Abstract:
The present invention relates to a power tool having a housing, a handle having an inlet passage and an outlet passage extending therethrough, and a pneumatic pressure seal/vibration isolator positioned between the handle. The present invention provides a tool that has an excellent handle to housing seal and does not exhibit heavy vibrations. The present invention is also the vibration isolator that seals the handle to the motor housing and reduces vibrational transmissions to a user. Also disclosed is a power tool having a vibration isolator coupled to the housing and handle, and a mechanism for allowing sliding rotation of the handle relative to the vibration isolator, thereby allowing the handle to point in a different direction other than toward the point of impact. The present invention also discloses a pneumatic power tool including a handle, a housing having a first longitudinal axis, and a vibration isolator rotatably coupling the handle to the housing, the vibration isolator including a central opening through which air passes that is not aligned with the first longitudinal axis.

Description:
This application is a divisional of Ser. No. 09/006,098 filed on Jan. 13, 1998. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to hand-held power tools. In particular, the present invention is concerned with power tools with a vibration isolator. Further, the present invention relates to the vibrator isolator. 
     BACKGROUND OF THE INVENTION 
     A recurring difficulty with hand-held power tools is a lack of an easily mounted vibrational isolator between the tool motor housing and the tool handle. Vibrations being transmitted to a tool handle can cause discomfort to certain user&#39;s. Another hurdle in the related art is pneumatically sealing the power tool handle to the motor housing where the handle delivers compressed air and exhausts expanded air to and from the motor housing. Yet another difficulty arises in arriving at tool handles that provide a convenient and comfortable hand/wrist position for a user. 
     Manufacturers and developers have created a number of vibration isolators to prevent vibration transmission to a user. For example, U.S. Pat. No. 2,058,583 to Forss, illustrates a vibration isolator 16 for isolating the handle 9 from the motor housing 1. U.S. Pat. No. 3,968,843 to Shotwell also provides a vibration isolator 30, 32, 34. Further, WO 94/16864 to Gwinn discloses a vibration isolator  10  enclosed within a power tool housing. The vibration isolators discussed above require elaborate handle to housing fastener setups that prevent the provision of adjustable handles and are limited to isolators being in alignment with the housing. 
     With regard to sealing the handle to the housing, separate sealing structures are oftentimes required altogether. For instance, in U.S. Pat. No. 3,968,843 to Shotwell, a liner 40 separate from the isolator 30 is used to provide a sealed passage. The additional structure adds weight and complexity to the power tool. The related art also fails to sufficiently address the sealing of a handle where the handle both delivers and exhausts air to and from the motor housing. 
     With regard to adjustable handles, the related art has utilized straight, side, angled or spade handles in order to achieve a correct hand/wrist position. The difficulty with this concept is that the operator has to do a variety of different jobs with the same tool. Thus, a straight handled tool may be ideal for one application but not ideal on another application where a turned or angled handle is better suited. 
     In an attempt to overcome this limitation, power tool developers and manufacturers have introduced adjustable type handles for their power tools and varied vibration isolators. For example, U.S. Pat. No. 4,522,270 issued to Kishi discloses a hand-held power tool which provides a handle that pivots angularly with respect to the tool housing. Similarly, U.S. Pat. No. 3,571,874 issued to Von Arx discloses a descaling device which also has a handle that pivots angularly with respect to the tool housing. These inventions allow the tool handle to be angularly pivoted toward or away from the tool attachment/impact point. This gives the operator an increased ability to find a more comfortable or efficient handle position which he or she lacked in the past. 
     While the aforementioned patents provide a certain amount of improvement with regard to handle comfort, there are still difficulties which these devices do not address. For instance, given that most tools have a trigger on the handle, these devices do not have the ability to change the direction of the trigger with respect to the tool housing. In other words, the trigger always faces in the same direction—towards the tool attachment/impact point. Under certain circumstances, in order to achieve the ideal hand/wrist position, an operator may want to have the trigger facing a direction other than that of the direction of the tool. Further, the rotatable handle tools heretofore used do not provide sufficient vibration isolation between the motor housing and handle and, further, do not address the sealing of the handle to the motor housing where such sealing is necessary. 
     Accordingly, until now, there has been a long-felt need for a power tool having a structure that vibrationally isolates and seals a handle to a motor housing in a single, easily mounted structure where the handle delivers/exhausts air to the housing. Further, there has been a long-felt need for a structure that addresses the above noted problems and also allows for adjustment of the handle relative to the motor housing. The present invention seeks to provide this functionality. 
     SUMMARY OF THE INVENTION 
     In a first general aspect in accordance with the present invention is provided a power tool including a housing, a handle, rotatably attached to the housing, having an inlet passage and an outlet passage extending therethrough, and a pneumatic pressure seal/vibration isolator between the motor and handle. The pneumatic pressure seal/vibration isolator includes a first rigid member operatively coupled to the housing, a second rigid member operatively coupled to the handle, and an elastomeric element extending between the first rigid member and the second rigid member. This aspect allows pneumatic pressure to pass through the handle yet provides for excellent vibration isolation. 
     In a second aspect in accordance with the present invention is provided a vibration isolator having a first member operatively coupled to the motor housing, a second member operatively coupled to the handle, and an elastomeric member extending between the first member and second member. The second member also includes a first portion operatively coupled to the elastomeric member and a second portion extending toward the first member. This aspect allows for excellent vibration isolation between the handle and motor housing. 
     In a third general aspect of the present invention is provided a power tool including a motor housing, a handle mounted to the motor housing having a pilot extending therefrom, and a vibration isolating seal positioned between the motor housing and the handle. The vibration isolating seal also includes an opening to operatively couple to the pilot. 
     In a fourth general aspect of the present invention is included a power tool including: a device for housing a motor, a device for holding the tool, and a device for rotationally connecting and pneumatically sealing the device for holding to the device for housing and for vibrationally isolating the device for holding from the device for housing. The above two aspects provide mechanisms by which the handle is rotatably connected and sealed to the motor housing while also being vibrationally isolated from the motor housing. 
     In a fifth aspect in accordance with the present invention is provided a power tool including: a housing, a handle, a vibration isolator operatively coupled between the housing and the handle, and a device for allowing sliding rotation of the handle relative to the vibration isolator. The vibration isolator and the device for allowing sliding rotation provide structure by which a power tool may have an adjustable handle while also vibrationally isolating the handle from the motor housing. 
     Lastly, in another general aspect of the present invention is furnished a pneumatic power tool comprising a handle, a housing having a longitudinal axis, and a vibration isolator rotatably coupling the handle to the housing, the vibration isolator including a central opening through which air passes, and wherein the central opening is in non-alignment with the longitudinal axis. This aspect provides a pneumatic tool with a vibration isolation but without the requirement that the isolator be located along the longitudinal axis of the housing. 
     The foregoing and other features and advantages of the present invention will be apparent from the following more particular description of the preferred embodiment of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred embodiments of this invention will be described in detail, with reference to the following figures, wherein like designations denote like elements, and wherein: 
     FIG. 1 is a side view of a power tool in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is a plan view of a vibration isolator in accordance with a preferred embodiment of the present invention; 
     FIG. 3 is a cross-sectional view of the vibration isolator in accordance with a preferred embodiment of the present invention; 
     FIG. 4 is an exploded partial cross-sectional view of the vibration isolator in accordance with a preferred embodiment of the present invention; 
     FIG. 5 is an exploded partial cross-sectional view of the vibration isolator in accordance with a preferred embodiment of the present invention; 
     FIG. 6 is an exploded partial cross-sectional view of a vibration isolator in accordance with a second embodiment of the present invention; and 
     FIG. 7 is a partial cross-sectional view of a power tool in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Although certain preferred embodiments of the present invention will be shown and described in detail, it should be understood that various changes and modifications may be made without departing form the scope of the appended claims. The scope of the present invention will in no way be limited to the number of constituting components, the materials thereof, the shapes thereof, the relative arrangement thereof, etc., and are disclosed simply as an example of the preferred embodiment. 
     Referring now to the drawings and more particularly to FIG. 1, there is shown a side view of a hand-held power tool  10  with the handle  14  in the straight-ahead position. The power tool basically comprises a motor housing  12 , a handle  14  and a coupling system, and more particularly a vibration isolator  20  that also acts to seal. The motor housing  12  extends along a longitudinal axis  11  and comprises a tool attachment area  68  at the forward end of the axis  11 , and a motor  13  at the rear end of the axis  11 . The handle extends generally perpendicularly from the motor housing  12  and includes an inlet bushing  39  at a lower end to attach a source of compressed air (not shown) to the handle. The handle  14  also includes an air intake passage  18  that provides compressed air to the motor housing  12  and an exhaust passage  67  to exhaust expanded air from the motor housing  12 . 
     The vibration isolator or vibration isolating seal  20  in accordance with the present invention is capable of the combined functions of coupling and sealing the motor housing  12  to the handle  14 , and vibrationally isolating the handle  14  from the motor housing  12 . As shown in FIGS. 2-5, the vibration isolator  20  generally includes a first rigid member or element  21  and a second rigid member or element  22  that are connected by an elastomeric member  26 . The vibration isolator  20  also includes a central axis  15  and a central opening  29  through which air passes as will be described infra. The rigid members  21 ,  22  may be made from a variety of rigid materials such as steel, aluminum or alloys thereof. The elastomeric member or element  26  may be made from any elastomeric material, e.g., rubber or synthetic elastomer such as neoprene. 
     As more particularly illustrated in FIGS. 2 and 5, the vibration isolator  20  includes a plurality of sets of apertures  50 - 53  for connection of the vibration isolator  20  to the motor housing  12 . Each set of apertures  50 - 53  includes an aperture in the first member  21 , the second member  22  and the elastomeric member  26 . The apertures in each member are aligned for insertion of a fastener  58  (shown only in FIG. 7) therethrough and into the motor housing  12 . The first member  21  has an aperture  54 , as shown in FIG. 5, that is slightly smaller than the apertures through the elastomeric member  26  and second member  22  to receive the head of the fastener  58 . 
     The second member  22  includes a first portion  23  and a second portion  24  which are bonded to the elastomeric member  26 . The second portion  24  extends from an edge of the first portion  23  towards the first member  21 . In a preferred embodiment of the present invention, the second portion  24  also includes a beveled edge  43 , the function of which will be described infra. 
     In the preferred embodiment of the present invention, as shown in FIGS. 3-5, the elastomeric member  26  is formed so as to enclose at least a portion of the first and second members  21 ,  22  to aid in pneumatically sealing the handle  14  to the motor housing  12  so that compressed air and expanded air can be delivered to and from the motor housing  12 , respectively. In particular, the elastomeric member  26  includes a covering portion  27  that extends around the first portion  23  of the second member  22  and a thin lip  42  that runs along an interior surface of the second portion  24  of the second member  22 . Furthermore, the elastomeric member preferably encircles or covers the first member  21  in its entirety. More specifically, the elastomeric member  26  includes a pair of leaflets  45 ,  46  that extend over the edges of the first member  21 , and a covering layer  28  that covers the remaining edge of the first member  21 . 
     It should be noted, however, that the first and second members need not be enclosed by the elastomeric element  26 . As shown in FIG. 6, the members  21 ,  22  may merely be bonded to the elastomeric member  26 . However, in this setting the members  21 ,  22  and the motor housing  12  must be more precisely machined so as to prevent leakage of compressed air and expanded air. Further, a gasket (not shown) may be required between member  21  and motor housing  12 . For example, the gasket could be incorporated into member  21  or an O-ring type feature or lip could be provided on the elastomeric member  26 . 
     Again referring to FIG. 1, the handle  14  is attached to the vibration isolator  20  by a pilot or pilot  66 . To connect the handle  14 , the pilot  66  is inserted into the second portion  24  of the second member  22 , which mates with the pilot  66 . A clamp ring  64  is then inserted into the pilot  66  to prevent removal. Further, the pilot  66  includes an elastomeric o-ring  62  that seals the pilot  66  against the second portion  24  of the second member  22 . The o-ring  62  can be made from any elastomeric material, for instance, rubber. To seal the air intake passages  18 ,  72  to the motor housing  12 , an intake seal  61  is provided which seals an intake pilot or flange  63  on the handle  14  to the motor housing  12 . The intake seal  61  can be made from any elastomeric material, e.g., rubber or synthetic elastomers such as neoprene. In combination, the seals  61  and  62  and flanges  63 ,  66  form a pair of concentric passages for intake and exhaust of air through the central opening  29  of the vibration isolator  20 . As an alternative, it is also contemplated that the intake seal  61  could be incorporated into the elastomeric member  26 . 
     In the preferred embodiment, the pilot  66  is cylindrical as is the first portion  24  of the second member  22 . The clamp ring  64  is circular and is adapted to bear against the bevel  43  formed on the first portion  24  of the second member  22 . This structure allows relatively frictionless sliding rotation of the handle  14  relative to the motor housing  12 . As a result, the handle  14  can rotate about the central axis  15  independent of motor housing  12  to better accommodate the user&#39;s comfortable use of the tool  10 . 
     The position to which the handle  14  is adjusted is preferably held by the back pressure of the elastomeric member  26  including covering layer  27 , and the intake seal  61 . The pressure, acting downwardly upon the handle  14 , aids in pressing/holding the clamp ring  64  against bevel  43 . It is also contemplated that a wavy spring (not shown) or similar structure be incorporated, for instance, along the top edge of the flange  66  for engagement with the motor housing  12  to position the handle  14 . However, direct metal to metal structure is to be avoided as it would potentially short circuit, i.e., prevent proper operation of, the vibration isolator  20 . Furthermore, if such structure were to be provided, the mechanism by which engagement with the motor housing  12  is created provide low friction in comparison to the torsional stiffness of the isolator  20  to avoid spring back of the handle  14  during adjustment. 
     In the preferred embodiment, the hand tool  10  is powered via compressed air. This is accomplished as follows. Air enters through inlet bushing  39  into intake passage  18 , passes through the throttle valve  40 , through passage  72 , and to a reverse valve (not shown) in the motor housing  12 . Air inlet bushing  39  may be secured to the tool handle  14  by means of a pin  17  and a groove  19 . This permits the inlet to turn freely relative to the handle  14 . 
     Air then passes to the motor housing and a valve system (not shown) in the motor housing  12 , then through the motor  13  in a conventional fashion to operate in the power tool. Air can exhaust from the motor housing  12  through handle exhaust passage  67 , then through diffuser  69 , and into the atmosphere. 
     As shown in FIG. 1, the tool is depicted in its standard “straight-ahead” position. That is, the trigger  70  is pointed in the same direction as the tool attachment device  68  on the front of motor housing  12 . This is the position that such tools are normally fixed for use. The tool attachment device  68  may comprise a square drive anvil, a chuck, or any other device which will allow for the attachment of sockets, wrenches, drill bits, or any other rotating attachment apparatus. 
     It should be recognized, however, that there are a number of advantages created by having the vibration isolator  20  and handle  14  in non-alignment with the longitudinal axis  11  of the motor housing  12 . The advantages are realized in that the present invention allows for many more comfortable settings for a user. For instance, FIG. 7 depicts the tool  10  with the handle  14  rotated 90° about the central axis  15  and shows the vibration isolator  20  and handle  14  connected to the motor housing  12 . Handle  14  is shown (along with trigger  70 ) facing in a leftward direction, while motor housing  12  (along with tool attachment device  68 ) is shown facing the forward direction. Thus, as depicted in this diagram, handle  14  and the tool housing  12  can be set to face in different directions. In particular, the handle  14  is fully rotatable (i.e., 360°) about the central axis  15  which allows for an unlimited number of handle positions. This allows the user to adjust the tool to obtain the correct wrist/hand position for the variety of jobs he or she may be doing while also vibrationally isolating the handle  14  from the motor housing  12 . 
     It should also be acknowledged, as shown in FIGS. 1 and 7, that the base of the handle  14  may be constructed such that it is cocked in a slightly backward position and such that it rotates about the central axis  15  of the vibration isolator  20  which is perpendicular to the longitudinal axis  11  of the motor housing  12 . This particular construction allows for more freedom in adjustment to better accommodate a user&#39;s comfort. However, it is possible to incorporate a system wherein the positioning of the handle  14  is provided in a different way. For instance, the handle  14  could rotate about an axis that is not perpendicular to the motor housing  12 . In particular, the position in which vibration isolator  20  connects to handle  14  could be constructed skewed, or angularly offset, to allow for a skewed connection of the vibration isolator  20  to the motor housing  12 . Similarly, the vibration isolator  20  may be attached to the motor housing  12  at a skewed or angularly offset position. 
     In the preferred embodiment, the motor housing  12  and the handle  14  are depicted as co-planar. However, it is envisioned that a system could be utilized in which the motor housing  12  and the handle  14  were not co-planar. Because of the design of the air intake and exhaust systems, along with the vibration isolating seal  20 , compressed air would still reach the motor housing  12  through the handle  14  and exhaust out of the handle while the handle  14  is in any rotated position. 
     As depicted in the drawings, the tool motor  13  is driven by compressed air. However, it is envisioned that the vibration isolating seal and rotatable handle system could be used for any fluid-driven power tool. Further, the rotatable handle system and vibration isolator could also be used on tools powered by other sources, e.g., electricity. 
     While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.