the following detailed description is of the best presently contemplated modes of carrying out the invention . this description is not to be taken in a limiting sense , but is made merely for the purpose of illustrating general principles of embodiments of the invention . the scope of the invention is best defined by the appended claims . referring to fig1 - 3 , the present invention provides a detachable shaver head 2 with a locking mechanism for locking the shaver head 2 to a handle base 1 . the handle base 1 is provided with a mounting base 3 for mounting the shaver head 2 . the upper end of the mounting base 3 provides a connection end face between the mounting base 3 and the shaver head 2 , and is provided with a circular groove 4 that has a plurality of spaced - apart bumps 5 provided in the sidewall of the groove 4 . the lower end of the shaver head 2 is provided with a round raised ring 6 that has a corresponding number of l - shaped grooves 9 provided on its outer side wall . the shaving head 2 is rotatable with respect to the mounting base 3 . a locking projection 7 is arranged on the upper end face of the mounting base 3 , and is capable of moving upwardly and downwardly . a sliding switch 10 is provided along the body of the handle base 1 and is connected to the projection 7 and is adapted to move the projection 7 up and down through its sliding motion . the bottom end face of the shaver head 2 is provided with a corresponding locking recess 8 that is aligned to the position of the projection 7 . the shaver head 2 is rotatable with respect to the mounting base 3 . to secure the shaver head 2 to the mounting base 3 , the shaver head 2 is lowered onto the mounting base 3 so that the raised ring 6 enters the circular groove 4 in a manner such that each bump 5 is aligned with a corresponding l - shaped groove 9 so that each bump 5 enters the short leg of the corresponding l - shaped groove 9 . see fig4 . the shaver head 2 is then rotated ( see fig5 ) so that the bumps 5 are now moved along the long leg of the corresponding l - shaped grooves 4 , locking the shaver head 2 to the mounting base 3 . the output shaft 12 of a motor passes through the mounting base 3 to be in transmission connection with the shaver head 2 . next , as shown in fig6 , the sliding switch 10 is moved upwardly to cause the projection 7 to be inserted into the locking recess 8 so as to prevent the shaver head 2 from further rotating with respect to the mounting base 3 . the shaver head 2 can be conveniently and quickly removed by reversing the steps shown in fig4 - 6 . the locking mechanism shown and described in fig1 - 6 is unique in its function because the shaver shaves in a pulling motion , so the shaver head 2 needs to be maintained in place , and not rotate or twist off while the user is shaving . this is especially important if the shaver head 2 is used in connection with a backshaver , since backshavers often have very long handles , so there is a large amount of torque or force that is paced put on this locking joint between the shaver head 2 and the handle base 1 . the present invention also provides a shaver head 2 that has adjustable - angles on multiple planes . this shaver head is more adaptable to different angles on the surfaces of a human body , and provides a better shaving result . the shaver head 2 shown and described above can be provided with the capability of shaving along adjustable - angles on multiple planes . referring now to fig7 and 8 , the shaver head 2 has a rotating base 22 and a head portion 21 . the head portion 21 is formed by two covers 21 a and 21 b that house conventional shaving components , such as a blade 28 and springs 29 , among other components . an elastic band 30 is fitted between the head portion 21 and the rotating base 22 . the rotating base 22 is formed by assembling a front base cover 22 a and a rear base cover 22 b to form a base housing . the lower end of the head portion 21 is provided with a connection shaft 23 for mounting with the rotating base 22 . left and right transverse rotating shafts 24 extend from opposite sides of the connection shaft 23 . corresponding left and right rotating positioning racks 25 are provided in the rotating base 22 at locations that are aligned with the rotating shafts 24 . left and right baffles 26 are arranged on opposite sides of the connection shaft 23 , below the rotating shafts 24 . return springs 27 are positioned in the rotating base 22 below the racks 25 , and are aligned with the two baffles 26 . the rotating base 22 is provided with four return springs 27 , with two return springs 27 positioned in each of the covers 22 a and 22 b , and aligned so that they form left and right pairs . each return spring 27 s positioned to be biased against a corresponding baffle 26 for providing a restoring force to the circumferential rotation of the connection shaft 23 . the left and right rotating positioning racks 25 are arranged on the left and right portions of the inner side of the base cover 22 b , respectively , for rotatably receiving and fixing the corresponding rotating shafts 24 . the connection shaft 23 is cylindrical and capable of rotating on the rotating base 22 along its own circumferential direction . the return springs 27 provide a restoring force to the circumferential rotation of the connection shaft 23 through the baffles 26 . the rotating positioning racks 25 and the rotating shafts 24 are provided , with the rotating shafts 24 driving the shaver head 2 to rotate longitudinally about the rotating positioning racks 25 . the interactions between these components allow the shaver head 2 to have adjustable - angles on multiple planes , so that this shaver head 2 is more adaptable to different angles on the surfaces of a human body , and provides a better shaving result . the handle base 1 and the shaver head 2 of fig1 - 8 can be used with any type of shaver , but can also be used with a backshaver . fig9 - 15b show the use of this shaver 2 and handle base 1 with a backshaver that has a pivoting handle that can be pivoted to different angles , and which has multiple sections to allow the handle to have a varying length . referring to fig9 - 13 , the backshaver has a first handle portion 32 that is pivotably connected to a second handle portion 33 by a joint 31 . the shaver head 2 and the handle base 1 are carried on an upper end of the first handle portion 32 . a movable handle 47 is sleeved outside the second handle portion 33 . a guide rail 48 is provided on the second handle portion 33 in an axial direction , so that the movable handle 47 can move along the guide rail 48 . the joint 31 is illustrated in greater detail in fig1 - 15b . the joint 31 allows for the angle between the handle portions 32 and 33 to be adjusted on a lock - step basis to any angle between zero degrees and a maximum angle ( e . g ., 135 degrees ), and then to be retained securely at the selected angle . the joint 31 includes a first joint housing 61 and a second joint housing 62 that are pivotably secured together to be pivotable with respect to each other . a circle of inner teeth 34 is arranged on a connection face between the first handle portion 32 and a connection end of the second handle portion 33 . two semi - circular blocks 57 are retained inside the first joint housing 61 , and each block 57 has one group of raised teeth 36 that encircles a driving block 35 . each group of raised teeth 36 is adapted to be meshed inside the inner teeth 34 . return springs 37 are arranged between the blocks 57 so that the two opposite groups of raised teeth 36 can be rotated with respect to the inner teeth 34 . this rotation is accomplished with the blocks 57 pushed against each other against the bias of the return springs 37 , so that the groups of raised teeth 36 can be rotated and meshed into different groups of corresponding inner teeth 34 . a circle of inner limiting teeth 38 is arranged on the other surface of the first handle portion 32 . a raised tooth plate 39 is provided inside the inner limiting teeth 38 ( see fig1 a and 14b ), and the raised tooth plate 39 is able to move up and down , so that the raised tooth plate 39 is limited in movement inside the inner limiting teeth 38 to be meshed with the inner limiting teeth 38 , or separated from the inner limiting teeth 38 the driving block 35 is secured to the raised tooth plate 39 , and the middle part of the driving block 35 is hollow . the raised tooth plate 39 is a generally round panel , and the edge of the raised tooth plate 39 is provided with a tooth profile that is adapted to be fitted with the inner limiting teeth 38 . thus , the raised teeth 36 move along the inner teeth 34 when force is applied to pivot the handle portions 32 and 33 . the return springs 37 exert pressure along the raised teeth 36 , causing the lock - step turning of the joint 31 . this is possible because the teeth on the raised tooth plate 39 are disengaged from the inner limiting teeth 38 ( as shown in fig1 b ). the outer side face of the first handle portion 32 is provided with an on switch that comprises a button 41 and a push rod 42 . the push rod 42 is positioned inside the hollow part of the driving block 35 . the output end of the push rod 42 is connected with an actuating rod 43 which is vertically connected with the raised tooth plate 39 . the button 41 drives the raised tooth plate 39 to move up and down through the push rod 42 and the actuating rod 43 . an off switch 44 is arranged on the outer side face of the second handle portion 33 , and the off switch 44 is vertically connected to the raised tooth plate 39 to enable the raised tooth plate 39 to move up and down . two sets of raised sub - teeth 45 are carried on the blocks 57 . the two raised sub - teeth 45 are coupled to each other through the return springs 37 , the outer side faces of both raised sub - teeth 45 are provided with tooth profiles that are adapted to be inserted into corresponding slots in the second joint housing 62 ( see fig1 ). this provides a locking force so that the block 57 remains stationary relative to the second joint housing 62 while the first handle portion 32 and the teeth 34 move around the teeth 36 and the block 57 . a fixing cover 49 is provided outside the on switch for fixing the button 41 of the on switch on the outer end face of the driving block 45 . similarly , another cover 46 is provided outside the off switch 44 for fixing the switch 44 on the opposite end face of the driving block 35 . a retainer piece 53 is provided between the cover 46 and the second joint housing 62 , and has a bore which receives a portion of the driving block 35 and the switch 44 , so as to align and retain the switch 44 within the joint 31 . a washer 51 is provided between the raised tooth plate 39 and the teeth 34 and 36 . the washer 51 enables the push rod 42 to slide in and out of it , thereby creating a locking function . in addition , the washer 51 will keep the push rod 42 in complete alignment within the joint 31 so when either side of the lock button 41 is pushed , it will cause the joint to lock or unlock . the joint 31 works based on the following basic principles . first , as the inner teeth 34 and the raised teeth 36 rotate with respect to each other , the relative rotation of the first handle portion 32 and the second handle portion 33 is a click - type rotation which provides a lock - step , so that a continuous rotation ( i . e ., with no lock step ) is avoided . this allows the user to accurately select the desired angle between the handle portions 32 and 33 . second , the raised tooth plate 39 and the inner limiting teeth 38 are configured so that the raised tooth plate 39 can move up and down through actuation of the on switch and the off switch 44 ; as a result , the raised tooth plate 39 can enter into or be separated from the inner limiting teeth 38 , thereby limiting the relative rotation between the first handle portion 32 and the second handle portion 33 . this allows the joint to be locked at the desired angle . fig1 a shows the two handle portions 32 and 33 oriented at a maximum angle of about 135 degrees , with the two ends 59 of the handle portions 32 , 33 acting as stop members to prevent the handle portions 32 , 33 from being pivoted beyond that maximum angle . in addition , the movable handle 47 is sleeved outside the second handle portion 33 , so that the length of the second handle portion 33 can be adjusted . while the description above refers to particular embodiments of the present invention , it will be understood that many modifications may be made without departing from the spirit thereof .