This invention relates to an offset printing press, and particularly to the control of the press temperature. The offset printing press has wide application throughout the printing industry. The printing press generally delivers ink from an ink supply through a series of rollers to a roller having the actual image to be imprinted thereon.

This image roller, in turn, transfers the ink in the desired pattern to the material being printed on. Many of these rollers are driven by a gear mechanism, usually from only one side of the press, and other rollers are rotated simply by the frictional engagement between that roller and adjacent rollers.

Virtually all rollers are mounted on bearings at the ends of the rollers. Printing quality depends a great deal upon maintaining uniform conditions in the press. One important condition is the temperature of the press, including the temperature of the ink and of the rollers on which the ink is transferred.

In addition, when the press is run after a long period of quiescence, the parts of the press will be at room temperature and must be warmed to operating temperature to provide consistent printing.

In certain presses, a water coolant flow is utilized to cool various portions of the press and attempt to maintain a uniform temperature within the press. However, it has been found that water cooling has not been totally effective at providing a consistent and uniform temperature within the critical components of the press. Therefore, a need exists to better control the temperature of these critical components.

In accordance with one aspect of the present invention, a printing press is provided which includes a frame mounting a plurality of rollers. A lubricating oil storage tank is used and an oil pump is provided to distribute the lubricating oil to the rollers for lubrication.

A heat exchanger is provided with a first side and a second side. The lubricating oil from the oil pump passes through the first side of the heat exchanger. A coolant source is provided which supplies a coolant to the second side of the heat exchanger. A lubricating oil temperature sensor senses the temperature of the lubricating oil or a critical component in the press and a control is provided to control the heat transfer from the lubricating oil to the coolant source to maintain the temperature of the lubricating oil or critical component about a set point.

In accordance with another aspect of the present invention, an offset printing press is provided which includes a frame mounting a plurality of rollers. A temperature sensor, source of coolant and source of heat are provided. A control is used to analyze the temperature sensed by the temperature sensor and permit a first rate of heat transfer to occur between the source of coolant or the source of heat to the press for a first temperature range about a set point and a second, increased rate of heat transfer to occur between the source of coolant or the source of heat when the temperature moves outside the first temperature range.

Referring now to FIGS. Many of the components of the press are well known, including a series of rollers which are rotated to transfer ink from a source of ink to the object being printed. The majority of the rollers are driven by a gear train on one side of the press and each of the rollers are typically supported by ball bearings at the ends of the rollers. The press 10 is provided with India No 1 Mobile Company lubricating system with lubricating oil being circulated from an oil sump 30 to various sites in the press requiring lubrication, such as the ball bearings supporting the rollers and the gear train driving the rollers.

The lubricating oil can be under pressure driven by an oil pump 29 or the oil pump 29 can simply lift the lubricating oil to the upper portions of the printing press where the oil will lubricate the components as it drips back to the sump.

This is illustrated by line 32 in the graph of FIG. At such a point, the operator has no choice but to shut down the press to allow the press to cool again into the preferred temperature range. Even with water cooling of the ink roller, the temperature rise of the printing press is only delayed somewhat, as illustrated by line 33 in FIG. With such cooling, a passage is usually formed through the ink roller s and cooling water is passed through this passage from one end of the roller s to the other.

Such cooling, by its very nature, will create somewhat of a temperature gradient across the roller as the water warms as it passes through the ink roller. The printing press 10 of the present invention is provided with a mechanism to cool the oil which includes a heat exchanger 38, a source of coolant 40 and a control 42 to control the quantity of heat transfer between the lubricating oil and the coolant supplied from the coolant source As will be explained hereinafter, the goal of the device is to aid in controlling the ink temperature at the point of application to a printing plate.

When this goal is achieved, this will aid in the improvement of print quality and lower waste. The transfer of heat from the lubricating oil removes accumulated heat from all the heat generating mechanical parts within the printing press. The source of coolant 40 can be chilled liquid, coolant air, direct freon or other refrigerant. The existing chilled water system in a plant can also be used. A temperature sensor 44 will be used to measure the temperature of the lubricating oil or of a key component or components in the printing press.

The temperature will be analyzed by the control 42 to determine the rate of heat transfer from the lubricating oil to the coolant in the heat exchanger 38 necessary to maintain the temperature of the lubricating oil or critical components at the desired set point temperature.

If the temperature sensor 44 is mounted at a specific point on the press, for example, a bearing hub, portion of the side frame, etc. The heat transfer rate is determined by the rate of flow of the coolant which is controlled by the control In a modification, a source of heat 46 can also be connected to the heat exchanger 38 which permits the lubricating oil to be heated. On any modern press that can produce close register printing, the press crew must rotate the press for some Watson Realty Company in the morning before the press is up to Royse Manufacturing Company for printing.

After the press has achieved operating temperature, the control 42 would then cool the lubricating oil as necessary to maintain a constant press temperature. If the oil temperature control 42 is operated around the clock, the lubricating oil would maintain the press at operating temperature through inactive periods and thereby eliminate the warmup period when the press is again activated.

By maintaining a stable temperature on the press bearings, gears, rollers and side frame, changes will be reduced Scranton Label Company the register over longer running periods.

Control of the lubricating oil temperature, in conjunction with Village Brewing Company Somerville Nj controlled ink rollers cooled by cooling water, will help reduce temperature variation across the press due to the higher temperature on the end of ink rollers.

Control of oil temperature will reduce this difference and help hold closer register over long running periods. With the present invention, Sges Company should be possible to achieve temperature control as shown by line 35 in FIG. Maintaining a controlled operating temperature range on the press will cause major components such as bearings and gears to have increased life and will allow those parts to seek and maintain a certain tolerance or fit.

This tolerance is maintained over indefinite periods by the cooling of the lubricating oil which will aid in holding color and register in the finished product. If desired, the cooling and heating capabilities of the lubricating oil can be combined with the existing control for water coolant flow through the ink rollers.

Both the zone control for the ink rollers and the lubricating oil temperature control may be contained in one enclosure Royse Manufacturing Company each printing unit. This enclosure would have a circulating pump for the water through the ink rollers, control circuits and mechanisms for controlling the hot and cold water flow, control circuits and mechanisms for controlling the temperature of the lubricating oil all controlled to provide a desired Royse Manufacturing Company temperature.

With reference to FIG. A multi-color press is made up of several single color units. Each printing unit is provided with an oil sump 30 and with a heat exchanger A single source of coolant 40 and source of heat 46 can be utilized but individual controls 42 will be provided for each of the printing units. The zone control system will include an individual circulation pump 29 for each printing unit. A series of check valves and solenoid valves permit the controllers 42 to provide the proper cooling Royse Manufacturing Company heating temperature to the lubricating oil in the particular printing unit.

With reference now to FIG. A control unit within the printing press is designed to use a form of fuzzy logic to maintain the temperature of the printing press within a narrow temperature range. Basically, the control will provide heat transfer to or from the printing press at a first lower rate if the temperature of the press varies from a set point by only a certain number of degrees.

If the temperature of the printing press lies outside that temperature range, i. Each of the printing units has a series of ink rollers whose temperature must be carefully controlled. To do so, each of the ink rollers has a coolant passage therethrough. A pump pumps the coolant fluid through line into the ink rollers to cool the rollers with the coolant being removed through lines If the ink rollers are maintaining the desired temperature, the water passing through the rollers is simply recirculated without the addition or removal of heat.

A bypass water solenoid valve is placed between line and line entering each pump which permits recirculation of the water from the rollers back into the inlet of the pump.

If the fluid provided to the ink rollers is designed to cool the ink rollers, at least some of the fluid flowing through the ink rollers is provided from a cold water storage through linecold water solenoid valve and line to the inlet of the pump The fluid is returned to the cold water storage through check valves and line If the fluid flowing through an ink roller is to heat the ink roller, at least some of the fluid flowing through the ink rollers is taken from a hot water storage through lines and to hot water solenoid valves and then to lines into the inlet of the pumps The fluid returns from the ink rollers through check valves and line A temperature sensor is mounted at each set of ink rollers to measure the temperature.

During that period, the bypass solenoid valve is maintained open and the bypass water is mixed with the hot or cold water at a predetermined ratio, for example 2. Should the temperature of the printing units continue to drift away from the set point, the control would be activated to shut the bypass solenoid valves so that only cooled water or heated water is provided to the printing press.

In addition to supplying purely cool or hot water, the rate of flow is increased due to the fixed capacity of the pumps During startup of the press, the temperature will be quite a bit lower than the set points of the individual printing units.

During this period, all bypass valves would be closed and only hot water would be used to raise the temperature of the press units to operating range. The hot water would be used to heat the press and the cold water is stored and used once the press reaches operating temperature for cooling the press. In a typical compressor operated cooling system, both hot and cold water can be produced simultaneously.

The compressor generates heat and this heat can be transferred to water in the hot water storage. The chilling coil can be used to chill the American Gas Light Company in the cold water storage.

The compressor operation is preferably controlled by the temperature of the chilled water storage. If the temperature of the hot water source is below the necessary storage temperature, auxiliary electric heaters can be turned on in order to maintain minimum temperature in the hot water storage. An efficiency is achieved by not operating the compressor and resistance heaters at the same time, thereby reducing the electric power used to maintain system temperature.

The printing press preferably uses two different temperature sensors. One sensor is a built-in water temperature sensor. Preferably, the operator will be able to select either the infrared sensor or water control sensor independently for each printing unit at the operator's control station.

Water temperature sensors will typically be used when the press is not running The Southern Connecticut Gas Company the infrared sensors may or may not be used when the press is running.

If desired, a switching circuit can be located in the control unit to switch from water control sensing to infrared sensing as the press becomes operational. The printing press illustrated in FIG. The circulation flows completely separated between the two printing units. If desired, the temperature change can be measured between the inlet and outlet of the cold and hot water storage. The fact that there is no mixing of common return water between printing units will allow the press to produce a much greater temperature difference between units than if there were a common return for mixing of the water.

By storing hot water in the hot water storage, the response time to a change in temperature on the printing press is much shorter since the system does not need to wait for a resistance heater to warm up. There will be indicators for the high pressure and low pressure switches of each compressor, also an indicator for the thermal disconnect on each compressor.

A flow switch is connected to each of the hot and cold water circulation pumps. There are indicators for the thermal disconnect on both pumps and the resistance heaters.

About

1929 The Royce Chemical Company was founded by Albert J Royce, Sr. as a Textile Chemical Manufacturing Company. It’s primary products were Sodium Hydrosulfite, Sodium Formaldehyde Sulfoxylate and Zinc Formaldehyde Sulfoxylate. Royce has remained in the production of Reductive Chemicals for almost 90 years.…

TRESU Royse Webshop

Royse Manufacturing Company was founded by Edwin H. Royse in 1961. It was the evolution of his father's heating and air conditioning service company that formed the basis of this new company. Mr. Royse positioned his young company in the graphic arts industry after engineering several innovative product designs for Dahlgren Manufacturing, USA.…

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Royce' Confect Co., Ltd. (株式会社ロイズコンフェクト, Kabushiki-gaisha Roizu Konfekuto), also known as E-Royce', is a Japanese chocolate manufacturing company. The company's central offices are located in Sapporo.Headquarters: Sapporo, Japan…

TRESU

TRESU is a highly specialized company offering flexible, customized solutions of flexo printing press machines and ancillary products and parts for flexo, digital and offset printing to the graphic industry.…