Variable cam adjustment arrangement
United States Patent Furman 1 1 VARIABLE CAM ADJUSTMENT ARRANGEMENT 175] Inventor: lrvin Furman, Denver. C010.  
 [73] Assignee: GAF Corporation, New York. NY.  
 {22] Filed: Dec. 22, 1972 [211 Appl. No.: 317,530  
 [52] US. Cl 118/8. 118/308. 222/52 [51] Int. Cl. B05c 11/10 [58] Field of Search 222/52; 118/4, 7, 8  
 [56] References Cited UNITED STATES PATENTS 2,704.530 3/1955 Nilsen et a1 118/8 X 3.595.204 7/1971 Mclntyre ct al. 118/8 3.676.032 7/1972 Meyer ct a1 222/52 X 3.737.338 6/1973 Kabelitz 118/7 X 3.742.899 7/1973 Alperin ct ul 118/8 X Primary Emminer-Drayton E. Hoffman Ass/stun! E.tamimu&#39;.loseph .1v Rolla Attorney, Agent. or FirmWalter C. Kehm&#39;. Samson B. Leavitt BRA @TCH  
 BLENDER EED QOLLER [57] ABSTRACT A control device is provided for use with an apparatus adapted for the disposition of granular material upon a moving sheet of substrate during the manufacture of roofing shingles. The control device comprises a rotatable cam driven by the shingle manufacturing apparatus and having a variable cam surface. a slidable switch adapted to periodically energize an electric clutch to control the disposition of the granular material, said switch having an actuating arm in contact with the cam surface, an electro-pneumatic transducer responsive to the speed of the moving sheet of substrate and adapted to emit an output signal proportional in magnitude to such speed, and a pnuematic cylinder controlled by the output signal of the trans ducer and having an extendible stem in engagement with the switch to slide said switch along the cam surface in a direction parallel to the axis of rotation of said cam a distance corresponding to the substrate feed speed, and thereby control the position of the switch actuating arm with respect to the variable cam surface to change the duration of the actuation of the switch, so that disposition of the granular material cor responds with the substrate speed.  
 3 Claims, 2 Drawing Figures ROLLER l VARIABLE (AH ADJUSTMENT ARRANGEMENT The present in\ention relates to control of apparatus employed in the process of depositing colored ceramic granules onto a moving web. More particularly. the present in\ ention is directed to an apparatus useful to control the operation of a granule blend and feed assembly in the production of asphalt roofing shingles.  
  In the production of roofing shingle materials. it is essential that the correct blend and mix of granule materials as applied to the asphalt roofing substrate be correctly and uniformly applied so as to avoid any une\ en distribution and defects in the final product. ln accor dance with the present invention a \ariable cam assembly is provided to control the operation of an electric brake clutch arrangement which is used in conjunction with a blender for depositing the ceramic granules. it is known in the manufacture of granular coated shin gles. to employ an apparatus having a hopper through which granules are fed. Such hopper cooperates with a blender feed roller for receiving and thereafter dispensing select amounts of granules on to a moving web of asphalt material. For dispensing correct amounts and colors of such granular material. it is important that a number of operational parameters all be controlled. For example. in order to obtain uniform patterns ofdistribution. particular care has to be paid to the registration between the sheet travel speed and the flow of such granular material. hi this connection. during the operation of blender feed roller. it is known to provide an electric bralve clutch to transmit intermittant rotary motion to the blender feed roller and thus control the deposition of the granular material.  
  In carrying out the above operation. a number of conunon problems arise. especially as they relate to variations due to clutch and brake slippage. sequencing mechanism variation. and different machine speeds with respect to fixed clutch and brake response times. Accordingly. to overcome these problems it has been common to control the electric clutch brake by means of a switch having an actuating arm in operative engagement with a rotatable cam ha\ing a uniformly indented surface portion. The cam is operatively connected for rotatable movement to a feed roller for the asphalt web material. and the switch is adapted to energile the electric clutch brake. and thus impart rotary motion to the granular blender feed roller whenever the actuating arm engages the indented cam surface (ie. the camin&#34; position l. This function is quite criti cal to correct granule disposition However. it has been found that as higher asphalt feed speeds are used during the production operation. the cam does not ade quately compensate for variations in the acceleration and deceleration of the blender feed roll. In this regard. with a continuous acceleration and deceleration of the granular feeding roll. the granules being released are not being deposited evenly on the coated asphaltcd moving web. Asa result. defects in the finished product occur due to a lack of uniformity in granule deposition. With this arrangement. even deposition can only occur when the blender feed roll is rotating at a constant speed so as to overcome any of the aforementioned irregularities.  
  The problem of uneven and short blend deposition of granular materials at machine speeds in excess of 300 feet a minute of travel (along a substrate upon which the granules are to be deposited) was one that was recognized as something that materially contributed to an unacceptable product. The difficulty arose only at speeds of travel in excess of the aforementioned amount. At lower speeds. the blender. while mixing different colors of granules. did not present any problems. In addition. feed speeds in excess of 500 feet per minute caused the granule drops to become almost ohliter ated.  
  The importance of good product quality at high product output speeds is essential to the making of a more efficient and less costly product when compared to comparable product manufactured at lower speeds. The deposition of colored ceramic granules with Liniform dispersion. color tone. and physical strength at high speeds is something that the prior art has long sought. Furthermore. since the difference between granule depositions at high and low speeds respectively. of the finished product when installed on a roofing substrate is readily noticeable. obviously. from an aesthetic point of view. a uniform product would tend to have greater sales appeal. Lastly. the previously mentioned problems all tend to increase the cost and labor associated with quality control implementation of the end product.  
  It has been discovered that the reason for uneven and short drops of granule material at high speeds is due to the inability ofelectric clutches to overcome the inertia forces necessary to start up the blender feed roll from a zero acceleration position to full machine speed. During this time. the cam switch is not alw in the &#34;camin position. that is the position in which the granule blender roll is engaged so that granular material can be fed from a feed hopper. Therefore. there is an uneven granule feed to the web of substrate material. This occurred because before the feed roll could attain its required speed. the switch for controlling the clutch was already in the camout&#34; position. thus disengaging the clutch and causing incomplete drops of granular material were deposited from the hopper. Furthermore. evenly deposited granule mixtures will only result when the blender feed roll is rotating at a constant speed. Until such constant speeds are attained. it is not possible to predict with any high degree of accuracy the color. form and shape of the ultimate dispersion of granular material on the moving web.  
  To overcome this problem. the instant invention employs a rotatable cam having a variable cam surface to provide a variable siie &#34;cant-in&#34; area. a slidable switch to control the electric clutch having an actuating arm in engagement with the cam surface. an electropneumatic transducer responsive to the speed of the asphalt feed roller. and a positioner coupled to the transducer and the switch to slidably move said switch along the cam surface in a direction parallel to the axis of rotation of the cam as the asphalt feed speed lluctuates and thereby control the position ofthe switch actu ating arm with respect to the variable cam surface. In this manner. the cam-in&#34; time is increased as the machine speed increases to thereby cause longer granule deposition intervals to be produced.  
  Accordingly. it is the main object of the present invention to obviate the defects of the prior art.  
  It is still a further object of the present invention to provide an apparatus adapted to function in conjunction with a granular feed assembly for allowing a uniform deposition of granular material upon a web of sheet material at high speeds of travel.  
  Another object of the present invention is to provide an apparatus adapted to increase the speed of travel by lengthening the cam-in&#34; time in relation to the machine speed by means of a novel cam configuration.  
  Still another object of the present invention is to pro- \ide a new and time] granule blending apparatus capa ble of insuring uniform deposition during acceleration and deceleration of the blending roller. In general. the control device of the present imention is adapted for use in conjunction with an asphalt shingle manufacturing apparatus of the type having at least one power driven feed roller for advancing asphalt substrate material. a blender feed roller for depositing granule material on the moving asphalt substrate. and an electric brake clutch for controlling the blender feed roller. and comprises a cam operatively connected for rotational movement to the power driven feed roller and having a cam surface which varies in shape across the face thereof; a slidable switch electrically connected to the brake clutch and having an actuating arm in sliding op erative contact with the cam surface to periodically en ergize and de-energizc said brake clutch in response to the rotational movement of said cam; pneumatic means having an estendible stem in operative engagement with said switch to move the switch along the cam surface in a direction parallel to the axis of rotation of the cam; and electro-pneumatic transducer means operativcly connected to the pneumatic means and responsive to the speed of the asphalt feed roller and adapted to emit an output signal proportional in magnitude to such speed. to actuate said pneumatic means to cause the stem thereof to move said switch along the cam sur face a distance corresponding to the magnitude of the output signal: said cam surface being shaped such that the duration of each switch actuation increases as the speed of the asphalt speed roller increases.  
  As additional features of the invention. the shape of the cam surface is manually adjustable.  
  The aforementioned objects will be best understood with respect to the specification. claims and accompanying drawings.  
  FKi. l illustrates a schematic representation of the instant invention.  
  FIG. 2 illustrates a top elevational view of how the invention can be adjusted.  
  According to FIG. I. a rotatable cylindrically shaped cam l is employed. the surface la of which is adjustable for movement around the periphery of sleeve 2. The cam I has an integral drive shaft 10. which is driven mechanically in the direction ofthe arrow from a feed roller of an asphalt shingle manufacturing apparatus. The cam surface has an indented portion In defined by step 4 on cam plate 41: and step 5 on the cam surface. which indented portion varies in size across the face ofthe cam, The relative position of such indented portion In can be adjusted by loosening the bolts 3 shown in FIG. 2 and revolving the cam body on the sleeve 2. in this manner. such indented portion. re ferred to as the cam-in position. can either he advanced or retarded by 30. This amount is predesigned into the apparatus consistent with the operating conditions of the granular application process. Other adjustments can be made by removing cam plate 411 or changing the the profile across the step 4 of cam plate 4a and this is shown by the relationship of steps 4 and S. A switch 6 is in circuit relation with the electric brake clutch (not shown) which controls the operation of the blender feed roller of the asphalt shingle manufacturing apparatus and is adapted to energize and deenergi7e said clutch.  
  The switch has an actuating arm 61: in operative sliding contact ith the surface of cam I and is adapted to activate the switch to energi/c the clutch upon engagement ith the indented surface portion In of the cam. (the camiir position). An electro-pneumatic transducer ll of a conventional type responsive to the feed speed of the asphalt substrate being coated is in circuit relationship with a pneumatic cylinder 7 via an actuator 8 is adapted to impart an input signal thereto. which in turn enables pressurized air from a suitable air supply preferably regulated between 20 psi and 100 psi. to activate the cylinder in direct magnitude proportion to such input signal. The air supplied to the cylinder 7 enters via actuator 8 and as this occurs. an actuator stem 9 of cylinder 7 in operative engagement with a slidable base 12 of switch 6; will slidably move the switch in a direction parallel to the axis of rotation of earn 1. thus varying the point ofengagement of arm 6a and the cam surface. As the asphalt sheet feed speed increases. the air pressure fed to cylinder 7 proportionally increases. due to a corresponding increase in the magnitude of the input signal from transducer II. In this manner. switch 6 is urged along the surface of cam I. [t can he seen that the circumferential length (distance between steps 4 and 5) of the indented cam surface portion la increases from right to left along the cam surface. so that the duration of the cam-in time likewise increases as the switch 6 is moved to the left. Thus. the duration of the brake clutch energization increases in proportion to the asphalt substrate feed speed.  
  By the aforementioned arrangement. it is possible to compensate for the increase in acceleration and deceleration of the blender feed roll especially at large speeds in excess of 300 feet per minute.  
  As can be understood from the aforementioned. a variable cam angle may be employed especially where the asphalt manufacturing operation requires intermittent feeding or marking by a rotating device as the web is traveling at a varied line of speed of travel.  
  It will be understood that the foregoing relates to only a preferred embodiment ofthe invention. and that it is intended to cover all changes and modifications of the invention. which do not constitute departures from the spirit and scope of the invention.  
 What is claimed:  
  l. A control device for use in conjunction with an asphalt shingle manufacturing device of the type having at least one power driven feed roller for advancing asphalt substrate material. a blender feed roller for de positing granular material on the moving asphalt substrate. and an electric brake clutch for controlling the operation of the blender feed roller. comprising. in combination. a cam operatively connected for rotational movement to the power driven feed roller and having a cam sure which varies in shape across the face thereof. a switch electrically connected to the brake clutch slidably disposed in close juxtaposition to said cam and having an actuating arm in sliding operative contact with the cam surface to periodically encrgize and de-energize said brake clutch in response to the rotational movement of said cam; pneumatic means having an extendible stem in operative engagement with said switch to move the switch along the cam surface in a direction parallel to the axis of rotation of said which the cam surl&#39;ace includes an indented portion defined by a pair of spaced apart steps extending in an axial direction substantially across the entire face of the cam. at least one of said steps being disposed at an angle with respect to the other of said steps. so that the distance therehetween varies from one end of the cam to the other end of the cam.  
 3. A control apparatus in accordance with claim 2. in  
 which the relative position ot the indented portion of the cam is adjustable.  
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