Rotary type electric razor

Abstract: A rotary type electric razor includes an arch-shaped external cutting edge (7) detachably engaged on the upper side of the main body case, an internal cutting edge driving unit (15) supported for its free vertical movement with respect to the main body case, a motor revolution-­ number detecting means (32) provided within the main body case, the internal cutting edge driving unit (15) comprising a rotary internal cutting edge (19) which rotates in sliding contact with respect to the internal face of the external cutting edge (7), an internal cutting edge driving chassis for rotatably supporting the rotary internal cutting edge, a motor (21) mounted on the internal cutting edge driving chassis. A drive transmitting means for transmitting the output of the motor to the rotary internal cutting edge (19) is integrally comprised in the chassis. The motor revolution number detecting means comprises a rotary member (32) which rotates with the shaft of the motor, and a photosensor/emitter opposite it. The motor chassis assembly is guided to prevent tilting during longitudinal sliding, which may cause revolution-counting errors.

Description: The present invention generally relates to a rotary type electric razor. Generally, there are some rotary type electric razors which comprise an internal cutting edge driving unit with a rotary internal cutting edge, a motor and a drive transmitting means for transmitting the motor output to the rotary cutting edge integrally engaged with an internal driving chassis. The internal cutting edge is adapted to be brought into closer contact with the internal surface of the external cutting edge by the internal cutting edge driving unit being urged upwards by a leaf spring within the main body case. Further, there are other reciprocating type electric razors described in, for example, JP-A-61-62381, wherein the revolution of the driving motor is detected to maintain the speed of the motor despite light weight variations of the load, making it possible always to effect the shaving operation under optimum conditions. Further, there exist means for detecting revolution of the motor of an electric razor, as shown in, for example, JP-A-62-10880. In this document, a reflection shape photosensor of a non-contact type is used to paste a reflection mark on the output shaft of the motor so as to detect the revolutions of the motor in accordance with the pulse-shaped output from the photosensor. The inventors have perceived a problem where a non-contact type of revolution sensor, for detecting movement of the motor output shaft, is mounted in a rotary type electric razor. In this case, the internal cutting edge driving unit has to be moved straight in the vertical direction so as to remove detection errors. When the motor output shaft is tilted through the vertical motion of the internal cutting edge driving unit, a positional shift is caused in the opposite direction with respect to the photosensor, thus causing detection errors. In a rotary type electric razor, the internal cutting edge driving unit is simply supported by a leaf spring within the main body case, when the internal cutting edge driving unit is engaged in a condition where it is being pushed upwards into the main body case. Its positional control in the longitudinal and side-to-side directions is thus unstable. When the external cutting edge is pressed against the skin, or is kept away from it, the internal cutting edge driving unit retaining the motor floats vertically in the inclined condition due to the variation in the pressing position and the pressing force. The rotary member to be detected slips out of place with respect to the photosensor, which is likely to cause errors in the detection of the revolution of the motor by the photosensor. CH-A-304,814 discloses a rotary type electric razor in which the motor is fixed relative to the main case. An internal cutting member is held against an external cutting mesh by springs, which permit only limited movement of the cutting edge. The object of the present invention is to provide a new type of rotary electric razor. According to the present invention there is provided a rotary type electric razor having: a main body case with an arched external cutting mesh at an upper portion thereof; a generally cylindrical internal cutting member rotatably supported on a side frame by a shaft; a drive motor mounted within the main body case; transmission means arranged between the drive motor and the internal cutting member so that operation of the drive motor causes rotation of the internal cutting member; spring means arranged to bias the internal cutting member against the external cutting mesh, and to allow the internal cutting member to be displaced downwardly; wherein: the internal cutting member, the side frame, the transmission means and the drive motor form an internal operation unit connected to the main body case through the spring means in such a way that the internal operation unit may be displaced as a single unit relative to the main body case. In this way, the present invention may also enable the provision of an improved rotary electric razor of the type referred to above, which is improved by the provision of a guiding arrangement for guiding the vertical movement of the internal cutting edge driving unit of the razor, so as to improve detecting accuracy of a motor revolution detecting means coupled to the driving unit through a photosensor. The present invention may also provide an improved rotary electric razor of the type referred to above, which is improved in the supporting construction of the internal cutting edge, the edge being shiftable up and down by a movable supporting member so that a rotating test for the internal cutting edge may be easily performed before assembling it into a body case. This improves efficiency of assembly of the internal cutting edge driving unit. In one preferred aspect of the present invention, there is provided a rotary type electric razor which includes an arch-shaped external cutting edge detachably engaged on the upper side of the main body case, an internal cutting edge driving unit supported for free vertical movement with respect to the main body case, and a motor revolution detecting means provided within the main body case, e.g. as shown in Fig 1(a) and (b). The internal cutting edge driving unit is composed of a combination of a rotary internal cutting edge, which rotates in sliding contact with the internal face of the external cutting edge; an internal cutting edge driving chassis for rotatably supporting the rotary internal cutting edge; a motor mounted on the internal cutting edge driving chassis; and a drive transmitting means for transmitting the output of the motor to the rotary internal cutting edge integrally engaged with it. The motor revolution detecting means is composed of a rotary member to be detected, which rotary member is engaged with the output shaft of the motor; and also, a photosensor opposite to the rotary member. A vertical motion guiding means, for controlling the non-vertical movement of the internal cutting edge driving unit (i.e., the movements in the longitudinal and right-left directions) is disposed between the peripheral face of the motor and the internal face of the main body case. Even when skin pressure is applied extensively or locally with respect to the external cutting edge, the internal cutting edge driving unit moves straight, in the vertical direction only, without any longitudinal or right-left inclination, due to its positional regulation by the vertical motion guiding means. Therefore, despite the vertical motion of the internal cutting edge driving unit, the distance between the photosensor and the rotary member to be detected (on the output shaft of the motor), and the relative position and angle of the central shaft of the rotary member to be detected, may be kept generally constant so as to prevent errors in detecting the motor revolution. In another aspect of the present invention, the razor comprises an internal cutting edge unit including a rotary internal cutting edge, an internal cutting edge supporting frame, a passive means such as an idler shaft or gear, and a transmitting means, wherein the rotary internal cutting edge is able to rotate by the application of the rotating force of the motor onto the passive means at the stage when the float supporting member and the motor are being assembled into one unit. This allows the rotational condition and efficiency of the rotary internal cutting edge to be checked before assembling it with the motor. Thereafter, the tested internal cutting edge unit is pre-assembled with the motor and float supporting member to form an internal operation unit, which is, then, adapted to be fixed onto the main body case through the float supporting member. The rotary internal cutting edge is thus easily assembled into the main body case after its rotational condition and efficiency have been checked. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will become apparent from the following description of a preferred embodiment thereof, with reference to the accompanying drawings, in which: Fig 1(a) is a side face view which schematically shows the essential portions of a rotary type electric razor in accordance with the present invention; Fig 1(b) is a front view of the portions of Fig 1(a); Figs 2-21 show one embodiment of the present invention, in particular: Fig 2 is a perspective view of the whole razor; Fig 3 is a longitudinal-section front view of the razor; Fig 4 is a longitudinal-section side view of the razor; Fig 5 is an exploded perspective view of the razor; Fig 6 is an exploded perspective view of a protective cap and an external cutting edge holder in the razor; Fig 7 is an exploded perspective view of an internal cutting edge driving unit; Fig 8 is a sectional view of an external cutting edge holder; Fig 9 is a sectional view showing an internal cutting edge unit being fitted; Fig 10(a) is a front view of a brush for use in cleaning the razor; Fig 10(b) is a perspective view showing the brush of Fig 10(a) in use; Fig 11 is a side view of a flock storing chamber; Fig 12 is a sectional view of the flock storing chamber of Fig 11 with the shutter closed; Fig 13 is a sectional view of the flock storing chamber with the shutter open; Fig 14 is an exploded perspective view of a flock discharging mechanism; Fig 15 is a longitudinal-section front view of the main body case bottom portion with a movable plug retracted; Fig 16 is a sectional view taken along the line X-X in Fig 15; Fig 17 is a longitudinal-section front view of the main body case bottom portion with the movable plug projected; Fig 18 is a sectional view taken along the line Y-Y in Fig 17; Fig 19 is a front view of a safety switch portion; Fig 20 is a longitudinal-section front view of a stand for the razor; Fig 21 is a sectional view taken along the line Z-Z in Fig 20; Fig 22 is a front view of a motor revolution detecting means, showing an alternative embodiment of the invention; Fig 23 is a view similar to Fig 1(b), showing a modification of a portion thereof; and Fig 24 is a perspective exploded view of portions of Fig 23. Before the description of the specific embodiments proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring now to the drawings, there is shown in Figs 1 to 21, a rotary type electric razor according to one preferred embodiment of the present invention. In Figs 2 to 4, the main body case 1 comprises abutting front and back cases 1a, 1b secured together with a screw 2 or the like. A pair of front and back circuit basic plates 3, 4 are engaged in the lower half portion of the main body case 1, with two chargeable batteries 5 (Ni-Cd or the like) being arranged between the basic plates 3, 4. A plug unit 6, for use in charging the batteries, is engaged with the case bottom. In Fig 3, Fig 6 and Fig 8, a reticulated external cutting edge 7 is curved into an arch shape on its holder 8 and engaged with the top portion of the main body case 1. The external cutting edge holder 8 is composed of an internal holder 8a and an external holder 8b which is superposed on the outer side thereof for its free separating operation, with the external cutting edge 7 being grasped between the superposed faces of the internal and external holders 8a, 8b. As shown in Fig 8, a rear end 7b on the stationary side of the external cutting edge 7 is calk-deposited on the rear wall portion of the internal holder 8a and also, a front end 7a on the movable side of the external cutting edge 7 is coupled through a zigzag-shaped spring 10 to a support plate 9 mounted on the front wall portion of the internal holder 8a, so that the external cutting edge 7 is normally pulled towards the side of the front end 7a on the movable side. The sliding resistance with the rotary internal cutting edge 19 of the external cutting edge 7 is made as small as possible. In order to narrow the front, back width of the external cutting holder 8, the front end 7a on the movable side of the external cutting edge 7 is extended along the downwardly expanded taper portion 13 formed on the front face of the internal holder 8a so as to make the winding angle small to the rotary internal cutting edge 19 of the external cutting edge 7 as shown in Fig 8. The supporting plate 9 is fixedly calk-deposited on the straight portion 14 formed vertically below the tapered portion 13 continuous with the front face of the internal holder 8a. Also, the upper and lower ends 10a, 10b of the zigzag-shaped spring 10 are pivoted rotatably with respect to the front end 7a on the movable side of the external cutting edge 7 and the support plate 9. Therefore, when the external cutting edge 7 has been pressed upon the skin, the external cutting edge 7 retracts, and deforms the spring 10 to effect downward movement. When the external cutting edge 7 is separated from the skin, it moves upwardly and is restored by the expansion restoring force of the spring 10. The external cutting edge 7 slides, in the vertical direction, a movable piece 34 which is integrally combined with the front end 7a on the movable side, onto the front face of the internal holder 8a in a form sunk a little lower than the taper portion 13 into one portion of the taper portion 13 and along the guide groove 13a formed parallel to the taper portion 13, so that it is guided straight and smoothly in the vertical direction. Also, since the spring 10 pivots at its upper and lower ends 10a, 10b rotatably with respect to the front end 7a on the movable side of the external cutting edge 7 and the support plate 9 in the vertical motion of the external cutting edge 7, so that the angle difference between the taper portion 13 on the front face of the internal holder 8a and the straight portion 14 is absorbed, the front end 7a on the movable side of the external edge 7 properly effects a shrinking and expanding deformation function so as to effect a smooth vertical motion on the taper portion 13. The right and left wall portions of the internal holder 8a are engaged and retained with an engaging pawl 12 having a knob attached to it engaged for its free appearance and disappearance through the spring 11 at the top ends on the right and left sides of the main body case 1. Therefore, in Fig 3, when the engagement pawl 12 with right and left knobs attached to it is depressed against the force of the spring 11, the external cutting edge 7, together with the external cutting edge holder 8, may be removed from the main body case 1. in Fig 6, reference numeral 116 shows a protective cap which is put on the external cutting edge holder 8 during periods of non-use. An internal cutting edge driving unit 15 is engaged with the main body case 1. The internal cutting edge driving unit 15 has an internal cutting edge driving chassis 16, an internal cutting edge unit 20, a motor 21 and a drive transmitting means 22 engaged integrally therewith, as shown in Fig 5. As shown in Fig 3 and Fig 7, the internal cutting edge driving chassis 16 is formed entirely in a U-shape as seen from the front, and has a right and left chassis 16a, 16b and a bottom chassis 16c. It is engaged with the main body case 1 so that the respective upper top ends of the right and left chassis 16a, 16b may project upwardly from the slot 18 of the upper wall 17 of the main body case 1. The clearance between the right and left chassis 16a, 16b and the respective slots 18 is filled up with a rubber 117 to prevent flock penetration. The internal cutting edge unit 20 has a rotary cutting edge 19 having a spiral cutting edge, and is detachably supported laterally between the upper end portions of the right and left chassis 16a, 16b, to project from the upper wall 17 of the main body case 1 so that the rotary internal cutting edge 19 may be rotated in slidable contact with the internal face of the external cutting edge 7. A motor 21 and a gear transmission type of drive transmitting means 22, for transmitting the rotation of the motor 21 to the rotary internal cutting edge 19, are mounted on the internal cutting edge driving chassis 16. A motor holder 23 is superposed on the bottom chassis 16c of the internal cutting edge driving chassis 16 and is integrally connected thereto with a screw. A both-shaft type of motor 21, which has shaft portions 25, 26 above and below the motor holder 23, is retained on the motor holder 23 in a vertical posture by means of screw 24. In Fig 3, the drive transmitting means 22 has an output gear 27 secured onto the upper portion of output shaft 25 which projects upwardly of the motor holder 23 and the bottom chassis 16c from the upper end of the motor 21; a power shaft 28 rotatably supported between the right and left chassis 16a, 16b above the bottom chassis 16c; a gear 29, which is secured onto the axial central portion of the power shaft 28, interlocked orthogonally with the output gear 27; and a gear 30, which is secured onto the right end of the power shaft 28, interlocked with a multistage gear 31 accommodated within the right chassis 16b. In Fig 3 and Fig 7, the internal cutting edge unit 20, which is detachably engaged between the upper end portions of the right and left chassis 16a, 16b, is composed of a combination of a cylinder type rotary internal cutting edge 19, a shaft 35 projecting from both the right and left ends of the rotary internal cutting edge 19, and an internal cutting edge holder 37 for rotatably supporting the shaft 35 on the right end side through a bearing 36 which is integrally engaged therewith. The internal cutting edge holder 37 has an open-bottomed housing 38 for accommodating the bearing 36, and a coupling frame 39 projected horizontally towards the left side from the lower portion of the housing 38. A gear 40a secured onto the shaft 35, and a gear 40b to be interlocked with it, are engaged above and below by two within the housing 38, with the peripheral face lower portion of the gear 40b on the lower side being confronted with the open bottom of the housing 38 so that it may be detachably engaged with the uppermost stage gear of the multistage gear 31 of the drive transmitting means 22. Fig 7 and Fig 9 show that, in the detachable construction at the upper end of the internal cutting edge driving chassis 16 of the internal cutting edge unit 20, a housing receiving portion 41 for receiving and supporting the housing 38 of the internal cutting edge unit 20 is provided on the top end side of the right chassis 16b. A housing 43, for accommodating a bearing 42 which detachably supports the shaft 35 on the left side of the rotary internal cutting edge 19, extends integrally from the top end side of the left chassis 16a so as to be higher than the housing receiving portion 41 on the right side. Also, as shown in Fig 9, a coupling hole 44 is formed in the lower portion of the housing 43 of the left chassis 16a, into which hole the tip end 39a of the coupling frame 39 of the internal cutting edge holder 37 is inserted, so as to be supported to allow it to slip freely off or on. Further, a locking means is provided on the left chassis 16a to prevent the tip end 39a of the coupling frame 39 from slipping out of the coupling hole 44. The locking means has an internal cutting edge disengaging button 45 adapted to slide vertically on the outer side of the left chassis 16a. A locking pawl 46, which is detachably connectable to the internal side of the tip end 39a of the coupling frame 39, projects integrally from the internal face of the internal cutting edge disengaging button 45. This disengaging button is normally urged upwardly by the spring 47 so as to retain an engaging condition in which the locking pawl 46 is engaged from below with the tip end 39a of the coupling frame 39. As shown in Fig 7, the guide frame 48 is integrally placed horizontally between the upper end portions of the right and left chassis 16a, 16b. A guide groove 49 is provided, its vertical position corresponding to that of the coupling hole 44, respectively before and after the internal face of the guide frame 48. The tip end 39a of the coupling frame 39 is inserted from the right end side into the guide groove 49 so as to engage slidably the whole of the internal cutting edge unit 20 horizontally in the left direction so that the tip end 39a of the coupling frame 39 may be inserted into the coupling hole 44. In order to engage the internal cutting edge unit 20 between the upper end portions of the left and right chassis 16a, 16b, the coupling frame 39 is slid into the guide groove 49 from right to left so as to insert the shaft 35 on the left side into the bearing 42 as shown in a two-dot chain line in Fig 9, and also so as to insert the tip end 39a of the coupling frame 39 into the coupling hole 44. In order to insert the tip end 39a of the coupling frame 39 into the coupling hole 44, the tip end 39a comes into contact with the taper of the locking pawl 46 of the internal cutting edge disengaging button 45, thus pushing down the button 45 against the elasticity of the spring 47. When the tip end 39a passes over the locking pawl 46, the button 45 automatically moves upwardly by the action of spring 47 so as to engage the locking pawl 46 against the internal side of the tip end 39a of the coupling frame 39 and effect the locking operation. As shown in Fig 3, the housing 38 of the internal cutting edge unit 20 conforms to the housing receiving portion 41 of the right chassis 16b in such a way that the gear 40b within the housing 38 is adapted to be interlocked with the gear 31 of the drive transmitting means 22. In the engaged condition of the internal cutting edge unit 20, the coupling frame 39 is inserted into the coupling hole 44, and also, the locking pawl 46 is locked into a slip preventing condition, so that regulation of the vertical, longitudinal, right and left movements of the internal cutting edge unit 20 is achieved. In this engaged condition, since the internal cutting edge unit 20 is integrally provided with an internal cutting edge holder 37, the internal cutting edge holder 37, and especially the housing 38, may be grasped by hand; it may thus be safely mounted without the need for direct contact with the spiral cutting edge of the rotary internal cutting edge 19. The engaged condition is easily achieved by sliding the coupling frame 39 onto the guide frame 48. Cleaning of the razor may be effected with the rotary internal cutting edge 19 engaged on the internal cutting edge driving chassis 16. As shown in Fig 10(a), a cleaning brush 50 comprises brush hair 52 of normal stiffness and brush hair 53 of greater stiffness, both provided on a handle 51. An arcuate concave portion 53a, shaped to correspond with the circumference of the rotary internal cutting edge 19, is cut from the edge of the brush hair 53. As shown in Fig 10(b), when the concave portion 53a of the harder brush hair 53 is applied to the surface of the rotary internal cutting edge 19 at one axial end, and the brush slid towards the other end, the brush hair 53 slides along the spiral-shaped edge groove from the one end of the cutting edge 19 to the other, forcing the cutting edge to be rotated so as to remove flocks. A projecting portion 51a is provided on the handle 51 of the cleaning brush 50, positioned above the harder brush 53, so as to prevent finger slippage. Therefore, safe cleaning may be effected by sliding the manually held brush along the rotary internal cutting edge 19, without injuring the fingers on the spiral-shaped cutting edge, because the fingers on the handle 51 are prevented from sliding in the direction of the spiral-shaped cutting edge by the finger-nonskid projecting portion 51a. In order to clean the rotary internal cutting edge 19, remove it or replace it with a new one, the internal cutting edge disengaging button 45 is lowered against the elastic force of spring 47, after the external cutting edge 7 together with the holder 8 has been disengaged from the top portion of the main body case 1. The locking pawl 46 is drawn downwardly out from the internal side of the tip end 39a of the coupling frame 39. The whole internal cutting edge unit 20 is then slid towards the right, so that the internal cutting edge unit 20 may be disengaged from the internal cutting edge driving chassis 16. In Fig 3 and Fig 7, the internal cutting edge driving chassis 16 has front and back supporting arms 54, which are elastically deformable in the vertical direction only, at the right and left ends of a motor holder 23 made of a plastics material. The integral supporting arms project horizontally in the right and left directions. The end 54a of each support arm 54 is fixedly engaged with a concave portion 55 provided in the internal wall of the main body case 1, so that the whole internal cutting edge driving unit 15 is supported to allow its free vertical motion through the elastic deformation of the right and left supporting arms 54. A compression spring 57 is interposed between the bottom side of the internal cutting edge driving chassis 16 and a spring receiver 56 secured on the side of the main body case 1. The whole internal cutting edge driving unit 15 is adapted so as normally to be urged upwardly on the external cutting edge side by the spring 57, so that the top surface of the rotary internal cutting edge 19 is adapted normally to come into close contact with the internal face of the external cutting edge 7. In Fig 3 and Fig 4, a vertical motion guide means 33, for regulating movement of the internal cutting edge driving unit 15 in the longitudinal and right/left directions, is provided between the motor 21 and the internal face of the main body case 1. As part of the vertical motion guide means 33, front and back position regulating ribs 58 project integrally from each internal face of the front and back cases 1a, 1b so as to guide the motor 21 between the front and back position regulating ribs 58 and inhibit movement of the whole internal cutting edge driving unit 15 in the front/back directions. Also, a longitudinal, elliptical concave portion 60 is formed on the internal face of the back case 1b, and also, a pin 61 projects from the motor holder 23, and the inhibition of movement of the internal cutting edge driving unit 15 in the right/left directions is also ensured by the slidable engagement of pin 61 into the concave portion 60 in the vertical direction only. In Fig 1(a) and Fig 4, it can be seen that within the main body case 1, a means 32 is provided in the lower portion of the motor 21 to detect revolution of the motor 21 from the lower portion output shaft 26. The revolution detecting means 32 has a roll-shaped rotary member 63 to be detected, which in turn has a reflection mark 62 attached at a constant pitch on its periphery. The rotary member 63 engages with the lower portion output shaft 26 of the motor 21. The detecting means 32 also comprises a reflection photosensor 64 with light receiving and emitting elements being juxtaposed in the same direction, the sensor being disposed opposite the rotary member 63 on the circuit basic plate 3 or 4. As shown in Fig 1(a), the photosensor 64 emits light from the light emitting element onto the peripheral face of the rotary member 63, senses the reflected light by means of the light receiving element, and takes a detecting signal 65 of the pulse rate proportional to the revolution number of the motor 21. The detection signal 65 from the revolution detecting means 32 is input into the revolution controlling circuit 66 of the motor 21. The controlling circuit 66 compares the value of the pulse-shaped detection signal 65 taken from the photosensor 64 with the value of a reference signal 67 so as to apply a drive voltage 68, corresponding to the difference between them, to the motor 21, thus maintaining a constant revolution speed. The detection signal 65 output from the revolution number detecting means 32 may be used even in the case where the need for re-charging is indicated by a display lamp or the like, i.e. when the revolution speed of the motor 21 has dropped due to drainage of the chargeable battery 5 in the electric razor, in addition to use of the rotation control of the motor 21. Since movement of the internal cutting edge driving unit 15 is restricted in the longitudinal and right/left direction by the vertical motion guide means 33 described above, the distance between the photosensor 64 and the rotary member 63 to be detected, and the relative position and the relative angle of the photosensor 64 with respect to the central axis of the rotary member 63, remain constant. Therefore, reflected light from the rotary member 63 may normally be received and detected positively by the light receiving element of the photosensor 64, without detection errors. In Fig 4, a switch case 69 is engaged, for its free sliding operation in the vertical direction, on the external face of the front case 1a. A stationary comb cutting edge 70 for side shaving use, and a movable comb cutting edge 71, are provided in the upper portion on the internal face of the switch case 69, so that each cutting edge may project upwardly. Also, a driving piece 72 is provided for receiving the motor output and transmitting it to the movable comb cutting edge 71. The switch case 69 is integrally combined with a moderation plate 73 (see Fig 5), arranged on the inner face of the front case 1a. The moderation plate 73 has a switch leaf spring 74 which is disengageably coupled to the switch terminal on the circuit basic plate 3 through the vertical sliding operation of the switch case 69, and a moderation arm 75 which is fittingly engageable with a moderation projection 59 projecting from the internal face of the front case 1a. The moderation projection 59 forms, in a circular-arc shape as seen from the front face, the front and back motion regulating ribs 58 projecting from the internal face of the front case 1a, as shown in Fig 1(b). It comprises three arc shapes in the vertical direction so as to be used as the front and back motion regulating ribs 58 and the moderation projection 59. The moderation projection 59 may however be provided separately from the front and back motion regulating ribs 58. By the gradual, stepwise, engagement of the moderation arm 75 with the moderation projection 59, the switch case 69 may be positioned and retained in a lower waiting position (switch off position) shown as a solid line in Fig 4; a motor starting position (switch on position) one step higher; a first upper projection using position, one step higher still, wherein the driving piece 72 for side shaving use is engaged with the side shave driving arm 76 on the upper portion output shaft 25 of the motor 21 to transmit a driving force to the movable comb cutting edge 71 and the stationary comb cutting edge 70, and also the rotary internal cutting edge 19 and the external cutting edge 7; and a second upper projection using position for using only the side shaving edges (the movable comb cutting edge 71 and the stationary comb cutting edge 70) one further step on. In Fig 4, reference character S1 shows the movement into the motor starting position from the lower waiting position of the switch case 69; reference character S2 shows the movement from the motor starting position into the first upper projection using position; and reference character S3 shows the movement from the first upper projection using position into the second upper projection using position. In Fig 4 and Fig 5, a locking button 77, for retaining the switch case 69 in the lower waiting position and preventing unexpected upward motion, projects from the hole 78 of the switch case. The locking pawl 79 projecting from the moderation plate 73 engages with the engagement portion (not shown) of the internal face of the front case 1a, as shown in Fig 5, to maintain the lower waiting position of the switch case 69. When the locking button 77 is depressed, the locking pawl 79 is disengaged from the engagement portion of the internal face of the front case 1a, to make it possible to slide the switch case 69 upwardly. In Fig 4 and Figs 11 to 14, a flock storing chamber 80, for storing flocks falling from the internal cutting edge 19, is formed below the rotary internal cutting edge 19 of the main body case 1. As shown in Fig 12, the flock storing chamber 80 is formed as a descent passage, its shape composed of a straight line portion 80b with the internal bottom face 80a being downwardly inclined, and a circular-arc portion 80c formed continuously downwardly therefrom, with an exhaust opening 81 being formed on the lower end side of the circular-arc portion 80c so as to confront the upper portion external side of the back case 1b. In the exhaust opening 81 of the flock storing chamber 80, a shutter 82 is rotatably pivotable by approximately 90 degrees around the shaft 83 between a position (see Fig 12) in which it closes the exhaust opening 81, and an open position (see Fig 13) in which it projects externally from the exhaust opening 81. The shutter 82 is operatively coupled to an opening and closing lever 84 which is provided on the side face of the main body case 1, and slidable in response to an applied force in the vertical direction, so that the shutter 82 can pivotally open and close around the shaft 83 by means of the sliding operation of the lever 84. Within the flock storing chamber 80, a raking blade 85 is pivotable by approximately 124 degrees around the shaft 86 between a waiting position (see Fig 12) and a raking terminal position (see Fig 13). It is to be noted that the shaft 83 and the shaft 86 exist on the same axis. As shown in Fig 12, in the waiting position of the raking blade 85, the frontage 87 for flock inflow use is formed so as to approximately conform in the downward tangent direction of the internal cutting edge circumference between the tip end 85a of the blade 85 and the straight line portion 80b of the internal bottom face 80a of the flock storing chamber 80. When the raking blade 85 is pivoted in the exhaust opening direction from the waiting position, the tip end 85a gradually approaches the circular arc portion 80b of the internal bottom face 80a. When the tip end 85a is pivoted along the circular arc portion 80b as far as the raking terminal position, flock on the internal bottom face 80a is raked out of the exhaust opening 81. In the pivotal range of the tip end 85a between the waiting position and the internal bottom face 80a, the pivoting operation of the raking blade 85 is operated with the opening of the shutter 82, so that the pivoting operation into the exhaust opening direction after that is automatically effected by the use of the restoring force of the spring 88. Thus, as shown in Fig 11 and Fig 14, the torsion coil spring 88 is entrained between the raking blade 85 and the main body case 1. The spring 88 has its one end 88a engaged into a hole 90 provided in the side wall 89 of the flock storing chamber 80 in the initial wound condition. The other end 88b extends through a groove 91 formed in a circular arc shape around the shaft 83 in the side wall 89 and is engaged into a hole 93 provided in the central position between the shaft 86 in the side wall 92 of the raking blade 85 and the tip end 85a. As shown in Fig 12, in the condition where the shutter 82 closes the exhaust opening 81 and the raking blade 85 is in its waiting position, the spring 88 pivotally urges the raking blade 85 upwardly with the spread restoring force, and the basic end 85b of the raking blade 85 comes into pressure contact with the top end 82a of the shutter 82 so as to retain the shutter 82 in a closed condition. In the condition where the shutter 82 is closed, the raking blade 85 is waiting in this manner, and flock which falls from the rotary internal cutting edge 19 flows into the flock storing chamber 80 through the front 87 and is stored. As shown in Fig 12, the gap between the circumference of the rotary internal cutting edge 19 (rotated in the direction of arrow P) and the guide frame 48 on the front side, gradually narrows from the upper part side in the internal cutting edge rotating direction to the lower part side, so that the flow speed of the flocks within the gap may be increased so as to guide the flocks smoothly into the front 87. The raking blade 85 in its waiting position functions to prevent flocks from being scattered externally from the front 87, although the flocks are scattered due to the rolling up of the air stream (shown by arrow M) caused within the flock storing chamber 80 by the rotation of the rotary internal cutting edge 19. In order to exhaust the flocks from within the flock storing chamber 80, the opening and closing lever 84 is slid upwardly so as to pivot open the shutter 82 around the shaft 83. Initially, the raking blade 85 is pressed by the top end 82a of the shutter 82, pivoted in the raking terminal position direction. At a certain point in time (a position where the distance between the movable point A and the stationary point B is at its shortest), when the movable point A, which is the point at which the raking blade 85 is coupled to one end 88b of the spring 88, has arrived at a dead point on a line segment ℓ connecting a stationary point B (which is the point at which the side wall 89 is coupled to the other end 88a of the spring 88) and the center of the shaft 86, as shown in Fig 11, the strongest winding deformation is applied upon the spring 88. Beyond the dead point, the spring 88 deforms and the basic end 85b of the raking blade 85 separates suddenly from the top end 82a of the shutter 82 due to the spread storing force, so as to pivot quickly as far as the raking terminal position. Thus, the flocks within the flock storing chamber 80 are raked externally, with force, from the exhaust opening 81 by the tip end 85a through the quick pivoting of the raking blade 85, and are ideally exhausted without the flocks becoming attached to the edges of the exhaust opening 81 or to fingers grasping the main body case 1. If the raking of the flocks is effected with the exhaust opening 81 directed at a given discarding place such as a trash box, the flocks are not scattered around. The raking blade 85 brings the end 92a of the side wall 92 into contact with the internal face of the shutter 82 in the raking terminal position, as shown in Fig 13. Thus, when the shutter 82 is pivoted closed by lowering the opening and closing lever 84, the raking blade 85 is pressed by the internal face of the shutter 82 so as to effect the returning pivot operation in the waiting position direction. When the spring 88 moves beyond the dead point in the segment ℓ, the raking blade 85 is automatically returned as far as the waiting position by the spread restoring force. In Fig 3, Fig 4, Fig 15 and Fig 16, a charging plug unit 6, to be engaged with the bottom side of the main body case 1, is composed of a plug basic plate 111 fixedly inserted between the front and back cases 1a, 1b (as shown in Fig 4), a stationary type socket 94 which is secured onto the lower face side of the plug basic plate 111 so as to be fed through a power supply cord, and a movable type plug 95 for charging use which is slidably engaged in the right and left directions with the lower face side of the same basic plate 111 so as to be insertable into a wall plug socket or the like and engageable therein. The stationary type socket 94 and the movable type plug 95 may be selectively used. A plug entrance and exit opening 96 is open on one side face of the bottom portion of the front and back cases 1a, 1b and an operation groove 97 is open in the bottom thereof. The plug entrance and exit opening 96 may be opened or closed with a plug cover 98 which is engaged slidably, for vertical operation, above the plug entrance and exit opening 96 on one side face of the front and back cases 1a, 1b. The corner of the front and back cases 1a, 1b, on the side having the opening 96, is formed into a sectional shape curved round in the vertical and longitudinal directions. The lower end portion of the plug cover 98 is also formed round corresponding to the shape of the corner of the front and back cases 1a, 1b (see Fig 15 and Fig 16). Therefore, if a user grasps the main body case 1 tightly, its corners never hurt the user's hands. In Fig 15 and Fig 16, the ]-shaped (at a plane view) plug cutting edge holder 101 is slidably engaged with the lower face of the plug basic plate 111 by a force applied in the right or left directions across both the front and back sides of the stationary socket 94. The plug cutting blade holder 101 is provided at its tip end 101a with a plug cutting edge inserting hole 102, and is provided on the front and back side faces with a hook engagement groove 103. The front and back hook engagement grooves 103 are slidably engaged with the front and back hooks 104 projecting downwardly from the front and back ends of the plug basic plate 111. The movable type plug 95 has a pair of front and back plug cutting edges 99 and a cutting edge stand 100 integrally combined with the basic end thereof. The movable type plug 95 has a plug cutting edge 99 inserted into a plug cutting edge insertion hole 102 of the plug cutting edge holder 101 across both the front and back sides of the stationary type socket 94. An operating knob 105 is mounted on the bottom side of the cutting edge stand 100. The operating knob 105 is integral with the movable type plug 95, is slidable in the right and left directions within the operation groove and is detachably connectible to the concave portions 106, 107 provided in the right and left positions of the operation groove 97. When the operating knob 105 is engaged into the concave portion 107 at the right end of the operation groove 97 as shown in Fig 15 and Fig 16, the movable type plug 95 is in a condition where the plug cutting edge 99 and the plug cutting edge holder 101 are withdrawn, accommodated in the interior of the plug entrance and exit opening 96. The plug cover 98 is slid upwardly to open the plug entrance and exit opening 96 and the operating knob 105 slid leftwards along the operation groove 97 after it has been disengaged from the concave portion 107 of the right end. The plug cutting edge 99 projects from the plug cutting edge insertion hole 102 and the plug entrance and exit opening 96 until the right end within the hook engagement groove 103 reaches the hook 104. Upon further sliding the operating knob 105 to the left, until it is engaged into the concave portion 106 at the left end of the operation groove 97, the plug cutting edge holder 101 is moved together with the plug cutting edge 99 in that direction through the engagement of the hook 104 and the right end of the interior of the hook engagement groove 103. As shown in Fig 17 and Fig 18, the plug cutting edge 99 projects from the plug entrance and exit opening 96 by a given amount, and also, the tip end 101a of the plug cutting edge holder 101 projects from the plug entrance and exit opening 96. In the projected condition of the plug cutting edge holder 101, its flat tip end 101a is set to become co-linear with a straight line portion S continuous above the portion R of the curved corner of the main body case 1. Even when the plug cutting edge 99 projects from the plug entrance and exit opening 96 of the curved corner during charging, the tip end 101a of the plug cutting edge holder 101 may be brought into face contact with the wall plug socket or the like C (see the two-dot chain line in Fig 17) so as to provide a stable and positive charging position. When charging is carried out using the movable type plug 95, the stationary type socket 94 is adapted to be closed by the socket cover 108 which is integrally formed on the bottom side of the cutting edge stand 100. When the movable type plug 95 is withdrawn into the plug entrance and exit opening 96 as before, the operating knob 105 has only to be slid within the groove 97 until it becomes engaged in the concave portion 107 at the right end of the operation groove 97. In Fig 19, a safety switch 109 is disposed within the back case 1b. In safety switch 109, the safety piece 110 projecting from one portion of the back case 1b is held pressed against the internal wall of the holder 8 during the ordinary times when the external cutting edge holder 8 is engaged with the main body case 1, to bring the stationary terminal 109a of the safety switch 109 into contact with the movable terminal 109b so as to close the power supply circuit. The safety piece 110 is released when the external cutting edge holder 8 is disengaged from the main body case 1, and the movable terminal 109b is separated from the stationary terminal 109a to open the power supply circuit. Accordingly, when the external cutting edge holder 8 is disengaged from the safety piece during cleaning for instance, accidental rotation of the rotary internal cutting edge 19 is prevented. Fig 20 and Fig 21 show a stand 112. The stand 112 has concave portions 116, 117, 118 and 119 formed to accommodate, in a leaning posture, an electric razor 113 constructed as described above; a power supply cord 114; a cleaning brush 50; and a case 115 for the electric razor 113. FURTHER EMBODIMENT OF THE INVENTION Although a reflection shape sensor is used as the photosensor 64 of the revolution detecting means 32 of the motor in the above-described embodiment, a rotary member to be detected (63) may be arranged on the output shaft of the motor 21 positioned equidistantly between the light receiving and emitting elements so as to function as a photointerruptor, as shown in Fig 22. A gear or a disc with a slit in it may be used as to rotary member 63 in this case. Also, in the above-described embodiment, the number of the revolutions is detected from the lower output shaft 26 of the motor 21. It may alternatively be detected from the upper output shaft 25. As is clear from the foregoing description, the internal cutting edge driving unit 15 is allowed to move straight only in the vertical direction, guided by the vertical motion guide means 33, so that its movements in the longitudinal and right/left directions are regulated, thus allowing the revolution of the motor 21 to be correctly detected by the detecting means 32. Since the vertical motion guide means 33 uses a motor 21, which is one of the components of the internal cutting edge driving unit 15, to guide an even, flat, smooth motor 21, the guide means 33 does not interfere with the internal cutting edge driving system on the internal cutting edge driving unit 15. Also, since the motor 21 is integrated with the internal cutting edge driving chassis 16, the vertical motion of the rotary internal cutting edge 19 may be guided positively and stably so as to improve the cutting quality of the razor. Furthermore, the internal cutting edge driving unit may be supported on the main body case 1 by a parallelogram link consisting of a pair of front and back supporting arms 54, 54 and 254, 254 in addition to the employment of a pair of springs 257 provided between the main body case 1 and the parallelogram link, as shown in Figs 23 and 24.

Claims: A rotary type electric razor having: a main body case (1), with an arched external cutting mesh (7) at an upper portion thereof; a generally cylindrical internal cutting member (19) rotatably supported on a side frame (64,37,38) by a shaft (35); a drive motor (21) mounted within the main body case (1); transmission means (22) arranged between the drive motor (21) and the internal cutting member (19) so that operation of the drive motor (21) causes rotation of the internal cutting member (19); spring means (54,57,254,257) arranged to bias the internal cutting member (19) against the external cutting mesh (7), and to allow the internal cutting member (19) to be displaced downwardly; characterised in that the internal cutting member (19), the side frame (37), the transmission means (22) and the drive motor (21) form an internal operation unit (15) connected to the main body case (1) through the spring means (54,57,254,257) in such a way that the internal operation unit may be displaced as a single unit relative to the main body case (1). A rotary type electric razor according to claim 1, having motor revolution detecting means (32) which is arranged to detect the rotation of the drive motor. A rotary type electric razor according to claim 2, wherein the motor revolution detecting means (32) comprises a photosensor (64) and a rotary member (63). A rotary type electric razor according to claim 2 or claim 3, having motor speed control means (66) which is arranged to alter the power supplied to the drive motor (21) in accordance with the output (65) of the motor revolution detecting means (32). A rotary type electric razor according to any one of the preceding claims, wherein the transmission means (22) comprises transmission gears (30,31) in a first side of the side frame (164,37,38). A rotary type electric razor according to any one of the preceding claims, wherein the external cutting mesh (7) is held under tension against the internal cutting member (19). A rotary type electric razor according to any one of the preceding claims, wherein the spring means (54,57,254,257) includes a flexible support (54) having one end fixed to the motor (21) or other part of the internal operation unit (15), another end (54a) fixed to the main body case (1), and a flexible hinged part between the ends. A rotary type electric razor according to claim 1, wherein the transmission means (22) comprises first gears (30,31) and second gears (40a,40b) within a first side of the side frame (16b,37,38); the internal cutting member (19) is removably mounted on the internal operation unit (15); and locking means (44,46) are provided at a second side of the side frame (16a,43), opposite the first side, the locking means (44,46) being arranged to lock the internal cutting member (19) in a mounted position in the internal operation unit (15) so that the first gears (30,31) engage the second gears (40a,40b). A rotary type electric razor according to claim 7, wherein the spring means (54,57,254,257) comprises, a further flexible support (254) spaced from and parallel to the first flexible support (54). A rotary type electric razor according to claim 1 in which connecting frames (48) connect first and second sides (38,43) of the side frame in which the internal cutting member (19) is held, to form a rectangular frame.

Inventors: YAMASHITA YASUO, YAMASHITA, YASUO
Applicants: HITACHI MAXELL, KYUSHU HITACHI MAXELL, LTD.
Application year: 1990
Main classification: B26B19
IPC codes: B26B19