Abstract: An automatic tool-changing device for industrial robots includes a gripper member located at the end of the robot arm and a coupling flange to which a tool is fixed. The gripper member has radially-movable engagement teeth adapted for insertion in projecting appendages carried by the flange, upon automatic clamping of the tool. The movement of the engagement teeth is driven by a pressurized-fluid jack housed in the gripper member.

Abstract: A ring-shaped component with slots in an end face for use in an electrical axial-field machine is formed by winding a ferromagnetic tape on a rotating winding arbor, coating the tape with a hardenable synthetic resin material at a point upstream of the winding station and baking the wound coated tape while maintaining the tape in the wound configuration. The resulting solid part is then subjected to an electro-erosion process wherein the part is automatically positioned by drive motors in response to signals from a numerical control unit.

Abstract: A method for making an electronic component, for example, a motor coil. The method comprises the steps of forming a plurality of conductive layers and interconnecting the layers to provide an electrically conductive path between the layers. In order to form interconnections between the layers which have a low electrical resistance and which can be formed in a high-speed automated process, a conductive paste is applied to one of the conductive layers and the layers are superposed to form the interconnections.

Abstract: A low current superconducting magnet, and a method of fabrication, having improved protection against quench damage. The magnet utilizes the technique of forming a twisted cable of a plurality of substantially parallel superconductor wires and then winding this cable in turns to form the desired magnet configuration. A curable potting material such as an epoxy is applied during winding so as to substantially fill all interstices between the wires. After winding the ends of the wires are connected so as to put each wire in a series array. The intermixing of the wires throughout the magnet winding, together with the heat transfer characteristics of the potting material, provides for many parallel paths for heat conduction to a cryogenic fluid to reduce potential thermal damage. Furthermore, a voltage limiting device, such as a diode pair, is connected across the adjacent ends of each wire.

Abstract: In an electronic chip placement machine with test function, there is provided a suction nozzle for holding a chip, a chip-regulation device for regulating the attitude of the chip by clamping the chip at portions having no electrodes probes for testing electrical characteristics of the chip. The tip portion of the suction nozzle is made of an insulating material such as a ceramic or a synthetic resin in order to avoid a short-circuit between electrodes of the chip through the nozzle. Therefore, the electrical characteristics of the chip can be tested without the separation between the nozzle and the chip. Furthermore, since one cycle of the operational process according to the present invention is shorter than that of the conventional operational process, it is possible to provide chip-test and placement machines whose structure is simple. As a result, productivity and durability can also be increased.

Abstract: The invention concerns a wiring tool to be employed in the cutter-terminal technique for wiring multipole electric connectors, contact strips, and similar structures, with a support and a retainer for the connector that accommodates the conductors that are to be connected and with the support capable of being displaced parallel to itself and to the retainer or vice versa, wherein the support and retainer constitute an interchangeable head that adapts to an extremely wide range of applications and that can be mounted on and dismounted from a transmission, characterized in that the transmission consists of a device that is driven by an electric motor.

Abstract: A semiconductor device mounted on a printed circuit board is disclosed. The semiconductor device is surrounded by a frame having a stopper portion on the inner wall thereof at a level higher than tops of bonding wires as well as a semiconductor element housed in the frame. An insulating resin is filled in the frame to protect the semiconductor element from external stress and humidity. A method of mounting a semiconductor device on a printed circuit board is further disclosed. In this method a sealing solid resin block is first sustained on a stopper portion provided on the inner wall of a frame surrounding a semiconductor element and bonding wires, and then melted to seal the semiconductor element and bonding wires.

Abstract: An electrical terminal has been described and illustrated which comprises a compliant retention section that has been sheared thereby forming resilient leg members joined at their ends and having outer radiussed surfaces for springably and frictionally engaging a plated through hole in an electrical panel member when the compliant retention section is inserted into the hole and inner shear surfaces which extend between the ends and into the ends to at least the outermost points of the ends so that the inner shear surfaces frictionally engage and move along each other when the resilient leg members are flexed inwardly upon insertion of the compliant retention section in the plated through hole.

Abstract: A method of manufacturing a semiconductor device employing a film carrier tape during process steps thereof is disclosed. Any test pad is not provided in the film carrier tape. Therefore, the semiconductor element carried in the film is cut at the leads and separated from the film carrier tape without conducting any electrical test. The separated semiconductor element is conducted the electrical test by installing it on a testing substrate which is provided to adapt to a large number of terminals.

Abstract: A method for preparing braided coaxial cable for termination is taught wherein a segment of the cable outer jacket is defined by an annular slit, lightly clamped and axially displaced, then clamped firmly and axially displaced in a reverse sense to cause the cable braid beneath such jacket to be displaced radially outwardly. The braid so displaced is then trimmed and removed with a further segment of the cable being defined by an annular slit which for the segment is axially displaced to cover over the cut ends of the braid, leaving the coaxial cable prepared for termination.

Abstract: A process of and an apparatus for producing a wire strand with a terminal which can reduce the number of types of wires used for production of wire harnesses and wherein a load to a controller in a wire processing apparatus can be reduced and software for processing can be changed easily. In the process and apparatus of the invention, data of designated matters providing information necessary for connection of a terminal to a wire string such as an application, a type and/or a processing procedure of the wire string are printed at portions of a wire on opposite sides of a position of the wire at which the wire is to be cut after the wire has been fed by metering, whereby the wire is thereafter subject to the successive necessary processings such as cutting and stripping of and connection of a terminal to the wire in accordance with the information printed on the wire.

Abstract: Automated insertion of pins (14) into apertures (12) in a backplane (10) is achieved by first shearing a predetermined number of pins from a continuous strip of pins (26). The sheared pins (12) are then engaged in a pin holder (134) which is indexed to locate the pins in registration with the apertures (12) in the backplane (10). The pin holder (134) is displaced towards the backplane (10) to insert the pins (14) into the apertures (12). As the pins are inserted, they are simultaneously engaged by a pair of guide fingers (244) which travel therewith to guide the engaged pins into the apertures without interfering with any previously inserted pins. The guide fingers disengage themselves from the pins once insertion thereof is substantially completed. An apparatus (10) is also described for carrying the above-described steps in sequence.

Abstract: A chain tube cutter has two plier-like levers with hand grips on one side of a pivot pin which projects from one lever through a slot in the other and chain-engaging arms on the other side of the pivot pin. A link cutting chain is secured to one arm. The other arm has notches for engaging a selected link of the chain after it is wrapped around the tube to be cut. Squeezing the hand grips together generally keeps the chain adjusted about the tube as it is cut by rotating the cutter relative to the tube, but to provide greater initial and operational adjustment, the pivot pin is variably positionable in the slot.

Abstract: The present invention comprises a handle having at least one coring assembly extending outwardly and away from one end of the handle. The coring assembly is a continuous ring of thin, stainless steel having a cross-section of a known geometric shape, a circle in the simplest form. The ring is joined to, or is an extension of, a thin zig-zag band portion which is joined to the handle.

Abstract: A combined scissor and pencil sharpener includes a pair of scissors having plastic looped handle portions one of which incorporates a pencil sharpener in order to offer the user dual access of both implements.

Abstract: A device attachable to a hunting knife, to adapt same for skinning and field dressing operation. The device comprises a guard member adapted to fit over only a tip portion of the knife blade, with a passage in the guard member receiving the tip portion of the blade, so that the guard member when attached leaves exposed a major portion of the blade cutting surface of the knife, while occluding the tip portion of the blade from cutting exposure. The attachment also features means for removably retaining the guard member in position at the tip portion of the knife blade, such as a leather thong extending through a hole in the proximal part of the guard member, whose end portions may be grasped to retain the guard member in position. The skinning and field dressing attachment device of the invention is readily detachably secured to the knife blade tip portion, to accommodate a quick and simple conversion of the hunting knife to skinning and/or field dressing operation.

Abstract: In a switching multicoordinate probe an accurate and accurately reproducible switching behavior is achieved by a plurality of bearing points, which all have the same elasticity. The bearing balls (14) and their countermembers (17) exhibit a sufficient number of degrees of freedom, in order to be able to accurately orient themselves with respect to each other during installation. After adjustment the contact zones of the individual bearing balls (14) with the inclined sectional surface (18) of their countermembers (17) form an accurate bearing arrangement for the probe retainer (10), which bearing arrangement lies in a plane prependicular to the stylus access (FIG. 1).

Abstract: A sextant for indicating the angular separation between two objects, including two members interconnected at a pivot point, means for adjusting the angle between the members to be indicative of the angular separation between the objects, the means for adjusting including coarse and fine adjustment means, and a pair of encoders for converting the respective positions of the coarse and fine adjustment means to signals which are together indicative of the angular separation. In other aspects, there is a single encoder having a track on the sextant arc and a sensor on the tangent arm; and an indicator tells the user when the sextant has been set to the prestored altitudes of reference celestial bodies.

Abstract: There is provided an optical viewing system, which is preferably a compass which eliminates the parallax and sighting problems of prior art optical systems. The compass includes a beam splitter which displays a sighted image both on a reference screen and a free-floating magnetized sphere or other moving surface. The sighted image on the reference screen and on the sphere are superimposed upon each other when viewed through one facet of the beam splitter. In this manner parallax is eliminated, thus the direction and elevation of the image may be readily and accurately determined.

Abstract: A base assembly for a machine tool includes a support arrangement between a metal base and a granite worktable which eliminates distortion caused by differential thermal expansion and contraction and which isolates the base from deformation due to the weight of a workpiece. The support arrangement preferably includes three spaced-apart blocks, each with a V-groove track, attached to the bottom of the granite worktable. The axes of the V-groove tracks intersect at a common point. The metal base includes three spherical projections located for engagement in each of the V-groove tracks. The support arrangement permits the granite worktable and the base to expand, contract and distort separately, while providing vertical support and lateral and rotational restraint. Several configurations of tracks and projections are disclosed.

Abstract: A multi-coordinate probe with a stylus is disclosed wherein the stylus has a mounting or seating location defining its zero position. The stylus is deflectable from the zero position in several coordinate directions and is urged by a restoring force back into its zero position. The mounting location of the stylus is formed by the cooperation of surface areas of a plurality of balls with associated surface areas of support members. The balls and the support members are centrally arranged about the axis of the probe. The balls are fixedly mounted on a mounting member while the support members, which preferably are in the form of cylinder bodies with a V-shaped groove in the surface facing the balls, are, during assembly of the probe, rotatable about their own axis and axially movable to accomplish the desired precision seating of the ball surfaces in the grooves. After the positioning is accomplished, the cylindrical bodies are immovably fixed within the probe casing.

Abstract: A presetting device for tools used in a press such as a platen press, including by a cradle for slidably receiving each of the tools and being mounted by a turret on a carriage which is shifted along a vertically extending column, which column can be rotated around a vertical axis on a base. The device enables positioning the height of the cradle and also rotating the cradle around both the horizontal and vertical axis to gain access to the tools during the setup operation.

Abstract: A method is disclosed for removing essentially all of the water from fine metal powders. The method involves contacting the powder particles which have water on at least some of the particle surfaces with a solution of a fluorocarbon solvent and a hydrophobic surfactant, with the amount of the surfactant being sufficient to form at least a monolayer adsorbed onto the particle surfaces, and with the amount of the solution being sufficient to at least fill the void volume of the particles, to displace essentially all of the water which is in contact with the water. The displaced water and the major portion of the solution which is not in direct contact with the powder is physically removed from the resulting treated powder. The powder is then dried at a temperature above the vaporization temperature of the fluorocarbon at the operating pressure of the drying equipment to remove the remainder of the fluorocarbon from the treated powder without removing significant amounts of surfactant therefrom.

Abstract: Disclosed is an apparatus and method for providing a shower of fog onto a web or a machine component in contact with a web or for applying a layer of moisture to a web. The fog, which as a temperature lower than the temperature of the surface of the web or the machine component to be cooled, is applied to the surface and is caused to evaporate by the difference in the temperatures. A supply of dry air is supplied to transport the evaporated fog from the region adjacent the surface to be cooled. Fog may be generated through the use of an air-atomizing nozzle which propels water and compressed air through a small orifice under pressure to create an atomized mist or fog. To achieve localized control of the application of fog, a plurality of air atomizing nozzles is mounted in a row extending in the cross machine direction of the apparatus. An air plenum extending parallel to the row of air atomizing nozzles is mounted on at least one side of the row.

Abstract: An automatic clothes dryer that initially determines the upper regulating or cycling temperature in accordance with the fabric type and desired dryness as input by the operator. If no desired dryness is input, a default dryness is assumed. Then, the controller measures the time period to reach the upper regulating temperature during the first heating cycle, and uses this information along with the fabric type and desired dryness to determine how many additional heating cycles will be executed to dry the clothes to the desired dryness. Further, the length of a subsequent cool down cycle is determined in accordance with the fabric type and desired dryness.

Abstract: There is a sports shoe with a sole (4) and an inflating device which is arranged under a convex part of the foot (3) and delimits a compression chamber (16) with a chamber body (1) as well as a chamber roof (14), the compression chamber having an inlet opening (17) and an outlet opening (18). It is desirable to improve the effect of the inflating device by minimizing the clearance space in the compression chamber. This is accomplished by forming the compression chamber (16) as a semi-lentil-shaped (dished) bowl which is conformed to fit the convex contour of the region of the foot (3) loading it and by having the inlet opening (17) as well as the outlet opening (18) arranged in the central area of the chamber (16). Since, on compression, the chamber cover will hug the bottom of the compression chamber, it is possible to produce a positive pressure commensurate with the down-stepping force applied.

Abstract: A greeting card comprising at least one lamina having portions which are foldable with respect to each other and an elastic band (22) for urging the portions of a folded the lamina from a first relative position in which the portions are contiguously disposed in adjacent planes into a second relative position in which the portions are disposed in mutually transverse planes and a first array (24) of the portions defines a display surmounting, and extending 3-dimensionally from, a second array (25) of the portions which defines a plinth for the first array. An auxiliary lamina (21) is provided to facilitate the insertion of the rubber band (22); it also contributes to the display (24).

Abstract: A lockable security picture frame, for enabling secure mounting of a picture depicting a therapeutic subject therein, adapted to enable such picture to be slipped thereinto and locked therein, so as to prevent removal thereof. The device includes a frame including a plurality of sides joined together, with a picture-receiving slot formed in one side of the frame through which the picture may be slipped into the frame. It further includes a lock, adapted to be mounted in the frame at a location in or contiguous with the picture-receiving slot, which includes a portion thereof which extends into such slot so as to block removal of the picture.

Abstract: The invention relates to a device for the cyclic rearrangement of a pile of rectangular or square sheets, especially a pile of photographic prints, having a first and a second frame part which may be moved relative to one another and parallel to the main plane of the pile, and having means that, on movement of the frame parts backwards and forwards, remove an individual sheet at one end of the pile and add it to the other end of the pile again, these means comprising:(a) a separating means to separate the individual sheet from the pile,(b) a feeding means to feed sheets to the separating means,(c) retaining means to hold the individual sheet in the first frame part and the remainder of the pile in the other frame part, and(d) a guide means to guide the separated individual sheet for the purpose of returning it to the other end of the remainder of the pile, wherein as the feeding means there is provided a transporter (22, 404, 420) engaging the sheet to be separated at its rear edge in the direction of transpo

Abstract: The present invention is directed to a toy cap gun which is battery operated. The present invention cap gun has a housing which has a general configuration of a gun with a barrel and a handle. A cap roll compartment and a battery operated cap advancing-repeat firing system is also located within the housing. In addition, there is a battery chamber located within the housing and electric circuitry is included which connects the battery chamber to a drive motor and to a switch which is connected to a trigger on the gun. The battery cap advancing repeat firing system has a drive motor, a gear system, a drive shaft, a cam, a spring-loaded hammer arm, a main spring, a strike plate, and a rotatable advance means. Uniquely, the cam is a step-function drop off cam which operates to open the hammer arm and then releases it so that it repeatedly strikes the strike plate so as to create automatic firing. The cam is uniquely trifunctional so as to operate a cap roll lock, a cap advance, and the hammer of the hammer arm.

Abstract: Locking devices for guns operate to lock the guns against inadvertent or unauthorized firing, and at the same time enable quick and controlled unlocking of guns, to enable their use, as against home intruders.

Abstract: A hanging cord is threaded through the top selvage of the net or web of a fishnet assembly and is secured at regularly spaced locations to separate anchor blocks which, in turn, are secured to the fishnet corkline. The anchor blocks have rigid bodies and swingable connectors with arms projecting from the block bodies for attachment of the hanging cord to the connector arms, such as by clips clamping the hanging line and having pins fitted through eyes in the arms. The securing of the anchor blocks to the corkline can be by straps threaded through the block bodies and tightenable to clamp the blocks to the corkline. The bottom selvage of the net can be connected to the lead line in the same manner by threading a separate hanging cord through the bottom selvage and securing it at regularly spaced intervals to corresponding anchor blocks clamped to the lead line.

Abstract: A metal fishing lure containing a light emitting diode therein which is in direct communication with one or more passageways formed by one or more holes in the lure. Light is thus allowed to pass directly from the interior of the diode to the exterior thereof. Two miniature hearing aid batteries inserted in the lure power the light emitting diode.

Abstract: A fishing pole having a tubular rod with a handgrip attached to its rearward end. A pump assembly is mounted in said handgrip and its inlet port is connected to a container formed within the handgrip that is filled with liquid fish scent. The output end of the pump assembly is connected to an output tube that passes through the interior of the tubular rod and which ends adjacent the forward end of the tubular rod. By actuating a trigger finger connected to the pump assembly, the liquid fish scent is pumped through the output tube and exits from its forward end in droplets of fluid that drip down onto a fishing line running through an eyelet tip that is positioned at the end of the tubular rod. The liquid fish scent in its droplet form will travel down the downwardly extending fishing line and apply itself to the hook and the bait which is attached thereto. Periodically while fishing, the fisherman can actuate the trigger finger a few times prior to casting to rewet the hook and bait.

Abstract: The fishing rod holder attaches to a fishing rod and supports the rod and reel at a desired angle when set on surfaces such as earth, ice or in a boat. The rod holder is used while still-fishing, a fishing technique whereby the rod and reel is not held in the hand while waiting for a fish to take the bait. The rod holder keeps the rod and reel out of sand, snow, mud, dirt, etc. The rod holder remains attached to the rod during all fishing activities. The rod holder detaches easily and folds flat for storage or carrying.

Abstract: A soft plastic-bodied fish attractor threadably mountable over a fish hook and including a guard collar wherein the barb is embedded for weedless retrieval. In a jig compatible embodiment, the attractor comprises a tubular forward portion which mounts in non-rotative relation to a jig head and which radially flares outward to a disk-like guard collar portion and from a rear surface of which a plurality of filamentary members extend. In an artificial worm embodiment, the guard collar is integrally molded with the body rearward of the head.

Abstract: A fishing apparatus for assisting an angler in the placement of a lure or bait in a lake or stream is disclosed. The apparatus provides parallel buoyant hulls having vertical planes depending downward therefrom with adjustable hydrofoils attached to the planes. The device further provides a release mechanism and spring-biased visible trip flag. Methods of use of the device are also disclosed.

Abstract: A portable live bait container for use by anglers to transport and facilitate use of live bait such as minnows or shrimp or the like. The container includes an outer impervious enclosure provided with a supporting carrying handle and an open top and an inner shell of similar configuration which is slideably and removably mounted through the open top into the outer enclosure. The inner shell is provided with a handle support for vertically raising the inner shell out of the outer shell and includes side walls which are impervious to water and a bottom wall which is provided with openings for the ingress or egress of water. In addition, the bottom wall is provided with a centrally disposed bowl-like portion tending to entrap live bait and a small amount of water therein when the inner portion is raised above the surrounding water level.

Abstract: An animal trap is disclosed comprising an elongate, preferably air impermeable housing at one end of which is disposed a bait hook operatively associated with a trigger mechanism releasing a gate at the other end of the housing, to close same. Simultaneously with the closing, the interior of the housing is filled with an anesthetic. Thus, the animal trapped inside expires in its sleep without suffering.

Abstract: A system and method for protecting a ground plot of foliage plants or the like from freezing contemplates a series of ground-level sprinklers throughout the plot and a shade cloth covering of the type having uniformly dispersed openings therein. Elevated sprinklers are provided above the shade cloth and ground-level sprinklers. During periods of freezing ambient temperatures, water is sprinkled through the elevated sprinklers whereby the water freezes in the openings of the covering and holds heat released during operation of the ground-level sprinklers under the covering. When the water droplets freeze into a thin sheet of ice on the covering, the ground-level sprinklers are turned on.

Abstract: An efficient process employing cytoplasmic male sterility is provided wherein seeds capable of forming F.sub.1 hybrid Glycine max plants and restorer plants for the same simultaneously are formed in bulk in a single planting area and the seed harvest subsequently is segregated to form two substantially uniform seed assemblages. The parent soybean plants are provided with distinctly colored maternally-derived seedcoats wherein the genes for seedcoat coloration are homozygous dominant in one parent and homozygous recessive in the other parent. The resulting seeds are harvested in bulk and are separated on the basis of the soybean seedcoat coloration. Soybean plants resulting from the planting of the seeds capable of forming F.sub.1 hybrids upon self-pollination form seeds which substantially uniformly exhibit maternally-derived light-colored seedcoats in the F.sub.2 generation thereby enabling the grower to produce a substantially uniform soybean harvest.

Abstract: A method and apparatus for growing a number of plants from cuttings, in a limited space, while mechanically resisting root entanglement. Tubes are placed in a container into which water is added. Plant cuttings are placed individually into the tubes such that the leaf portion of each plant is supported by a tube and the stem portion is suspended in water inside the tube. When roots develop, a growing medium may be added to prolong root growth or the plant may be removed from the tube for permanent planting. Methods of root growth stimulation are also disclosed.

Abstract: Apparatus for propagation of plant seedlings including a cell chain comprising a series of cells rigidly connected to form a group of aligned cells each group being pivotal relative to its adjacent group by a link cell to form a continuous chain of cells able to be mechanically handled by transport devices or concertined into a solid block of cells having little or no wastage of space.

Abstract: A viewing and oral communications assembly for doors generally rectangular in shape, having mirror surfaces to transmit images from positions adjacent to the door through the assembly and having audio communication slots which are closed by expansion of intumescent material in the presence of heat.

Abstract: A combined slide guide and pivot pin for engaging the sash balance of a double-hung window assembly, and for riding in a guide rail of the master frame jamb of the window assembly to retain the guide rail in alignment relative to the sash window when the window is slided, utilizes a unitary metal member having, at a first end, a notched upper surface adapted to engage the sash balance, and having a cross-bar, as a slide guide, disposed proximate the first end with bevelled upper and lower surfaces.

Abstract: A sliding window to be installed in a rough frame opening in a wall. The window comprising a frame including a sill, header, two jamb members and a removable mullion. Contained in the frame are a fixed panel and a sliding panel. A locking handle is provided for the sliding panel. More importantly the removable mullion allows the fixed panel to be secured in the left or right hand side of the frame as desired. Seals and frame features prevent air and sound leakage particularly under stress from a heavy wind. Also disclosed is an anti-lift stop device to prevent removal of the movable panel.

Abstract: A brake mechanism utilizes the tension of a spring acting upwardly and the weight of a window acting downwardly to produce a force couple for applying a frictional force to hold a window sash in a preselected position in a sash run. The mechanism is utilized in combination with a jamb liner defining an elongated sash run provided with a C-shaped guide channel in its plow region. The channel has co-planar, laterally spaced, flanges defining a longitudinally extending slot therebetween. A brake component has a pair of shoe portions disposed in the channel adjacent respective internal flange surfaces. The brake component rotates in the channel to move the shoe portions into frictional engagement with the internal flange surfaces. A columnar element rigid with the brake component extends through the slot and presents means disposed outside the channel for applying a torque to rotate the brake component inside the channel.

Abstract: A centerless grinding machine comprising a grinding wheel on a rotational sleeve supported by a hydrostatic bearing means on a stationary spindle fixed to a grinding wheel table, a regulating wheel supported by a hydrostatic bearing on a spindle fixed to a regulating wheel table, and a blade for supporting a workpiece. Both wheel tables supporting the corresponding wheel are guided along a hydrodynamic sliding guide way to which a uniform pre-load is applied by hydrostatic bearings, and a servo mechanism is provided to compensate for frictional forces generated on the feed guide way, whereby it is possible to accomplish fine positioning of the corresponding wheel table and to grind the outer periphery of the workpiece with high precision and efficiency.

Abstract: A manhole for an urban sanitary system comprises a cover 2, a frame 1 for receiving the cover, a toric elastomeric sealing ring G1 interposed between the frame and the cover, and a soundproofing ring G2 on which the cover seats. The locking of the cover on the frame and the support of the cover on the rings G1and G2 are implemented by a plurality of flanges 4 recessed in the frame and bolted thereto.

Abstract: Roof-mounted devices for providing drainage channels through ice dams that may form on a roof under winter conditions are spaced along the margin of the roof, each device comprising an elongated, heat-collecting metal plate which is installed in a transversely upright position between an adjacent pair of shingles. The plate extends longitudinally in a downward direction along the slope of the roof with its lower end portion projecting clear of the roof. Opposed, major vertical surfaces are thus presented by the plate and are black in color to maximize the collection of solar energy thereby causing a drainage channel to form along the surfaces through dams of ice or snow.