Abstract:
A hedgetrimmer having a blade assembly that includes a sawblade for cutting through larger branches and other vegetative foliage. The blade assembly includes a reciprocating blade having an integrally formed sawblade portion that moves back and forth cutting motion. The other blade is fixed and includes a bevelled interior edge that helps debris being cut to pass over the blade and prevent getting stuck.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 14/848,960 filed Sep. 9, 2015, entitled HEDGETRIMMER WITH SAW BLADE. The entire disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to vegetation cutting devices, specifically hedgetrimmers having a blade assembly with saw-like teeth for cutting through large branches. 
       BACKGROUND OF THE INVENTION 
       [0003]    Vegetation cutting devices such as hedge trimmers are known power operated tools for cutting hedges and other foliage and vegetation. Typically hedge trimmers are powered by a gas engine or electric motor that drives a blade assembly comprising a pair of reciprocating blades. The teeth on the blades are spaced from one another so that while reciprocating, they create gaps for bush and hedge branches to enter and be cut. These blade teeth have cutting edges along their flanks so that they create a shearing cutting action when the blades reciprocate. However, occasionally large branches are encountered that are too big to enter the gap, or even if they can enter, are too thick to be cut by the blades. Therefore, it would be advantageous to have blade assemblies having cutting edges along the tips of the teeth so as to create a saw-like cutting action to be able to cut through thicker branches. 
         [0004]    Such blade assemblies in hedgetrimmers are known in the art, and are shown for example in U.S. Pat. No. 3,751,805 (“the &#39;805 patent”). In the &#39;805 patent, the sawblade is attached to the reciprocating hedgetrimmer blade using a nut and bolt, which are spot welded to the blade. The process of welding bolts to the hedgetrimmer blade and using a nut and bolt increases the complexity and manufacturing cost of such as design. 
         [0005]    Another example is U.S. Pat. No. 3,217,408 (“the 408 patent”) which shows a hedgetrimmer with a saw blade that is again bolted to the reciprocating blade of a hedgetrimmer. Here, however, the saw blade is fixed on a first side of the hedgetrimmer blade with the hedgetrimmer teeth on a second side. Therefore, only one side of the hedgetrimmer has the shearing cutting teeth which limits its versatility. 
         [0006]    Yet another example is U.S. Pub. No. 2012/0167741 which shows a pair of hedgetrimmer blades that have integrally formed end sections that have teeth that are sharpened to their tips to provide a saw-like action to cut through thicker branches. However, because the blades are integrally formed, they would require entirely new tooling to manufacture, and therefore increases manufacturing costs. 
         [0007]    Therefore, it would be advantageous to have a hedgetrimmer blade assembly that includes a saw blade for cutting through thick branches. Furthermore, it would be advantageous to have a blade assembly that is easy and cost efficient to manufacture. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    Therefore, according to an aspect of the invention, the present invention is directed to a hedgetrimmer having a sawblade, where the hedgetrimmer has a housing containing a motor, and a blade assembly extending out from the housing, having a first and second blade for cutting vegetation. The first and second blade include cutting teeth forming a first configuration. A sawblade is secured to a distal end of the blade assembly with the sawblade having cutting teeth forming a second configuration. 
         [0009]    In one aspect of the invention, the sawblade can include one of a notch or a projection, and the one of the blades of the blade assembly can have the other of a notch or a projection so that the sawblade is secured to the hedgetrimmer blade by securing the notch to the projection. This structure allows for a cost efficient method of manufacturing the combined hedgetrimmer blade and sawblade. Additionally, the sawblade can be integrally manufactured with the hedgetrimmer blade if desired. 
         [0010]    In another aspect of the invention, the sawblade can be formed integrally with one of the one of two reciprocating blades. Alternatively, the hedgetrimmer may have only a single reciprocating blade, and the other blade may be fixed. In this case, the sawblade can be formed integrally on the reciprocating blade. 
         [0011]    In another aspect of the invention, the hedgetrimmer can include a bracket secured to the support bar to support vegetation as it&#39;s being cut by the sawblade assembly. This helps stabilize the vegetation for improved cutting. Additionally, a guard bar can be provided that is pivotally secured a distal end of the support bar, with the guard bar being movable between a retracted position and an extended position where it&#39;s tip extends beyond the blade assembly. In this way, the guard bar helps to protect any structure from being damaged by the moving sawblade. 
         [0012]    A method of manufacturing the hedgetrimmer blade of the present invention is also disclosed, where a standard blade having a series of cutting teeth on a first and second side is further stamped so that selected cutting teeth are reshaped to form the projections used to secure the sawblade. The sawblade, having corresponding apertures are then pressfit onto the projections to secure the sawblade. Other machining or finishing processes can be performed to further secure the sawblade to the hedgetrimmer blade. 
     
    
     
       BRIEF DESCRIPTION OF THE INVENTION 
         [0013]    Further features and advantages of the present invention will be better understood by reference to the following description, which is given by way of example and in association with the accompanying drawings, in which: 
           [0014]      FIG. 1  is a front perspective view of a hedgetrimmer according to an embodiment of the invention; 
           [0015]      FIG. 2  is a perspective view of the saw blade assembly of  FIG. 1 ; 
           [0016]      FIG. 3  is a top view of  FIG. 2 ; 
           [0017]      FIG. 4  is a bottom view of  FIG. 2 ; and 
           [0018]      FIG. 5A  is an embodiment of  FIG. 1  showing a guard bar in the retracted position; 
           [0019]      FIG. 5B  is similar to  FIG. 5A , with the guard bar in the extended position; 
           [0020]      FIG. 6  shows the blade assembly and the sawblade assembly; 
           [0021]      FIG. 7  shows a perspective view of a hedgetrimmer with an integral sawblade; 
           [0022]      FIG. 8  shows a detailed view of the sawblade of  FIG. 7 ; and 
           [0023]      FIG. 9  shows a front end view of the hedgetrimmer of  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]      FIG. 1  shows a hedgetrimmer  10  according to an embodiment of the present invention. The hedgetrimmer  10  has a housing  12  containing an electric motor  13 . The housing includes a rear handle  14  and a front auxiliary handle  16 . A user is required to place his hands on both handles to securely and safely operate the tool. In a preferred embodiment, the motor  13  is an electric motor powered by a rechargeable battery. Alternatively, the electric motor can be powered by mainline electricity provided through an electrical cord, or could be an engine powered by gasoline or other combustible fuel. 
         [0025]    The hedgetrimmer includes a blade assembly  18  having a pair of reciprocating blades, a top blade  20  and a bottom blade  22 . See  FIG. 2 . The blades are secured to a support bar  24  and the support bar  24  is fixedly secured to the housing  12 . The top and bottom blades  20 ,  22  are operatively connected to the electric motor  13  to move them linearly back and forth in a reciprocating manner. The blades  20 ,  22  include elongate apertures  25  (only a portion of which can be seen in  FIG. 2 ) which allow fasteners  26  to secure the blades to the support bar  24 , while allowing them to move linearly relative to the support bar. 
         [0026]    The top blade  20  is made up of a series of first teeth  20   a , and similarly the bottom blade  22  is made up of a series of second teeth  22   a . The teeth  20   a  and  22   a  are spaced from one another to create gaps for the entry of debris and other vegetation to be cut by the blades. The gaps are sized so that most hedge and bush vegetation can enter the gap and be cut by the flanks of the teeth  20   a ,  22   a  through a shearing action. 
         [0027]    Occasionally, branches or other debris will enter the gap for which the hedgetrimmer lacks the power to cut the branch, or some branches may be too large to enter the gap. In those situations, the hedgetrimmer blade assembly  18  is equipped with a saw blade assembly  28  that is able to cut through such debris as further described below. 
         [0028]    Referring to  FIG. 1 , the blade assembly  18  includes two sections, first section, labelled A in  FIG. 1 , extends the length of the support bar  24  and includes the standard hedgetrimmer blade teeth  20   a ,  22   a . A second section, labelled B, includes the saw blade assembly  28  for cutting through branches and other debris. This saw section B, includes a first side  30  whose cutting teeth are identical to the hedgetrimmer teeth  20   a ,  22   a  in section A. However, on the opposite side  32 , the blade assembly  18  is made up of the teeth  20   a ,  22   a  from the top saw blade  34  and a bottom saw blade  36 , respectively. See  FIG. 3 . Importantly, this section of the blade assembly does not include the support bar  24 . 
         [0029]    Referring to  FIGS. 3 and 4 , the saw blades  34 ,  36  include cutting teeth  34   a ,  36   a , respectively, whose cutting teeth are spaced closer together and have cutting surfaces at their tips. The gap between these cutting teeth  34   a ,  36   a  should be small enough to ensure that a user&#39;s fingers cannot enter and be accidentally cut. In this way, the saw blades  34 ,  36  are designed so that only the tips of the teeth  34   a ,  36   a  perform the cutting action to cut through a thick branch via the reciprocating motion of the blades  20 ,  22 . In a preferred embodiment, the top saw blade  34  is attached to the top blade  20 , using an aperture  38  on the saw blade  34  that is frictionally secured to a projection  40  on the blade  20 . See  FIG. 6 . Similarly, the bottom saw blade  36  includes an aperture  38   a  to secure it to a projection  40   a  on the bottom blade  22 . The projection  40  is shown as circular, but it should be appreciated that it can take any shape. Alternatively, the saw blades  34 ,  36  can be formed integrally with the respective blades  20 ,  22 . 
         [0030]    One of the advantages of using the apertures and projections to secure the sawblade to the blade is that it simplifies manufacturing. For example, a standard hedgetrimmer blade would have its teeth extend all the way to the end of the blade. This standard blade is typically stamped from a piece of metal. To create the projections  40  from the standard hedgetrimmer blade, a second stamping action can be performed that removes the excess material (shown in shadow in  FIG. 6 ) from a hedgetrimmer tooth  20   a  to leave only the projection  40 . The sawblade  34  is separately manufactured with the aperture  38  and then press fit onto the projection  40 . Preferably, the press fit attachment would be strong enough to secure the sawblade  34  to the hedgetrimmer blade  20 , but further processing could be performed, such as welding, if desired. 
         [0031]    This two-step process is preferable to simply manufacturing the sawblade integrally with the hedgetrimmer blade because it allows for the use of existing manufacturing tools. Using existing tooling provides the flexibility to continue to manufacture standard hedgetrimmer blades, and only when the sawblade attachment is needed, the manufacturer can then take the additional step of stamping the hedgetrimmer blade to form the protrusion and attach the sawblade. A stamping tool to form the protrusion is much cheaper than the tool necessary to form a hedgetrimmer blade. So this process requires only the new stamping tool rather than an entirely new set of tools for the hedgetrimmer blade with the integral sawblade. 
         [0032]    However, it should be understood that the sawblade could be manufactured integrally with the hedgetrimmer blade, as shown in  FIGS. 7-9 . Although this may require additional upfront costs, the resultant blade would be stronger and more durable. To possibly help offset the increased cost, only a single hedgetrimmer blade could include the sawblade portion.  FIG. 7  shows a hedgetrimmer having a blade assembly  100  having a top blade  102  and a bottom blade  104 , with only the bottom blade  104  having a sawblade portion  106 . 
         [0033]    The fixed top blade  102  is made up of a set of short teeth  102   a  on both sides of the support bar  24 , and the reciprocating bottom blade  104  is made up of a set of long teeth  104   a  on both sides of the support bar  24 . In this way, both sides of the support bar have corresponding set of long and short teeth. Alternatively, top blade could be made up of long teeth on one side and short teeth on the other side, and the bottom blade can reversed so that each side of the support bar  24  can have corresponding long teeth and short teeth similar to what shown in  FIG. 7 . 
         [0034]    Importantly, the top blade  102  includes a bevelled edge  108  along an inner edge of the blade. The bevelled edge  108  provides a ramp to help separate any branch or other debris being cut, so that the branch or debris can easily pass over the top blade  102 . Without the bevelled edge  108 , the top blade  102  would present a sheer face that could block the passing of the branch or debris. It should be understood that the bevelled edge  108  can be of any shape or configuration so long as it assists in helping cut debris pass over the blade assembly. 
         [0035]    Referring now to  FIGS. 2, 3 and 7 , an L-shaped bracket  42  is shown that is used to support a branch as it&#39;s being cut. The bracket  42  has base portion  44  that is secured to the support bar  24 . The support bar  24  is generally U-shaped, with a central channel  24   a . The base portion  44  is secured within this channel  24   a  using a nut and bolt or any other similar means. The bracket also includes a support arm  46  that is perpendicular to the base portion  44 . The support arm  46  is used to brace a branch or other debris that&#39;s being cut, and keep it stationary as the saw assembly  28  cuts through it. Without the bracket  42 , a branch would be more likely to simply move away from the saw assembly  28  as it&#39;s brought into engagement with the branch. 
         [0036]    Referring now to  FIGS. 5A and 5B , a further embodiment of the invention is shown having a guard bar  48 . The guard bar is pivotally secured in the central channel  24   a  of the support bar  24 . As shown, it is placed on top of the bracket  42 , and fixed to the sides of the U-shaped support bar  24  by a pin  50  that acts as an axle allowing the guard bar to rotate. The guard bar has two positions, a first closed position shown in FIG.  5 A shows the guard bar  48  folded back onto the support bar  24 .  FIG. 5B  shows a second open position where the guard bar  48  is extended out. When in this position, the tip of the guard bar extends beyond the blade assembly  18 . The guard bar  48  prevents the blade assembly from damaging a structure when the hedgetrimmer is in use, such as when there are hedges or bushes along a building or other structure. This helps to protect the structure itself from damage, as well as the hedgetrimmer. Additionally, the tip of the guard bar  48  can include a rubber tip  52  to further protect the structure from damage. The tip  52  does not have to be rubber, but can be any resilient material that can absorb an impact and prevents scuffing or leaving other visible marks. The guard bar  48  can be locked in the closed or open through the frictional engagement with the sides of the U-shaped channel. Additionally, more secure lock can be used to secure the guard bar in either position. 
         [0037]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure