Patent Publication Number: US-2023158621-A1

Title: Power tool including a battery pack isolation system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/408,602, filed Aug. 23, 2021, which is a continuation of U.S. patent application Ser. No. 16/287,807, filed Feb. 27, 2019, now U.S. Pat. No. 11,117,234, which is a continuation of U.S. patent application Ser. No. 14/270,547, filed May 6, 2014, now U.S. Pat. No. 10,232,479, which claims priority to U.S. Provisional Patent Application No. 61/820,032, filed May 6, 2013, the entire contents of each are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to power tools and, more particularly, to battery pack isolation systems for power tools. 
     Power tools (e.g., reciprocating saw, drill, circular saw, jigsaw, etc.) generate vibrational forces during operation of the power tool. By nature, some power tools (e.g., reciprocating saws) generate more aggressive vibrational forces than other power tools (e.g., drills). It is advantageous to isolate the vibrational forces within the power tools so that the vibration forces do not propagate to a battery pack that powers the power tools. Excess vibrational forces exerted on the battery pack can limit the life cycle of the battery pack. 
     SUMMARY 
     In one embodiment, the invention provides a power tool including a housing, a motor positioned substantially within the housing, a drive mechanism supported by the housing and coupled to the motor, a battery pack electrically coupled to the motor, and an isolation system. The isolation system includes an interface member positioned substantially within the housing. The interface member receives a portion of the battery pack to electrically couple the battery pack to the motor. The isolation system also includes a plurality of isolators coupled between the housing and the interface member to isolate the battery pack from the housing during operation of the power tool. 
     In another embodiment, the invention provides an isolation system for a power tool. The power tool includes a housing, a motor positioned substantially within the housing, a drive mechanism supported by the housing and coupled to the motor, and a battery pack electrically coupled to the motor. The isolation system includes an interface member positioned substantially within the housing. The interface member is configured to receive a portion of the battery pack to electrically couple the battery pack to the motor. The isolation system also includes a plurality of isolators coupled between the housing and the interface member to isolate the battery pack from the housing during operation of the power tool. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a power tool including a battery pack isolation system. 
         FIG.  2    is a side view of the power tool with a portion of a housing removed. 
         FIG.  3    is a perspective view of a battery pack of the power tool. 
         FIG.  4    is an end perspective view of a portion of the power tool without the battery pack. 
         FIG.  5    is an exploded perspective view of a portion of the power tool including the battery pack isolation system. 
         FIG.  6    is a perspective view of the battery pack isolation system. 
         FIG.  7    is a side view of an isolator of the battery pack isolation system. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
     DETAILED DESCRIPTION 
       FIGS.  1  and  2    illustrate a power tool  10 . The illustrated power tool  10  is a multi-tool operable to oscillate a cutting blade, a scraping blade, a sanding sheet, and the like. In other embodiments, the power tool  10  may be, for example, a reciprocating saw, a drill, a circular saw, a jigsaw, a band saw, a screwdriver, an angle or straight grinder, a hammer drill, or an impact wrench. In such embodiments, the power tool  10  may be operable to oscillate, rotate, reciprocate, or otherwise drive other types of output elements such as drill bits, saw blades, and the like. 
     The illustrated power tool  10  includes a housing  14 , a motor  18 , a drive mechanism  22 , an output element  26 , and a battery pack  30 . The housing  14  includes two clamshell halves  34 A,  34 B that are connected together to enclose the motor  18  and the drive mechanism  22 . When connected together, the clamshell halves  34 A,  34 B define a grip portion  38  and a battery support portion  42  of the housing  14 . The grip portion  38  is configured to be grasped by a user during operation of the power tool  10 . The battery support portion  42  is configured to indirectly support the battery pack  30  on the housing  14 , as further described below. 
     As shown in  FIG.  2   , the motor  18  and the drive mechanism  22  are positioned substantially within the housing  14  in front of the grip portion  38 . In some embodiments, the drive mechanism  22  is positioned within a gear case inside of and/or supported by the housing  14 . The drive mechanism  22  is coupled to the motor  18  to be driven by the motor  18 . When energized, the motor  18  drives the drive mechanism  22  to oscillate the output element  26 . 
     The output element  26  is coupled to an output shaft or spindle (not shown) of the drive mechanism  22 . The illustrated output element  26  is located at an opposite end of the housing  14  from the battery pack  30 , but may alternatively be located in other locations on the housing  14  relative to the battery pack  30 . In the illustrated embodiment, the output element  26  is a cutting blade that is oscillated during operation of the power tool  10 . In other embodiments, the output element  26  may be a different type of element (e.g., a scraping blade, a sanding sheet, etc.) and/or may be driven in a different manner (e.g., rotated, reciprocated, etc.) by the drive mechanism  22 . 
     The battery pack  30  is supported at the battery support portion  42  of the housing  14  and electrically coupled to the motor  18 . During operation of the power tool  10 , the battery pack  30  supplies power to the motor  18  to energize the motor  18 . The illustrated battery pack  30  is an 18 volt Li-ion power tool battery pack. In other embodiments, the battery pack  30  may have different voltages (e.g., 12 volts, 14.4 volts, 28 volts, etc.) and/or chemistries (e.g., NiCd, etc.). 
     As shown in  FIG.  3   , the battery pack  30  includes a connection portion  46  and a securing mechanism  50 . In the illustrated embodiment, the connection portion  46  includes two parallel, spaced apart rails  54  such that the battery pack  30  is a slide-on-style battery pack. In other embodiments, the battery pack  30  may be a tower-style battery pack that is at least partially inserted into the housing  14  of the power tool  10 . The connection portion  46  also includes terminals  58  to electrically connect the battery pack  30  to a motor or other device. The securing mechanism  50  includes two latches  62  (only one of which is shown) for releasably securing the battery pack  30  to the power tool  10 . The latches  62  extend from the connection portion  46  adjacent the rails  54 . An actuator  66  is coupled to each latch  62  to facilitate manually operating (e.g., moving) the latches  62  relative to the connection portion  46 . 
     As shown in  FIGS.  4 - 6   , the power tool  10  also includes an isolation system  70  to connect the battery pack  30  to the housing  14 . The isolation system  70  mechanically isolates the battery pack  30  from the housing  14  during operation of the power tool  10 . That is, in contrast to a damping system that reduces the magnitude of vibrations that are transferred to a battery pack, the isolation system  70  isolates the battery pack  30  from at least some vibrations caused by the motor  18  and the drive mechanism  22 . The overall transfer of vibrations, particularly high frequency vibrations, to the battery pack  30  during operation of the power tool  10  is greatly reduced. The isolation system  70  is configured to allow the housing  14  to move in six degrees of freedom (i.e., forward-backward, up-down, and side-to-side) relative to the battery pack  30  such that certain frequencies of vibrations are not transferred to the battery pack  30 , regardless of the direction of that particular vibration. 
     The illustrated isolation system  70  includes an interface member  74 , isolators  78 , and a terminal block  82 . As shown in  FIGS.  4  and  5   , the interface member  74  is captured between the two clamshell halves  34 A,  34 B of the housing  14 . The illustrated interface member  74  includes two parallel, spaced apart rails  86  that correspond to the rails  54  ( FIG.  3   ) of the battery pack  30 . The interface rails  86  are configured to engage the battery pack rails  54  to connect and support the battery pack  30  on the housing  14 . The interface member  74  also defines two recesses  90  adjacent the rails  86 . The recesses  90  are configured to receive the latches  62  ( FIG.  3   ) of the battery pack  30  to releasably secure the battery pack  30  to the interface member  74 . In other embodiments, the interface member  74  may be configured to receive a tower-style battery pack and/or battery packs having different securing mechanisms. 
     The interface member  74  also includes two elastomeric members  94  positioned adjacent the rails  86  on either side of the terminal block  82 . The elastomeric members  94  are positioned adjacent opposite ends of the rails  86  from the recesses  90  that receive the battery pack latches  62 . Stated another way, the elastomeric members  94  are position at a closed end of the interface member  74  opposite from an open end of the interface member  74  that receives the battery pack  30 . The illustrated elastomeric members  94  are rubber cylinders that fit within corresponding notches in the interface member  74 . The elastomeric members  94  engage the connection portion  46  ( FIG.  3   ) of the battery pack  30  when the battery pack  30  is connected to the interface member  74 . In particular, the elastomeric members  94  take up clearances or tolerances between the battery pack  30  and the interface member  74  to preload the latches  62  of the battery pack  30 . Such an arrangement creates a relatively tight engagement between the battery pack  30  and the interface member  74  such that the battery pack  30  and the interface member  74  do not move (e.g., vibrate) relative to each other. In some embodiments, the elastomeric members  94  may be omitted. 
     As shown in  FIG.  5   , the isolators  78  are positioned between the interface member  74  and the housing  14  to isolate the interface member  74 , and thereby the battery pack  30 , from the housing  14 . In the illustrated embodiment, the isolation system  70  includes six isolators  78 . In other embodiments, the isolation system  70  may include fewer or more isolators  78 . Each isolator  78  is a generally annular member and is composed of an elastomeric or rubber material, such as polyurethane. In other embodiments, the isolators  78  may have other shapes and configurations and/or may be composed of other suitable materials. 
     As shown in  FIGS.  5  and  6   , the isolators  78  are positioned on posts  98 ,  102  that extend from the interface member  74  and are received in openings  106  formed in the housing  14 . The illustrated interface member  74  includes six posts  98  extending from opposing sidewalls  110 A,  110 B of the member  74 , with three posts  98  extending from each sidewall  110 A,  110 B. In the illustrated embodiment, isolators  78  are only positioned on two of the three posts  98  on each sidewall  110 A,  110 B, although in other embodiments an isolator  78  may be positioned on every post  98 . The interface member  74  also includes an upper projection  114  from which two additional posts  102  extend. The upper projection  114  is located halfway between the opposing sidewalls  110 A,  110 B and extends perpendicularly from an upper surface  118  ( FIG.  6   ) of the interface member  74 . In other embodiments, the isolators  78  may be positioned on posts that extend from the housing  14  and received in openings formed in the interface member  74 . The isolators  78  connect the interface member  74  to the housing  14  such that the interface member  74  does not directly contact the housing  14 . As such, the interface member  74  and the battery pack  30  are indirectly supported on the battery support portion  42  of the housing  14  through the isolators  78 . 
       FIG.  7    illustrates one of the isolators  78  in more detail. The illustrated isolator  78  has a double-taper design. That is, the isolator  78  tapers from its mid portion  122  toward a central longitudinal axis  126  of the isolator  78 . The isolator  78  thereby decreases in diameter from the mid portion  122  to both outer faces  130 A,  130 B (i.e., the diameter at the mid portion  122  of the isolator  78  is greater than the diameter at either outer face  130 A,  130 B of the isolator  78 ). The double-taper design provides clearance for the isolator  78  to deflect and deform when the isolator  78  is compressed during operation of the power tool  10  (e.g., when the housing  14  vibrates relative to the interface member  74  and pushes against the isolator  78 ). 
     Referring back to  FIGS.  4  and  5   , the terminal block  82  is mounted to the interface member  74  between the rails  86 . The illustrated terminal bock  82  is a separate piece from the interface member  74 , but is supported by the interface member  74 . In some embodiments, a biasing member (e.g., a coil spring) may be positioned between the terminal block  82  and the interface member  74  to help clamp the terminal block  82  within the member  74 . In other embodiments, the terminal block  82  may be integrated into the interface member  74  such that the terminal block  82  and the interface member  74  are a single piece. 
     The terminal block  82  includes electrical contacts that engage the terminals  58  ( FIG.  3   ) of the battery pack  30  when the battery pack  30  is connected to the interface member  74 . The terminal block  82  is electrically coupled to the motor  18  to provide power from the battery pack  30  to the motor  18 . Since the terminal block  82  is directly mounted to the interface member  74  and not to the housing  14 , the terminal block  82  is also isolated from the housing  14  through the isolators  78  such that vibrations of the power tool  10  are not transferred to the battery pack  30  through the terminal block  82 . 
     The isolation system  70  mechanically isolates the battery pack  30  from the housing  14  of the power tool  10  such that vibrations from the motor  18  and the drive mechanism  22  are not transferred to the battery pack  30  during operation of the power tool  10 . Depending on the particular type of power tool, the isolation system  70  may be configured to isolate the battery pack  30  from different frequencies, or ranges of frequencies, of vibrations. For example, the spring rate (e.g., material, shape, etc.) of the isolators  78  may be varied to isolate specific operational frequencies for particular types of power tools. In addition, the shape of each isolator  78  may be changed to vary spring rate, dampening properties, and/or abrasion resistance. 
     Although the invention has been described with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention. For example, in further embodiments, the battery pack isolation system  70  may be used with other types of electrical devices that vibrate during operation, such as vacuum cleaners, outdoor power equipment (e.g., blowers, chain saws, edgers, trimmers, lawn mowers, etc.), or vehicles (e.g., automobiles, motorcycles, scooters, bicycles, etc.). 
     Various features and advantages of the invention are set forth in the following claims.