Patent Publication Number: US-6701700-B2

Title: Lawnmower-attached edge trimmer apparatus

Description:
RELATED APPLICATION 
     This application is a divisional application of my prior application Ser. No. 09/612,993, filed Jul. 10, 2000, now U.S. Pat. No. 6,434,920. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to powered edge trimmer devices and, more particularly, to edge trimmer devices attached to power lawnmowers. 
     2. Description of the Prior Art 
     When grass is cut, it is often desirable to trim edges of sidewalks, driveways, and the like. Currently, three types of edge trimmers are known in the prior art: a first has manually operated blades; a second has a power-driven blade in a separate and distinct edge trimmer device; and a third employs an edge trimmer device in conjunction with a power-driven lawnmower. With particular attention being paid to the edge trimmers associated with power-driven lawnmowers, throughout the years, a number of innovations have been developed, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 3,686,839; 3,789,591; 4,378,668; 4,551,967; and 4,718,221. More specifically, each of U.S. Pat. Nos. 3,686,839 and 4,551,967 discloses an edge trimmer associated with a lawnmower wherein the edge trimmer is powered by the lawnmower by using a drive belt. It is well known that drive belts stretch and crack with age. Moreover, the drive belt must be used with accompanying pulleys. To eliminate the complexities associated with the use of drive belts, it would be desirable if a lawnmower-attached edge trimmer device could operate without using a drive belt. 
     U.S. Pat. No. 3,789,591 discloses a power lawnmower having an auxiliary flexible drive shaft for an edger head. A separate and distinct drive disk is provided above the lawnmower blade on the drive shaft. A spring-biased driven friction wheel is selectively placed in frictional contact with the drive disk. The friction wheel itself is part of an assembly which is pivotally connected to the body of the lawnmower. To avoid the use of a spring (which may fatigue) and to avoid the use of a pivoted connection (which may need regular lubrication), it would be desirable if a lawnmower-powered edge trimmer does not operate by using a spring or a pivoted connection assembly. 
     U.S. Pat. No. 4,378,668 discloses a lawnmower-powered edge trimmer which employs a plurality of whip blades which are kept in constant motion even when the blades are not being used for trimming. When retractable guards are retracted, the whip blades are permitted to extend outward to be used for trimming. When the retractable guards are returned to their original positions, the whip blades are once again prevented from trimming. It is wasteful of energy to keep whip blades in constant rotation even when they are not being used for trimming. For this reason, it would be desirable if a lawnmower-powered edge trimmer does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming. 
     U.S. Pat. No. 4,718,221 an edger and trimmer that is carried by a lawnmower body, but the lawnmower engine does not power the cutting action of the edger and trimmer. More specifically, a cutting disk that is selectively raised or lowered by an operator. When the cutting disk is raised, it does not contact the ground. However, when the cutting disk is lowered, the cutting disk contacts the ground and trims the grass as a result of the lawnmower being pushed along the ground by an operator. No power is tapped from the lawnmower engine to be sent to the cutting blades. Some grass will not readily be cut by a relatively slow moving cutting disk as described above that is not powered by the lawnmower engine. 
     Still other features would be desirable in a lawnmower-attached edge trimmer apparatus. For example, there are many lawnmowers currently in use that do not contain edge trimmer features. In this respect, it would be desirable if a conventional lawnmower could be retrofitted to provide a lawnmower-powered edge trimmer. With respect to retrofitting, conventional lawnmowers come in a variety of sizes. More specifically, the circumferences of the housings for the cutting blades of lawnmowers may differ from one lawnmower to another. In this respect, it would be desirable if a lawnmower-attached edge trimmer apparatus that is retrofitted to a lawnmower could be adjusted to a variety of sizes of lawnmower housings. 
     Thus, while the foregoing body of prior art indicates it to be well known to use lawnmower-attached edge trimmer devices, the prior art described above does not teach or suggest a lawnmower-attached edge trimmer apparatus which has the following combination of desirable features: (1) does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming; (2) can be retrofitted to a conventional lawnmower; (3) can be adjusted to a variety of sizes of lawnmower housings; (4) has a manually controlable connect/disconnect between the attached auxilliary trimmer apparatus and the main lawnmower drive; and (5) includes easy adjustment of the angular orientation of the attached trimmer cutting blades or filaments to conveniently control the width of cut of the auxilliary cutting apparatus. The foregoing desired characteristics are provided by the unique lawnmower-attached edge trimmer apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident. 
     SUMMARY OF THE INVENTION 
     To achieve the foregoing and other advantages, the present invention, briefly described, provides an edge trimmer apparatus attached to a lawnmower which has a drive shaft and which has a blade housing having a lower housing wall, wherein the drive shaft rotates around a longitudinal axis. The lawnmower-attached edge trimmer apparatus includes a combined flywheel and blade assembly which includes a flywheel portion connected to the lawnmower drive shaft. A plurality of blade members extend radially out from the flywheel portion. An attachment assembly is connected onto portions of the lower housing wall of the blade housing. A trimmer assembly is attached to the attachment assembly. The trimmer assembly includes a bearing portion connected to the attachment assembly, a rotatable shaft assembly received by the bearing portion, a driven wheel connected to a proximal end of the rotatable shaft assembly, and a trimmer blade connected to a distal end of the rotatable shaft assembly. A protective shroud is connected to the attachment assembly. 
     The rotatable shaft assembly is adjustable along its longitudinal axis. More specifically, the rotatable shaft assembly includes a first segment which carries the driven wheel. A second segment of the rotatable shaft assembly carries the trimmer blade. A length-adjustment assembly is connected between the first segment and the second segment. 
     The blade members lie in a blade plane. The flywheel portion includes a driving surface which lies in a driving plane. The driving plane is spaced apart from the blade plane longitudinally along the longitudinal axis by a clearance distance. 
     The attachment assembly includes a first clamp assembly attachable to a first portion of the lower housing wall of the blade housing. The first clamp assembly includes a first U-shaped bracket member which slips over a portion of the lower housing wall of the blade housing. A set of nuts and bolts connect the first U-shaped bracket member to the lower housing wall. The first U-shaped bracket member includes a pair of bearing-receiving apertures for receiving the bearing portion of the rotatable shaft assembly. 
     The attachment assembly can further include a second clamp assembly attached to a second portion of the lower housing wall of the blade housing. An adjustable-length strut assembly can be connected between the first clamp assembly. The second clamp assembly includes a second U-shaped bracket member which slips over a portion of the lower housing wall of the blade housing. A set of nuts and bolts for connect the second U-shaped bracket member to the lower housing wall. 
     The adjustable-length strut assembly includes a pair of first telescopic members connected to the first clamp assembly and a pair of second telescopic members connected to the second clamp assembly. 
     In accordance with additional embodiments of the invention, the edge trimmer apparatus includes a drive member supported by the drive shaft above the blade housing. A power transmission assembly is connected to the drive member and is supported by the blade housing. A trimmer blade unit is supported by and driven by the power transmission assembly. 
     In accordance with another embodiment of the invention, the drive member can be a drive pulley supported by the drive shaft. The power transmission assembly includes a gear-containing transmission unit supported by the lower housing wall of the blade housing. An endless belt is connected between the drive pulley and the gear-containing transmission unit, and a trimmer blade unit is supported by and driven by the gear-containing transmission unit. The gear-containing transmission unit includes a first bevel gear assembly connected to the lower housing wall of the blade housing. The first bevel gear assembly supports and drives the trimmer blade unit. A pulley/gear transmission support bracket is supported by the first bevel gear assembly. The pulley/gear transmission support bracket includes a vertical first bracket portion and a horizontal second bracket portion. The vertical first bracket portion is connected to the first bevel gear assembly. A driven pulley is supported in an overhead manner by the horizontal second bracket portion of the pulley/gear transmission support bracket. A gear-driving shaft is connected to the driven pulley, and a second bevel gear assembly is connected to the gear-driving shaft. The second bevel gear assembly is enmeshed with the first bevel gear assembly. 
     The first bevel gear assembly includes a bearing portion connected to the lower housing wall of the blade housing. A gear shaft portion is retained by the bearing portion and supports the trimmer blade unit. A first bevel gear is supported by the gear shaft portion. A protective shroud is connected to the vertical first bracket portion of the pulley/gear transmission support bracket. 
     In accordance with another embodiment of the invention, the drive member can be a ring gear. In this case, the power transmission assembly includes a longitudinal drive shaft assembly supported by the blade housing. The longitudinal drive shaft assembly includes a geared end enmeshed with the ring gear. A shaft portion extends horizontally from the geared end, and a coupler end is located at a distal end of the shaft portion. The coupler end is connected to the trimmer blade unit. A bearing jacket jackets the shaft portion of the longitudinal drive shaft assembly. Jacket-support brackets support the bearing jacket and are supported by the blade housing. The coupler end of the longitudinal drive shaft assembly includes a well portion. 
     In accordance with another embodiment of the invention, the trimmer blade unit includes a blade, a rigid key-carrying portion is connected to the blade, and a key portion is received in the well portion of the longitudinal drive shaft assembly. The rigid key-carrying portion includes external threads. A threaded lock nut is supported by the bearing jacket and engages the external threads of the rigid key-carrying portion of the trimmer blade unit for locking the longitudinal drive shaft assembly to the trimmer blade unit. A spring assembly can be placed between the trimmer blade unit and the longitudinal drive shaft assembly for urging the trimmer blade unit toward the longitudinal drive shaft assembly. 
     In accordance with another embodiment of the invention, the trimmer blade unit includes a blade, a blade-retaining shaft supports the blade, and a shaft-bearing assembly supports the blade-retaining shaft. A flexible power cable assembly is connected to the blade-retaining shaft for connection to the longitudinal drive shaft assembly. A hinged trimmer-unit-support assembly is connected to the lower housing wall of the blade housing and supports the shaft-bearing assembly. The blade lies in a blade plane. 
     The flexible power cable assembly includes a proximal end connected to the blade-retaining shaft. A flexible cable portion is connected to the proximal end, and a key portion is connected to the flexible cable portion. The key portion is received in the well portion of the longitudinal drive shaft assembly. The longitudinal length of the well portion of the shaft portion of the longitudinal drive shaft assembly is equal to or greater than the combined length of the key portion and the flexible cable portion of the flexible power cable assembly. 
     The hinged trimmer-unit-support assembly includes a fixed support member connected to the lower housing wall of the blade housing, a movable support member that supports the shaft-bearing assembly, and a hinge pin connecting the fixed support member and the movable support member together, whereby the movable support member can be rotated around the fixed support member. An orientation lock is connected between the fixed support member and the movable support member for locking the fixed support member and the movable support member at a selected angular orientation. 
     In accordance with yet another embodiment of the invention, a manually actuatable control cable is attached through suitable means to the drive shaft supported on the lawnmower housing between the drive wheel and the auxiliary trimmer apparatus to control engagement and disengagement thereof. Additionally, angular orientation adjustment means for the auxiliary trimmer assembly relative to the main rotation shaft axis of the lawnmower are provided to assure precise control of the width of cut afforded by the auxiliary trimmer apparatus. 
     The above brief description sets forth rather broadly the more important features of the present invention in order that the detailed description thereof that follows may be better understood, and in order that the present contributions to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will be for the subject matter of the claims appended hereto. 
     In this respect, before explaining several preferred embodiments of the invention in detail, it is understood that the invention is not limited in its application to the details of the construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood, that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception, upon which disclosure is based, may readily be utilized as a basis for designing other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     It is therefore an object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which has all of the advantages of the prior art and none of the disadvantages. 
     It is another object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which may be easily and efficiently manufactured and marketed. 
     It is a further object of the present invention to provide a new and improved lawnmower-attached edge trimmer apparatus which is of durable and reliable construction. 
     An even further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such lawnmower-attached edge trimmer apparatus available to the buying public. 
     Still yet a further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which can operate without using a drive belt. 
     Still another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus that does not operate by using a spring or a pivoted connection assembly. 
     Yet another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming. 
     Even another object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus that can be retrofitted to a conventional lawnmower. 
     Still a further object of the present invention is to provide a new and improved lawnmower-attached edge trimmer apparatus which can be adjusted to a variety of sizes of lawnmower housings. 
     These together with still other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof. Such description makes reference to the annexed drawing wherein: 
     FIG. 1 is a perspective view showing a first embodiment of the lawnmower-attached edge trimmer apparatus of the invention attached to a lawnmower. 
     FIG. 2 is a side view of the embodiment of the lawnmower-attached edge trimmer apparatus shown in FIG. 1, also showing a path of cutting of the trimmer blade below ground level. 
     FIG. 3 is a partial cross-sectional view of the embodiment of the lawnmower-attached edge trimmer apparatus of FIG. 1 taken along line  3 — 3  thereof. 
     FIG. 4 is a partial bottom view of the embodiment of the invention shown in FIG. 3 taken along line  4 — 4  thereof. 
     FIG. 5 is an exploded perspective view of the embodiment of the invention shown in FIG.  4 . 
     FIG. 6 is a partial top view of a second embodiment of the invention. 
     FIG. 7 is a partial side view of the embodiment of the invention shown in FIG.  6 . 
     FIG. 8 is a partial side view of a third embodiment of the invention. 
     FIG. 9 is an enlarged partial perspective exploded view of a coupling employed in the embodiment of the invention shown in FIG.  8 . 
     FIG. 10 is a partial elevational view of a fourth embodiment of the invention. 
     FIG. 11 is an enlarged partial perspective exploded view of a coupling employed in the circled region  11  of FIG.  10 . 
     FIG. 12 is a partial elevational view of a fifth alternatively preferred embodiment of the invention showing transmission means for selectively manually controlling the operation of the embodiment of FIGS. 10 and 11. 
     FIG. 13 is a cross-sectional view taken along line  13 — 13  of FIG.  12 . 
     FIG. 14 is a partial elevational view of a sixth alternatively preferred embodiment of the invention showing a simplified power transmission assembly coupled between the trimmer assembly and a friction drive assembly with the driven member of the transmission assembly being mounted above the drive assembly. 
     FIG. 15 is a partial elevational view of a variation of the sixth alternatively preferred embodiment of the invention showing the driven member of the transmission assembly being mounted below the drive assembly. 
     FIG. 16 is a top plan view of a lawnmower including a seventh alternatively preferred embodiment of the invention wherein the trimmer assembly includes means for adjusting the angular relation of the trimmer assembly in azimuth relative to the lawn mower housing. 
     FIG. 17 is an elevational view of the alternative embodiment of FIG.  16 . 
     FIG. 18 is a partial elevational view of the alternatively preferred embodiment of FIGS. 16 and 17 invention showing power transmission assembly and its bracket assembly. 
     FIG. 19 is a partial bottom view of the alternatively preferred embodiment of FIGS. 16-18. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the drawings, a number of embodiments of a new and improved lawnmower-attached edge trimmer apparatus embodying the principles and concepts of the present invention will be described. 
     Turning to FIGS. 1-5, there is shown a first embodiment of the lawnmower-attached edge trimmer apparatus of the invention generally designated by reference numeral  10 . In its preferred form, lawnmower-attached edge trimmer apparatus  10  includes is attached to a lawnmower  11  which has a drive shaft  12  and which has a blade housing  13  having a lower housing wall  17 . The drive shaft  12  rotates around a longitudinal axis  15 . A combined flywheel and blade assembly  14  includes a flywheel portion  16  connected to the lawnmower drive shaft  12 , and a plurality of blade members  18  extend radially out from the flywheel portion  16 . An attachment assembly is connected onto portions of the lower housing wall  17  of the blade housing  13 . A trimmer assembly is attached to the attachment assembly. The trimmer assembly includes a bearing portion  34  connected to the attachment assembly, a rotatable shaft assembly  36  received by the bearing portion  34 , a driven wheel  38  connected to a proximal end  40  of the rotatable shaft assembly  36 , and a trimmer blade unit  42  connected to a distal end  44  of the rotatable shaft assembly  36 . A protective shroud  46  is connected to the attachment assembly. 
     The rotatable shaft assembly  36  is adjustable along its longitudinal axis  48 . More specifically, the rotatable shaft assembly  36  includes a first segment  50  which carries the driven wheel  38 . A second segment  52  of the rotatable shaft assembly  36  carries the trimmer blade unit  42 . A length-adjustment assembly  54  is connected between the first segment  50  and the second segment  52 . 
     The blade members  18  lie in a blade plane  22 . The flywheel portion  16  includes a driving surface  20  which lies in a driving plane  24 . The driving plane  24  is spaced apart from the blade plane  22  longitudinally along the longitudinal axis  15  by a clearance distance  26 . 
     The attachment assembly includes a first clamp assembly  33  attachable to a first portion of the lower housing wall  17  of the blade housing  13 . The first clamp assembly  33  includes a first U-shaped bracket member  35  which slips over a portion of the lower housing wall  17  of the blade housing  13 . A set of nuts  37  and bolts  39  connect the first U-shaped bracket member  35  to the lower housing wall  17 . The first U-shaped bracket member  35  includes a pair of bearing-receiving apertures  41  for receiving the bearing portion  34  of the rotatable shaft assembly  36 . 
     The attachment assembly can further include a second clamp assembly  56  attached to a second portion of the lower housing wall  17  of the blade housing  13 . An adjustable-length strut assembly  58  can be connected between the first clamp assembly  33 . The second clamp assembly  56  includes a second U-shaped bracket member  57  which slips over a portion of the lower housing wall  17  of the blade housing  13 . A set of nuts  59  and bolts  61  for connect the second U-shaped bracket member  57  to the lower housing wall  17 . 
     The adjustable-length strut assembly  58  includes a pair of first telescopic members  60  connected to the first clamp assembly  33  and a pair of second telescopic members  62  connected to the second clamp assembly  56 . 
     To retrofit a lawnmower  11  with the lawnmower-attached edge trimmer apparatus  10  of the invention. An original lawnmower blade is first removed from the drive shaft  12  of the lawnmower  11 . Then, the combined flywheel and blade assembly  14  is attached to the drive shaft  12  and is secured thereto by washer  63  and a nut  65 . An aperture is drilled into a portion of a lower housing wall  17  which is large enough for receiving the bearing portion  34  of the rotatable shaft assembly  36  with a tight fit. The first U-shaped bracket member  35  is slipped over the lower housing wall  17 , and the bearing-receiving apertures  41  are placed in registration with the drilled hole in the lower housing wall  17 . Then, the rotatable shaft assembly  36  is passed through the bearing-receiving apertures  41  and the drilled hole in a proximal to distal manner so that the bearing portion  34  of the rotatable shaft assembly  36  is placed in a tight fit with the lower housing wall  17  and the bearing-receiving apertures  41 . Then, the driven wheel  38  is attached to the proximal end  40  of the first segment  50  of the rotatable shaft assembly  36 , and the trimmer blade unit  42  is attached to the distal end  44  of the second segment  52  of the rotatable shaft assembly  36 . A nut  67  is used to attached the driven wheel  38  to the first segment  50 , and a washer  69  and nut  71  are used to attach the trimmer blade unit  42  to the second segment  52  of the rotatable shaft assembly  36 . 
     Bolt-receiving apertures  73  are present in the first U-shaped bracket member  35 , and bolt-receiving apertures  75  are present in the second U-shaped bracket member  57 . Registrable holes are drilled in the lower housing wall  17 , and bolts  39  are placed through those holes and the bolt-receiving apertures  73 . The nuts  37  are used to secure the first U-shaped bracket member  35  to the lower housing wall  17 . Similarly, additional registrable holes are drilled in the lower housing wall  17 , and bolts  61  are placed through those holes and the bolt-receiving apertures  75 . The nuts  59  are used to secure the second U-shaped bracket member  57  to the lower housing wall  17 . 
     The first telescopic members  60  and the second telescopic members  62  of the adjustable-length strut assembly  58  are adjusted to span the distance between the first U-shaped bracket member  35  and the second U-shaped bracket member  57 . The adjustable-length strut assembly  58  serves to stabilize and brace the presence of the trimmer assembly on the lawnmower  11 . 
     After the lawnmower-attached edge trimmer apparatus  10  is installed on the lawnmower  11 , the apparatus is ready for operation. Under circumstances when the trimmer blade unit  42  is not in use, the length-adjustment assembly  54  is adjusted so that the first segment  50  is pulled toward the second segment  52 . When this is done sufficiently, the driven wheel  38  is pulled off of the driving surface  20  of the combined flywheel and blade assembly  14 . When this occurs, the trimmer blade unit  42  is not is driven. 
     On the other hand, when the trimmer assembly is to be used to trim a sidewalk, driveway, and the like, the length-adjustment assembly  54  is adjusted in a reverse manner so that the first segment  50  is moved away from the second segment  52 . When this is done a sufficient amount, the driven wheel  38  is moved into contact with the driving surface  20 . In this orientation, when the motor of the lawnmower  11  is in operation, and the drive shaft  12  is rotating, the combined flywheel and blade assembly  14  is in rotation, and the driven wheel  38  is turned by the driving surface  20  of the combined flywheel and blade assembly  14 . Rotation of the driven wheel  38  is transmitted through the rotatable shaft assembly  36  to the trimmer assembly causing the trimmer blade unit  42  to rotate. 
     As shown in FIG. 2, the trimmer blade unit  42  has a sufficiently long radius such that distal portions of the trimmer blade unit  42  move below ground level  51 . When this occurs, the trimmer blade unit  42  can perform its trimming function for sidewalks, driveways, and the like. The depth of penetration of the trimmer blade unit  42  into the ground is indicated by curved broken line  53 . 
     The mechanical implementation of the length-adjustment assembly  54  can take a variety of known forms. For example, the first segment  50  and the second segment  52  of the rotatable shaft assembly  36  can be in a form of a well known split shaft. Different lockable positions of the split shaft can be employed. Alternatively, the first segment  50  can be in the form of a threaded bolt, and the second segment  52  can be in the form of a complementary threaded well. A lock nut can be used to lock the first segment  50  into a selected adjustment position with respect to the second segment  52 . 
     It will be appreciated that the combined flywheel blade assembly may be dispensed with in favor of a separate flywheel and blade mounted one above the other on shaft  12  of mower  11 . In such optional arrangement, the flywheel preferably will be mounted above the adjustable length strut assembly  58  with the usual lawn mower blade being mounted below the strut assembly as viewed for example in FIG.  3  and with due consideration given to a required lengthening of drive shaft  12 . 
     Further, if desired, a flexible shaft assembly can be interposed between the rotatable shaft assembly  36  and the trimmer blade unit  42 . When this is done, a handheld trimmer assembly can be provided. 
     In accordance with additional embodiments of the invention, the edge trimmer apparatus includes a drive member supported by the drive shaft  12  above the blade housing  13 . A power transmission assembly is connected to the drive member and is supported by the blade housing  13 . A trimmer blade unit  42  is supported by and driven by the power transmission assembly. 
     As shown in FIGS. 6 and 7, the drive member can be a drive pulley  80  supported by the drive shaft  12 . The power transmission assembly includes a gear-containing transmission unit supported by the lower housing wall  17  of the blade housing  13 . An endless belt  82  is connected between the drive pulley  80  and the gear-containing transmission unit, and a trimmer blade unit  42  is supported by and driven by the gear-containing transmission unit. The gear-containing transmission unit includes a first bevel gear assembly  87  connected to the lower housing wall  17  of the blade housing  13 . The first bevel gear assembly  87  supports and drives the trimmer blade unit  42 . A pulley/gear transmission support bracket is supported by the first bevel gear assembly  87 . The pulley/gear transmission support bracket includes a vertical first bracket portion  85  and a horizontal second bracket portion  86 . The vertical first bracket portion  85  is connected to the first bevel gear assembly  87 . A driven pulley  88  is supported in an overhead manner by the horizontal second bracket portion  86  of the pulley/gear transmission support bracket. A gear-driving shaft  89  is connected to the driven pulley  88 , and a second bevel gear assembly  90  is connected to the gear-driving shaft  89 . The second bevel gear assembly  90  is enmeshed with the first bevel gear assembly  87 . 
     The first bevel gear assembly  87  includes a bearing portion  91  connected to the lower housing wall  17  of the blade housing  13 . A gear shaft portion  92  is retained by the bearing portion  91  and supports the trimmer blade unit  42 . A first bevel gear  93  is supported by the gear shaft portion  92 . A protective shroud  46  is connected to the vertical first bracket portion  85  of the pulley/gear transmission support bracket. 
     In using the second embodiment of the invention, when the drive shaft  12  of the lawnmower  11  rotates, the drive pulley  80  also rotates. The rotation of the drive pulley  80  causes the endless belt  82  to rotate which causes the driven pulley  88  to rotate. Rotation of the driven pulley  88  causes the gear-driving shaft  89  to rotate which causes the second bevel gear assembly  90  to rotate. Rotation of the second bevel gear assembly  90  causes the enmeshed first bevel gear  93  of first bevel gear assembly  87  to rotate. Rotation of the first bevel gear  93  causes the gear shaft portion  92  to rotate, and rotation of the gear shaft portion  92  causes the trimmer blade unit  42  to rotate. A lock nut  94  is used to lock the trimmer blade unit  42  onto the gear shaft portion  92  of the first bevel gear assembly  87 . 
     In accordance with the third embodiment of the invention shown in FIGS. 8 and 9, the drive member can be a ring gear  95 . In this case, the power transmission assembly includes a longitudinal drive shaft assembly supported by the blade housing  13 . The longitudinal drive shaft assembly includes a geared end  97  enmeshed with the ring gear  95 . A shaft portion  98  extends horizontally from the geared end  97 , and a coupler end  99  is located at a distal end of the shaft portion  98 . The coupler end  99  is connected to the trimmer blade unit  42 . A bearing jacket  110  jackets the shaft portion  98  of the longitudinal drive shaft assembly. Jacket-support brackets  111  support the bearing jacket  110  and are supported by the blade housing  13 . The coupler end  99  of the longitudinal drive shaft assembly includes a well portion  115 . 
     The trimmer blade unit  42  includes a blade  112 . A rigid key-carrying portion  113  is connected to the blade  112 , and a key portion  114  is received in the well portion  115  of the longitudinal drive shaft assembly. The rigid key-carrying portion  113  includes external threads  119 . A threaded lock nut  116  is supported by the bearing jacket  110  and engages the external threads  119  of the rigid key-carrying portion  113  of the trimmer blade unit  42  for locking the longitudinal drive shaft assembly to the trimmer blade unit  42 . In addition, another lock nut  117  is part of the trimmer blade unit  42  and is used to secure the blade  112  to the rigid key-carrying portion  113  of the trimmer blade unit  42  for locking the longitudinal drive shaft assembly to the trimmer blade unit  42 . spring assembly  118  can be placed between the trimmer blade unit  42  and the longitudinal drive shaft assembly for urging the trimmer blade unit  42  toward the longitudinal drive shaft assembly. The well portion  115  at the end of the longitudinal drive shaft assembly and the key portion  114  of the trimmer blade unit  42  together form a slip shaft. 
     In using the embodiment of the invention shown in FIGS. 8 and 9, power from the drive shaft  12  is transmitted to the ring gear  95  which rotates. The geared end  97  of the longitudinal drive shaft assembly is caused to rotate by the ring gear  95 . The rotation of the geared end  97  is transmitted down the shaft portion  98  to the coupler end  99  and the well portion  115 . The key portion  114  of the trimmer blade unit  42  is caused to rotate by the well portion  115  of the longitudinal drive shaft assembly. The key portion  114  causes the rigid key-carrying portion  113  to rotate which causes the blade  112  to rotate. 
     In accordance with the fourth embodiment of the invention shown in FIGS. 10 and 11, The trimmer blade unit  42  includes a blade  112 . A blade-retaining shaft  128  supports the blade  112 . A shaft-bearing assembly  130  supports the blade-retaining shaft  128 . A flexible power cable assembly  120  is connected to the blade-retaining shaft  128  for connection to the longitudinal drive shaft assembly. A hinged trimmer-unit-support assembly  126  is connected to the lower housing wall  17  of the blade housing  13  and supports the shaft-bearing assembly  130 . The blade  112  lies in a blade plane  143 . 
     The flexible power cable assembly  120  includes a proximal end  138  connected to the blade-retaining shaft  128 . A flexible cable portion  133  is connected to the proximal end, and a key portion  132  is connected to the flexible cable portion  133 . The key portion  132  is received in the well portion  115  of the shaft portion  98  of the longitudinal drive shaft assembly. The longitudinal length of the well portion  115  of the shaft portion  98  of the longitudinal drive shaft assembly is equal to or greater than the combined length of the key portion  132  and the flexible cable portion  133  of the flexible power cable assembly  120 . 
     The hinged trimmer-unit-support assembly  126  includes a fixed support member  140  connected to the lower housing wall  17  of the blade housing  13 , a movable support member  142  that supports the shaft-bearing assembly  130 , and a hinge pin  144  connecting the fixed support member  140  and the movable support member  142  together, whereby the movable support member  142  can be rotated around the fixed support member  140 . An orientation lock  146  is connected between the fixed support member  140  and the movable support member  142  for locking the fixed support member  140  and the movable support member  142  at a selected angular orientation. 
     In using the fourth embodiment of the invention, the blade  112  can be oriented in substantially any angle of orientation ranging from vertical to horizontal. In FIG. 10, the blade  112  is oriented horizontally. In broken lines, a top portion of protective shroud  46  is oriented vertically. This represents an orientation in which the blade  112  is oriented vertically. To change the orientation of the blade  112 , the orientation lock  146  is loosened, the movable support member  142  is rotated around the hinge pin  144  so that the desired angle of orientation between the movable support member  142  and the fixed support member  140  of the hinged trimmer-unit-support assembly  126  is obtained, and the orientation lock  146  is retightened. 
     It is noted that when the movable support member  142  moves toward the fixed support member  140 , the key portion  132  and a distal portion of the flexible cable portion  133  of the flexible power cable assembly  120  move deeper into the well portion  115  of the shaft portion  98  of the longitudinal drive shaft assembly. When the movable support member  142  is substantially parallel to the fixed support member  140 , substantially all of the flexible cable portion  133  of the flexible power cable assembly  120  is retained by the well portion  115  of the shaft portion  98  of the longitudinal drive shaft assembly. 
     It is frequently desired to selectively manually control the operation of the blade  112  relative to the main drive shaft  12 . For this purpose, an auxiliary transmission means may be provided. Turning to FIGS. 12 and 13, there is shown a preferred auxiliary transmission means comprising a manually actuatable “dog clutch” assembly generally indicated by reference numeral  220 . When “dog clutch” assembly  220  is employed, the geared end  97 , rather than being directly fixed to an end of longitudinal shaft  98  as described above, instead is carried on a collet  222  loosely fitted over the end of drive shaft  98  and adapted for limited lateral slidable movement parallel to the central axis of shaft  98  as indicated by arrow  224 . Collet  222  has a radially enlarged flange or shoulder  226  at the end thereof opposite to geared end  97  substantially as shown. A control lever  228  is pivotally supported on housing  13  by means of a pair of spaced upstanding lugs  230 ,  232  and transverse pivot pin  234  to permit pivotal movement of the lever relative to the housing and in the direction of arrow  224 . The bottom end of lever  228  is in the form of a bifurcation  236  entrained about the outer circumferential edge of shoulder  226  of slidable collet  222 . Collet  222 , in turn, is fixed against relative rotation on shaft  98  by a key  240  suitably seated in a known manner in complementary grooves in the bore of the collet and on the outer surface of the shaft  98 , respectively (see FIG.  13 ). The key and key grooves are such to permit slidable movement of collet  222  relative to shaft  98  in the direction of arrow  224 , all of the while securely affixing the collet to the shaft  98  for rotation therewith about the shaft&#39;s central longitudinal axis in a manner believed apparent to those with ordinary skill in this art. As a result of the foregoing arrangement of parts, it will be observed that selective manual movement by an operator (symbolically represented by digit  242 ) of lever  228  will be effective to cause slidable movement of collet  222  on shaft  98  and concomitantly, cause engagement or disengagement of geared end  97  from ring gear  95  as desired without necessarily cutting power to main blade shaft  12 . Thus, in accordance with the present invention, the “dog clutch” assembly  220  of FIGS. 12 and 13, yields increased flexibility of operation by assuring independent control of rotation of the main mower blade and the trimmer blade  112 , and renders even more safe the operation of the disclosed apparatus. 
     FIGS. 14 and 15 show a sixth alternatively preferred embodiment comprising a simplified version of the invention wherein the power transmission assembly comprises a fixed shaft mounted on a bracket assembly supported between the drive wheel assembly and the trimmer assembly. In this alternative embodiment, the power transmission assembly includes a longitudinal drive shaft assembly supported by the blade housing  13 . The longitudinal drive shaft assembly includes at its proximal end a friction drive roller  250  engaging the beveled upper annular surface  252  of friction drive wheel  254  which latter is suitably fixed to shaft  12  for rotation therewith. A shaft portion  98  extends horizontally from the drive roller end, and a bearing block or coupler end  258  is located at the opposed other distal end of the shaft portion  98 . The bearing block or coupler end  258  is suitably connected to the trimmer assembly by means of shaft extension  260  extending through an opening  262  in lower side wall  17 . In this embodiment, the edger assembly is a trimmer assembly of the filament type and preferably includes a hub assembly  264  having the well known flexible filaments  266  extending radially therefrom substantially as shown. The hub assembly, in turn, is coupled to a bushing  268  via fastener  270  which bushing is suitably connected to shaft extension  260  extending through opening  262 . A removable protective shroud  272  for the hub assembly and filaments may optionally be suitably supported on the outer surface of lower side wall  17 . 
     In accordance with this alternative preferred form of the invention, shaft  98  is supported for rotation about its central longitudinal axis by a bracket assembly which includes a proximal bifurcated inboard portion  274 , a central portion  276  and a distal end portion  278 . Bifurcated portion  274  includes first and second flanges  280 ,  282 , respectively, for defining a first journal bearing axis  284  for a first cantilever bearing block  286  orthogonally connected to drive shaft portion  98  whereas distal end portion  278  defines a second journal bearing axis  288  for a second cantilever bearing block  290  orhtogonally connected to drive shaft portion  98  at a longitudinally spaced location substantially as shown. Cantilever bearing blocks  286 ,  290  are suitably journaled to the bracket assembly bifurcated portion and end portion, respectively, so that shaft portion  98  may be supported by the bracket assembly yet be permitted to rotate about axes  284 ,  288 . See also FIG.  19 . The bracket assembly is suitably affixed to the underside of the housing  13  substantially in the position illustrated preferably by a multiplicity of nuts and bolts, or other well known fasteners, (not shown) extending through central portion  276  and the confronting portion of housing  13 . 
     Coupled to shaft portion  98  between drive roller  250  and first cantilever bearing block  286 , via bearing block  292 , is a cable control assembly comprising an upstanding (vertical) post  294 , a spiral compression spring  296 , and a control cable  298  suitably connected to the top end of post  294  through opening  300  in housing  13 . Control cable  298  extends to a conventional ratchet-type cable release control (not shown) mounted on the handle bar or other remote location of the mower so that actuation thereof by an operator is effective selectively to cause up and down movement of bearing block  292  between first and second positions, a first position where spring  296  urges drive roller  250  into engagement with rotating friction wheel surface  252  and a second position where the cable is tensioned sufficiently to compress the spring and cause upward movement of bearing block  292  sufficiently to disengage friction drive roller  250  from drive surface  252 . By the foregoing arrangement, it will be appreciated that the transfer or application of rotational energy between the drive wheel (flywheel)  254  and the trimmer assembly via the power transmission assembly selectively may be manually controlled by an operator of the lawn mower. 
     In FIG. 15, there is shown an arrangement similar to FIG. 14, but for the drive roller  250  on shaft portion  98  being located below the friction drive wheel  301  in engagement with lower beveled annular surface  302 . Hence, selective operation of cable  298  by an operator is effective to cause up and down movement of bearing block  292  between first and second positions, a first position where drive roller  250  is urged into engagement with rotating friction wheel surface  302  against the compressive force of spring  296 , and a second position where the cable is relaxed sufficiently to enable the compression spring to cause downward movement of bearing block  292  sufficiently to disengage the friction drive roller from drive wheel bottom surface  302 . 
     Turning now to FIGS. 16-19 there is illustrated a variation of the embodiment of FIG. 14 or  15  wherein the power transmission assembly and the edger/trimmer assembly are both mounted on the frame of the lawn mower in such a manner as to have an azimuth adjustment capability. Thus, as best seen in FIG. 16, the trimmer assembly, bracket assembly, and cable assembly are adapted for adjustable movement relative to the frame of the mower about the lawnmower&#39;s main central blade rotation axis  15 . In order to accomplish such adjustable movement, a series of arcuate slots at different radial distances from the central axis  15  are provided in the top wall of frame  13 . First arcuate slot  306  located proximal to axis  15  has control cable  298  of the cable assembly extending therethrough. Second and third arcuate slots  308  and  310 , situated at greater radial distances, respectively, from main axis  15  have extending therethrough externally threaded stud bolts  310  preferably attached integrally to central portion  276  of the bracket assembly. Matingly affixed to the upstanding ends of the stud bolts are complementary internally threaded wing nuts  313 . A fourth arcuate slot  314  is provided in the side wall of frame  17  to allow passage of the shaft extension  260  distally located on shaft portion  98 . It will be appreciated that by loosening wing nuts  313 , the entire trimmer assembly and bracket assembly units are capable of being slidingly adjusted within the range defined by arcuate slots  306 ,  308 ,  310  and  314  azimuthly relative to axis  15  and then affixed in place at a desired adjusted angular orientation merely by retightening the wing nuts sufficiently with the extent or range of such movement being indicated for example, by the dashed outline showing the extreme positions of the trimmer edger assembly in FIG.  16 . By azimuthly adjusting the trimmer assembly in accordance with the invention as described above, variations in the width of cut afforded by the trimmer assembly selectively may be controlled, thus creating a more efficient mowing/edging/trimming process. As mentioned above, a protective shroud  272  optionally may be provided as shown by the dashed-line outline in FIG. 17 suitably affixed to the sidewall to protect the hub and filaments of the trimmer assembly. The shroud will be removably mounted so that it may easily be removed and then re-affixed after adjustment of the desired azimuth angle of the trimmer assembly. 
     The components of the lawnmower-attached edger or trimmer apparatus of the invention can be made from inexpensive and durable metal, plastic and other suitable known materials. In this regard, it will be especially advantageous to fabricate all or a portion of gear  95 , geared end  97  or friction drive roller  250  from hard rubber materials or the like as this will help to minimize vibration and noise. 
     As to the manner of usage and operation of the instant invention, the same is apparent from the above disclosure, and accordingly, no further discussion relative to the manner of usage and operation need be provided. 
     It is apparent from the above that the present invention accomplishes all of the objects set forth by providing a new and improved lawnmower-attached edge trimmer apparatus that is low in cost, relatively simple in design and operation, and which may advantageously be used without using a drive belt. With the invention, a lawnmower-attached edge trimmer apparatus is provided which does not operate by using a spring or a pivoted connection assembly. With the invention, an auxiliary cutting apparatus is provided which does not employ trimmer blades that are in constant motion, even when the trimmer blades are not being used for trimming. With the invention, a lawnmower-attached edge trimmer apparatus is provided which can be retrofitted to a conventional lawnmower. With the invention, a lawnmower-attached edge trimmer apparatus is provided which can be adjusted to a variety of sizes of lawnmower housings. 
     The terms “edger” and “trimmer” are used throughout this specification to refer broadly to an assembly attached to a lawnmower for affecting an auxiliary cutting process with respect to that carried out by the main lawnmower blade. Hence, the terms “edger” and “trimmer” are to be construed interchangeably. 
     Thus, while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that many modifications thereof may be made without departing from the principles and concepts set forth herein, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use. 
     Accordingly, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification. 
     Finally, it will be appreciated that the purpose of the annexed Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. Accordingly, the Abstract is neither intended to define the invention or the application, which only is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.