Abstract:
A conduit-bending level has a pair of bubble levels oriented in such a manner as to facilitate the bending of conduit in a first plane and a second plane that is perpendicular to the first plane. This bending operation is preferably conducted without having to detach the conduit-bending level from the conduit in order to make the second bend.

Description:
BACKGROUND 
     Electricians use conduit to contain and protect internal wiring. The conduit is usually mounted on wall or ceiling structure. The mounting operation requires custom fitting of the conduit by bending, cutting and joining operations. 
     U.S. Pat. No. 6,088,407 issued to Parker shows a bending machine that is used in conduit-fitting operations. The bending occurs in a vertical plane coincident with an elongate axis of symmetry in the tubing or conduit. A spirit or bubble level attaches by use of a thumbscrew to an opening of the distal end of the conduit to assist with bending operations. The spirit level is positioned to sense level in a horizontal plane, i.e., a plane that is perpendicular to the plane of bending. Proper use of the spirit level in this manner assures that the conduit bends are aligned such that the bent conduit as a final product will fit flush against a planar wall or ceiling that ultimately supports the conduit in the intended environment of use. 
     U.S. Pat. No. 5,167,075 issued to Weldy et al. shows a different type of conduit-bending level. This device has two spirit levels. The level is shaped as a “T” where the body of the level is shaped and sized to slide into the mouth of a conduit opening. A first spirit level senses in the horizontal plane perpendicular to the plane of bending, similar to what is seen in respect to Parker&#39;s &#39;407 patent discussed above. A second spirit level is provided that can exist coaxially with the elongate or longitudinal axis of the conduit. The positioning of this second spirit level facilitates us of a protractor arm assembly where the second spirit level indicates when bending is achieved with respect to a degree as set by the protractor arm. 
     Another type of conduit-bending level is shown in U.S. Pat. No. 4,272,208 issued to Yakkel. This device is designed to fit over the mouth of the conduit opening and contains two spirit levels. Both spirit levels are oriented perpendicularly to the elongate axis of the conduit. 
     A problem exists in the art where conventional conduit-bending levels are intended for use in bending conduit in a single plane. Thus, for example, if there is a need to bend conduit 90° in a first transition from horizontal to up along the plane of the wall, the bending level must be repositioned on the conduit to make a second bend in a direction that is perpendicular to the plane of the wall. This need sometimes arises where the conduit must proceed in a different orientation to run along the ceiling of a room or to bridge the connecting corners of two walls. When the bending level is repositioned for the second bend, it is difficult or impossible to re-orient the level to sense at a true 90° with respect to the first bend orientation. 
     SUMMARY 
     The presently disclosed instrumentalities advance the art and overcome the problems outlined above by providing a conduit-bending level has a pair of bubble levels oriented in such a manner as to facilitate the bending of conduit in a first plane and a second plane that is perpendicular to the first plane. This bending operation is preferably conducted without having to detach the conduit-bending level from the conduit in order to make the second bend. 
     According to one embodiment, the conduit-bending level includes a body that projects a first tine and a second tine to present a gap therebetween. The gap presents an open end and is sized to receive a tubular body between the first and second tines. A thumbscrew includes a knob and a threaded member. The threaded member has a tip located remotely from the knob. At least one of the first and second tines has an internally threaded opening complementary to the threaded member and positioned for advancement and retraction of the tip in the gap by selective rotation of the knob. The body defines also an opening that presents an opening axis of symmetry. A first aperture proceeds through the opening in a first transverse axial orientation with respect to the opening axis of symmetry. A first bubble level is mounted in the first aperture with a first axial alignment operable to indicate a horizontal condition when tubing is bent in a first plane. A nose contains structure for mounting a second buddle level in transverse-normal axial orientation with respect to the first axial alignment of the first bubble level such that conduit may be bent in a second plane that is perpendicular to the first plane without having to detach the conduit-bending level from the conduit. 
     In one embodiment, the mounting structure for the second bubble level includes the body having a nose that defines a second aperture and there being a second bubble level mounted in the second aperture in transverse-normal orientation with respect to the first axial alignment of the first bubble level. 
     The conduit-bending level may be used by first attaching the conduit-bending level to the open mouth of a piece of conduit. The conduit is bent in a first plane by use of one of the first bubble level and the second bubble level to indicate a horizontal condition. After this first bend, the conduit may be rotated 90° for bending of the conduit in a second plane perpendicular to the first plane by use of the other one of the first bubble level and the second bubble level. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top right front perspective view of a conduit-bending level according to one embodiment; 
         FIG. 2  is a top plan view thereof; 
         FIG. 3  is a bottom plan view thereof; 
         FIG. 4  is a left side elevation view thereof; 
         FIG. 5  is a right side elevation view thereof; 
         FIG. 6  is a rear plan view thereof; and 
         FIG. 7  is a front plan view thereof. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a conduit-bending level  100  from a top right front perspective. A body  102  includes a first tine  104  and second tine  106 , separated by gap  108 . The tines  104 ,  106  optionally have radiused edges  111 ,  112 ,  114  proximate gap  108 . As in the case of tine  104 , the radiused edges  110 ,  114  may be separated by a flat face  116 . This arrangement facilitates better alignment on the curved wall of tubing in the intended environment of use. Tine  106  defines an internally threaded aperture for receipt of a thumbscrew  120 . The thumbscrew  120  is alternatively received in internally threaded aperture  120  in tine  104 , as befits right or left-handed operation of the conduit-bending level  100 . The thumbscrew  120  presents an axis of elongation  122  indicating a path of travel that is achieved commensurate with selective rotation of the thumbscrew  120  on arc  124  to advance or retreat pointed tip  126  within gap  108 . 
     The body  102  defines an aperture  128  extending with an elongate axis of symmetry  130  in transverse-normal orientation with respect to the axis of elongation  122 . An opening  132  crosses aperture  128  with an elongate axis of symmetry  134  extending in transverse-normal relationship with respect to the elongate axis of symmetry  130  and in parallel with axis of elongation  122 . A first spirit or bubble level  136  is received within the opening  132  and is operable for viewing to indicate a level condition from within the aperture  128  when face  140  is horizontal or, more particularly, when the elongate axis of symmetry  136  is in a horizontal plane. 
     The body  102  includes a nose  138  that projects outwardly from face  140 . The nose  138  contains a through opening  140  presenting an elongate axis of symmetry  142  that runs in a transverse-normal orientation with respect to the axis of elongation  122 . A second spirit or bubble level  144  resides in the through opening  140 . The structure that defines through-opening  140  is partially removed to create a shelf area  146  for viewing of the bubble level  144  to indicate a level condition when face  140  is perpendicular to horizontal or, more particularly, when the elongate axis of symmetry  142  is in the horizontal plane. 
       FIG. 2  is a top plan view that provides additional detail of the conduit-bending level  100  shown with respect to  FIG. 1  and retains like numbering of identical parts. It will be appreciated that when face  140  is horizontal, as shown in  FIG. 2 , a bubble  200  located between lines  202 ,  204 , indicates a level condition. Rotation of the thumbscrew  120  advances and retracts pointed tip  126  within gap  108  by the action of threaded male member  206  interacting with the internally threaded aperture  118  (not shown in  FIG. 2 ). As shown in  FIG. 2 , the tines  104 ,  106  are not radiused, since radiusing is an option according to one embodiment of what is shown and described. 
       FIG. 3  is a bottom plan view of the conduit-bending level  100 . The bubble  200  is viewable from a bottom perspective when bottom face  300  is horizontal. 
       FIG. 4  is a left side elevation view of the conduit-bending level  100 . In this case, the faces  140 ,  300  are in a horizontal position, so bubble level  144  as shown in  FIG. 4  does not indicate a level condition relative to wall  400  where bubble  404  is outside of lines  406 ,  408 .  FIG. 5  is a right side elevation view of the conduit-bending level  100  indication also a non-level condition as indicated by the bubble level  144 . 
       FIG. 6  is a rear plan view of the conduit-bending level  100 , and  FIG. 7  is a front plan view thereof. These views provide additional detail with respect to what is shown with respect to  FIG. 1 . Concerning  FIG. 6 , it will be appreciated that the radiusing  600  facilitates tool application to a wide variety of piping diameters. The radiusing reduces stress concentration in the tines, together with wear and tear on the tines. If the radius is not provided then it remains necessary to debur the tool edge, so the radiusing does not add an extra machining process step. The radiusing on both tines is the same. The gap  108  has an open rear end  602  for the receipt of tubing or conduit. Bending proceeds on a machine, for example, as shown in U.S. Pat. No. 6,088,407 where the first bubble level  136  assures that bending occurs in a first vertical plane that is normal to horizontal. The conduit  600  may then be rotated 90° as shown in  FIG. 8  while keeping the conduit-bending level  100  in place on the conduit. Use of the second bubble level  144  in this rotated position assures that bending occurs in a plane that is perpendicular or normal to the first vertical plane. Much trouble and uncertainty over alignment is thereby eliminated. 
     Those skilled in the art will appreciate that the foregoing discussion teaches by way of example, and not by limitation. Insubstantial changes may be made with respect to what is shown and described without departing from the true scope and spirit of the claimed invention. Accordingly, the inventor hereby states his intent to rely upon the Doctrine of Equivalents in protecting the invention.