Mid-handle drill construction and assembly process

Abstract

A power tool can include a gear case, a motor having first and second sets of lead wires, a housing assembly, and a field case. The field case may include a front portion configured for engaging the gear case and a rear portion. The housing assembly may include first and second generally symmetrical housing segments configured for engaging the field case and forming a mid-handle grip. The first set of lead wires may be routed through the front portion of the field case directly to a trigger switch assembly. A method for assembling a mid-handle power tool is also provided and may include routing lead wires through a ventilation path between the field case and trigger assembly.

1 . A power tool housing assembly comprising:
 a base housing segment and a cover housing segment generally symmetrical to the base housing segment, each housing segment comprising a plurality of assembly bosses defining a respective plurality of apertures accessible from an exterior of the housing assembly, the base housing segment further comprising at least one intermediate fastening boss defining an aperture accessible from an interior of the housing assembly; and   a field case having at least one cooperating assembly fastening boss configured for attaching the field case to an interior of the base housing segment,   wherein the field case, base housing segment, and cover housing segment cooperate to form a housing assembly that includes an end cap and a mid-handle grip integrally connected via a bridge section and having a longitudinal parting line.   
     
     
         2 . A power tool housing assembly according to  claim 1 , further wherein the field case comprises at least one wire retention member configured to secure at least one lead wire within the bridge section. 
     
     
         3 . A power tool housing assembly according to  claim 1 , wherein the field case defines an aperture forming a ventilation path that provides fluid communication between the field case and an interior of the mid-handle grip. 
     
     
         4 . A power tool housing assembly according to  claim 1 , wherein the field case further comprises at least one assembly boss defining an aperture configured to align with one of the base and cover housing segment assembly boss apertures such that a threaded fastening device can engage each of the base housing segment, cover housing segment, and field case. 
     
     
         5 . A power tool housing assembly according to  claim 1 , wherein at least a portion of the field case defines an exterior surface of the housing assembly. 
     
     
         6 . A power tool housing assembly according to  claim 1 , wherein at least one of the base housing segment and the cover housing segment further comprises an attachment member located a distance past the mid-handle grip and configured to attach with a gear case. 
     
     
         7 . A power tool housing assembly comprising:
 a motor field case;   first and second clamshell segments coupled to the motor field case, the first and second clamshell segments being shaped generally symmetrical to each other and joined to each other along a part line extending longitudinally along the tool, the first and second clamshell segments forming a mid-handle grip for the power tool and an end cap for the motor field case that are connected via a bridge section;   wherein the motor field case, the first and second clamshell segments each form an exposed part of an overall tool housing.   
     
     
         8 . A power tool housing assembly according to  claim 7 , wherein the motor field case defines an aperture forming a ventilation path that provides fluid communication between the field case and an interior of the mid-handle grip and wherein the mid-handle grip comprises a vent to provide fluid communication between the interior of the mid-handle grip and the exterior of the tool. 
     
     
         9 . A power tool housing assembly according to  claim 7 , further comprising a metal gear case forming an exposed part of the overall tool housing located adjacent the mid-handle and an attachment member configured for securing a ground screw operable to ground a metal gear case. 
     
     
         10 . A power tool housing assembly according to  claim 7 , further comprising at least one wire retention member configured to secure at least one lead wire within the bridge section. 
     
     
         11 . A method of assembling a mid-handle power tool, comprising:
 coupling a gear case cover to a gear case housing cooperating attachment features located inside an outer radial periphery of the gear case housing, thereby creating a combined gear case housing assembly;   coupling a field case assembly to the combined gear case housing assembly using cooperating attachment features located outside an outer radial periphery of the gear case housing;   coupling each of a pair of clamshell housing elements, which together comprise a mid-handle grip, to the field case assembly; and   coupling the pair of clamshell housing elements to each other;   wherein each of the gear case housing, the field case assembly, and the pair of clamshell elements forms a part of a final exterior housing the mid-handle power tool.   
     
     
         12 . A method according to  claim 11 , wherein coupling each of the pair of clamshell housing elements to the field case assembly comprises coupling one of the pair of clamshell housing elements to the field case assembly and thereafter coupling the other one of the pair of clamshell housing elements to the field case assembly. 
     
     
         13 . A method according to  claim 12 , further comprising retaining wires in the one of the pair of clamshell housing elements prior to coupling the other one of the pair of clamshell elements. 
     
     
         14 . A method according to  claim 11 , further comprising coupling each of the pair of clamshell housing elements to the gear case housing. 
     
     
         15 . A method according to  claim 14 , wherein the step of coupling each of the pair of clamshell housing elements to the gear case housing and the step of coupling the coupling the pair of clamshell housing elements to each other occurs simultaneously. 
     
     
         16 . A method according to  claim 11 , wherein the step of coupling each of a pair of clamshell housing elements to the field case assembly comprises providing an end cap for the field case assembly. 
     
     
         17 . A method according to  claim 11 , wherein the step of coupling a gear case cover to a gear case housing comprises screwing screws into cooperating threads located in an interior of the gear case housing, the screws and cooperating threads being the cooperating attachment features. 
     
     
         18 . A method according to  claim 17 , wherein screwing screws into cooperating threads comprises locating a head of each of the screws below an outer surface of the gear case cover. 
     
     
         19 . A method according to  claim 17 , wherein the step of coupling the field case assembly to the combined gear case housing assembly comprises screwing screws into cooperating threads located in protruding bosses of the gear case housing, the screws and cooperating threads being the cooperating attachment features.