly  10  includes a housing  12 , a reel  14  (as shown in  FIGS. 4 and 5 ) rotatably mounted in the housing  12 , and an elongated blade  16  having an end hook member  34  on a free end  20  thereof. The elongated blade  16  is arranged to be wound on the reel  14  and to be extendable through an opening  22  in the housing  12 . 
     In one embodiment, the housing  12  is constructed to easily and comfortably fit in a hand of the user because it optimizes the use of space within the housing  12  to house the blade  16 , a coil spring  32  (as shown in  FIGS. 4 and 5 ) and other cooperating components. The details of the internal structure of the housing  12  and the blade  16  mounted therein are shown in  FIGS. 4-6 . In one embodiment, the housing  12  and the reel  14  are constructed of, for example, a molded plastic material. 
     As can be clearly seen from  FIG. 2 , the housing  12  of the rule assembly  10  has an overall width dimension HW larger than a width dimension HW 1  of the housing near the opening  22  in the housing  12  from where the elongated blade  16  extends. For example, in one embodiment, the width of housing  12  is bit thinner near the opening  22  (towards a front lower portion of the housing) in comparison with the portion of the housing  12  at a central axis A that passes through the axis of rotation of the reel  14 . An overall width dimension W of the hook portion  152  of the end hook  34  is greater than the width dimension HW 1  of the housing  12  near the opening  22  in the housing  12  from where the elongated blade  16  extends, and smaller than the overall width dimension HW. 
     As shown in  FIG. 6 , the housing  12  includes a pair of cooperating housing members  40 ,  42 . In one embodiment, the housing members  40 ,  42  are made of, for example, a molded plastic material. Each housing member  40 ,  42  includes an end wall  44 ,  46 , respectively, having a peripheral wall  48 ,  50 , respectively, extending from a periphery thereof and terminating in a free edge  52 ,  54 , respectively. The pair of cooperating housing members  40 ,  42  are movable toward one another in an axial direction into cooperating relation to define the housing  12  (where “axial direction” refers to the direction of the axis of rotation of the reel  14  defined by a reel spindle  15 ). 
     When the housing members  40 ,  42  are fixed together in the assembled rule assembly  10 , the free edges  52 ,  54  are interengaged as shown in  FIG. 6 . It can be thus appreciated that the end walls  44 ,  46  can be considered the side walls of the assembled housing, the housing having side surfaces  393 , a top surface  395 , a front surface  397 , a back surface  398 , and bottom surface  399 . A plurality of axially extending bolts  58  extend through one of the housing members  42  and threadedly engage the other housing member  40  at spaced positions adjacent the peripheral walls  48 ,  50 . The housing members  40 ,  42  are also fixed together by the threaded engagement of bolts  68  with the fixed reel spindle  15 . The axially extending spindle  15  is fixed at a central portion of the housing  12 . In one embodiment, the fixed spindle  15  has a noncircular interengaging recess-projection connection (shown in  FIG. 6  and described below) at each end thereof generally with a central interior region  62 ,  64 , respectively, of the end walls  44 ,  46  of the housing  12 . Each end of the fixed spindle  15  is interiorly threaded to threadedly receive the bolts  68  therein. The bolts  68  extend through central holes  70 ,  72  formed in the respective adjacent end walls  44 ,  46  of the housing  12  and threadedly engage internal threading  73  in each end of the spindle  15 . Each bolt  68  extends through a recess-projection connection  75 , when each bolt  68  is disposed in a respective central hole  70 ,  72  and threaded interior  73 . A clip  77  is secured to one side of the housing  12  by one of the bolts  68 . The clip  77  is generally used to attach the rule assembly  10  to the belt of a user, or other attachment point. In one embodiment, the belt clip  77  is made from, for example, a metal material. 
     In one embodiment, the spindle  15  is constructed of, for example, a molded plastic material or a nylon material. The construction of the recess-projection connections  75  between the ends of the spindle  15  and the walls  44 ,  46  is shown in cross-section in  FIG. 6 . Each recess-projection connection  75  is identical. In one embodiment, projections  74  having exterior noncircular cross-sections are integrally formed on the walls  44 ,  46  and are received within recesses  76  having complementary non-circular interior cross-sections formed on each end of the spindle  15 . The noncircular interior and exterior cross-sections cooperate to prevent rotation of the spindle  15  with respect to the housing  12  when the ends of the spindle  15  are mounted on the projections  74  in the assembled rule assembly  10 . Each end of the spindle  15  extends through a hole  79  of circular cross-section formed in opposite sides of the reel  14 . The portions of the spindle  15  that extend through the holes  79  in the reel  14  have circular exterior cross sections. A flange  81  on the spindle  15  engages an annular groove  83  in the reel  14  surrounding the hole  79  to guide the rotation of the reel on the spindle. Thus, the reel  14  is rotatably mounted on the spindle  15  for bi-directional rotational movement of the reel with respect to the housing  12 . As shown in  FIGS. 4 and 6 , the spindle  15  is internally slotted to receive the one longitudinal end  37  of the spring  32  to thereby secure the one end  37  of the spring  32  to the spindle  15 . 
     The reel  14  includes two reel members  78 ,  80  ( FIG. 6 ). In one embodiment, the reel  14  is made from, for example, a molded plastic material. The reel member  78  includes a integral cylindrical wall portion  28  about which the blade  16  is wound. In one embodiment, the reel member  80  is disk shaped. Each reel member  78 ,  80  includes an outwardly extending cylindrical wall portion  88 ,  90 , respectively, formed around the hole  79 . An annular edge portion  84  on the wall portion  82  is received within an annular groove  86  formed within the reel member  80  to help hold the reel  14  together. The abutting engagement of the wall portions  88 ,  90  on the reel  14  with the end walls  44 ,  46  of the housing  12  maintain the edge portion  84  within the groove  86  in the assembled rule assembly  10 . 
     The housing members  40 ,  42  include portions along the abutting free edges thereof  52 ,  54 , respectively, of tongue and groove construction ( FIG. 6 ) to help secure the molded housing members  40 ,  42  of the assembled rule assembly  10  together. In one embodiment, at a top portion of the housing  12 , a wall portion  92  formed on edge  54  is received within a groove  94  formed along a portion of the edge  52 ; and an integral wall portion  93  formed on edge  52  is disposed in underlying, abutting relation to wall portion  50  of the housing member  44 . At a bottom portion of the housing  12 , a wall portion  95  formed along a length of edge  54  is received within a recess  97  formed on a portion of the wall portion  48  of housing member  40 . 
     When viewed from the side elevational view, the housing  12  includes only two corner portions (see  FIG. 4 , for example)  96 ,  98 . One corner  96  is adjacent the housing opening  22  and the other corner portion  98  is at an opposite bottom end of the housing  12 . The two bolts  58  are positioned in the two corner portions  96 ,  98 , respectively, of the housing  12 . Thus, it can be appreciated that the housing  12  is secured together using threaded fasteners in only three locations (from the point of view of one looking at the side elevational view of, for example,  FIG. 4 ): at the opposite corners  96 ,  98  (bolts  58 ) at the bottom portion of the housing  12  and in the center of the housing  12  (bolts  68 ). This use of the bolts  68  on opposite ends of the reel spindle  15  allows the housing  12  to be secured together without using any bolts in a peripheral top portion or portions of the housing  12 . 
     As shown in  FIGS. 3-4 , because the housing  12  does not require bolts in the upper periphery of the housing  12 , the top portion  108  of the housing  12  can be made to have a relatively arcuate profile ( FIG. 2 , for example) that generally conforms to the profile of the reel  14 , thus minimizing the footprint of the housing  12 , eliminating corners in the upper portion of the housing  12  and providing a comfortable curved top surface to receive the palm of a user&#39;s hand. This arc-shaped upper surface of the housing  12  also increases impact resistance of the housing  12  in case the assembly  10  is dropped. 
     A peripheral portion of housing  12  is provided with a coating  110  around the gripped portion of the housing  12  to provide increased frictional engagement between the housing  12  and a user&#39;s hand and to provide a relatively soft comfortable surface for the user&#39;s hand. In one embodiment, the coating  110  is made from, for example, a rubber-like material. 
     The housing  12  includes a bottom wall  109  ( FIGS. 4-5 ) having an exterior portion  107  at an end position adjacent the housing opening  22  which projects below an exterior surface portion  108  extending therefrom toward an opposite end  113  of the bottom wall  109  to provide a finger grip enhancing configuration  119  for a gripping hand of the user. In the illustrated embodiment, the bottom wall  109  ( FIGS. 3-4 ) has the forward end portion  107  disposed adjacent the housing opening  22  and the rearward end portion  113  at the opposite end of the bottom wall  109 . The portion  108  of the wall  109  therebetween is generally recessed to provide the finger grip enhancing configuration  119  for the gripping hand of the user. In one embodiment, this recessed area or gripping area  119  on the bottom of the housing  12  is covered with, for example, the overmolded rubber material or a rubber-like polymeric material. It can thus be appreciated that the housing  12  is constructed to be easily held in one hand of a user such that the user&#39;s fingers engage the finger grip enhancing portion  119  and the user&#39;s palm and thumb are generally in overlying relation with a top portion of the housing  12 . 
     In one embodiment, a holding assembly  124  is constructed and arranged to be manually actuated to hold the blade  16  in any position of extension outwardly of the housing opening  22  and to release the blade  16  from any position in which it is held. The structure and operation of the holding assembly  124  is best appreciated from a comparison of  FIGS. 4-5 . The holding assembly  124  includes a holding member  126  mounted on the housing  12  for movement in opposite directions between a normally inoperative position ( FIG. 4 ) and a holding position ( FIG. 5 ). It can be appreciated that the blade holding member  126  is an arcuate member that is movable along an arcuate path between the two positions as aforesaid. The holding member  126  has an interior free end portion  128  that is movable into wedging engagement with the tangentially extending portion of the blade  16  to engage and hold the blade against an interior holding structure  130  ( FIG. 5 ) on the housing  12  when the holding member  126  is in its holding position. The free end portion  128  includes a central recess  129  ( FIG. 2 , for example) that is described in detail below. The holding member  126  has an exterior thumb engaging portion  132  configured to be moved digitally to selectively move the holding member  126  from its normally inoperative position and its holding position. The exterior thumb engaging portion  132  is shown in  FIGS. 1-2 . 
     In one embodiment, the holding member  126  is an integral structure made of, for example, an appropriate durable flexible plastic material. The thumb engaging portion  132  is connected by an integral outwardly extending neck portion  134  to an elongated arcuate flexible body portion  133  that terminates in the interior free end  128 . The outwardly extending portion  134  is slidably held within and guided by a slot  136  formed within a front part of housing  12  by the members  40 ,  42 . The movement of a lower portion of the holding member  126  is guided by a pair of tabs  131  integrally formed on respective housing members  40 ,  42  (only one tab is shown in the figures). An integral locking structure  138  on the holding member  126  engages holding structure  140  ( FIG. 5 ) integrally formed on the housing  12  to releasably lock the holding member  126  in the holding position in wedging engagement with the blade  16 . 
     In one embodiment, to lock the blade  16  in a given position of extension, the user (while holding the blade  16  outwardly of the housing  12  against the spring force of the coil spring  32 ) slides the thumb engaging portion  132  downwardly with respective to the housing  12  causing the locking structure  138  to slide over a ramped surface  142  on the holding structure  140  and causing the free end  128  to move in a locking direction with respect to the blade  16 . The flexible plastic locking structure  138  bends resiliently outwardly slightly as it passes over the holding structure  140 . After the free end  128  contacts the blade  16 , continued movement of the thumb engaging portion  132  in the locking (downward) direction thereafter wedges the free end  128  of the flexible body portion  133  against blade  16  to hold the blade  16  in place against the spring force of the coil spring  32  and moves the locking structure  138  into abutting engagement with a locking surface  141  on the holding structure  140 . The holding member flexes slightly as the free end  128  is wedged against the blade  16 . The abutting engagement between the locking structure  138  and the locking surface  141  locks the holding member  126  in its holding position. It can be understood from  FIG. 5  that the blade  16  is held in an extended position (against the spring force of the coil spring  32 ) between the free end  128  of the body portion  133  and the interior holding structure  130  by the downward force exerted by the wedged body portion  133 . The interior holding structure  130  (not visible in detail) is a series of longitudinally spaced, transversely extending ribs that are constructed and arranged to support the convex side of the blade  16 . When viewed from the point of view of  FIG. 5  (i.e., on a transversely directed line of sight), the top surfaces (not visible in the FIGS.) of the ribs cooperate to provide a generally downwardly sloped support (in a direction toward the opening  22 ) for the blade  16 ; and when viewed from the front, (i.e., on a longitudinally directed line of sight) the top surfaces (not visible in the figures) of each rib of the interior holding structure  130  are transversely spaced in a concave array to receive and support the convex side of the blade. 
     To release the blade  16 , the user pulls upwardly on the thumb engaging portion  132  which causes the locking structure  138  on the plastic holding member  126  to move resiliently outwardly and past the locking surface  141  to release the holding member  126  from engagement with a blade  16 . The holding member  126  resiliently returns to its normal arcuate shape. It can be appreciated from  FIG. 2  that the recess  129  on the free end  128  of the holding member  126  defines two transversely spaced teeth  147  which have spaced arcuate side surfaces  144  sized to conform to the concave surface of the blade  16  to hold the same in locked position. 
     It can be understood that the use of the holding member  126  when a, measurement is being taken is optional. When taking a measurement, the user typically holds the housing  12  in one hand and manually pulls the blade  16  out of the housing  12  with the other hand. When a sufficient length of blade  16  has been withdrawn from the housing  12 , the user can lock the blade  16  with respect to the housing  12  using the holding member  126  to prevent the blade  16  from retracting back into the housing  12  (under the spring force of spring  32 ) when the user releases the blade  12 . When the measurement has been taken, the user simply releases the holding member  126  from holding engagement with the blade  16  by moving the free end  128  thereof out of wedging engagement with the blade  16  in the manner described above. If the holding member  126  is not used during the taking of a measurement, the user can simply hold the blade  16  with his other hand while the measurement is being taken or, alternatively, the hook member  34  can be placed in hooking engagement with the work-piece to hold the blade  16  outwardly of the housing  12  in a controlled and steady manner against the spring force of spring  32  while the measurement is being taken. 
     When the blade  16  is released after taking the measurement, the spring  32  rotates the reel  14  with respect to the housing  12  in a blade-winding direction to wind the blade  16  around the reel  14 . A relatively short free end portion of the blade  16  has a clear film  158  of plastic material adhered to the concave side thereof ( FIG. 11 ) to protect the blade  16  while the same is out of the housing  12  and while the blade  16  is being retracted under the spring force of the spring  32  back into the housing  12 . In one embodiment, the film is made of polyurethane and is adhered to the blade by an acrylic adhesive. It is also contemplated to use polyester to construct the film. In one embodiment, the film has a thickness dimension of approximately 0.0005 inches. It is within the scope of the invention to apply this film to the blade of any known tape rule assembly. 
     The free end  20  of the blade  16  is frequently handled by the user and this handling can over time cause the numbering and markings on the concave side of the blade  16  to wear off or become difficult to read. The film  158  prevents this wear because it covers the numbering and markings on the free end of the blade and thereby protects the same from being worn off. 
     In one embodiment, the blade  16  is formed of a ribbon of metal (e.g., the metal being steel), and the top concave surface of the blade is printed with measuring lines and digits (not shown) for measuring lengths and distances. A first longitudinal end  18  of the blade  16  is connected to a first longitudinal end  35  of the coil spring  32  and the second longitudinal free end  20  of the blade  16  extends generally outwardly of the reel  14 . The blade  16  is constructed and arranged with respect to the housing  12  to extend generally from a position tangential of the reel  14  outwardly through the opening  22  provided in the housing  12  (as shown, for example, in  FIG. 4 ). 
     The reel  14  is mounted in the housing  12  by the reel spindle  15  that is secured within the housing  12 . In one embodiment, the reel  14  is made of a molded plastic and is provided with a slot or an opening  26  in a central cylindrical wall portion  28  thereof. The one end  18  of the blade  16  terminates in a hook-like structure  30  that engages the first longitudinal end  35  of the coil spring  32  to connect the end  18  of the blade  16  to the coil spring  32  ( FIGS. 4 ,  5 ). 
     The coil spring  32  is constructed and arranged between the housing  12  and the reel  14  to rotate the reel  14  with respect to the housing  12  in a direction to wind the elongated blade  16  about the reel when the blade  16  is extending outwardly of the housing opening  22 . The coil spring  32  is generally enclosed within the central wall portion  28  of the reel  14  ( FIGS. 4-6 ). The first longitudinal end  35  of the coil spring  32  extends through the opening  26  and engages the first longitudinal end  18  of the blade  16 , and a second longitudinal end  37  of the coil spring  32  hookingly engages the spindle  15 . The spindle  15  is rigidly mounted to the housing  12  in a manner described above. In one embodiment, the spring  32  is a thin, flat ribbon of metal (e.g., the metal being steel). 
     The blade  16  is generally movable between a fully retracted position outwardly of the housing  12  to a fully extended position. The fully retracted position of the blade  16  is shown in  FIG. 4  and the fully extended position of the blade is shown (in fragmentary view) in  FIG. 5 . It can be appreciated from a comparison of  FIG. 4  and  FIG. 5  that as the blade is unwound from the reel  14 , the coil spring  32  is wound around the rigidly fixed spindle  15 . This winding of the spring around the spindle stores energy in the spring to provide spring powered rewinding of the blade  16  around the reel  14  when the extended blade is released. 
     The blade  16  may be constructed of a ribbon of sheet metal that is shaped during the manufacturing to have a normal or memory configuration that has a generally arcuate or concavo-convex transverse cross-section. When a portion of the blade  16  is wound about the reel  14 , the wound portion has a flat transverse cross-section and the wound layers of the coiled blade provide the wound blade with an abutting volute coil configuration. In other words, when the blade  16  is wound around the reel  14 , it has the flat cross-section and when the blade  16  is withdrawn from the housing  12  to measure an object, it returns to the concavo-convex cross-section. Thus, the coil spring  32  is constructed and arranged between the housing  12  and the reel  14  to rotate the reel  14  about the spindle  15  with respect to the housing  12  in a direction to wind up the elongated blade  16  when extending outwardly of the housing opening  22  in a normal concavo-convex cross-sectional configuration onto the reel  14  in an abutting volute coil formation in a flattened cross-sectional configuration. The concavo-convex cross-section provides the extended blade with rigidity and maintains the blade essentially straight in the longitudinal direction. 
     The concavo-convex cross-section of the blade  16  generally provides the unsupported blade  16  with blade standout. The concavo-convex cross-section of the blade  16  generally includes an arcuate central section  36  and integral end sections  38 . In various embodiments, the concavo-convex cross-sectional configuration of the blade  16  can be of the type described in commonly assigned U.S. Pat. No. 6,324,769, that is hereby incorporated by reference in its entirety. 
       FIGS. 7-12  show different views of the end hook member  34 . As shown in  FIGS. 7-12 , the end hook member  34  includes a mounting portion  150  and a hook portion  152  bent at a generally right angle from an end of the mounting portion  150 . In one embodiment, the end hook member  34  is formed of, for example, a sheet metal material of a predetermined thickness. 
     In one embodiment, the hook portion  152  has a generally U-shaped configuration. In one embodiment, the mounting portion  150  has a generally concavo-convex configuration. In another embodiment, the mounting portion  150  has a generally flat configuration. 
     As shown in  FIGS. 1-4 , the end hook member  34  is mounted on the free end  20  of the blade  16  with the mounting portion  150  thereof secured in engagement with a concave (upper) side of the free end  20  of the blade  16  and in overlying relation thereto. 
     In one embodiment, the connection between the free end  20  of the blade and the mounting portion  150  may permit limiting sliding movement therebetween. 
     Specifically, as shown in  FIGS. 4 ,  9  and  11 , the mounting portion  150  is provided with large holes  167  ( FIGS. 4 ,  9  and  11 ) and a plurality of rivets  169  extend through the holes  167  to slidably mount the end hook member  34  to the blade  16  for limited longitudinal relative movement between the end hook member  34  and the blade  16  (i.e., the diameter of each hole  167  is greater than the diameter of the associated rivet  169  by an amount approximately equal to the desired amount of hook movement). The limited sliding engagement allows the blade  16  to be measured externally from an external surface  161  of the U-shaped hook portion  152  or internally from an internal surface  163  of the U-shaped hook portion  152 . In other words, the sliding movement of the end hook member  34  allows an accurate measurement to be taken with either surface  161  or  163  in abutting relation with the work-piece; the hook member  34  slides longitudinally with respect to the blade  16  a distance approximately equal to the thickness of the hook portion  152  (where the thickness is measured from surface  161  to surface  163 ) so that a measurement taken with either surface  161  or  163  in abutting engagement with the work-piece will yield an accurate measurement. 
     In one embodiment, the distribution of the mass in the hook portion  152  is such that at least half of the mass of the hook portion  152  lies above an upper surface  380  (as shown in  FIG. 7 ) of the elongated blade  16 . In other words, in one embodiment, a larger portion of the mass of the hook portion  152  (and the mounting portion  150 ) is above an axis D-D (as shown in  FIG. 7 ) passing through the upper surface  380  (as shown in  FIG. 7 ) of the blade  16 . In another embodiment, the distribution of the mass in the hook portion  152  is such that at least half of the mass of the hook portion  152  lies above the mounting portion  150  of the end hook member  34 . These configurations of the end hook member  34  allows for increased top catching capability of the end hook member  34 . In one embodiment, the top catching capability of the end hook member  34  generally refers to the ability of a portion the end hook  34  to hookingly engage with a work-piece to facilitate extension of the blade  16  and to temporarily secure the blade to the work-piece while a measurement is being taken. In such an embodiment, the portion of the end hook  34  may be a) located above the blade  16  and b) located above and to the side of the blade  16 . 
     In one embodiment, the U-shaped hook portion  152  including a bight section  160  and spaced leg sections  162  extending upwardly from the bight section  160 . In one embodiment, the bight section  160  of the U-shaped hook portion  152  is configured to extend downwardly, below a convex side of the free end  20  of the blade  16 . The bight section  160  of the hook portion  152  of the hook member  34  provides an under-catch structure that can hookingly engage a work-piece to facilitate extension of the blade  16  and to temporarily secure the blade to the work-piece while a measurement is being taken. 
     In one embodiment, as shown in  FIG. 7 , the leg sections  162  extend laterally outwardly beyond the longitudinally extending edges of the blade  16  to provide a side catch surface on each side of the blade  16  that can be used to hook the blade  16  to an object or work-piece. The side catch structure provided by the legs  162  can function to secure the free end  20  of the blade  16  during a measurement. The side catch structure provided by the leg sections  162  also allow the blade  16  to be easily and steadily held in a position relative to a surface of the work-piece, thereby allowing a longitudinally extending edge of the blade  16  to be held against the work-piece. In one embodiment, when the convex side of the blade  16  is against the work-piece, the longitudinal edges are normally spaced from the surface because of the concavo-convex cross-section of the blade  16 . The side catch provided by the legs  162  of the hook member  34  can be hooked over an edge of the work-piece to allow the user to hold steadily a longitudinal edge of the blade  16  very close to or directly against the work-piece when the convex side of the blade  16  is against the work-piece, which facilitates reading a measurement. 
     In one embodiment, as shown in  FIG. 7 , the leg sections  162  extend laterally beyond transversely spaced corners  171  of the free end  20  of the blade  16 . In the illustrated embodiment, as shown in  FIG. 7 , the side surface  328  of leg sections  162  extend (at its laterally outermost point, when taking a vertical or plumb tangent line to the side surface  328  as shown) laterally beyond transversely spaced corners  171  of the free end  20  of the blade  16  by a distance of X (shown in  FIG. 7 ). In one embodiment, the leg sections  162  extend laterally beyond transversely spaced corners  171  (as shown in  FIG. 4 ) of the free end  20  of the blade  16  by at least a distance of 0.08 inches (i.e., by a distance equal to or greater than 0.08 inches). In one embodiment, as seen in  FIG. 4 , the corners  171  at the front edge of the blade are chamfered or angled. 
     In one embodiment, as shown in  FIG. 7 , the upper portions of the leg sections  162  extend generally upwardly and outwardly above the concave side of the blade  16  to provide structure above the concave surface of the blade  16  to hookingly engage the work-piece to facilitate extension of the blade  16  and to hold the free end  20  of the blade  16  while a measurement is being read. For example, the blade  16  can be placed against a work-piece such that the concave side of the blade  16  is facing the work-piece and such that the opposite longitudinal edges of the blade  16  abut a surface on the work-piece at a point where they measurement is to be read. When the blade  16  is in this position, the upwardly extending portions of the legs  162  on the hook member  34  can be used to hold the free end  20  of the blade  16  against the work-piece. 
     In one embodiment, the leg sections  162  extend upwardly above both the mounting portion  150  and the spaced corners  171  of the free end  20  of the blade  16 . In the illustrated embodiment, as shown in  FIG. 7 , the upper surface of leg sections  162  extend upwardly above transversely spaced corners  171  of the free end  20  of the blade  16  by a distance of Y, at a maximum height as shown. In one embodiment, the leg sections  162  extend upwardly above the spaced corners  171  of the free end  20  of the blade  16  by at least a distance of 0.08 inches (i.e., by a distance equal to or greater than 0.08 inches). 
     In one embodiment, with a substantial increase in the size and width of the end hook member  34 , the end hook member  34  is to be protected from side and corner impacts. 
       FIG. 15A  shows a front plan view of the rule assembly. As shown in  FIG. 15A , at least a portion of forward lower corner portions  360  of the housing  12  are exposed (i.e., extended beyond the notched or recessed edge portions  342  at the lower, opposite ends of the hook portion  152 ). In one embodiment, the blade  16  (i.e., along the end hook  34  attached to the free end  20  thereof) of the rule assembly  10  is constructed and arranged to be movable from a first position (as shown in  FIG. 15A ) to a second position (as shown in  FIG. 15B ) to the end hook  34  upon impact (e.g., the tape rule housing being accidently dropped). In other words, as shown in  FIG. 15B , sufficient clearance and/or movability of the blade and end hook  34  parts allows the end hook  34  to be pushed upwards (from its position as shown in  FIG. 15A  to the position in  FIG. 15B ) to protect the end hook  34  from bring bent upon impact. In one embodiment, as shown in  FIG. 15B , a large portion (i.e., in comparison with  FIG. 15   a ) of the forward lower corner portions  360  of the housing  12  extend beyond the notched or recessed edge portions  342  at the lower, opposite ends of the hook portion  152  upon impact. In other words, in one embodiment, as shown in  FIG. 15B , the notches  342  permit a sufficient portion of the forward lower corner portions  360  of the housing  12  to be exposed upon impact to prevent or at least reduce the likelihood of hook portion  152  from being bent/damaged upon impact. In one embodiment, when the rule assembly  10  is dropped in an orientation to have a corner impact (shown in  FIG. 16A ), the recessed edge portions  342  of the end hook member  34  are constructed and arranged to allow (or provide access to) the lower corner portions  360  of the housing  12  to receive the majority of the force upon a corner impact. 
     In one embodiment, when the rule assembly  10  is dropped in an orientation to have a side impact (shown in  FIG. 16B ), the housing  12  of the rule assembly  10  is constructed and arranged to first receive the impact. In one embodiment, during a side impact (shown in  FIG. 16B ) of the rule assembly  10 , the end hook member  34  is protected because an overall width dimension HW (as shown in  FIG. 2 ) of the housing  12  of the rule assembly  10  is wider than the width dimension W (as shown in  FIG. 7 ) of the end hook member  34 . In one embodiment, during the side impact (shown in  FIG. 16B ) of the rule assembly  10 , the housing  12  of the rule assembly  10  is constructed and arranged to receive and absorb the impact in order to protect the end hook member  34  from bending due to the side impact (shown in  FIG. 16B ). 
     In one embodiment, the end hook member  34  may not contact the ground during a side impact. Specifically, when the rule assembly  10  is dropped in such an orientation (to have a side impact) that the end wall  44  or  46  (as shown in  FIG. 6 ) of the rule assembly  10  generally lies parallel a surface (i.e., ground) on which it impacts (or the central axis A (as shown in  FIG. 2 ) that passes through the axis of rotation of the reel  14  is generally perpendicular to the surface (i.e., ground) on which it impacts), then the end hook member  34  may not contact the ground during a side impact. This is at least in part because the thickness of the housing towards central portions thereof (e.g. along axis A), is such that the hook member  34  is signed and configured such that it will not contact an impact surface that is perpendicular to axis A. 
     In one embodiment, as shown in  FIGS. 7-12 , the end hook member  34  includes a pair of generally upwardly extending side edges  328 , a generally laterally extending lower edge  330 , and a generally laterally extending upper edge  332 . 
     In one embodiment, as shown in  FIGS. 7-12 , the laterally extending lower edge  330  includes a pair of lowermost surfaces  334  lying along a common line or axis A-A and separated by an upwardly extending groove or notch portion  336 . In another embodiment, the laterally extending lower edge  330  including the pair of lowermost surfaces  334  may lie along a curved line, such as a convex line (i.e., instead of the straight line). 
     In one embodiment, as shown in  FIGS. 7-12 , each of the upwardly extending side edges  328  extend along a line B-B that forms an angle that is between 85° and 100° with respect to the common line A-A along which the laterally extending lower edge  330  extends. 
     In one embodiment, as shown in  FIGS. 7-12 , the laterally extending upper edge  332  includes a pair of uppermost surfaces  338  lying along a common line or axis C-C and separated by an downwardly extending U-shaped portion  340 . In another embodiment, the laterally extending upper edge  332  including the pair of uppermost surfaces  338  may lie along a curved line (i.e., instead of the straight line). In one embodiment, the U-shaped portion may include a pair of inwardly sloping edges  382  and  384 , as shown in  FIG. 7 , and a connecting portion  386  constructed and arranged to join the two inwardly sloping edges  382  and  384 . In one embodiment, the U-shaped portion  340  may include a pair of notch or groove portions  388  and  390  positioned at the area in which the connecting portion  386  join to the inwardly sloping edges  382  and  384 . 
     In one embodiment, upper inner corners  392  and  394  at which the inwardly sloping edges  382  and  384  join with the laterally extending upper edge  332  are generally rounded or chamfered. In one embodiment, upper outer corners  396  and  398  at which the upwardly extending side edges  328  join with the laterally extending upper edge  332  are generally rounded or chamfered. 
     In one embodiment, as shown in  FIGS. 7-12 , the end hook member  34  includes recessed edge portions  342  disposed at corner portions at which the upwardly extending side edges  328  and the laterally extending lower edge  330  intersect. In one embodiment, the recessed edge portions  342  are constructed and arranged to protrude inwardly from a point  329  at which the upwardly extending side edges  328  and the laterally extending lower edge  330  intersect. 
     In one embodiment, as shown in  FIGS. 7-12 , the recessed edge portions  342  are constructed and arranged to extend between a first point  344  and a second point  346 . In one embodiment, the first point  344  is at the end of the laterally extending lower edge  330  and the second point  346  is at the end of the upwardly extending side edge  328 . In one embodiment, the linear distance between the first point  344  and the second point  346  is at least equal to 0.125 inches (i.e., is equal to or greater than 0.125 inches). 
     In one embodiment, the recessed corner portions  342  constructed and arranged to connect with the upwardly extending side edge  328  at the second point  346  and to connect with the laterally extending lower edge  330  at the first point  344 . In one embodiment, corners that lie on the first point  344  and the second point  346  are generally rounded or chamfered. 
     As clearly shown in  FIG. 12 , in one embodiment, the end hook member  34  includes at least a burred portion (e.g., an area of roughness)  348  disposed on a portion of the end hook  34  that is positioned above the elongated blade  20 . In one embodiment, the minimum height of the burred portion  348  is at least 0.003 inches from base to peak. In one embodiment, the height of burred portion  348  is between 0.010 to 0.015 inches. 
     In one embodiment, the burred portions  348  disposed (i.e., in multiple orientations) on the end hook  34  are constructed and arranged to hookingly engage the end hook  34  with the work-piece while a measurement is being read. 
     In one embodiment, the burred portions  348  disposed on the end hook member  34  are constructed and arranged to provide the end hook member  34  with an extra catching capability (i.e., when using the end hook member  34  to take measurements of a work-piece that is in an orientation other than directly below the blade  16 ). Also, in one embodiment, by having an end hook member  34  with burred portions  348  in multiple orientations accuracy is maintained. 
     In one embodiment, the burred portions  348  are disposed in multiple orientations on the end hook  34 . In one embodiment, the burred portions  348  are disposed on the uppermost surfaces  338  of the leg sections  162 . In one embodiment, the burred portions  348  are disposed on the upwardly extending side edges  328  of the end hook  34 . In one embodiment, the burred portions  348  are disposed on the laterally extending lower edge  330  of the end hook  34 . In one embodiment, the burred portions  348  are disposed on the portions of the end hook  34  beyond the curvature of the blade  16 . 
     In one embodiment, as shown in  FIG. 12 , the burred portions  348  project inwardly towards the tape rule body (to the right in  FIG. 12 ) from the peripheral edge portions of the end hook  34 . For example, the burred portions  348  may extend from the top portions  351  of inner surface  349  of the hook member  34  (adjacent the uppermost edges or surfaces  338 ). In addition (or alternatively), the burred portions  348  may be adjacent side edges  328  and extend from portions of the inner surface  349  that are near or adjacent side edges  328  of the end hook  34 . Furthermore, the burred portions may alternatively or additionally be formed adjacent the bottom or lower edge  330  of the hook member  34  and extend inwardly toward the tape rule housing side of the hook member  34  (to the right in  FIG. 12  as shown). In one embodiment, these burred portions (e.g., an area of roughness)  348  are formed during a stamping operation of the end hook  34 . In other words, after the stamping operation, the peripheral edges of the end hook member  34  are not de-burred, leaving burrs  348  intact to provide a gripping attribute to the edges of the hook member  34 . 
     In one embodiment, the recessed edge portions  342  are constructed and arranged, as shown in  FIG. 13C , such that when the end hook member  34  hookingly engages with a work-piece with a large radius, the recessed edge portions  342  are constructed and arranged to engage with curved surface portions  350  of the work-piece  352 . 
       FIGS. 13A-C  show the end hook member  34  of the extended blade  16  engaging with a work-piece  352  having two perpendicular, planar surface portions  353  and  355  with a curved (i.e., with a large radius) surface portion  350  at an interface therebetween. As shown in  FIG. 13A , first the burred portions  348  disposed on the inner surface  349  adjacent the side edge  328  of the end hook member  34  are brought into contact with the planar surface portion  353  of the work-piece  352 . As shown in  FIGS. 13A and 13B , when the side burred portions  348  disposed on the inner surface  349  adjacent the side edge  328  of the end hook member  34  come in contact with the planar surface portion  353  of the work-piece  352 , the end hook member  34  is constructed and arranged to rotate (as the blade  16  twists slightly) until the corner point (or the first point)  344  disposed at the intersection of the laterally extending lower edge  330  and the curved or recess edge portion  342  contacts the curved surface  350  or planar surface  355  of the work-piece  352 , thus, stabilizing the end hook member  34 .  FIG. 13C  shows the end hook member  34  in a stable configuration, where the recessed edge portions  342  of the end hook member  34  engage with the curved surface portion  350  of the work-piece  352 , while the second point  346  (at the intersection between the curved or recess edge portion  342  and the side edge  328 ) disposed at the end of the upwardly extending side edge  328  is still in contact with the planar surface portion  353  of the work-piece  352 . Thus, the second point  346  contacts the first planar surface  353 , while curved edge  342  of the end hook  34  lies adjacent to the curved surface  350  of the work piece, and the first point  344  contacts a portion of the curved surface  350  or planar surface  355 . During this operation, the lower portion of the end hook  34  is disposed slightly more closely to the tape rule housing (the hook member  34  is disposed at a slight angle) 
     In one embodiment, as shown in  FIGS. 7 and 10 , the mounting portion  150  has a length dimension L, and the hook portion  152  has a width dimension W. In one embodiment, to increase side catching capability of the end hook  34  while limiting weight of the end hook  34 , the width dimension W of the hook portion  152  (i.e., face of the end hook  34 ) is larger than the length L of the mounting portion  150  (i.e., shank of the end hook  34 ). That is, in one embodiment, a ratio of the width dimension W of the hook portion  152  to the length dimension L of the mounting portion  150  is greater than or equal to 1. 
     In one embodiment, as shown in  FIGS. 7 and 11 , the mounting portion  150  has a top surface area TA, and the hook portion  152  has a front surface area FA. In one embodiment, to increase side catching capability of the end hook  34  while limiting weight of the end hook  34 , the front surface area FA of the hook portion  152  (i.e., face of the end hook  34 ) is made larger than top surface area TA of the mounting portion  150  (i.e., shank of the end hook  34 ). That is, in one embodiment, a ratio of the front surface area FA of the hook portion  152  to the top surface area TA of the mounting portion  150  is greater than or equal to 1.1. Also, because the thickness of the metal is approximately uniform, the ratio of the weight of the hook portion  152  to the mounting portion  150  is similarly greater than or equal to 1.1. 
     As noted above, the mass of the mounting portion  150  (i.e., shank) of the end hook  34  is limited by having a ratio of the front surface area FA of the hook portion  152  to the top surface area TA of the mounting portion  150  is greater than or equal to 1.1 and/or a ratio of the width dimension W of the hook portion  152  to the length dimension L of the mounting portion  150  is greater than or equal to 1. 
     In one embodiment, as shown in  FIG. 14 , if the hook portion&#39;s width W is divided into three equal length sections  354 ,  356 , and  358 , at least two-thirds of the mass of the hook portion  152  lies outside a center section  356  that comprises one third of the hook portion&#39;s width. More specifically, in one embodiment, as shown in  FIG. 14 , the hook portion  152  may include a central section  356 , and opposing side sections  354  and  358  on opposite sides of the central section. The sections  354 ,  356  and  358  each include a width dimension that is equal to one-third of the width dimension W of the hook portion  152 . In one embodiment, at least two-thirds of the mass of the hook portion  152  lies outside the central one third of the width of the hook portion  152  (i.e., face) of the end hook  34 . 
     In one embodiment, by moving additional mass of the end hook  34  outboard of the central axis of the end hook  34 , the end hook  34  acts as a stabilizer. This construction of the end hook  34  (i.e., where two-thirds of the mass of the hook portion  152  lies outside the center section  356 ) reduces roll of the blade  16  when the blade  16  is extended from the housing  12 . This is achieved because the moment of rotational inertia of the end hook  34  is increased. In one embodiment, the moment of inertia of the end hook  34  is taken with respect to a plane in which the hook portion  152  of the end hook  34  lies. By increasing the overall inertia of the end hook  34 , in relation to the axis of rotation that runs parallel to the blade length, the rule assembly  10  is stabilized. This gives the user a more stable rule assembly  10  and more opportunity to “recover and adjust” if the blade  16  begins to roll. 
     When the blade  16  is fully retracted into the housing  12  (as shown in  FIGS. 1 ,  3  and  4 ), the blade  16  may be extracted by pulling the hook member  36  from behind the lower edge  330  (i.e., below the blade  16 ) of the hook member  34 . In one embodiment, the end hook  34  gives the user access to extract the hook member  34  from behind the side edges  328  as well. For example, in one embodiment, when the blade  16  is fully retracted into the housing  12  (as shown in  FIGS. 1 ,  3  and  4 ), a gap G (as shown in  FIG. 17 ) is located behind the upwardly extending side edges  328  of the end hook  34 . In other words, in one embodiment, when the end hook member  34  rests against the housing  12 , the rear portions of the end hook member  34  immediately behind side edges  328  are free and do not rest or abut against the housing  12 . This gap G (as shown in  FIG. 17 ) located behind the upwardly extending side edges  328  of the hook portion  152  of the end hook  34  allows the user to extract the blade  16  along the side edges  328  of the hook member  34 . In such embodiment, the blade  16  may be extracted by the user by inserting a finger in the gap G (as shown in  FIG. 17 ) located behind the upwardly extending side edges  328  of the hook portion  152  of the end hook member  34 . 
     As can be appreciated from  FIG. 17 , the housing tapers, so as to have a tapered region  391 , as it transitions from the side surfaces  393  to the front surface  397  at a region near the opening in the housing that receives the tape rule blade. The tapered region  391  narrows the width of the housing as it approaches the opening  22  in the housing so that the hook is wider than the housing at a region where the hook portion abuts the housing and/or near the opening. As shown, the housing may be wider than the end hook  34  at regions spaced from the opening  22 . This is one possible construction for forming the gap G, but other configurations are also possible. 
     In one embodiment, the end hook may be formed from various types of steel material. For example, in one embodiment, the end hook is formed from high carbon steels. 
       FIGS. 18-22  show portions and dimensions of various parts of the end hook in accordance with an embodiment of the present invention. The portions and dimensions of various parts of the end hook shown in  FIGS. 18-22  are intended to be merely exemplary and not limiting in any way. The various parts of the end hook shown in  FIGS. 18-22  are drawn to scale in accordance with one embodiment, although other scales and shapes may be used in other embodiments. The dimensions of various parts of the end hook as shown in  FIGS. 18-22  are measured in inches unless indicated otherwise. In one embodiment, the dimensions of various parts of the end hook, as shown in  FIGS. 18-22 , are up to 10 percent greater than or up to 10 percent less than those illustrated. In another embodiment, the dimensions of various parts of the end hook, as shown in  FIGS. 18-22 , are up to 5 percent greater than or up to 5 percent less than those illustrated.  FIG. 21  illustrates a radius R of the recessed edge portions  342 . In one embodiment, a non-limiting range for the radius R of the recessed edge portions  342  is between 0.03 to 0.4 inches. 
     The aspects described above of the end hook including the extra top catch and side catch capabilities, burrs in multiple orientations, recessed edge portions, a ratio of the front surface area of the hook portion to the top surface area of the mounting portion is greater than or equal to 1.1, a ratio of the width dimension of the hook portion to the length dimension of the mounting portion is greater than or equal to 1, two-thirds of the mass of the hook portion lies outside a center section that comprises one third of the hook portion&#39;s width, at least half of the mass of the hook portion lies above the elongated blade, and/or an overall width dimension of the hook portion of the end hook is greater than the width dimension of the housing near the opening in the housing from where the elongated blade extends can be used separately or in combination with one another. 
     Similarly, the general teachings of the dimensions and/or construction of the housing, for example, lower corner portions of the housing are constructed and arranged to extend beyond the recessed edge portions of the end hook member can be used separately or in combination with any other aspect. 
     One skilled in the art will understand that the embodiment of the rule assembly  10  shown in the figures and described above is exemplary only and not intended to be limiting. It is within the scope of the invention to provide any known rule assembly with any or all of the features of the present invention. For example, the end hook constructed according to the principles of the present invention can be applied to any known rule assembly. 
     Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. In addition, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.