US 3622205 A
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United States Patent  Inventor Frank J. Zamboni Paramount, Calif. ] App]. No. 48,143  Filed June 22, 1970  Patented Nov. 23, 1971  Assignee Frank J. Zamboni & Co.
 ICE RINK RESURFACING MACHINE 8 Claims, 4 Drawing Figs.
 US. Cl 299/24, 37/5, 172/500  lnt.Cl E0lh 5/12  Field of Search 299/24-27, 36-41; 172/500; 37/4, 5. 12
 References Cited UNITED STATES PATENTS 2,763,939 9/1956 Zamboni 299/24 Primary E.raminer- Ernest R. Purser A!!0rneyHerbert E. Kidder ABSTRACT: An ice rink resurfacing unit is disposed transversely across the rear of an automotive vehicle and has runners at its ends which run on the ice. The unit is connected to the vehicle by two laterally spaced lift arms, which are pivoted on the vehicle for vertical swinging movement, and connected to the arms is a hydraulic lift cylinder which raises the arms to elevate the unit to transport position. Pivoted on the rear ends of the arms for vertical swinging movement are flexible joint members, each of which is connected to the resurfacing unit at a point spaced fore-and-aft from the pivot axis. A spring bears against the said member at a point spaced radially from the pivot axis, exerting a torque on the member, causing it to press the unit downwardly with yielding spring pressure.
PAIENTEDNOV 2 H 3.622.205
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BACKGROUND OF THE INVENTION This invention pertains to ice rink resurfacing machines, and more particularly to a machine of the class wherein a resurfacing unit is disposed transversely across the rear of an automotive vehicle and is connected thereto by towing linkage. The unit slides on the ice, and has a sharp-edged blade that takes a light shaving cut on the surface of the ice. A worm screw conveyor collects the shaved ice from in front of the blade and moves it in toward the center of the unit, where it is picked up, elevated, and dumped into a bin on the vehicle. Machines of this same general type are shown in my earlier U.S. Pat. Nos. 2,642,679 and 2,763,939.
One of the problems with machines of this type is that as the blade loses some of its sharpness, it has a tendency to chatter or slip over the ice without cutting unless it is forcibly held down into the ice. The depth of cut is gauged from the surface of the ice, and for that reason the ice-conditioning unit has its own runners that run on the ice, whereby the cutting edge of the blade is fixedly positioned with respect to the surface of the ice, and the draft connection between the unit and the towing vehicle has provision for relative vertical movement between them. In order to gain added downward pressure on the unit (over and above its own weight) so as to hold the blade down into the ice, it is desirable to transfer some of the weight of the vehicle to the unit. It is also desirable that this transfer of weight from the vehicle to the unit be resilient, so as to allow the unit to yield upwardly under excessive pressure, and in addition, the transfer of weight should be relatively unaffected by jouncing of the vehicle on it springs and pneumatic tires. Moreover, it is necessary that the conditioning unit be capable of being elevated to transport position when it is being transported from one place to another.
SUMMARY OF THE INVENTION The primary object of the present invention is to provide a new and improved ice rink resurfacing machine in which the conditioning unit extending transversely across the rear of the towing vehicle is connected to the latter by means embodying provision for transferring a substantial portion of the weight of the vehicle to the unit.
Another object of the invention is to provide a machine of the class described in which the weight-transferring means is resilient to allow the conditioning unit to yield upwardly in the event of excessive pressure, and in which the downward pressure exerted on the unit is relatively unaffected by jouncing of the vehicle.
A further object of the invention is to provide a weighttransferring mechanism in the draft connections, which allows the conditioning unit to be raised and lowered between working and transport positions, without requiring any change or adjustment in the weight-transfer mechanism.
These objects are achieved in the present invention by providing a flexible, spring-loaded joint between the draft tongues and the conditioning unit, whereby when the unit is lowered to the ice, the said joint is rocked about a horizontal pivot axis, causing the joint to exert a downward pressure against the unit as a result of stressing a spring on the draft tongue. The draft tongue is rigidly positioned with respect to the towing vehicle by means of a hydraulic lift cylinder, and vertical movement of the conditioning unit relative to the vehicle is accommodated by rocking movement of the springloaded joint. The downward pressure exerted by the springloaded joint represents a transfer of a portion of the weight of the vehicle to the unit, and the amount of such pressure can be increased or decreased by means of an adjusting screw. When the hydraulic lift cylinder is actuated, the draft tongues are raised, lifting the conditioning unit to transport position, during which operation the flexible joint member rotates about its pivot until the spring is unloaded, before the unit begins to raise.
Other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment thereof, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cut away side elevation of an ice rink resurfacing machine embodying the invention;
FIG. 2 is a rear view of the same, also cut away in part to reveal certain portions of the mechanism;
FIG. 3 is an enlarged fragmentary sectional view taken at 3-3 in FIG. 2; and
Flg. 4 is a fragmentary side elevational view of a detail, as seen from 4-4 in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the reference numeral 10 designates the ice rink resurfacing machine in its entirety. The machine consists of an ice surface conditioning apparatus 12 disposed across the rear end of an automotive vehicle 14, to which it is operatively connected in a manner to be described hereinafter. The vehicle 14 is preferably of the four-wheel drive variety, and mounted on the top of the vehicle chassis is a large, open-top bin 16, into which shaved ice removed from the surface of the skating rink ice is thrown. The bin 16 is pivoted at its front end for forward dumping, and hydraulic means is provided for tilting the bin up about its forward pivot axis. Mounted on the chassis of the vehicle below the bin 16 is a water tank 18, which carries replacement water for spreading over the shaved ice to fill in crevices or cuts, and to restore the ice to its original level. The operator sits in an operators seat 20 at the rear of the machine on the left-hand side thereof, where he can manipulate the various controls for driving the vehicle and operating and adjusting the ice resurfacing apparatus.
The ice conditioning apparatus 12 consists of a transversely extending frame 21 made up of welded steel beams and plates, which is supported at its ends on fore-and-aft extending end plates 22, the bottom edges of which rest upon the ice and serve as runners to support the frame. The frame 21 is connected to the vehicle by a pair of laterally spaced, fore-and-aft extending lift arms 23, which are pivoted intermediate their ends on two chassis frame members 24 extending rearwardly from the back end of the vehicle. The pivot connection of the lift anns 23 to frame members 24 is by means of pivot bolts 25, and these allow the arms 23 to swing in parallel vertical planes.
Mounted on the frame 21 of the ice conditioning apparatus is a transversely disposed, sharp-edged blade 26 which is inclined to the surface of the ice, and is adjustable, for angle of incidence and depth of cut. Adjusting for angle of incidence is by means of a hand wheel 27 mounted on the top end of a shaft 28, which is connected at its lower end to an adjusting screw on the apparatus 12.
The shaved ice is collected from in front of the blade 26 by means of a transversely extending worm conveyor 29, which is mounted on a shaft 30. Shaft 30 is joumaled at its ends in bearings mounted on the end plates 22, and the spiral flights of the worm conveyor 29 are interrupted in the center, with the flights on each side of center being turned in opposite directions so that when the shaft rotates in one direction, shaved ice is moved inwardly toward the center from both ends of the blade.
The worm conveyor shaft 30 is preferably driven by a hydraulic motor (not shown) which is supplied with high pressure fluid from a suitable pump on the vehicle, said fluid being carried to the motor and returned to the pump through flexible hoses 31.
The shaved ice brought in toward the center of the apparatus 12 by the worm conveyor 29 is picked up and dumped into the bin 16 by means of a vertical worm screw elevator 32 which turns within a cylindrical housing 33. The open, bottom end of the housing 33 is disposed a few inches above the ice,
just ahead of the open center section of conveyor 29, so that shaved ice accumulated by the latter is picked up by the worm screw elevator 32 and carried up the housing 33 to a slinger mounted on the top end thereof. The slinger 37 hurls the shaved ice forwardly into the bin 16 through an opening in the rear end of the bin,
As mentioned earlier, the lift arms 23 are pivoted intermediate their ends on pivot bolts 25, and the rear ends of the arms are connected to the conditioning apparatus 12 by means which will be described presently. The front ends of the arms 23 are solidly connected together by a transverse pipe 34, and welded to the pipe near its midpoint are two closely spaced, upwardly extending arms 35. Disposed between the arms and pivotally connected thereto is a piston rod 36, the upper end of which passes through the bottom end of a hydraulic cylinder 38. The top end of the cylinder is pivotally connected to a bracket 40 mounted on the vehicle. The cylinder 38 is supplied with high-pressure fluid from a pump and valves (not shown) on the vehicle, and the fluid is piped to opposite ends of the cylinder through flexible hoses 42.
The rear ends of the lift arms 23 are each connected to the ice conditioning apparatus 12 by means of a flexible joint member 44, which is best shown in FIG. 4. The member 44 is preferably L-shaped, or angle-shaped, as shown, with a horizontal leg 45 and a vertical leg 46. Member 44 may conveniently be made by welding two pieces 45 on opposite sides of a single piece 46 at the upper end of the latter; piece 46 being the same width as the lift arm 23, and therefore the facing sides of the two pieces 45 being spaced apart the exact distance to receive the rear end of arm 23 between them. At their front ends (i.e., the left-hand ends, as seen in FIG. 4), the pieces 45 are connected to the arm 23 by a pivot pin 48, which passes through aligned holes in the members 45 and 23. The bottom end of leg 46 fits loosely between two parallel foreand-aft extending bars 50 on the top side of unit 12, and is connected thereto by a pivot pin 52.
The top edges of horizontal leg pieces 45 are provided with a smoothly crowned portion 53, and bearing downwardly on this portion is the toe 54 of a leaf spring 55, the said toe being curled upward slightly to form a rounded contacting surface on its underside. The front end of leaf spring 55 is bolted to a bracket 56 that is welded to the top side of arm 23, and the intermediate portion of the spring passes through an inverted U- shaped strap 58, the legs of which pass down over opposite sides of arm 23 and are welded thereto. An adjusting screw 60 is screwed down through a tapped hole in the portion of strap 58 bridging the spring, and the bottom end of the screw bears against the top side of the spring. By turning the screw 60 down (i.e., clockwise) the said portion of the spring is bent downwardly toward the lift arm 23, causing the toe 54 to exert increased downward pressure against the member 44%.
By virtue of the construction described above, the flexible joint member 44 exerts a downward pressure on the conditioning unit 12 at a point spaced in the fore-and-aft direction (in this case, rearwardly) from the pivot axis of pin 48, while spring 55 exerts a pressure against member 44 at a point spaced radially from pivot axis 48, causing member 44 to thrust downwardly against unit 12 with a yielding spring pressure. While the machine is in operation, the lift arms 23 are held rigid with respect to the vehicle 14 by the lift cylinder 38 and piston rod 36, and all relative vertical movement between the unit 12 and arms 23 is accommodated by rocking movement of the flexible joint members 44 about their pivot axes 48.
When the conditioning unit 12 is to be picked up for transport, the hydraulic cylinder 38 is actuated, causing the piston rod 36 to push the front ends of lift arms 23 downwardly about their pivot axis 25, which has the effect of raising the rear ends of the arms. During the initial lifting movement of the rear ends of arms 23, the flexible joint members 44 rotate in the clockwise direction until the spring 55 is fully unloaded, after which the unit 12 hangs from the lift arms on the pivot pins 48.
While I have shown and described in considerable detail what I believe to be the preferred form of the invention, it will be understood by those skilled in the art that various changes can be made within the scope of the following claims. For example, lift arms 23 might be pivoted on the vehicle 34 at their front ends, and the hydraulic lift cylinder 38 connected to the lift arms at some point intermediate their ends. Or, the member 44 and springs 55 might take other forms than those shown above.
1. An ice rink resurfacing machine comprising, in combination:
an automotive towing vehicle having draft means consisting of at least one arm extending rearwardly from the back end of the vehicle and pivoted for vertical swinging movement; and power-lift means connected to said arm to raise and lower the rear end thereof;
an ice conditioning unit disposed transversely across the rear of said vehicle; said unit including a sharp-edged blade disposed to take a shaving cut in the surface of the ice, and means for removing the shaved ice from in front of the blade; and
means connecting said ice conditioning unit to said arm to be towed thereby, said means including a spring-loaded flexible joint member pivoted on said arm for rocking movement in a vertical plane, said member being connected to said unit at a point spaced horizontally from its pivot axis, and said spring-loading causing a torque to be exerted on said flexible joint in the direction to exert a downward pressure on said unit.
2. An ice rink resurfacing machine as in claim 1 wherein said flexible joint member is pivoted on the rear end of said arm and extends rearwardly therefrom, said member being connected to said unit at a point spaced rearwardly from its pivot axis, and a spring acting upon said member in a direction to cause the latter to exert a downward pressure on said unit.
3. An ice rink resurfacing machine as in claim 2, wherein said spring is attached at one end to said arm and bears at the other end against said member at a point spaced radially from the pivot axis thereof.
4. An ice rink resurfacing machine as in claim 3, wherein said spring comprises a leaf spring, one end of which is attached to said arm and the other bears against said member, and adjustable means on said arm bearing against said spring at a point intermediate its ends to vary the pressure exerted by said other end against said member.
5. An ice rink resurfacing machine as in claim 1, wherein said draft means consists of a pair of laterally spaced, foreand-aft extending arms which are joined together into a single unitary member, said arms extending rearwardly from the back end of the vehicle and being pivoted for vertical swinging movement;
each of said arms being connected at its rear end to said unit by a flexible joint member which is attached to the unit in a manner whereby the member is able to exert a downward pressure against said unit; and
spring means acting against said member in the direction to cause the member to thrust downwardly against the unit.
6. An ice rink resurfacing machine as in claim 5, wherein each of said flexible joint members is pivoted on its associated arm for swinging movement in a vertical plane, and said spring means being attached at one end to said arm and bearing at the other end against said member at a point spaced radially from the pivot axis thereof.
7. An ice rink resurfacing machine as in claim 6, wherein said spring means comprises a leaf spring, one end of which is attached to said arm and the other bears against said member, and adjustable means on said arm bearing against said spring at a point intermediate its ends to vary the pressure exerted by said other end against said member.
8. An ice rink resurfacing machine as in claim 5, wherein said arms are pivoted intermediate their ends on said vehicle, and are connected together at their front ends by a transverse a leaf spring attached at one end to said arm and extending rearwardly over the top edge of said member. the rear end of said spring bearing downwardly against said member directly over said vertical leg; and
an adjusting screw on said arm bearing downwardly against said leaf spring intermediate the ends thereof, so as to vary the pressure exerted by the rear end of the spring against said member.