Abstract:
A lawnmower raking attachment comprising a plurality of flexible tines anchored to a tine head held rotatable and lockable between the side arms of a U-shaped frame near the close end. Each tine extending downwardly, having the free end bent forwardly to engage the thatch during the forward travel, having each at least one slidable and rotatable bead. A first and second frame supports with vertical slots having the upper end open to accept pivotally a shaft connecting the open end of the U-shaped frame. Latch arms are disposed pivotally on the frame supports to prevent the shaft to escape from the support slots but allowing to rotate to adopt stable operational or resting positions. Stoppers affixed to the frame supports limit the rotational travel of the U-shaped frame. A finger arm pivoted on one frame side near the shaft engages one stopper and prevents the rake frame from going to the resting position unless is manually disengaged.

Description:
This is a continuation-in-part of application Ser. No. 09/130,028 filed Aug. 6, 1998, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     The well known hand rakes do an excellent job but require extraordinary human effort. Raking the lawn, in addition to cleaning the lawn, improve the aeration of the soil which is very important for a healthy lawn. Modern lawnmowers have powerful suction effect to remove some thatch that is not trapped by the grass or is not too close to the ground. They do not provide the scratching effect necessary to remove trapped thatch and for soil aeration. It has long been recognized the possibility of using an attachment to the lawnmower for raking purposes. U.S. Pat. No. 4,541,230 issued on Sep. 17, 1985 is too complicated for the common home maintenance lawn person. In order for a lawnmower raking attachment to perform an effective raking operation, it must have tines that satisfy two conditions. First they must be very flexible to flex in a longitudinal and transverse directions relative to the travel direction of the lawnmower. Secondly they must be close spaced to be able to carry forward tiny thatches. Satisfying these conditions cause the tines to entangle with each other requiring manual disengagement. In any raking device there is a tendency of the thatch to be hooked by the tines in an accumulative manner requiring manual removal. 
     SUMMARY OF THE INVENTION 
     The principal object of the present invention is to provide a lawnmower raking attachment that overcomes the problems confronted by a lawnmower raking attachment, is simple, of light weight and economical to manufacture. 
     It is also an object of the present invention to provide a lawnmower raking attachment that scratches the soil for thatch removal and aeration. 
     A further object of the present invention is to provide a lawnmower raking attachment that is safe to operate. 
     The present invention provides a plurality of flexible tines anchored to a raking head held rotatably between the two side arms of a U-shaped frame and near its close end. A transverse shaft at the open end of said U-shaped frame pivots in a first and second frame supports. Said first and second frame supports are attached to the forward end of a lawnmower. Stoppers are disposed on said first and second frame supports to limit the rotational travel of said U-shaped frame in the forward and backward directions, allowing said U-shaped frame to adopt a forwardly stable operational position, or an upwardly stable resting position. Said raking head can be rotated and locked into a position to adjust the pressure of said tines on the ground by a first and second thumbscrews. Said tines have their free ends bent to facilitate the engagement of the tines with the thatches. Each tine has at least one heavy slidable bead. When the lawnmower moves forward said plurality of tines scratch the soil loosening the thatches, sucking some or moving some forward where they can be collected. Moving the lawnmower backward disengages the tines from the soil and releases the thatches trapped or hooked by the tines. Said beads allow the tines to be spaced very close without entangling with each other during the raking operation due to the rolling effect among them. Close spacing of tines is very desirable for moving tiny thatch like small leaves during raking operation. In addition said beads prevent any thatch to be hooked beyond the bead making easy their removal by simply moving the lawnmower a little backward. The normal vibration of the lawnmower is transmitted to said beads increasing the penetration of said tines in the lawn surface. Said U-shaped frame can be rotated backward manually and maintained in a resting position by two of said support stoppers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is side elevation view of the lawnmower raking attachment in resting position. 
     FIG. 2 is a side elevation of the lawnmower raking attachment in operative position. 
     FIG. 3 is a front elevation view of the lawnmower raking attachment in resting position. 
     FIG. 4 is a front view of the tines and raking head. 
     FIG. 5 is a partial enlarged side view of the tines and raking head seen on lines  5 — 5  of FIG.  4 . 
     FIG. 6 is an elevation view of the U-shaped frame that holds the raking head rotatably and capable to be locked. 
     FIG. 7 is a front view of the supports and tie brace of the U-shaped frame. 
     FIG. 8 is an enlarged external side view of the U-shaped frame support seen on lines  8 — 8  of FIG.  3 . 
     FIG. 9 is an enlarged internal view of the U shaped frame support seen on lines  9 — 9  of FIG.  3 . 
     FIGS. 10 through 19 show alternatives for: raking frame, means to lock the rake head, means to latch rotatably the frame shaft, means to attach the frame supports to the lawnmower, and additional means to maintain tine separation. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 through 9 the lawnmower raking attachment generally designated  10 , has a plurality of flexible tines  11  anchored to a raking head member  12 . Said tines  11  are made of very flexible steel and preferably of round cross section. Two tines  11  are formed by bending a long heat treated steel rod in a U-shape. The close end of the U-shaped tines is secured with screws  13  to said raking head member  12 . Said tines  11  extend downwardly from the raking head. Said raking head member  12  has a first and second end caps  14  and  14   a  respectively. Said end caps  14  and  14   a  have respectively threaded bores  15  and  15   a  on line with the axis of said raking head member  12 . Said tines  11  have a small portion  16  of their free end bent in planes perpendicular to an axial plane of said raking head member  12 . Said tines  11  may be built from untreated steel rods and hardened after all bends are made. Beads  17  are preferably of ellipsoidal shape and of heavy material. Said beads  17  have a bore along their axis of diameter greater than the diameter of said tines  11 . Each tine  11  is inserted inside the bore of at least one bead  17  before  16  is bent. Said beads  17  can rotate and slide on said tines  11  but are prevented to escape by said  16 . Said beads  17  may have an axial slot to introduce said tines  11  into said axial bore that can be closed by compression after said tines  11  are introduced into said axial bore. Tine rack  18  is disposed in a plane perpendicular to the plane of said tines  11 . Said tine rack  18  is secured to said raking head  12  by screws  19 . Groves width of said tine rack  18  are sized to embrace two integral tines  11 . The purpose of said tine rack  18  is to maintain proper separation of said tines  11 . 
     U-shaped frame  20  has a transverse shaft  21  through a first and second bores  22  and  22   a  at each arm near its open end. Said shaft  21  has perpendicular bores at both ends to accept a first and second cotter pins  23  and  23   a . Purpose of said  23  and  23   a  is to maintain said shaft in place. A first and second bores  24  and  24   a  located respectively in each arm of  20  near its close end, accept a first and second thumbscrews  25  and  25   a  respectively. Said  25  and  25   a  threads respectively in said  15  and  15   a . Said U-shaped frame  20  may be provided with reinforcing diagonal braces. Ensemble of said tines  11  and said raking head  12  is held between arms of said U-shape frame and near its close end by said  25  and  25   a  at any desired angular position to adjust the pressure of said tines  11  on the ground. 
     Frame supports  26  and  26   a  are braced by member  27 . Said brace  27  has bores  28  and  28   a  to be secured to the forward end  29  of the lawnmower. Said frame supports  26  and  26   a  are equidistant from a lawnmower central vertical plane perpendicular to  29 . Said supports  26  and  26   a  have respectively slots  30  and  30   a  perpendicular to a horizontal plane with the upper ends  31  and  31   a  open to accept simultaneously said shaft  21 . Retaining cotter springs  32  and  32   a  are secured to said frame supports  26  and  26   a  by bolts  33  and  33   a . Purpose of said  32  and  32   a  is to keep the ensemble of said tines  11 , raking head  12  and U-shape frame  20  rotatably inside said slots  30  and  30   a , and at the same time allow their installation and removal easily. Stoppers  34  and  34   a  limit backward rotation of said frame  20 . Stoppers  35  and  35   a  limit forward rotational travel of said frame  20 . Now the operation of the lawnmower raking attachment can be explained and understood. Said frame supports  26  and  26   a  are secured to a conventional lawnmower by bolts through said bores  28  and  28   a . Said shaft  21  with said U-shape frame  20  is positioned in said slots  30  and  30   a , and pushed down until said shaft is captured in a retaining fashion by said cotter springs  32  and  32   a . Then said U-shape frame  20  is rotated forward until is stopped by said  35  and  35   a . The pressure of said tines  11  on the ground is adjusted by means of said  25  and  25   a . During the forward travel of the lawnmower with said raking attachment  10  in operative fashion the thatches are moved forward and some thatches are hooked by said tines  11  or trapped between them. By simply moving the lawnmower a little backward said rake frame swing backward to some degree in which position and the backward travel of the lawnmower said tines  11  release any thatch hooked or trapped. The normal vibration of the lawnmower is transmitted to said beads  17  increasing said tines  11  penetrating and release actions. 
     Referring to FIG.  10  through FIG. 14 description of elements already described are omitted. U-shaped raking frame  100  has its close end wider than its open end to allow for longer raking heads  101 . Said raking head  101  have disposed elongated arms  102  and  102   a  attached respectively to each end of said  101  and extending outwardly. Said arms  102  and  102   a  have respectively a smooth circular bores  103  and  103   a  near the point of attachment to said  101 . Said bores  103  and  103   a  are collinear. Said arms  102  and  102   a  have square bores  104  and  104   a  respectively at their free ends. Said bores  104  and  104   a  are collinear. Said U-shape frame  100  has threaded bores  105  and  105   a  disposed in each arm of  100 . Said bores  105  and  105   a  are collinear and near the close end of  100 . Said bores  105  and  105   a  accept dog point screws  106  and  106   a . Dog point screws  106  and  106   a  have a portion of their end thread ground to a cylindrical shape to yield a pivoting point for bores  103  and  103   a  when threaded through said bores  105  and  105   a  respectively. A first and second elongated locking arms  107  and  107   a  have longitudinal slots  108  and  108   a  respectively. Said  107  and  107   a  have disposed respectively bores  109  and  109   a  at one end. Pivot bolts  110  and  110   a  are disposed respectively in each arm of  100  equidistant from said  103  and  103   a  respectively. Said pivot bolts  110  and  110   a  accept bores  109  and  109   a  respectively. Lock nuts  111  and  111   a  are set to allow said arms  107  and  107   a  to rotate freely. Spacers  112  and  112   a  are disposed between said arms  107  and  107   a  and each arm of said  100  to provide alignment. Carriage bolts  113  and  113   a  are inserted through said bores  104  and  104   a  and said slots  108  and  108   a  respectively. By tightening wing nuts  114  and  114   a  the angular position of said raking head  101  relative to said raking frame  100  is locked providing means to adjust the pressure of tines  11  on the ground. 
     Two-piece clamps  115  are located at a moderate distance from said raking head  101 . Said clamps  115  have matching grooves in their contacting surfaces to accept tines  11 . Each clamp  115  grips together at least to tines  11  to help maintain separation of said tines  11 . Each tine  11  is coiled  128  between said  115  and said  16  in a plain perpendicular to said frame  100  to increase tine flexibility. 
     According to another embodiment not shown in the accompanying drawings said tine head  101  and said elongated arms  102  and  102   a  are made of high impact plastic and the tines  11  are inserted during the molding process. 
     Referring now to FIGS. 15 through 19 description of elements already described are omitted. Latching arms  116  and  116   a  are disposed pivotally on frame supports  26  and  26   a  around screws  33  and  33   a  respectively. Said screws  33  and  33   a  are set to provide friction between said latching arms  116  and  116   a  and said frame supports  26  and  26   a  respectively to retain said shaft  21  rotatably in the bottom of said  31  and  31   a . Said latching arms  116  and  116   a  have slots  117  and  117   a  respectively. Said slots  117  and  117   a  have respectively one end open. Sides of said slots  117  and  117   a  are defined in a fashion to be tangent to said shaft  21  when pivoted on  33  and  33   a  respectively. Said latching arms  116  and  116   a  can be rotated toward shaft  21  until said shaft  21  touches the bottom of said slots  117  and  117   a  in which position stay by the friction provided by  33  and  33   a . Two-piece clamps  118  and  118   a  are clamped to the front end of a lawnmower. Said clamps  118  and  118   a  consist of two pieces each with their contacting surfaces shaped to conform with the cross section of the front end  29  of the lawnmower. Screws  119  and  119   a  close said clamps  118  and  118   a . Dowel pins  120  and  120   a  maintain alignment of the two halve of  118  and  118   a.    
     Horizontal arms of angular brackets  121  and  121   a  are bolted respectively to the top of the outer halve of said  118  and  118   a . Brace bar  27  is bolted to the vertical arm of said  118  and  118   a . Said brace bar  27  may be mounted directly on the front surface of the outer halve of said  118  and  118   a . Stopper seat  122  is defined to slide in a longitudinal slot  123  along one arm of  100  and near its open end. When said stopper seat  122  is in its uppermost position said rake frame  100  can be rotated to its resting position. When said stopper seat  122  is in its lowest position said raking frame  100  can not be rotated enough to reach the resting position and is forced to rotate to the operational position generally by gravity. 
     FIG. 19 shows another alternative to prevent said rake frame  100  from going to the resting position during the raking operation. Intentionally latching arm  116  is omitted in FIG. 19 for clarity. Elongated finger arm  124  is disposed pivotally on said on one side arm of  100  near shaft  21 . Shoulder screw  125  provides the pivot point for said  124 . The end  126  of said  124  near the pivot point is bent in a manner to limit its rotation. The other end shape  127  is fashioned in a manner to engage with said stopper  35  preventing said  100  from going to resting position. In order to rotate said  100  to resting position said  124  have to be disengaged manually by simply rotating said  124  to a release position slightly away from said  35 . 
     The present disclosure contains that contained in the appended claims as well as that of the foregoing description. Although the invention has been disclosed in its preferred forms with a certain degree of particularity, it is understood that the invention of the preferred form has been made by way of example, that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.