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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
     The present invention relates to the field of shingle removing apparatus in general, and in particular to a powered shingle removing machine, which is pushed across a shingled roof, and which uses a powered, oscillating blade mechanism to lift and remove previously installed shingles. 
     Residential and commercial building constructions generally have roof decks which are covered with a protective layer of shingles. Shingles are generally placed in overlapping, aligned rows and the shingles are secured in place by a combination of nails, staples or other fasteners and adhesive. 
     Any shingle, regardless of type, will eventually deteriorate due to exposure to ultraviolet light from the sun, moisture from precipitation, etc. While it is common to install a second layer of new shingles over a single existing layer, eventually the older shingles must be removed for roof refurbishing. Building codes will typically limit the permissible number of shingle layers. This is a physically demanding task when performed by hand without the use of power machinery. Generally, various manually operated scraping tools, such as modified flat shovels, are used to wedge between the shingles and the underlying roofing paper or sheathing, with the front edge of the shovel shearing or pulling the roofing nails which held the shingles in place and breaking adhesive bonds between shingles. The physical effort involved, particularly when performed on a steep sloping roof, is taxing. 
     As any roofer is all too well aware, mechanical shingle removing devices substantially reduce the amount of physical exertion that is required to strip shingles from a roof. However, they are also difficult to maneuver on a roof surface due to the fast and continuous oscillating movement of the blade. Thus, the workman must stop the motor to push the machine forward for removing additional shingles, which slows the removal process and increases the cost of removal. 
     It is therefore desirable to provide a shingle removing apparatus which improves the driving mechanism and improves the time efficiency and workman efficiency for removing shingles. 
     Accordingly, the present invention is directed to a shingle removing apparatus which overcomes one or more of the problems as set forth above. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention overcomes many of the shortcomings and limitations of the prior art devices discussed above and teaches the construction and operation of several embodiments of a shingle removing apparatus adapted for continuously removing the shingles without having to stop the motor to move removal apparatus. The present apparatus can improve the overall efficiency of the entire shingle removing process as compared to the prior art with respect to work efficiency. 
     In one aspect of the present invention, the present shingle removing apparatus includes a handle, a stripper member, a drive assembly and a drive linkage assembly with lost motion mechanism. The handle has a proximal end and a distal end. The stripper member is adapted for inserting under a shingle and has a first end portion and a second end portion. The first end portion of the stripper member is operatively coupled to the proximal end of the handle such that the second end portion of the stripper member is reciprocally moveable up and down. The drive assembly drives at least a portion of the stripper member and the drive linkage assembly causes at least a portion at a free end of the stripper member through a lost motion mechanism to reciprocally move up and down to thereby remove shingles. The drive assembly is operatively connected to the stripper member to selectively effect pivoting movement of the stripper member relative to the handle. The lost motion mechanism allows the stripper member to intermittently not be driven. The drive linkage assembly in one embodiment comprises a crank arm, a first link and a second link to provide lost motion connection. The crank is coupled to the drive assembly for rotation thereby. 
     In another aspect of the present invention, the drive linkage assembly provides a lost motion connection between a crank arm and a link arm. The crank arm is pivotally coupled to the drive assembly. The link arm has first and second end portions, and includes an elongated slot spaced from the second end portion. The crank arm is pivotally associated with the slot so as to provide lost motion connection. The second end portion of the link arm is operatively engaged with the stripper member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view of a first embodiment of the present shingle removing apparatus constructed in accordance with the teachings of the present invention. 
         FIG. 2  is a perspective side view of the shingle removing apparatus of  FIG. 1 . 
         FIG. 3  is a side view of the shingle removing apparatus of  FIG. 1 . 
         FIG. 4  is an exploded perspective view of the drive link assembly in accordance with the teachings of the present invention. 
         FIG. 5  is a side view of the gear assembly of one housing portion of the shingle removing apparatus of  FIG. 1  with portions broken away to show internal detail. 
         FIG. 6  is a perspective view of another embodiment of the stripper removing apparatus. 
         FIG. 7  is an exploded perspective view of a drive link assembly. 
     
    
    
     It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. Like numbers utilized throughout the various Figures designate like or similar parts or structure. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention involves the provisions of a shingle removing apparatus wherein the drive linkage assembly includes a lost motion mechanism that effects intermittent movement of the stripper member during continuous rotation of a crank arm so that an operator does not need to stop a motor to go forward for removing more shingles. The present shingle removing apparatus improves the overall efficiency of the shingle removing job as compared to the prior art apparatus with respect to time efficiency and worker efficiency in removing the shingles. 
     As best shown in  FIGS. 2-4 , the shingle removing apparatus  10  comprises a drive system including a drive assembly  80  and a drive linkage assembly  40 . The apparatus  10  includes a stripper member  50 , such as a stripping blade, preferably having a toothed free end portion  52  for inserting under shingles. The shingle removing apparatus  10  is generally operated by using the drive assembly  80 , whereby the stripper member  50  lift nails out of a roofing substrate. As illustrated in  FIG. 1 , the shingle removing apparatus  10  of the present invention is positioned on the surface from which material is to be removed such as a shingled roof. The operator positions himself or herself behind the shingle removing apparatus  10 . The operator grips the handle  20  and may advance the shingle removing apparatus  10  on wheels  53 . The shingle removing apparatus  10  is actuated by depressing a trigger  62  which will energize a motor  60  causing a drive shaft  25  to rotate. The drive assembly  80  will effect an oscillatory and reciprocal motion to the stripper member  50  through the drive linkage assembly  40 . The operator, by use of the grip  23  and/or handle  20 , advances the leading edge  51  of the stripper member  50  beneath the roofing material to be removed. As the leading edge  51  contacts the underside of the shingles  1 , the shingles  1  and any fasteners are lifted upwardly along with the fastener such as staples or nails. After the leading edge has lifted a section of shingles  1  from the surface, the operator proceeds forward so that the stripper member  50  is positioned between the next remaining layer of shingles  1  and removal is accomplished in a similar manner. 
     Referring to the drawings more particularly by reference numbers, the numeral  10  in  FIGS. 1-3  identifies one embodiment of a shingle removing apparatus. 
     In one aspect of the present invention, the shingle removing apparatus  10  includes a handle  20 , a drive assembly  80 , a drive linkage assembly  40  and a stripper member  50  for forcibly removing shingles  1  as illustrated in  FIGS. 1-7 . The handle  20  comprises an elongated tubular housing  22 , an on/off switch such as a trigger  62  disposed adjacent its distal end portion  24 , a transversely extending secondary handle  23  disposed on its intermediate portion and a mount member  54  disposed on its proximal end portion  26 . The handle  20  is hollow and can have an internal bearing (not shown) for supporting a drive shaft  25 . The stripper member  50  can be a shingle removing blade, which is operatively coupled to the drive assembly  80  for effecting movement of the stripper member  50  relative to the handle  20  through the drive linkage assembly  40 . The stripper member  50  is in the form of a plate with teeth  52  on the leading edge  51 . The stripper member  50  has a leading edge  51  which engages the shingles and fasteners to be removed. A stripper member  50  has a trailing edge portion and the beveled free end  51 . 
     The shingle removing apparatus  10  is powered by the motor  60  which may be hydraulic, pneumatic or electric with controls suitably located on the handle  20 . The motor  60  can be secured to the free end portion  24  of the handle  20  by a bolt  65  and a bracket  63 . Alternatively, the motor  60  can be bolted onto suitable motor mount in a motor casing with its controls preferably on the distal end portion of the handle  20 . (not shown) 
     Turning now to  FIGS. 2-4 , it can be seen that rearwardly extending mounting brackets  57  are provided with an aperture disposed proximate the lower end of the trailing edge of the mounting bracket  57 . The mounting brackets  57  are positioned in spaced apart relationship and the proximal end portion  26  of the handle  20  is inserted between the two mounting brackets  57 . The mounting brackets  57  are secured to the proximal end portion  26  of the handle  20  by means of latch pins  58 , each extending through respective holes  59 . A plurality of holes  59  on each mounting bracket  57  permits adjustment of the vertical angular orientation of the handle  20 . The mounting brackets  57  include a plurality of aligned holes  59  which allow the operator to adjust angular relationship between the handle  20  and the mount member  54 . In one embodiment, the shingle removing apparatus  10  includes an optional wheel unit  53  positioned adjacent the proximal end portion  26  of the handle  20 . The wheel unit  53  can include a pair of wheels  53  mounted on an axle which extends through the apertures in the mounting bracket  57  for moving the apparatus  10  about a roof surface. The rearwardly tapered mount member  54  is attached to the mounting bracket  57 . In another embodiment, the mount member  54  can be directly connected to the handle  20 . The stripper member  50  is pivotally connected to the mount member  54  by means of outer and inner hinge sockets  55  respectively, mounted on a hinge pin  56 . 
     The stripper member  50  is driven by the motor  60  mounted to the handle  20 . The drive assembly  80  comprises the motor  60  operatively connected to the drive shaft  25  that can be enclosed by a tubular housing portion  22  of the handle  20  and which extends from the motor  60  to a worm gear  32 , as illustrated in  FIG. 5 . The lower end of the drive shaft  25  connected to a gear assembly  30  including a ring gear  34  and worm gear  32 . Preferably, at least the lower portion of the drive shaft  25  is flexible to accommodate the angular adjustment between the handle  20  and the mount member  54 , for convenience of construction, the drive shaft  25  can be a flexible drive cable. The drive shaft  25  is operatively coupled to the worm gear  32  in a conventional manner as illustrated in  FIG. 5 . The worm gear  32  is suitably mounted in a housing  31  and is operatively engaged with a ring gear  34 . The motor  60  is actuated by means of the trigger  62 . Preferably the motor  60  is a variable speed motor with speed being selected by the trigger  62 . In a preferred embodiment the motor  60  is a variable speed drill motor with a chuck coupling the motor  60  to the drive shaft  25 . 
     The drive assembly  80  includes a gear assembly  30  for coupling the drive shaft  25  to drive linkage assembly  40 ,  70  to effect reciprocative movement of the stripper member  50 . The shingle removing apparatus  10  of the present invention includes a drive linkage assembly  40  that provides lost motion oscillating driving of the stripper member  50 . The motor  60  drives the drive shaft  25  to ultimately rotate a crank arm  42  as illustrated in  FIGS. 4 and 7 . It will be understood that the driving mechanism used to translate rotational motion of the drive shaft  25  into rotating motion of the crank arm  42  is not critical, and any driving mechanism known in the art may be used to translate rotational rotation of the drive shaft  25  into rotating motion of the crank arm  42  or the crank arm  72 . 
     The present shingle removing apparatus  10  includes the drive linkage assembly  40  providing preferred lost motion mechanism as illustrated in  FIGS. 2-4 . In one embodiment, the drive linkage assembly  40  includes the crank arm  42 , a first link  44  and a second link  48 . The crank arm  42  is positioned on the exterior of the housing  33  and is rotated by the drive assembly  80 . The crank arm  42  is adapted for moving the first link  44  which is pivotally connected to the crank arm  42  by means of a pivot pin  49 . The first link  44  includes an elongated slot  45  spaced apart from the pivotal connection of the crank arm  42  and the first link  44 . The second link  48  includes a follower  47  which is movably received in the elongate slot  45  to form a lost motion pivotal connection. The slot  45  receives the follower  47  for free movement of the follower  47  along the elongated slot  45 . The elongated slot  45  has a length sufficient to effect intermittent movement of the stripper member  50  during continuous rotation of the crank arm  42 . As a result, the lost motion mechanism delays movement of the stripper member  50  during a predetermined portion of the rotation of the crank arm  42 . In this regard, an operator can move the shingle removing apparatus  10  forward without manually stopping the motor due to effect a time delay in the movement of the stripper member to insert it under more shingles  1 . When the crank arm  42  is initially rotated by a gear assembly  30 , the stripper member  50  is permitted to rotate through a predetermined “lost motion” connection before establishing a direct-drive driving connection therewith to delay lifting or lowering the leading edge  51  of the stripper member  50 . Once the direct-drive driving connection is established, further rotation of the crank arm  42  will cause the stripper member  50  to lift or lower. This “lost motion” feature advantageously aids in going forward for removing next shingles. The operator can proceed rapidly and safely as slow return of the stripper member  50  to the set up position is accomplished by the lost motion mechanism. It is preferred that the drive assembly be constructed so that the direct drive portion of a crank arm rotation is preferably adjacent 3 o&#39;clock and 9 o&#39;clock portion of the crank arm  42  to provide mechanical advantage during the lifting movement of the stripper member  50  and less impact from the follower  47  following out at the each of the slot  45 . 
     An alternate embodiment of the shingle removing apparatus  10  of the present invention is shown in  FIGS. 6 and 7 . The drive linkage assembly  70  includes a crank arm  72  and a link arm  76 . The crank arm  72  is pivotally connected to the gear assembly  30  and is rotated by the gear assembly  30 . The link arm  76  is pivotally coupled to the eccentric portion  71  of the crank arm  72  by means of a follower  79 . The link arm  76  has first end and second end portions, the second end portion being operatively engaged with a second link  77 , the first end portion being pivotally connected to the eccentric portion of the crank arm  72 . The second link is secured to the upper surface of the stripper member  50 . The link arm  76  includes an elongated slot  73  spaced apart from the pivotal connection of the link arm  76  to the second link  77 . The crank arm  72  includes the follower  79  which is mounted to and pivotally engaged with the elongated slot  73  through the lost motion connection. The elongated slot  73  receives the follower  79  for free movement of the follower  79  along the elongated slot  73 . The elongated slot  73  has a length sufficient to effect intermittent movement of the stripper member  50  during continuous rotation of the crank arm  72 . As a result, the lost motion mechanism delays movement of the stripper member  50 . The drive linkage assembly  70  further comprises two discs  78  which are positioned in spaced apart relationship with the lost motion connection between the discs to shield a pinch point. 
     In conclusion, the shingle removing machine greatly facilitates the removal of shingles from a roof. The time delay of the drive arm actuation oscillates and reciprocates the shingle removing blades in an efficient pattern. 
     Moreover, it will be understood that although the terms first, second and third are used herein to describe various features, elements, regions, layers and/or sections, these features, elements, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one feature, element, region, layer or section from another feature, element, region, layer or section. Thus, a first feature, element, region, layer or section discussed below could be termed a second feature, element, region, layer or section, without departing from the teachings of the present invention. 
     Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. 
     Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow. The scope of the disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Summary:
The present invention discloses a shingle removing apparatus which includes a handle, a stripper member, a drive assembly and a drive linkage assembly with lost motion mechanism. The stripper member is adapted for inserting under a shingle has a first end portion and a second end portion. The drive assembly drives at least a portion of the stripper member and the drive linkage assembly causes at least portion of the stripper member to reciprocally move up and down to thereby remove the shingle. The drive linkage assembly provides a lost motion mechanism which allows the stripper member to intermittently not be driven.