US3412875A

US3412875A - Laundry stacker

Info

Publication number: US3412875A
Application number: US665776A
Authority: US
Inventors: Weir Henry John
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-09-06
Filing date: 1967-09-06
Publication date: 1968-11-26
Anticipated expiration: 1985-11-26
Also published as: GB1175824A; DK115247B; SE343828B; DE1610299A1; NL6712112A; BE703481A

Description

Nov. 26, 1968 H. J. WEIR 3,412,875

LAUNDRY STACKER Filed Sept. 6, 1967 Fi .1. Mg 3 HENRY JOHN WEIR,

"mung J; HJMgAM United States Patent LAUNDRY STACKER Henry John Weir, The Yetts, Sedbury, Chepstow, Monmouthshire, England Filed Sept. 6, 1967, Ser. No. 665,776 Claims priority, application Great Britain, Sept. 6, 1966, 39,868/ 66 5 Claims. (Cl. 214-6) ABSTRACT OF THE DISCLOSURE A stacker for stacking laundry articles when they have been folded after laundering comprising a table having a smooth upper surface inclined to the horizontal, on to which surface articles to be stacked are fed; a stop which abuts against the lower edge of the table; and means for withdrawing the table rapidly away from the stop to allow any article thereon to drop on to a stack beneath the table. For particularly rapid withdrawal of the table a two-way air ram may be employed in a pneumatic circuit which allows either side of the ram to be vented.

The invention relates to a stacker for stacking laundry articles when they have been folded after laundering.

According to the invention a laundry stacker comprises a table having a smooth upper surface inclined to the horizontal, on to which surface articles to be stacked are fed; a stop having a substantially vertical surface which abuts against the lower edge of said inclined table surface; and means for withdrawing the table rapidly away from the stop to allow any article thereon to drop on to a stack beneath the table.

With such an arrangement it is important to achieve as rapid a withdrawal as possible since the more rapid the action the less will be the effect of any lateral drag on the article and the more accurately will the articles be stacked. In order to achieve a particularly rapid withdrawal the invention contemplates the provision, as means for withdrawing the table, of a double-acting air ram linked to the table; a two-way valve to which the two sides of the air ram are coupled in such a way as would simultaneously connect one side to a source of pressurised air and the other side to exhaust, or the other side to the source of pressurised air and the one side to exhaust, in dependence on the state of the valve; and an intermediate air valve connected in series between said two-way valve and the side of the air ram which is exhausted on withdrawal of the table, the intermediate valve being arranged to couple said side to the two-way valve except when the table is in the position to receive laundry articles, when the intermediate valve vents said side to exhaust. In this way an inherent disadvantage of a system which utilises merely a two-way valve of the kind described is overcome. This disadvantage is that there is always a compressed air supply connected directly to one side of the air ram or the other. With the air ram in the extreme position corresponding to the loading position of the table the compressed air supply is on the side of the air ram which is to be exhausted when the table is withdrawn. Therefore, on actuation of the two-way valve, it would be necessary, as the table is withdrawn, to exhaust the compressed air contained in the air ram. With the provision of an intermediate valve as described above it is ensured that there is no such compressed air to be exhausted. This allows a much more rapid action of the air ram.

Preferably the intermediate valve is situated beneath the table and has an actuating arm with which the table co-operates at all times except when it is in the position to receive laundry articles, co-operation of the table with the operating arm coupling the air ram through the in- 'ice termediate valve to the two-way valve and release of the operating arm coupling said side of the air ram to exhaust.

Preferably the two-way valve is reversed before the air ram and the table reach their fully withdrawn positions. This provides a buffer action for the table as it approaches the limit in the withdrawn position. The twoway valve is preferably a solenoid operated valve and the means for reversing the valve com-prises a microswitch mounted to be actuated by the table as it approaches the fully withdrawn position.

The means for actuating the solenoid valve to withdraw the table preferably comprises a delay device capable of responding to a timing signal and adapted to provide a suitable delay after receipt of the timing signal before actuating the two-way valve. Conveniently, the timing signals are derived from a folding mechanism preceding the stacker which folds the articles to be stacked.

The invention will further be described with reference to the accompanying drawings of which:

FIGURE 1 is a schematic elevational view of a laundry stacker in accordance with the invention;

FIGURE 2 is a pneumatic circuit diagram of the air ram and actuating valve of the laundry stacker; and

FIGURE 3 is a circuit diagram of the actuating arrangement for the solenoid valve.

Referring to FIGURE 1 the laundry stacker comprises a conveyor 1 which runs in the direction indicated by the arrow and on to which are fed laundry articles previously folded by a folding machine (not shown). The conveyor deposits the folded articles on to a table 2 which has an upper, smooth, inclined surface 3. The articles are prevented from sliding from the surface by a stop bar 4 which abuts against the lower edge of the surface 3.

Table 2 is capable of being withdrawn to a position indicated in broken line at 2:1 by a double acting air ram 5. A solenoid operated two-way air valve 6 operates the air ram to withdraw the table on receipt of a signal from a timing device (not shown) which responds to a timing signal from the folding device and after a predetermined delay issues the signal to actuate the air ram. In this way it is ensured that a predetermined time elap-ses after the final folding of the article, the time being sufficient to allow the article to be fed on to the table 2.

The arrangement is such that the air ram 5 acts to withdraw the table rapidly away from: stop bar 4 and thereby remove it from beneath the article, the article being allowed to drop on to a pile 7 formed beneath table 3 on a second table 8. After dropping the article the table 2 is returned to its normal position abutting stop bar 4. A counter 9 is operated by the table 2 as it is withdrawn and is effective to count the number of times the table is withdrawn. After a predetermined count the counter closes a circuit to operate a further air ram 10 which is effective to push the stack 7 sideways to the position illustrated at 7a where an operator can collect the stack. Counter 9 is capable of being set to operate at any desired count and, for example, may be set to operate at 20 articles where the articles are relatively large, such as pillowcases, for example, or at 60 articles for table linen, etc.

The side of the air ram 5 which is exhausted on withdrawal of table 2 is connected to valve 6 through an intermediate valve 11 which is arranged beneath table 2 and has an actuating arm 12 operated by contact with table 2. The operation of this valve will be described more fully with reference to FIGURE 2.

A microswitch 13 is mounted so as to be operated by table 2 when it is approaching its fully withdrawn position. This microswitch is connected in circuit so as to reverse the condition of solenoid valve 6 at this time and thereby provide an air cushion of pressurised air within air ram 5 to decelerate and return table 2 at the appropriate time.

FIGURE 2 shows the pneumatic circuit diagram for the operation of air ram 5. Solenoid operated valve 6 has two

outlets

14 and 15 to atmosphere (exhaust). An inlet 16 is connected to a source of pressurised air '17. The piston of air ram 5 is shown in the position corresponding to the loading position of table 2 shown in full line in FIGURE 1. When the table 2 is to be withdrawn the piston is moved to the left and the left-hand side of air ram 5 is thereby exhausted. It will be seen that the two sides of air ram 5 are connected to valve 6, the righthand side directly and the left-hand side through the intermediate valve 11. With the intermediate valve 11 released, that is, with operating arm 12 free of table 2, as shown in FIGURES 1 and 2, it is elfective to vent the left-hand side of ram 5 to atmosphere. Operation of valve 6 applies air under pressure to the right-hand side of ram 5 and projects the piston and table 2 leftwards. Initial movement of the table 2 operates valve 11 so that the lefthand side of the air ram is then connected to valve 6, still to exhaust. When the table 2 nears its fully withdrawn position microswitch 13 (FIGURE 1) is operated and is effective to reverse valve 6 and thereby apply air under pressure to the left-hand side of ram 5 and exhaust the right-hand side. This provides a buffering action against movement of the table, arrests the table and returns it to its loading position. The interlock of the operating circuit for valve 6 is such that release of microswitch 13 is not effective to again reverse the valve.

It is important to note that without the provision of the intermediate valve 11 and with direct connection of the left-hand side of ram 5 to valve 6 the left-hand side of the air ram would be filled with compressed air until the valve 6 was reversed. Thus it would be necessary to exhaust this compressed air on withdrawal of the table. Therefore, venting the left-hand side of the air ram to atmosphere in the Way described is effective in speeding "the operation of the air ram and the withdrawal of table 2.

FIGURE 3 is a circuit diagram illustrating the connection of the operating circuit for solenoid valve 6. Two supply terminals of opposite polarity are shown at 18 and 19, a relay 20 being connected to terminal 18 and through an external switch 21 to terminal 19. Switch 21 is closed by operation of the folding device for the articles when the final fold is made. This energises relay 20 which closes tWo contacts of the

relay

22 and 23. Contact 22 is a holding contact for relay 20 and contact 23 energises a delay device 24. After a predetermined delay corresponding to the time necessary for the article to reach the table 2 after having been folded by the folding device, device 24 closes a contact 25 which energises the solenoid 26 of valve 6. Microswitch 13 is connected between contacts 22 and terminal 19 and i effective on actuation by table 2 to open the holding circuit for relay 20 thereby deenergising the relay and de-activating device 24 so as to de-energise relay 26 and reverse valve 6.

I claim:

1. A laundry stacker comprising a table having a smooth upper surface inclined to the horizontal, on to which surface articles to be stacked are fed; a stop having a substantially vertical surface which abuts against the lower edge of said inclined table surface; and means for Withdrawing the table rapidly away from the stop to allow any article thereon to drop on to a stack beneath the table and wherein the means for withdrawing the table comprises a double-acting air ram linked to the table; a twoway valve to which the two sides of the air ram are coupled in such a way as would simultaneously connect one side to a source of pressurised air and the other side to exhaust or the other side to the source of pressurised air and the one side to exhaust, in dependence on the state of the valve; and an intermediate air valve connected in series between said two-way valve and the side of the air ram which is exhausted on withdrawal of the table, the intermediate valve being arranged to couple said side to the two-way valve except when the table is in the position to receive laundry articles, when the intermediate valve vents said side to exhaust.

2. A laundry stacker as claimed in claim 1 wherein the intermediate valve is situated beneath the table and has an actuating arm with which the table co-operates at all times except when it is in the position to receive laundry articles, co-operation of the table with the operating arm coupling the air ram through the intermediate valve to the two-Way valve and release of the operating arm coupling said side of the air ram to exhaust.

3. A laundry stacker as claimed in claim 1 wherein reversing means is provided for reversing the two-way valve before the air ram and the table reach their fully Withdrawn positions.

4. A laundry stacker as claimed in claim 3 wherein the two-way valve is a solenoid operated valve and the reversing means comprises a micro-switch mounted to be actuated by the table as it approaches its fully withdrawn position.

5. A laundry stacker as claimed in claim 1 wherein the two-way valve is actuated by means comprising a delay device capable of responding to a timing signal and adapted to provide a suitable delay after receipt of the timing signal before actuating the two-way valve.

FOREIGN PATENTS 881,259 11/1961 Great Britain.

GERALD M. FORLENZA, Primary Examiner. R. J. SPAR, Assistant Examiner.