Patent Publication Number: US-10321753-B2

Title: Stress control brush

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of International Application No. PCT/CN2016/076669 filed on Mar. 18, 2016, which is based upon and claims priority to Chinese Patent Application No. 201510153033.4 filed on Apr. 2, 2015, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The disclosure relates to a brush, more particular to a stress control brush. 
     BACKGROUND 
     Good teeth brushing habits help people to maintain oral hygiene and avoid tooth decay. In order to keep oral hygiene, people brush their teeth every day with a strong force hoping to prevent their teeth from decay. However, according to a report, researchers pointed out that when teeth are brushed too hard, the surface of the teeth and the gums is damaged, increasing the risk of having decay and periodontal disease. 
     WO international publication No. 01/21035 discloses a toothbrush which can automatically release excessive tooth brushing force. The brush head of said brush is pivoted on the handle, and two opposite ends of the flat elastic plate connect the brush head and the handle, respectively, so that the angle between the brush head and the handle is a fixed value. When the brushing force is over the predetermined force value, the elastic plate is bent and deformed so that the angle between the brush head and the handle is changed significantly. When the force is continuously applied on the toothbrush with the flat elastic plate, the angle between the brush head and the handle is changed more significantly so that the toothbrush cannot maintain the normal function of a toothbrush; therefore, the damage on the teeth and gums caused by excessive brushing force can be avoided. 
     U.S. Pat. No. 6,327,734 discloses a sensing and signaling system for tooth brushes which reminds the user that the force applied to the teeth has exceeded a critical value. The toothbrush includes a brush-head member and a dome member which is collapsible and recoverable. The brush-head member includes a striking element extended away from a rear surface of the brush-head member and in contact with a surface of the dome member. When stress from the brush-head member is applied on the teeth of the user, the brush-head member is moved toward the toothbrush and transfers the stress to the dome member by the striking member. When an excessive force is applied by the user to the brush-head against the teeth, the dome member is collapsed so that the brush-head is moved toward the toothbrush to remind the user. When the excessive force is removed, the dome member recovers to the original shape and pushes the brush-head member back to the original position. 
     Taiwan utility patent No. M492666 discloses a stress control brush, wherein the stress control brush uses feedback from the elastic plate to remind the user that the brushing force is over the predetermined force value. In the stress control brush, the elastic plate connects the brush head and the handle. When the brushing force is over the predetermined force value, the elastic plate is in the collapsed bending state, and the angle between the brush head and the handle is changed significantly so that the stress control brush cannot maintain the normal toothbrush function; therefore, the damage on the teeth and gums caused by the excessive brushing force can be avoided. The brush head has a limiting part, and the handle has a limiting part. When the elastic plate is in the collapsed bending state, the limit parts of the brush head and the handle abut against each other so as to restrict the bending curvature of the elastic plate. 
     Although the tooth brushes described above are capable of notifying users whether or not the stress applied to teeth during brushing hurts the teeth and gums, some problems still exist with these tooth brushes. The tooth brush disclosed in the WO international publication No. 01/21035 has a problem that when the stress exceeds a predetermined value, the angle between the brush head and the handle is changed significantly and is temporarily disabled, and the tooth brush could even generate a plastic deformation which makes the tooth brush disabled; moreover, the predetermined force, which causes the deformation of the tooth brush, and the actual trigger force, which causes the deformation of the toothbrush when users are brushing their teeth, are different each time. If users want to clean the particularly dirty parts of the teeth such as the residue between teeth, this toothbrush may not fulfill the users&#39; demands of having to brush with a stronger force. 
     The tooth brush disclosed in U.S. Pat. No. 6,327,734 has complicated structures and mechanisms of force transfer, and the structure of said tooth brush is also complicated to assemble. When the toothbrush is in use, the complicated structure and the tiny interspaces cause the deformation trigger force of the brush could be different each time, and the residues and contaminants are easily kept inside the brush head which is hard to be clean up and hard to keep dry. Bacteria significantly grow when the environment is too humid and the residues and contaminants are kept in the brush head such that this brush easily becomes unclean and increases the possibility of inflection. 
     The stress control brush disclosed in Taiwan utility patent No. M492666 has an elastic plate having a slight bending state and a collapsed bending state when the stress control brush is in use. The difference between the elastic coefficient of the elastic plate in the slight bending state and the elastic coefficient of the elastic plate in the collapsed bending state is small, and some users may not be able to feel the force feedback generated by the elastic plate when using this stress control brush. 
     SUMMARY 
     An embodiment of the present disclosure provides a stress control brush including a handle, a brush head, and a feedback component. The brush head is pivoted on the handle, and the brush head is pivotable in an angular range relative to the handle. The feedback component is installed between the handle and the brush head. The feedback component is resilient and has a protruding state and a breakdown-sunken state. The feedback component is pressed by the brush head and in the breakdown-sunken state when the brush head is pivoted relative to the handle, and a feedback is provided by the feedback component. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become better understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and are not limitative of the present disclosure, and wherein: 
         FIG. 1  is a schematic view of a stress control brush in a first embodiment of the present disclosure; 
         FIG. 2  is an exploded view of the stress control brush in the first embodiment of the present disclosure; 
         FIG. 3A  is a schematic view of a first type feedback component in the first embodiment of the present disclosure; 
         FIG. 3B  is a side view of the first type feedback component in the first embodiment of the present disclosure; 
         FIG. 3C  is a schematic view of a force-displacement curve of the first type feedback component in the first embodiment of the present disclosure; 
         FIG. 4A  and  FIG. 4B  are cross-sectional views of the stress control brush in the first embodiment of the present disclosure; 
         FIG. 5A  is a schematic view of a second type feedback component in the first embodiment of the present disclosure; 
         FIG. 5B  is a side view of the second type feedback component in the first embodiment of the present disclosure; 
         FIG. 5C  is a schematic view of a force-displacement curve of the second type feedback component in the first embodiment of the present disclosure; 
         FIG. 6  is a schematic view of a stress control brush in a second embodiment of the present disclosure; 
         FIG. 7  is an exploded view of the stress control brush in the second embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional view of the stress control brush in the second embodiment of the present disclosure; 
         FIG. 9  is a cross-sectional view of a stress control brush in a third embodiment of the present disclosure; 
         FIG. 10A  to  FIG. 10C  are schematic views of stress control brushes in a fourth embodiment to a sixth embodiment of the present disclosure; 
         FIGS. 11A and 11B  are schematic views of a stress control brush in a seventh embodiment of the present disclosure in different viewing angles. 
         FIGS. 12A and 12B  are exploded views of the stress control brush in the seventh embodiment of the present disclosure in different viewing angles; 
         FIG. 12C  is a schematic view of a feedback component in the seventh embodiment of the present disclosure; 
         FIG. 13  is a cross-sectional view of the stress control brush in the seventh embodiment of the present disclosure; and 
         FIGS. 14A and 14B  are cross-sectional view of the stress control brush in the seventh embodiment of the present disclosure in different pivot directions. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing 
     Please refer  FIG. 1  to  FIG. 3C .  FIG. 1  is a schematic view of a stress control brush in a first embodiment of the present disclosure.  FIG. 2  is an exploded view of the stress control brush in the first embodiment of the present disclosure.  FIG. 3A  is a schematic view of a first type feedback component in the first embodiment of the present disclosure.  FIG. 3B  is a side view of the first type feedback component in the first embodiment of the present disclosure.  FIG. 3C  is a schematic view of a force-displacement curve of the first type feedback component in the first embodiment of the present disclosure. 
     The stress control brush  100  in the first embodiment of the present disclosure includes a brush head  110 , a feedback component  120 , a handle  130 , and a pivoting component  140 . The brush head  110  includes a bristle seat  111 , a plurality of bristle bundles  112 , a first limit part  113 , a first pressing part  114 , and two first pivot parts  115 . The bristle seat  111  has a front surface  1111  and a back surface  1112  which are opposite to each other, and two side surfaces  1113  located between the front surface  1111  and the back surface  1112 . The plurality of bristle bundles  112  are installed at the front surface  1111 . The back surface  1111  of the bristle seat  111  can further have a tongue cleaning part (not shown in the figures) for the user to clean the tongue. 
     The first limit part  113  is located at the back surface  1112  and extends toward a direction away from the bristle seat  111 . The first pressing part  114 , for example, is a pillar, and the first pressing part  114  is located at the front surface of the bristle seat  111  and extends toward a direction away from the bristle seat  111 . In other embodiments of the present disclosure, the first limit part and the first pressing part can be two plates. 
     In the first embodiment of the present disclosure, the extending direction of the first limit part  113  and the extending direction of the first pressing part  114  are parallel to each other, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the extending direction of the first limit part and the extending direction of the first pressing part form an angle not equal to zero. The two first pivot parts  115  are respectively located at the two side surfaces  1113 , and there is a distance between the two first pivot parts  115 . The first limit part  113 , the first pressing part  114 , and the two first pivot parts  115  together form an accommodating space  116 . 
     In the first embodiment of the present disclosure, the bristle seat  111 , the first limit part  113 , the first pressing part  114 , and the first pivot parts  115  are made of polymer, and the bristle seat  111 , the first limit part  113 , the first pressing part  114 , and the two first pivot parts  115  are integratedly formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the bristle seat, the first limit part, the first pressing part, and the two first pivot parts can be assembled or formed in one piece. 
     Please refer  FIG. 3A  to  FIG. 3C , the feedback component  120 , for example, is an elastic plate including a protrusion  121 , a side part  122 , and three sustaining parts  123 . The protrusion  121  includes a first protrusion part  1211  and a second protrusion part  1212 . The second protrusion part  1212  protrudes out of a surface of the first protrusion part  1211 , wherein the first protrusion part  1211  and the second protrusion part  1212  have the same protruding direction, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the first protrusion part  1211  and the second protrusion part  1212  have different protruding directions. 
     In other embodiments of the present disclosure, the first protrusion part and the second protrusion part have two opposite protruding directions. The side part  122  surrounds an edge of the first protrusion part  1211  so that the feedback component  120  has a disk structure; therefore, the feedback component  120  has a high elastic coefficient which is similar to a rigid body structure so that the first protrusion part  1211  can provide significant feedback, such as a sudden flexural movement, when the first protrusion part  1211  generates a sunken-deformation. The three sustaining parts  123  are located at the side part  122 , and the three sustaining parts  123  have a protruding direction opposite to the protruding direction of the first protrusion part  1211  and the second protrusion part  1212 . In the first embodiment of the present disclosure, the side part  122  surrounds the first protrusion part  1211 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, a part of the edge of the first protrusion part may not be surrounded by the side part. In the first embodiment of the present disclosure, the quantity of the sustaining parts  123  is three, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the quantity of the sustaining parts can be less than three or more than three. In some embodiments of the present disclosure, the feedback component can be an elastic dome. 
     The first protrusion part  1211  is resilient and has a protruding state and a sunken state so that the feedback component  120  has a protruding state and a breakdown-sunken state. When the feedback component  120  is in the protruding state, a vertical distance which the second protrusion part  1212  moves toward a plane A where the sustaining parts  123  are located is D. When a force applied at a side of the first protrusion part  1211 , which is close to the second protrusion part  1212 , is smaller than a critical elastic force, and the deformation of the first protrusion part  1211  is still in the elastic limit, the first protrusion part  1211  is elastically deformed from the protruding state to the sunken state so that the moving distance D is increased. When the force applied on the first protrusion part  1211  is removed, the elastic force of the first protrusion part  1211  turns the first protrusion part  1211  from the sunken state back to the protruding state. As a result, when a force larger than the critical elastic force is applied at the second protrusion part  1212 , the second protrusion part  1212  protruding from the first protrusion part  1211  turns the first protrusion part  1211  from the protruding state to the sunken state so that the feedback component  120  in the protruding state is turned to the breakdown-sunken state, and the moving distance D is significantly increased. 
     The handle  130  includes a grip  131 , a second limit part  132 , an auxiliary limiting part  133 , a second pressing part  134 , and a second pivot part  135 . The grip  131  has a front surface  1311  and a back surface  1312  which are opposite to each other, and two side surfaces  1313  of the grip  131  which are opposite to each other and located between the front surface  1311  and the back surface  1312 . The second limit part  132  is located at the back surface  1312  of the grip  131 . The auxiliary limiting part  133  is located at the front surface  1311  of the grip  131 . The second pivot part  135  connects the grip  131  and the second pressing part  134 . In the first embodiment of the present disclosure, the second pressing part  134  is a protrusion on the grip  131 , but the disclosure is not limited thereto. A side of the second pressing part  134  close to the front surface  1311  of the grip  131  has a recess  1341 . The recess  1341  has a bottom surface  13411 . In the first embodiment of the present disclosure, the grip  131 , the second limit part  132 , the auxiliary limiting part  133 , the second pressing part  134 , and the second pivot part  135  are made of polymer, and the grip  131 , the second limit part  132 , the auxiliary limiting part  133 , the second pressing part  134 , and the second pivot part  135  are integrally formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the grip, the second limit part, the auxiliary limiting part, the second pressing part, and the second pivot part can be formed by assembling or in one piece. 
     The second pressing part  134  and the second pivot part  135  of the handle  130  are located in the accommodating space  116  of the brush head  110 . The front surface  1311  of the grip  131  and the front surface  1111  face the same direction. The second pivot part  135  of the handle  130  is pivoted to the two first pivot parts  115  of the brush head  110  through the pivoting component  140  so that the brush head  110  can be pivot relative to the handle  130 . As a result, the second pressing part  134  located in the accommodating space  116  can be relatively close to or away from the first pressing part  114 . The feedback component  120  is located in the recess  1341 . The sustaining parts  123  of the feedback component  120  are in contact with the bottom surface  13411  of the recess  1341  so that the first protrusion part  1211  keeps a distance from the bottom surface  13411 . The first protrusion part  1211  and the second protrusion part  1212  of the feedback component  120  protrude toward a direction away from the bottom surface  13411 , and the second protrusion part  1212  is in contact with a side of the first pressing part  114  facing the accommodating space  116 . 
     When the brush head  110  pivots relative to the handle  130  so that a distance between the first pressing part  114  and the second pressing part  134  is changed, the first pressing part  114  presses the second protrusion part  1212  and further deforms the first protrusion part  1211 , such as bring the first protrusion part  1211  to generate a sunken-deformation. Once a force over the critical force is applied at the first protrusion part  1211 , the first protrusion part  1211  generates the sunken-deformation so that the feedback component  120  is in the breakdown-sunken state. By the design of the second protrusion part  1212  protruding out of the first protrusion part  1211 , the first pressing part  114  constantly applies the force at the second protrusion part, which means the location of the first protrusion part  1211  being pressed is constant so that the critical elastic force which causes the sunken-deformation of the first protrusion part  1211  of the feedback component  120  to be close to a constant value each time, and therefore, the stress control effect of the stress control brush  100  is improved. In the first embodiment of the present disclosure, the protrusion  121  includes a first protrusion part  1211  and a second protrusion part  1212 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the protrusion can include a first protrusion part where a concave region is located. The first pressing part can have a bulge corresponding to the concave region on the first protrusion part. When the brush head is pivoted relative to the handle, the bulge protruding out from the first pressing part can press the first protrusion part at the concave region and further bring the first protrusion part to generate a sunken-deformation. 
     The first limit part  113  extends from the bristle seat  111  toward the second limit part  132  of the handle  130 . The first pressing part  114  extends from the bristle seat  111  toward the auxiliary limiting part  133  of the handle  130 . In the first embodiment of the present disclosure, the first limit part  113  and the first pressing part  114  are pillars respectively extending from the brush head  110  toward the second limit part  132  and the auxiliary limiting part  133 . The second limit part  132  and the auxiliary limiting part  133  are surfaces of the handle  130 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the second limit part and the auxiliary limiting part are stop blocks protruding from the surface of the handle. 
     Please refer to  FIG. 4A  and  FIG. 4B .  FIG. 4A  and  FIG. 4B  are cross-sectional views of the stress control brush in the first embodiment of the present disclosure. As shown in  FIG. 4A , when the stress control brush  100  is in a non-using state, the brush head  110  bears no external force, and the feedback component  120  is in a protruding state. In detail, as shown in  FIG. 4A , the handle  130  has the bottom surface  13411 , the brush head  110  has a surface  1141  facing the bottom surface  13411  of the handle  130 , the feedback component  120  is installed between the bottom surface  13411  and the surface  1141 , the feedback component  120  has a convex surface  12111  and a concave surface  1213  opposite each other, the convex surface  12111  faces one of the bottom surface  13411  and the surface  1141 , and the concave surface  1213  faces the other one of the bottom surface  13411  and the surface  1141 . The first protrusion part  1211  of the protrusion  121  is at a protruding state so that the second protrusion part  1212  is in contact with the first pressing part  114 . At this time, the first limit part  113  keeps a distance from the second limit part  132 , and the first pressing part  114  and the auxiliary limiting part  133  are pressed against each other. As shown in  FIG. 4B , when the user is brushing teeth, the teeth apply a counterforce (first force F 1 ) to the central location of the plurality of bristle bundles on the bristle seat  111  so that the first force F 1  takes the pivoting component  140  as a fulcrum to generate an applying-force torque relative to the handle  130 . The elastic force of the first protrusion part  1211  of the feedback component  120  is applied to the first pressing part  114  through the second protrusion part  1212  so that the elastic force takes the pivoting component  140  as a fulcrum to generate a resistance torque relative to the handle  130 . When the user uses a brushing force smaller or equal to the critical force to brush the teeth, the teeth and the gums are not damaged by the excessive brushing force. When the brushing force equal to the critical force is used, the elastic force of the feedback component  120 , which achieves a torque equivalent with the brushing force, is the critical elastic force. 
     When the first force F 1  is smaller than or equal to the critical force, the force applied on the feedback component  120  is smaller than or equal to the critical elastic force. Since the feedback component  120  has a high elastic coefficient similar to a rigid body, the first protrusion part  1211  generates a negligible deformation when bearing a force smaller than or equal to the critical elastic force. At this time, the feedback component  120  is in a slightly sunken-state, the brush head  110  is slightly pivoted relative to the handle  130 , and the moving distance D of the second protrusion part  1212  toward the plane A (bottom surface  13411 ), where the sustaining parts  123  are located is only increased slightly. The resistance torque generated by the elastic force of the first protrusion part  1211  in the feedback component  120  is equal to the applying-force torque generated by the first force F 1 . 
     When the first force F 1  is larger than the critical force, the force applied on the feedback component  120  is larger than the critical elastic force so that the structure of the first protrusion part  1211  of the feedback component  120  is collapsed and generates a significant sunken elastic deformation. At this time, the feedback component  120  is in the breakdown-sunken state, and the brush head  110  is significantly pivoted relative to the handle  130 , the moving distance D of the second protrusion part  1212  toward the plane A (bottom surface  13411 ), where the sustaining parts  123  are located is significantly increased. The resistance torque generated by the elastic force of the first protrusion part  1211  of the feedback component  120  is smaller than the applying-force torque generated by the first force F 1 . The significant bending and deformation of the stress control brush  100  makes the stress control brush  100  generate the feedback to the user so as to remind the user to stop brushing their teeth with enough brushing force to damage the teeth and the gums. The feedback to the user provided by the stress control brush  100  includes a force feedback, a sound feedback, or a deformation feedback. For example, during the deformation of the first protrusion part  1211  in the feedback component  120 , the sudden change of the force feedback makes the user feel the sudden flexural deformation, the deformation of the first protrusion part  1211  generates the noise as a reminder, and continuously using the bent stress control brush  100  during the deformation of the first protrusion part  1211  is inconvenient. 
     When the user uses the tongue cleaning part (not shown in the figures) of the stress control brush  100  to clean the tongue, the brush head  110  bears a second force with a direction opposite to the direction of the first force F 1 , and the feedback component  120  is in the protruding state, the first protrusion part  1211  of the protrusion  121  is in the protruding state so that the second protrusion part  1212  is in contact with the first pressing part  114 . At this time, the first limit part  113  keeps a distance from the second limit part  132 , and the first pressing part  114  and the auxiliary limiting part  133  are pressed against each other. 
     With a significant pivot of the brush head  110  relative to the handle  130 , once an angle between an extension line of the brush head  110  and an extension line of the handle  130  reaches a, the first limit part  113  having the extension direction toward the second limit part  132  presses against the second limit part  132  so as to stop the pivoting of the brush head  110  relative to the handle  130 . Then the moving distance D of the second protrusion part  1212  toward the plane A (bottom surface  13411 ), where the sustaining parts  123  are located, cannot be increased anymore so as to prevent the first protrusion part  1211  of the feedback component  120  from overly sunken-deformation which generates an unrecoverable plastic deformation. 
     In addition, when the first limit part  113  and the second limit part  132  are pressed against each other, the user can apply a larger force to the brush head  110  for cleaning the particularly dirty parts of the teeth such as the residue between teeth without causing a situation where the stress control brush  100  is overly deformed and disabled use. 
     In addition, the critical elastic force of the feedback component  120  can be adjusted through the difference of the area, the thickness, the curvature of the protrusion, and the material. In the first embodiment of the present disclosure, the feedback component  120  is made of steel, the feedback component  120  has a disk shape, and the protrusion  121  has a circle shape, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the protrusion can have an oval shape, a ball shape, or a rectangular shape, and the feedback component can be made of the polymer with high elastic coefficient or metals. 
     In the first embodiment of the present disclosure, the feedback component  120  is a first type feedback component, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the feedback component can be a second type feedback component  120 ′. Please refer to  FIG. 5A  to  FIG. 5C .  FIG. 5A  is a schematic view of a second type feedback component in the first embodiment of the present disclosure.  FIG. 5B  is a side view of the second type feedback component in the first embodiment of the present disclosure.  FIG. 5C  is a schematic view of a force-displacement curve of the second type feedback component in the first embodiment of the present disclosure. The second type feedback component  120 ′ is similar to the first type feedback component  120 , and the difference between the first type feedback component  120  and the second type feedback component  120 ′ is that the second type feedback component  120 ′ further includes three supporting parts  124 ′. Each of the three supporting parts  124 ′ has a first end  1241 ′ and a second end  1242 ′ which are opposite to each other. Each of the first ends  1241 ′ of the supporting parts  124 ′ is connected to the side part  122 ′. Each of the second ends  1242 ′ of the supporting parts  124 ′ is extended toward a direction away from the first protrusion part  1211 ′, the second protrusion part  1212 ′, and the side part  122 ′. The extending direction of the second end  1242 ′ is opposite to the protruding direction of the first protrusion part  1211 ′ and the second protrusion part  1212 ′. Each of the supporting parts  124 ′ is resilient so that the second end  1242 ′ of the supporting part  124 ′ can be moved close to or away from the side part  122 ′. In some embodiments of the present disclosure, the quantity of the supporting part  124 ′ is three, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the quantity of the supporting part can be one, two, or more than three. In some embodiments of the present disclosure, the extending direction of the second end  1242 ′ is opposite to the protruding direction of the first protrusion part  1211 ′ and the second protrusion part  1212 ′, but the disclosure is not limited thereto. In other embodiments of the present disclosure, an obtuse angle is between the extending direction of the second end  1242 ′ and the protruding direction of the first protrusion part  1211 ′ and the second protrusion part  1212 ′. 
     Due to the influence of the structure of the first protrusion part  1211 ′, the elastic coefficient of the first protrusion part  1211 ′ is larger than the elastic coefficient of each of the supporting parts  124 ′ and the total elastic coefficient of all the supporting parts  124 ′. As a result, the force applied on each of the supporting parts  124 ′, to generate an elastic deformation, is smaller than the force applied on the first protrusion part  1211 ′ to generate an elastic deformation. When the stress control brush  100  is in use, the second protrusion part  1212 ′ of the second type feedback component  120 ′ is pressed by the force, and the deformation starts from each of the supporting parts  124 ′, and the moving distance D of the second protrusion part  1212  toward the plane B where the supporting parts  124 ′ are located is increased. After the sustaining part  123 ′ arrives at the plane B, the next is that the first protrusion part  1211 ′ starts to deform so that the moving distance D is increased continuously. 
     Since the stress control brush is assembled by the brush head  110  and the handle  130 , the distance between the first pressing part  114  of the brush head  110  and the bottom surface  13411  of the recess  1341  of the handle  130  has a tolerance. When the sum of the tolerance the distance between the first pressing part  114  of the brush head  110  and the bottom surface  13411  of the recess  1341  of the handle  130  is larger than the vertical distance between the second protrusion part  1212  and the plane A where the sustaining parts  123  are located, the first type feedback component  120  can move in the recess  1341  to generate an abnormal sound. 
     In contrast, in the second type feedback component  120 ′, the supporting parts  124 ′ are resilient and can be moved toward or away from the side part  122 ′ so that the supporting parts  124 ′ can fill the tolerance of the distance between the first pressing part  114  and the bottom surface  13411  of the recess  1341 ; therefore, the second protrusion part  1212 ′ and the supporting parts  124 ′ of the second type feedback component  120 ′ are respectively kept in contact with the first pressing part  114  and the bottom surface  13411  of the recess  1341 . As a result, the second type feedback component  120 ′ cannot move in the recess  1341 , and the abnormal sound is prevented. 
     In addition, in the first embodiment of the present disclosure, the feedback component  120  is located in the recess  1341  of the second pressing part  134 , but the disclosure is not limited thereto. In one embodiment of the present disclosure, the feedback component is clamped between a surface of the first pressing part and a surface of the second pressing part which are facing each other. 
     Please refer to  FIG. 6  to  FIG. 8 .  FIG. 6  is a schematic view of a stress control brush in a second embodiment of the present disclosure.  FIG. 7  is an exploded view of the stress control brush in the second embodiment of the present disclosure.  FIG. 8  is a cross-sectional view of the stress control brush in the second embodiment of the present disclosure. The stress control brush in the second embodiment of the present disclosure is similar to the stress control brush in the first embodiment of the present disclosure, and the differences between the stress control brush in the second embodiment and the stress control brush in the first embodiment are explained herein, and the same structures thereof are not repeated herein. 
     The stress control brush  200  in the second embodiment of the present disclosure includes a brush head  210 , a feedback component  220 , a handle  230 , and a pivoting component  240 . The brush head  210  includes a bristle seat  211 , a plurality of bristle bundles  212 , two first limit parts  213 , a first pressing part  214 , and two first pivot parts  215 . The bristle seat  211  has a front surface  2111  and a back surface  2112  which are opposite to each other, and two side surfaces  2113  which are opposite to each other and located between the front surface  2111  and the back surface  2112 . The plurality of bristle bundles  212  is located at the front surface  2111 . The two first limit parts  213  are respectively located at two ends of the back surface  2112  close to the two side surfaces  2113 , and the two first limit parts  213  keep a distance between each other. The first pressing part  214  is located at the front surface  2111 . A side of the first pressing part  214 , facing the same direction with the back surface  2112 , has a recess  2141 . The recess  2141  has a bottom surface  21411 . The two first pivot parts  215  are respectively located at two side surfaces  2113 , and the two first pivot parts  215  keep a distance from each other. The two first limit parts  213 , the first pressing part  214 , and the two first pivot parts  215  form an accommodating space  216  together. In the second embodiment of the present disclosure, the bristle seat  211 , the bristle bundles  212 , the first limit part  213 , the first pressing part  214 , and the first pivot part  215  are made of polymer, and the bristle seat  211 , the two first limit parts  213 , the first pressing part  214 , and the two first pivot parts  215  are integrally formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the bristle seat, the two first limit parts, the first pressing part, and the two first pivot parts can be formed by assembling or in one piece. 
     The handle  230  includes a grip  231 , two second limit parts  232 , an auxiliary limiting part  233 , a second pressing part  234 , and a second pivot part  235 . The grip  231  has a front surface  2311  and a back surface  2312  which are opposite to each other, and two side surfaces  2313  which are opposite to each other and located between the front surface  2311  and the back surface  2312 . The two second limit parts  232  are respectively located at two ends of the back surface  2312  of the grip  231  close to the two side surface  2312  of the grip  231 . The auxiliary limiting part  233  is located at the front surface  2311  of the grip  231 . The second pivot part  235  connects the grip  231  and the second pressing part  234 . The second pressing part  234  is a protrusion extending toward a direction away from the grip  231 . In the second embodiment of the present disclosure, the grip  231 , the second limit part  232 , the auxiliary limiting part  233 , the second pressing part  234 , and the second pivot part  235  are made of polymer, and the grip  231 , the second limit part  232 , the auxiliary limiting part  233 , the second pressing part  234 , and the second pivot part  235  are integrally formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the grip, the second limit part, the auxiliary limiting part, the second pressing part, and the second pivot part can be assembled or formed in one piece. 
     The feedback component  220  is located in the recess  2141  of the first pressing part  214 . The sustaining parts  223  located at the side part  222  of the feedback component  220  are in contact with the bottom surface  21411  of the recess  2141 . The first protrusion part  2211  and the second protrusion part  2212  of the feedback component  220  protrude toward a direction away from the bottom surface  21411  and are in contact with a side of the second pressing part  234  facing the first pressing part  214 . In detail, as shown in  FIG. 8 , the handle  230  has a surface  23411 , the brush head  210  has the bottom surface  21411  facing the surface  23411  of the handle  230 , the feedback component  220  is installed between the surface  23411  and the bottom surface  21411 , the feedback component  220  has a convex surface  22111  and a concave surface  2213  opposite each other, the convex surface  22111  faces one of the surface  23411  and the bottom surface  21411 , and the concave surface  2213  faces the other one of the surface  23411  and the bottom surface  21411 . In other embodiments of the present disclosure, the protrusion can include a first protrusion part where a concave region is located. The first pressing part can have a bulge facing the concave region on the first protrusion part. When the brush head pivots relative to the handle, the bulge protruding out from the first pressing part can press the first protrusion part at the concave region and further bring the first protrusion part to generate a sunken-deformation. 
     In the second embodiment of the present disclosure, the two first limit parts  213  and the first pressing part  214  are two pillars that respectively extend toward the second limit part  232  and the auxiliary limiting part  233  from the brush head  210 . The two second limit parts  232  and the auxiliary limiting part  233  are surfaces of the handle  230 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the second limit part and the auxiliary limiting part are stop blocks that protrude from the surface of the handle. 
     In addition, an opening (not shown in the figures) can be on the front surface  2111  and communicated with the accommodating space  216  so that the user can flush out the toothpaste foam from the accommodating space  216  with water. An elastic auxiliary bulge (not shown in the figures) is located at the front surface  2111 , and the elastic auxiliary bulge protrudes toward and is in contact with the connecting area which connects the grip  231  and the second pressing part  234  so as to reduce the shake of brush head relative to the handle which is caused by manufacturing tolerance. 
     Please refer to  FIG. 9 .  FIG. 9  is a cross-sectional view of a stress control brush in a third embodiment of the present disclosure. The stress control brush in the third embodiment of the present disclosure is similar to the stress control brush in the first embodiment of the present disclosure. And the difference between the stress control brush in the third embodiment and the stress control brush in the first embodiment is that the locations of the pressing part and the limiting part of the brush head and the locations of the pressing part and the limiting part of the handle are respectively exchanged, and the same structures thereof are not repeated herein. 
     The stress control brush  300  in the third embodiment of the present disclosure includes a brush head  310 , a feedback component  320 , a handle  330 , and a pivoting component  340 . The brush head  310  includes a bristle seat  311 , a plurality of bristles  312 , a first limit part  313 , a second limit part  314 , a first pressing part  315 , and a first pivot part  316 . The handle  330  includes a grip  331 , an auxiliary limiting part  332 , a second pressing part  333 , and two second pivot parts  334 . The auxiliary limiting part  332 , the second pressing part  333 , and the two second pivot parts  334  together form an accommodating space  335 . 
     The first pressing part  315  and the first pivot part  316  of the brush head  310  are located in the accommodating space  335  of the handle  330 . The first pivot part  316  of the brush head  310  is pivoted between the two second pivot parts  334  of the handle  330  through the pivoting component  340  so that the brush head  310  is pivotable relative to the handle  330 . As a result, the first pressing part  315 , located in the accommodating space  335 , can move close to or away from the second pressing part  333  so as to apply the force at the feedback component  320  located between the first pressing part  315  and the second pressing part  333 . When the brush head  310  bears a first force F 1  which is larger than the first critical force, the feedback component  320  bears a force larger than the critical elastic force and is in the breakdown-sunken state, and the first limit part  313  and the auxiliary limiting part  332  can press against each other when the brush head  310  is pivoted relative to the handle  330 . 
     In the third embodiment of the present disclosure, the auxiliary limiting part  332  and the second pressing part  333  are pillars respectively extending toward the first limit part  313  and the second limit part  314  from the handle  330 . The first limit part  313  and the second limit part  314  are surfaces of the brush head  310 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the first limit part and the second limit part are stop blocks that protrude from the surface of the handle. 
     Please refer to  FIG. 10A  to  FIG. 10C  and table  1 .  FIG. 10A  to  FIG. 10C  are schematic views of stress control brushes in a fourth embodiment to a sixth embodiment of the present disclosure. Table  1  shows the experiment data regarding to the quantity of the bristle bundles of the stress control brush, the length of the brush head, the critical elastic force of the feedback component, and other parameters in the some embodiments of the present disclosure. In table  1 , the experiment data are the calculation results of bending a feedback component having a fixed size, wherein a situation that two teeth are in contact with  24  bristle bundles is assumed, the total pressure applied on the teeth is 150 g. Since the stress control brushes in the fourth embodiment to the sixth embodiment are similar to the stress control brush in the first embodiment, the differences between the stress control brush in the fourth embodiment to the sixth embodiment and the stress control brush in the first embodiment are explained herein, and the same structures thereof are not repeated herein. 
     In the stress control brush  400 , the stress control brush  500 , and the stress control brush  600  in the fourth embodiment to the sixth embodiment of the present disclosure, the quantity of the bristle bundles are 12 bundles, 20 bundles, and 24 bundles at a central region for installing the bristle bundles on the bristle seat  411  of the brush head  410 , the bristle seat  511  of the brush head  510 , and the bristle seat  611  of the brush head  610 , respectively, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the quantity of the bristle bundles at the central region can be any number except 12 bundles, 20 bundles, and 24 bundles. The force applied on the tooth by a single bristle bundle is constant. During the teeth brushing, when the quantity of the bristle bundles in contact with the teeth is increased, the counterforce applied on the brush head  410 , the brush head  510 , and the brush head  610  is increased. Generally, two teeth are in contact with the bristle bundles at the same time. Since the size of the permanent teeth, the deciduous teeth, and the oral cavities of adults and children are different. In order to let each user be able to choose a suitable stress control brush according to the size of the user&#39;s oral cavity and teeth, the size and the material of the feedback component is design to be adjusted according to the quantity of the bristle bundles on the brush head having a different size so as to obtain different critical elastic forces and make sure the teeth and gums of different users will not cause excessive tooth brushing force when the users brush their teeth with a suitable stress control brush. 
     In the stress control brush  400 , the stress control brush  500 , and the stress control brush  600  of the fourth embodiment to the sixth embodiment, the lengths from the central of the bristle bundle regions of the brush head  410 , the brush head  510 , and the brush head  610  to the pivoting component  440 , the pivoting component  540 , and the pivoting component  640 , respectively, are L 1 , L 1 , and L 2 . In the fourth embodiment to the sixth embodiment of the present disclosure, L 1  is 0.06 meters, L 2  is 0.065 meters, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the length between the center of the bristle bundle region to the pivoting component can be shorter than 0.06 meters and also can be longer than 0.065 meters. The size and the material of the feedback component is designed to be adjusted according to the different brush head lengths so as to obtain different critical elastic forces and make sure the teeth and gums of users will not apply excessive tooth brushing force when they brush their teeth with the stress control brush having a different brush head length. For example, when the user uses the stress control brush in contact with two teeth with the quantity of the bristle bundles being 24 bundles, and the length from the center of the bristle bundle region to the pivoting component is 0.056 meters, the feedback component in the stress control brush with a critical elastic force being 1.21875 kg is selected so as to avoid the teeth and gums bearing excessive force during tooth brushing. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 A 
                 B 
                 C 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 Quantity of bristle bundles in contact 
                 24 
                 20 
                 12 
               
               
                 with two teeth (bundle) 
               
               
                 Force applied by single bristle bundle 
                 0.00625 
                 0.00625 
                 0.00625 
               
               
                 (kg) 
               
               
                 Total pressure on two teeth 
                 0.15 
                 0.125 
                 0.075 
               
               
                 (kgw/cm 2 ) 
               
               
                 Length between the center of the 
                 0.065 
                 0.06 
                 0.06 
               
               
                 bristle bundle region and the pivoting 
               
               
                 component (m) 
               
               
                 Applying-force torque (kg · m) 
                 0.00975 
                 0.0075 
                 0.0045 
               
               
                 Length between the central point of 
                 0.008 
                 0.008 
                 0.008 
               
               
                 the protruding part of the feedback 
               
               
                 component and the pivoting 
               
               
                 component (m) 
               
               
                 Critical elastic force of the feedback 
                 1.21875 
                 0.9375 
                 0.5625 
               
               
                 component (kg) 
               
               
                 Resistance torque (kg · m) 
                 0.00975 
                 0.0075 
                 0.0045 
               
               
                   
               
            
           
         
       
     
     According to the stress control brush of the present disclosure, when the user uses an appropriate force to brush teeth, the disk structure of the feedback component makes the elastic coefficient of the feedback component to be similar to the elastic component of a rigid body, and the deformation of the feedback component is pretty small. Once the user uses a force which can cause damage to the teeth and the gums, the feedback component is collapsed with the protrusion generating the elastically sunken-deformation so that the stress control brush also generates a significant deformation such as bending. The significant deformation of the stress control brush provides a feedback to the user so as to remind and stop the user from brushing their teeth with the brushing force capable of causing damage the teeth and gums. For example, the user feels a sudden flexural deformation or hears a noise when the user is using the stress control brush which notifies the user that the current brushing force can damage the teeth and gums. 
     Please refer to  FIG. 11A  to  FIG. 14B .  FIGS. 11A and 11B  are schematic views of a stress control brush in a seventh embodiment of the present disclosure in different viewing angles.  FIGS. 12A and 12B  are exploded views of the stress control brush in the seventh embodiment of the present disclosure in different viewing angles.  FIG. 13  is a cross-sectional view of the stress control brush in the seventh embodiment of the present disclosure.  FIGS. 14A and 14B  are cross-sectional view of the stress control brush in the seventh embodiment of the present disclosure in different pivot directions. The stress control brush  700  in the seventh embodiment of the present disclosure is similar to the stress control brush  200  in the second embodiment of the present disclosure, and the differences between the stress control brush in the seventh embodiment and the stress control brush in the second embodiment are explained herein, and the same structures thereof are not repeated herein. 
     The stress control brush  700  in the seventh embodiment of the present disclosure includes a brush head  710 , a feedback component  720 , a handle  730 , and a pivoting component  740 . The brush head  710  includes a bristle seat  711 , a plurality of bristle bundles  712 , a first pressing part  713 , two first pivot parts  714 , and an elastic auxiliary bulge  715 . The bristle seat  711  has a front surface  7111 , a back surface  7112 , two side surfaces  7113 , and an opening  7114 . The front surface  7111  and the back surface  7112  are opposite to each other. The two side surfaces  7113  are opposite to each other and located between the front surface  7111  and the back surface  7112 . The plurality of bristle bundles  712  is located at the front surface  7111 . The first pressing part  713  is located at the front surface  7111 . A side of the first pressing part  713  facing the same direction with the back surface  7112  has a recess  7131 . The recess  7131  has a bottom surface  71311 . The two first pivot parts  714  are respectively located at two side surfaces  7113 , and the two first pivot parts  714  keep a distance from each other. The first pressing part  713  and the two first pivot parts  714  form an accommodating space  716  together. The opening is on the front surface  7111  and communicated with the accommodating space  716  so that the user can flush out the toothpaste foam from the accommodating space  716  with water. The elastic auxiliary bulge  715  protrudes from the first pressing part  713 . 
     In the seventh embodiment of the present disclosure, the bristle seat  711 , the bristle bundles  712 , the first pressing part  713 , and the first pivot parts  714  are made of polymer, and the bristle seat  711 , the first pressing part  713 , and the two first pivot parts  714  are integrally formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the bristle seat, the first pressing part, and the two first pivot parts can be assembled or formed in one piece. 
     The handle  730  includes a grip  731 , an auxiliary limiting part  732 , a second pressing part  733 , and a second pivot part  734 . The grip  731  has a front surface  7311  and a back surface  7312  which are opposite to each other, and two side surfaces  7313  which are opposite to each other and located between the front surface  7311  and the back surface  7312 . The auxiliary limiting part  732  is located at the front surface  7311  of the grip  731 . The second pivot part  734  connects the grip  731  and the second pressing part  733 . The second pressing part  733  extends toward a direction away from the grip  731 . Specifically, the second pressing part  733  extends into the accommodation space  716 . The second pressing part  733  has an edge  7331 , two auxiliary bulges  7332 , and a pressing bulge  7333 . The two auxiliary bulges  7332  protrude out from the edge  7331  and toward the two first pivot parts  714 , respectively. The edge  7331  is a space apart from the two first pivot parts  714  so that a gap G, which is communicated with the accommodating space  716 , is formed between the two first pivot parts  714  and the second pressing part  733 . The gap G is also used for flushing out the toothpaste foam from the accommodating space  716  with water. The two auxiliary bulges  7332  are used for minimizing the shake of the bristle seat  712  relative to the grip  731  in the axial direction of the pivoting component  740 . 
     In the seventh embodiment of the present disclosure, the grip  731 , the auxiliary limiting part  732 , the second pressing part  733 , and the second pivot part  734  are made of polymer, and the grip  731 , the auxiliary limiting part  732 , the second pressing part  733 , and the second pivot part  734  are integrally formed, but the disclosure is not limited thereto. In other embodiments of the present disclosure, the grip, the second limit part, the auxiliary limiting part, the second pressing part, and the second pivot part can be formed by assembling or in one piece. In the seventh embodiment of the present disclosure, the second pressing part  733  has two auxiliary bulges  7332 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the second pressing part  733  has no auxiliary bulge. 
     The elastic auxiliary bulge  715  is located at the front surface  7111 , and the elastic auxiliary bulge  715  protrudes toward and abuts against the second pivot part  734 . Therefore, the shake of brush head relative to the handle, which is caused by manufacturing tolerance, is reduced by the elastic auxiliary bulge  715 . 
     The feedback component  720  is located in the recess  7131  of the first pressing part  713 . The sustaining parts  723  located at the side part  722  of the feedback component  720  are in contact with the bottom surface  71311  of the recess  7131 . The protrusion  721  of the feedback component  720  protrudes toward a direction away from the bottom surface  71311 . The protrusion  721  has a concave  7211  located at a surface of the protrusion  721  away from the bottom surface  71311 . The location of the concave  7211  corresponds to the bulge  7333  of the second pressing part  733 . In the seventh embodiment of the present disclosure, the protrusion  721  has a concave  7211 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the protrusion has no concave  7211 . 
     When the first force F 1 , greater than a critical force, is applied to the brush head  710  along a direction toward the front surface  7111 , the bristle seat  711  is pivoted relative to the grip  731  in a direction A, the bulge  7333  presses the protrusion  721  at the concave  72111  and brings the protrusion  721  to generate a sunken-deformation. When the deformed protrusion  721  touches the bottom surface  71311 , the movement of the protrusion  721  and the bulge  7333  are restricted so as to restrict the pivotable angle between the bristle seat  711  and the grip  731  in the direction A. 
     When the second force F 2  is applied to the brush head  710  along a direction toward the back surface  7112 , the bristle seat  711  is pivoted relative to the grip  731  in a direction B which is opposite to the direction A, an edge  7132  of the first pressing part  713  and the auxiliary limiting part  732  are abut against each other to restrict the pivotable angle between the bristle seat  711  and the grip  731  in the direction B. The auxiliary limiting part  732  is stop blocks protruding from the surface of the handle  730 , but the disclosure is not limited thereto. In other embodiments of the present disclosure, the auxiliary limiting part is a surface of the handle. 
     In addition, the feedback component in the stress control brush of the present disclosure has a protrusion structure so that the elastic coefficient of the feedback component is significantly higher than the elastic coefficient of the conventional curved feedback component. As a result, when the user brushes teeth with the brushing force smaller than the critical force, the deformation of the stress control brush in the present disclosure is much smaller than the deformation of the brush with the curved feedback component. Once the user brushes teeth with the brushing force larger than the critical force, the feeling of a sudden flexural deformation as the feedback generated by the stress control brush in the present disclosure is significantly higher than the frustrated feeling generated by the brush with curved feedback component so that the feedback effect of the stress control brush in the present disclosure is significantly improved 
     In addition, when the brush head of the stress control brush in the present disclosure bears a brushing force larger than the first critical force, the brush head is pivoted relative to the handle so that the first limit part and the second limit part are pressed against each other to stop the brush head to pivot relative to the handle and the overly sunken-deformation of the protrusion of the feedback component which generates an unrecoverable plastic deformation and breaks the stress control function of the brush. 
     In addition, when the stress control brush in the present disclosure is in use, the mechanism, which the force is directly transmitted to the protrusion of the feedback component in contact with the brush head through the brush head, can avoid the loss of the force during the transmittance by passing to many movable component so that the value of forces which cause the deformations each time can be consistent for improving the stress control effort. 
     In addition, in the stress control brush of the present disclosure, when the first limit part and the second limit part are pressed against each other, the user can apply a larger force to the brush head for cleaning the particularly dirty parts of the teeth such as, residue between teeth, without a situation where the stress control brush is overly deformed and disabled to use. 
     In addition, in the present disclosure, the first limit part is located at the outside of the brush head, and the second limit part is located at the outside of the handle, and the pivot structure is located at the outside of the oral cavity during teeth brushing; therefore, the residues and the contaminants in the oral cavity have difficulty getting into the pivot structure, and there are few gaps where the contaminants can easily collect, and the brush is easy to be cleaned and kept dry, while avoiding the residues and the contaminants breading bacteria in the humid environment and generating a hygiene issue regarding to increasing the possibility of infection.