Abstract:
A construction-grade hand tool has interchangeable tool heads that can withstand significant impact, pulling, and twisting forces. The tool heads may include a shovel, a rake, a hoe, a bow saw, a broom, a fork, pruning shears, and other construction and fire fighting tool heads. A tool head adapter securely connects these tool work heads to a handle which may be a telescoping handle. The tool head adapter is connected to the tool head in a manner that provides a strong, impact-resistant connection between the adapter and the tool head. The handle may include a shock absorber structure. The adapter is configured to be securely and tightly received by a clamping and/or quick-release receptacle on the end of the handle.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. provisional applications 61/102,272 filed Oct. 2, 2008, 61/147,312 filed Jan. 26, 2009, and 61/173,587 filed Apr. 28, 2009; the disclosures of each are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The invention generally relates to hand tools and, more particularly, to a hand tool with interchangeable work heads and telescoping handles. Specifically, the invention relates to construction-grade hand tools having interchangeable work heads with adapters designed to maintain a secure connection between the work head and the handle that can withstand the impact, twisting, and pulling forces imparted on construction-grade tools. 
         [0004]    2. Background Information 
         [0005]    Shovels, rakes, hoes and the like have been made non-interchangeable with wooden, non-telescopic handles for thousands of years. More recent versions of such tools have handles made of steel, aluminum, or fiberglass. Tools with interchangeable work heads are also known in the art. Those in the construction industry, landscaping, and fire fighting professions desire tools that can withstand extreme working conditions wherein significant impact, pulling, and twisting forces are imparted on the tools during their normal use. Users of this type have generally not adopted tools with interchangeable work heads because the tools have not been designed for heavy work and significant forces. Workers in the fire fighting industry wish to have multiple tools in a mobile package. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention provides a construction-grade hand tool having interchangeable work heads that can withstand significant impact, pulling, and twisting forces. The work heads can be quickly interchanged. As such, one configuration of the invention provides a professional-grade hand tool that includes a plurality of tool work heads; each of the tool work heads being connected to a tool head adapter; a telescoping handle having a tool head adapter locking mechanism; and each of the plurality of tool work heads being interchangeably lockable to the telescoping handle with the tool head adapter locking mechanism. The work heads may include a shovel, a rake, a hoe, a bow saw, a broom, a fork, pruning shears, and other construction and fire fighting tool work heads. The invention provides a tool head adapter that securely connects these tool work heads to a handle which may be a telescoping handle. The tool head adapter is connected to the tool work head in a manner that provides a strong, impact-resistant connection between the adapter and the tool work head. These connections may be welds, pins, bolts, screws, or interference fits as dictated by the type of work head being used. The other end of the adapter is configured to be securely and tightly received by a clamping and/or quick-release receptacle on the end of the handle. 
         [0007]    The invention provides an adapter is configured to prevent the tool work head from rotating when the tool work head is secured to the handle. In one configuration, the adapter includes a cylindrical male shank that is received in a female receptacle carried by the handle. The female receptacle has a rotational clamping member that clamps onto the male shank to provide a secure connection between the tool handle and the tool work head. 
         [0008]    In one configuration, the invention provides an adapter having a combined rotational clamping and push button locking features. In one configuration, the tool head adapter includes a recess that receives an end of a pivoting locking member carried by the handle. The pivoting locking member adds a secondary secure locking connection between the handle and the tool work head. In another configuration, the user choose to not use the clamping mechanism and simply use the pivoting locking member to hold the tool work head to the handle. This option is useful for some tool work heads. In still another configuration, the pivoting locking member may be provided without the clamping member. 
         [0009]    The invention also provides a hand tool having a handle with an internal shock absorbing member that receives and buffers longitudinal impact forces received by the tool work head. In one configuration, the shock absorbing member is a structure disposed inside the handle tube closest to the tool adapter with adapter abutting one end of the structure and the other end of the structure abutting the device that clamps the handle tubes together. 
         [0010]    The invention provides such a tool with a telescoping handle having tubular fiberglass handle sections. The handle may be configured to provide handle adjustments of 2-4 feet, 4-8 feet, 6-12 feet, and 8-16 feet. 
         [0011]    The invention provides a kit having a hand tool that itself includes a plurality of interchangeable work heads and a telescoping handle that all fit within a pack adapted to be carried by a single person. The kit also may include a second telescoping handle. This kit allows the user to readily transport a variety of construction grade tools to a remote location while walking. 
         [0012]    In one configuration, the invention provides a hand tool that includes a tool work head; a tool head adapter having a first shank and a second shank with a shoulder defined between the first and second shanks; the tool head adapter being connected to the tool work head; a handle having a tool head adapter locking mechanism carried by an inner tube; a shock absorbing structure disposed inside the inner tube; the shock absorbing structure defining an opening; the second shank of the adapter disposed in the opening defined by the shock absorbing structure; at least a portion of the first shank being disposed inside the inner tube; the shoulder of the adapter abutting the shock absorbing member; and the tool head adapter locking mechanism having a clamped configuration and an unclamped configuration; a portion of the tool head adapter locking mechanism surrounding a clamping portion of the first shank of the adapter and being clamped against the clamping portion of the first shank of the adapter to secure the tool head adapter to the inner tube. 
         [0013]    Another configuration of the invention provides a hand tool that includes a tool work head; a tool head adapter having a first shank and a second shank with a shoulder defined between the first and second shanks; the tool head adapter being connected to the tool work head; a handle having a tool head adapter locking mechanism carried by an inner tube; the first and second shanks of the tool head being frictionally received by the handle with the shoulder abutting a portion of the handle; and the tool head adapter locking mechanism having a clamped configuration and an unclamped configuration; a portion of the tool head adapter locking mechanism surrounding a clamping portion of the first shank of the adapter and being clamped against the clamping portion of the first shank of the adapter to secure the tool head adapter to the inner tube. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a side elevation view of the handle. 
           [0015]      FIGS. 2A-2C  show three different tool work heads secured to tool head adapters. 
           [0016]      FIG. 3A  is a section view taken along line  3 A- 3 A of  FIG. 1 . 
           [0017]      FIG. 3B  is a section view taken along line  3 B- 3 B of  FIG. 1 . 
           [0018]      FIG. 3C  is a section view taken along line  3 C- 3 C of  FIG. 1 . 
           [0019]      FIG. 4  is a section view similar to  FIG. 3A  depicting an alternative configuration for the adapter locking mechanism. 
           [0020]      FIGS. 5A-5H  depict a variety of configurations for the tool head adapter. 
       
    
    
       [0021]    Similar numbers refer to similar parts throughout the specification. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    An exemplary configuration of the tool of the invention generally includes a handle  4 , a tool head adapter  6 , and at least one tool work head  8 . Tool may be configured for a wide variety of jobs by removing one tool work head  8  and replacing it with a different tool work head  8 . An adapter locking mechanism  10  is used to secure tool head adapter  6  to handle  4  in a manner that allows the tool to withstand substantial forces associated with a construction-grade tool. Tool work heads  8  may include a shovel, a rake, a hoe, a bow saw, a broom, a fork, pruning shears, and other construction and fire fighting tool work heads. 
         [0023]    Tool head adapter  6  includes first  20  and second  22  shanks wherein second shank  22  is stepped down from first shank  20 . In the exemplary configuration, first  20  and second  22  shanks have circular cross sections with the diameter of second shank  22  being smaller than the diameter of first shank  20 . First shank  20  has a diameter of one inch while second shank  22  has a diameter of three-quarter inch. A shoulder  24  is defined between shanks  20  and  22 . Shoulder  24  is disposed at a right angle to the longitudinal dimension of adapter  6 . Tool head adapter  6  may be configured for a variety of different tool work heads  8  as shown in  FIGS. 5A-5H .  FIG. 5A  depicts first shank  20  connected to a standard thread used to connect tool work head  8 .  FIG. 5B  depicts a structure defining a slot configured to receive a portion of a saw blade.  FIG. 5C  depicts an adapter structure having a tapered end that may be used with a shovel.  FIG. 5D  depicts another configuration of adapter  6  having an elongated shank designed to fit into an opening of a tool work head  8 .  FIGS. 5E-5F  depict an adapter  6  having an oval shank configured to be used with a sledgehammer, pick, mattock, or an axe.  FIGS. 5G-5H  depict an adapter configuration having a hole configured to receive an elongated shank such as that on a leaf rake. 
         [0024]    The end of second shank  22  is beveled to assist in the insertion of adapter  6  into the end of handle  4 . Second shank  22  may define an optional bore  26  that reduces the weight of adapter  6 . 
         [0025]    A clamping portion of the outer surface of first shank  20  of tool head adapter  6  is knurled  28 , grooved, or otherwise textured to improve the frictional connection between handle  4  and adapter  6 . Tool head adapter  6  is made from steel in the exemplary configuration but also may be made from aluminum, plastic, ceramic, or other hard materials. 
         [0026]    In a basic form, handle  4  includes a single non-telescoping tube section configured to receive tool head adapter  6 . When a single tube section is used, the locking components depicted in  FIG. 3B  are not used. In some applications, handle  4  is configured to selectively telescope such that it may be adjusted different lengths and be locked at those lengths by the user. In the telescoping configuration, handle  4  generally includes an outer tube section  30  and an inner tube section  32  that slides at least partially into outer tube section  30  when the user unlocks a handle locking assembly  34 . Handle locking assembly  34  may be used to configure the length of handle  4  at essentially any length between a minimum length dimension and a maximum length dimension. Handle  4  also includes adapter locking assembly  10  that selectively secures adapter  6  to the distal end of handle  4 . Although  FIG. 1  depicts only inner  32  and outer  30  tube sections, handle  4  may be provided with one or more intermediate tube sections that each telescope as described above and are each locked by a locking assembly similar to handle locking assembly  34 . When an intermediate tube section is used, inner tube section  32  slides into the intermediate tube section and the intermediate tube section slides into outer tube section  30 . Exemplary handles  4  may be configured to provide handle adjustments of 2-4 feet, 4-8 feet, 6-12 feet, and 8-16 feet. The collapsed condition of handle  4  allows handle  4  to be carried in a pack (backpack, gunny sack, duffel bag) with a plurality of tool heads  8 . This kit of the pack, handle  4 , and heads  8  may be readily carried to remote locations by a single person allowing the person to have access to multiple tools at the remote location. 
         [0027]    Outer tube section  30  includes an outer tube  36  having a circular tubular cross section. Outer tube  36  may be made from fiberglass or other materials such as metal, plastics, or composites. In the exemplary configuration, outer tube  36  is a one and a half inch outer diameter fiberglass tube with a wall thickness of less than one eighth of an inch so that a one and one quarter inch outer diameter inner tube  40  may slide inside outer tube  36 . Outer tube  36  has an outer skin and an inner skin with a corrugated or honeycombed inner layer so that tube  36  is light for its strength. The end of outer tube  36  opposite handle locking assembly  34  is at least partially wrapped by a grip  38 . Grip  38  may be a rubber sleeve that is adhesively connected to the outer surface of outer tube  36 . 
         [0028]    Inner tube section  32  includes an inner tube  40  that extends between handle locking assembly  34  and adapter locking assembly  10 . Inner tube  40  has an outer skin and an inner skin with a corrugated or honeycombed inner layer so that tube  36  is light weight for its strength. As shown in  FIG. 3A , the first end of inner tube  40  receives at least a portion of first shank  20  and the entire second shank  22  to form a secure connection between handle  4  and adapter  6 . 
         [0029]    The second end of inner tube  40  is disposed inside outer tube  36 . A sleeve  42  is disposed around and is secured to a portion of the second end of inner tube  40 . Sleeve  42  may be secured to inner tube  40  with an adhesive. Sleeve  42  does not have to be continuous. An alternative to the continuous structure of sleeve  42  is a plurality of material strips  42 . Sleeve  42  allows inner tube section  32  to slide back and forth within outer tube  36  without binding. The first end  44  of sleeve  42  abuts handle locking assembly  34  to stop inner tube section  32  in its extended position as shown in  FIG. 3B . 
         [0030]    The second end of inner tube  40  is connected to an expandable locking mechanism  46  that selectively locks inner tube  40  to outer tube  36  by when it is selectively expanded to a locked condition. Expandable locking mechanism  46  includes a mounting block  48  disposed inside the second end of inner tube  40 . A mechanical connected  50  is used to secure inner tube  40  to mounting block  48 . Connector  50  also may be used to help secure sleeve  42  to inner tube  40 . Expandable locking mechanism  46  includes a pair of shoes  52  that expand outwardly when a cam  54  is rotated to a locked position. Cam  54  is an elongated member disposed between shoes  52  and engages cam follower portions of shoes  52  to push shoes  52  outwardly when cam  54  is rotated. Shoes  52  have elastomeric gripping surfaces that engage the inner surface of outer tube  36 . Cam  54  is connected to and rotates with mounting block  48  so that the user of handle  4  may rotate locking mechanism  46  to a locked position by rotating inner tube  40  with respect to outer tube  36 . Rotation of tube  40  in the opposite direction unlocks mechanism  46 . 
         [0031]    A shock absorbing structure  60  is disposed inside inner tube  40 . Structure  60  has an abutment end  62  against which shoulder  24  abuts when adapter  6  is inserted into handle  4  so that shock forces experienced by tool work head  8  are at least partially transferred to structure  60 . Shock absorbing structure  60  may be made from PVC. Shock absorbing structure  60  may be a hollow tube or a solid structure. Structure  60  defines an opening  64  that frictionally receives second shank  22  of adapter  6 . Shock absorbing structure  60  may be made from the PVC described above or a plastic, polymer, rubber, or wood material. The materials may be dense or foamed. Structure  60  receives shock forces from adapter and deadens the shock forces so that the user&#39;s hands and arms do not absorb all of the forces. As described above, structure  60  abuts expandable locking mechanism  46  and transfers a portion of the shock forces to the expandable locking mechanism  46  which further deadens the forces transferred to the user through the use of shoes  52  having the elastomeric portions. 
         [0032]    The combination of the frictional connections between shank  20  and tube  40 , the frictional connection between shank  22  and structure  60 , and the abutment between shoulder  34  and end  62  provides a tight connection between handle  4  and adapter  6  that prevents tool work head  8  from wobbling with respect to handle  4 . 
         [0033]    Adapter locking assembly  10  includes inner  70  and outer  72  portions that cooperate to lock adapter  6  to handle  4  and resist rotational movement between adapter  6  and handle  4 . Inner portion  70  is secured to the outer surface of inner tube  40  with an adhesive or a mechanical connector. Inner portion  70  includes a grip  74 , an intermediate tube  76  having outwardly disposed thread  78 , and a plurality of clamping fingers  80  that define an outer cam follower surface  82 . Clamping fingers  80  define a rearward-facing ledge. The first end of inner tube  40  abuts the rearward-facing ledge of clamping fingers  80 . 
         [0034]    Outer portion  72  defines a cup  84  having inwardly disposed thread  86  configured to threadedly engage thread  78 . Rotation of outer portion  72  moves outer portion  72  up and down along the length of inner portion  70  as a result of the threaded connection between threads  78  and  86 . Outer portion  72  defines a cam  88  disposed to engage cam follower surface  82  when outer portion  72  is moved toward grip  74  of inner portion  70  to force clamping fingers  80  radially inwardly to clamp against first shank  20  of adapter  6 . Clamping fingers  80  engage clamping portion  28 . Tightening outer portion  72  against inner portion  70  thus locks inner tube  40  to adapter  6 . 
         [0035]    Handle locking assembly  34  has the same elements as adapter locking assembly  10  and the same reference numerals are used to identify the parts of handle lock assembly  34  in  FIG. 3B  as  FIG. 3A . Clamping fingers  80  of handle locking assembly  34  clamp against the outer surface of inner tube  40 . The combination of handle locking assembly  34  and expandable locking mechanism  46  provides a secure connection between outer tube section  30  and inner tube section  32 . The two locking points provided by the two locking mechanisms  34  and  46  are spaced apart from one another and work in opposite directions. 
         [0036]    An alternate adapter locking assembly  10  is depicted in  FIG. 4  wherein a locking pin  100  is used to secure adapter  6  to inner tube  40 . Locking pin  100  may be used alone or in combination with adapter locking assembly  10 . Locking pin  100  is movable between a locked configuration and an unlocked configuration. When locking pin  100  is in the locked configuration, locking pin  100  extends through inner tube  40  and into a recess  102  defined by first shank  20  of adapter  6 . In an alternative configuration, locking pin  100  may extend through inner tube  40  and shock absorbing structure  60  and into a recess defined by second shank  22  of adapter  6 . In another configuration, a pair of locking pins  100  may be used in both of these configurations. In the unlocked configuration, locking pin  100  is moved out of recess  102  so that adapter  6  may be removed from handle  4 . In the configuration depicted in  FIG. 4 , first shank  20  is elongated to extend past adapter locking mechanism  10 . 
         [0037]    In one configuration, a thumb lever  104  is used to allow the user to lift pin  100  out of recess  102 . A spring  106  is provided to bias pin  100  downwardly. Spring  106  may be located in a variety of places and provided in a variety of shapes and structures to provide this biasing force. A flat metal V-shaped spring  106  is depicted. A coil spring  106  carried on pin  100  also may be used. Spring  106  provides force that biases locking pin  100  toward recess  102  so that pin  100  will automatically snap into place when recess  102  is aligned with pin  100 . Thumb lever  104  is also configured to lift pin  100  out of recess  102  when the user depresses thumb lever  104  toward inner tube  40 . These structures may be located in a housing  108 . 
         [0038]    In another configuration, pin  100  may be used with spring  106  without lever  104 . In this configuration, the user pulls directly on pin  100  to remove it from recess  102 . 
         [0039]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described. Throughout the description and claims of this specification the word “comprise” and variations of that word, such as “comprises” and “comprising,” are not intended to exclude additives, components, integers, or steps.