[dizzlekush]

I found a few different instructions to making BAP stock solutions. For my testing i would like a 10,000ppm (1.0%) BAP stock solution so i could easily control ppm for testing

examples

5ml BAP stock solution + 995ml combined water, saponins, and surfactant =
50ppm BAP spraying solution

2.5ml BAP stock solution + 997.5ml combined water, saponins, and surfactant =
25ppm BAP spraying solution

10ml BAP stock solution + 990ml combined water, saponins, and surfactant =
100ppm BAP spraying solution


anyway here they are:

0032]From the above description it can be inferred that 6-benzyladenine, if applied at suitable times and with suitable doses onto fruitlets and/or unripe young fruits of the actinidia genus, can increase size and weight of ripe fruits and change positively their form, without jeopardizing their firmness and other quali-quantitative parameters.

[0033]The addition of natural substances such as leonardite, and/or its active components, or similar compounds, or of low toxicity natural compounds with surfactant and/or surfactant-tackifying properties, such as ethoxylated sorbitan monolaurate and/or the others as mentioned above, increases the activity of 6-benzyladenine to a significant extent.

[0034]Said natural substances can be added to 6-benzyladenine alone or in any combination.

[0035]For instance, a formulation comprising 6-benzyladenine in association with leonardite, and/or one or more of its active substances, and with ethoxylated sorbitan monolaurate, and/or at least a surfactant and/or surfactant tackifier chosen among those described above, has proved particularly useful.

[0036]The preferred application is spraying in aqueous solution, carried out by means of current equipment normally used for applying plant protection products and/or plant hormones onto plants. Said application is executed one or more times on young fruitlets starting from few days after petal drop until fruits, which are still unripe, have stopped growing and have reached the size of ripe fruits.

[0037]Said composition shall preferably be in liquid form, although solid formulations are not at all excluded, such as for instance powders, granulates or pills or water-soluble tablets.

[0038]In case of liquid formulations, 6-benzyladenine and most components listed above will be present in solution; however, some of them that are less soluble in water (leonardite for instance) can be used in suspension.

[0039]Generally speaking, the formulations according to the invention are prepared by dissolving first a suitable amount of potassium hydroxide in water, preferably lukewarm water, so as to reach a basic pH for stabilizing 6-benzyladenine in time; then (if required by the formulation) ethoxylated lauryl sulfate or the desired surfactant and/or surfactant-tackifier is added; 6-benzyladenine is usually added as final component, keeping the solution under stirring. Leonardite, if required, can be added at any time.

[0040]Preferably, 6-benzyladenine is then prepared by solubilization in water, after adding strong bases, in concentrations of 10,000 to 500,000 ppm, preferably of 20,000 to 100,000 with respect to solution volume.

[0041]By mere way of non-limiting example, the following contains some possible examples of concentrated mother liquor, in which the weights of the single components are in grams per 100 grams of composition.

Recipe A
pure 6-benzyladenine 9.35 g;
potassium hydroxide 5.0 g;
water to 100 g.

Recipe B
pure 6-benzyladenine 2.0 g;
monopropylene glycol 20.0 g;
water to 100 g.

Recipe C
pure 6-benzyladenine 9.35 g;
ethoxylated monolauryl sulfate 10.0 g;
potassium hydroxide 5.0 g;
water to 100 g.

Recipe D
pure 6-benzyladenine 9.35 g;
nonyl phenol 4.0 g;
chipped potassium hydroxide 4.25 g;
leonardite 2.0 g;
water to 100 g.

[0042]It should be kept in mind that the concentrations referred to by way of example in the previous recipes as well as those referred to as preferred for 6-benzyladenine refer to concentrated mother liquor.

[0043]More to the point, the low values contained in the table of the experimental tests above are due to the fact that said concentrated mother composition is not used as such but it is diluted before use in water of spraying machines, for instance at a dose of 100 ml per 100 liters of water.

[0044]Suppose for instance a formulation containing 100 g of 6-benzyladenine per liter of solution, corresponding to a concentration of about 100,000 ppm of 6-benzyladenine with respect to solution volume.

[0045]If 100 ml of this concentrated product are diluted in 100 liters of water before use, a dilution of 1,000 will be obtained. The final concentration of 6-benzyladenine will be therefore of 100 ppm.

https://www.patsnap.com/patents/view/EP1579768A1.html

The percentage ratios of the components of the formulations are to be considered as % by weight with respect to a total weight of 100 grams of final formulation.
In a reactor equipped with stirrer and heating and cooling means, a basic solution is prepared by dissolving under stirring at a temperature of about 35°C an amount of 90% potassium hydroxide, corresponding to 4.25% by weight of the final formulation, in an amount of water of 82.30% by weight.
The solution thus obtained is gradually added under constant stirring with an amount of ethoxylated lauryl sulfate corresponding to 4% by weight of the final formulation.
Eventually, still under stirring, an amount of 98% 6-benzyladenine corresponding to 9.45% by weight of the final formulation is added.
The resulting solution is cooled at room temperature under stirring, then it is packed so as to obtain the desired concentrated mother liquor.

Following the procedure described in Example 1, the following concentrated formulations were prepared.

2)
98% 6-benzyladenine 9.45%;
polyethoxylated alkylaryl ether 4.00%;
humic acids 0.01%;
90% potassium hydroxide 4.25%;
water 82.29%.

3)
98% 6-benzyladenine 9.45%;
ethoxylated sorbitan monooleate 4.00%;
90% potassium hydroxide 4.25%;
water 82.30%.

4)
98% 6-benzyladenine 9.45%;
ethoxylated sorbitan monooleate 4.00%;
humic acids 0.01%;
90% potassium hydroxide 4.25%;
water 82.29%.

5)
98% 6-benzyladenine 9.45%;
amine salt of ethoxylated and
phosphorylated polyaryl phenol 4.00%;
ethoxylated alcohol 3.00%;
90% potassium hydroxide 6.25%;
water 77.25%.

6)
98% 6-benzyladenine 9.45%;
polyethoxylated alkylaryl ether 4.00%;
90% potassium hydroxide 4.25%;
water 82.30%.

https://ip.com/patapp/EP1579768A1

Directions for making BAP Stock Solution (1mg/ml)

100mg BAP (Benzylaminopurine)
1ml 30% KoH (Potassium Hydroxide)
99ml Distilled Water

BAP will not dissolve in water, so KoH is usually used as the solvent. Add the 100mg of BAP to 1ml of KoH. Carefully stir the mixture until the BAP has fully dissolved. The slowly add the 99ml of distilled water.

At this point I usually place 10ml of the stock solution into small vials and freeze any of them that I am not going to immediately use. Then when you need to make a batch of stem prop medium, all you need to do is thaw one vial of the stock BAP solution.

https://orchidvault.com/node/70

Preparation of 6-BA Stock Solution (1 mg/ml):

[0055] 100 mg 6-BA was weighed and dissolved in 1 ml 1 N potassium hydroxide for 5 minutes, then 10 ml distilled water was added for complete dissolution. The resulting solution was brought to 100 ml with distilled water and stored at room temperature for later use.

https://patents.com/us-20110160444.html

The composition of claim 6, wherein the amount of 6-benzyladenine is about 2.0% by weight, the amount of potassium hydroxide is about 1.13% by weight, and the amount of water is about 96.87% by weight.

https://www.faqs.org/patents/app/20100216641

I've been under the impression bap is dangerous/carcinogen and wouldn't want it in my medical garden.

[dizzlekush]

Originally Posted by swisscheese

I've been under the impression bap is dangerous/carcinogen and wouldn't want it in my medical garden.

well its an understandable fear but you've been under the wrong impression. BAP is used to grow apples, pistachios, spinach, and other crops regularly

here's the toxocology info on bap
Inhalation, rat: LC50 = 5.2 gm/m3;
Oral, mouse: LD50 = 1300 mg/kg;
Oral, rat: LD50 = 2125 mg/kg;
Oral, rat: LD50 = 1.3 gm/kg;
Skin, rabbit: LD50 = 5 gm/kg;

with a spray solution at 40-100 mg per liter, BAP only shows slight danger to the person working with the solution, and no danger for people consuming crops.

"In acute toxicity studies, N6-Benzyladenine is slightly toxic by the oral route and produces moderate eye irritation; it has been placed in Toxicity Category III (the second-to-lowest of four categories) for these effects. It is of relatively low acute dermal and inhalation toxicity, and is only a slight irritant to the skin; it has been placed in Toxicity Category IV for these effects. N6-Benzyladenine does not appear to be a skin sensitizer or mutagenic.
In a subchronic toxicity study using rats, N6-Benzyladenine caused decreased food consumption, decreased body weight gain, increased blood urea nitrogen, and minimal changes in kidney tissue. It shows some evidence of causing developmental toxicity and maternal toxicity.

Dietary Exposure
Although N6-Benzyladenine has two food crop-related uses (on fruit- bearing apple trees and spinach grown for seed), it is exempt from the requirement of a tolerance because it is a biochemical pesticide used at a rate of less than 20 grams of active ingredient per acre. Therefore, the Agency will revoke the existing tolerance and establish an exemption from the requirement of a tolerance for the currently registered uses of this pesticidal compounds on apples and spinach.
Because the use rate is low and application precedes harvest by approximately four months, the potential for dietary exposure is considered to be negligible.

Occupational and Residential Exposure
Pesticide workers (mixers, loaders and applicators) may be exposed to N6-Benzyladenine during application. Dermal exposure is expected to be moderate to high for workers who open, pour, mix and load the pesticide, and to applicators using hand sprayers and air blast equipment.
To reduce worker exposure, EPA is requiring use of the personal protective equipment (PPE) and Restricted Entry Interval set forth in the Agency's Worker Protection Standard (WPS). Because formulated products that contain N6-Benzyladenine are in Toxicity Category II, use of the following PPE is required: long-sleeved shirt and pants, socks, chemical- resistant footwear, chemical-resistant gloves, respiratory protection devices, and protective eyewear. Although the PPE requirement is based on the acute toxicity of the end-use product, it will mitigate exposure substantially and thus will serve to protect pesticide handlers from potential developmental toxicity effects. Further, the Restricted Entry Interval of 12 hours set forth in the WPS will be required, reducing the risks of post- application exposure to benzyladenine.

Human Risk Assessment
N6-Benzyladenine is of moderate to relatively low acute toxicity, but has been demonstrated to cause developmental toxicity and maternal toxicity in laboratory animals. The potential for dietary exposure is negligible. Applicator exposure and risk of developmental and maternal toxicity will be reduced through use of personal protective equipment (PPE) and the Restricted Entry Interval (REI) set forth in the Worker Protection Standard (WPS)."

and here's another link that show the changes made to these limitations:
https://www.epa.gov/oppbppd1/biopesti...ces_116801.htm

basically just lessening the restrictions even further. BAP isn't a really dangerous substance, however handling the stock solutions and working solutions could be fairly toxic due to potassium hydroxide, sodium hydroxide or other caustic chemicals. so there are precautions when working with BAP that have to be respected (skin, eye, respiratory protection when spraying), but other than that, BAP used properly does not have health risks for us.

[GP73LPC]

Originally Posted by swisscheese

I've been under the impression bap is dangerous/carcinogen and wouldn't want it in my medical garden.

you're thinking of BPA...

[dizzlekush]

I originally posted this on the "gibberellin + jasmonic acid = more trichomes?" thread, but since i felt it was pertinent to this thread, ive posted it here as well.

Cytokinins (6-BAP specifically) have shown to have equal or greater abilities in increasing trichome production over gibberellins. Now recognize that the increased production of GLANDULAR TRICHOMES ONLY can possibly increase production of cannabinoids, terpenoids and other phytochemicals. MeJA increases glandular trichome development more so than cytokinins or gibberellins, or at least interacts with the genes that initiate phytochemical production in glandular trichomes, while cytokinins and gibberellins do not. Cytokinins usually have similar (slightly less usually) amounts of overall induced increased trichome production as MeJA, and more so than Gibberellins.

I was not able to find any studies where MeJA was co-applied with cytokinins and trichome production was quantified. there is obvious antagonism between jasmonates and cytokinins, since jasmonates stunt mitosis, while cytokinins promote it. so it is possible that co-applying GIBB with MeJA will be more effective than co-applications with cytokinin when it comes to trichome production, since GIBBs promote cell elongation instead of division, while jasmonates have no effect on cell size.

Temporal Control of Trichome Distribution by MicroRNA156-Targeted SPL Genes in Arabidopsis thaliana
Nan Yu, Wen-Juan Cai, Shucai Wang, Chun-Min Shan, Ling-Jian Wang, and Xiao-Ya Chena

The production and distribution of plant trichomes is temporally and spatially regulated. After entering into the flowering stage, Arabidopsis thaliana plants have progressively reduced numbers of trichomes on the inflorescence stem, and the floral organs are nearly glabrous. We show here that SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes, which define an endogenous flowering pathway and are targeted by microRNA 156 (miR156), temporally control the trichome distribution during flowering. Plants overexpressing miR156 developed ectopic trichomes on the stem and floral organs. By contrast, plants with elevated levels of SPLs produced fewer trichomes. During plant development, the increase in SPL transcript levels is coordinated with the gradual loss of trichome cells on the stem. The MYB transcription factor genes TRICHOMELESS1 (TCL1) and TRIPTYCHON (TRY) are negative regulators of trichome development. We show that SPL9 directly activates TCL1 and TRY expression through binding to their promoters and that this activation is independent of GLABROUS1 (GL1). The phytohormones cytokinin and gibberellin were reported to induce trichome formation on the stem and inflorescence via the C2H2 transcription factors GIS, GIS2, and ZFP8, which promote GL1 expression. We show that the GIS-dependent pathway does not affect the regulation of TCL1 and TRY by miR156-targeted SPLs, represented by SPL9. These results demonstrate that the miR156-regulated SPLs establish a direct link between developmental programming and trichome distribution.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2929091/

Functional Specialization of the TRANSPARENT TESTA GLABRA1 Network Allows Differential Hormonal Control of Laminal and Marginal Trichome Initiation in Arabidopsis Rosette Leaves
Lies Maes, Dirk Inzé and Alain Goossens

Trichome initiation in Arabidopsis (Arabidopsis thaliana) is controlled by the TRANSPARENT TESTA GLABRA1 (TTG1) network that consists of R2R3- and R1-type MYB-related transcription factors, basic helix-loop-helix (bHLH) proteins, and the WD40 protein TTG1. An experimental method was designed to investigate the molecular mechanisms by which jasmonates, cytokinins, and gibberellins modulate Arabidopsis leaf trichome formation. All three phytohormones provoked a seemingly common effect on cell patterning by promoting trichome initiation but caused strikingly distinct effects on cell and trichome maturation. The phytohormonal control was mediated by transcriptional regulation of the established TTG1 complex and depended on the R2R3-MYB factor GLABRA1. However, unsuspected degrees of functional specialization of the bHLH factors and a resultant differential molecular regulation of trichome initiation on leaf lamina and leaf margins were revealed. Trichome formation on leaf lamina relied entirely on GLABRA3 and ENHANCER OF GLABRA3. Conversely, TRANSPARENT TESTA8 (TT8) was particularly important for marginal trichome development. This hitherto unknown role for TT8 in trichome formation further underscored the functional redundancy between the three TTG1-dependent bHLH proteins.

https://www.plantphysiol.org/content/148/3/1453.full

Integration of cytokinin and gibberellin signalling by Arabidopsis transcription factors GIS, ZFP8 and GIS2 in the regulation of epidermal cell fate
Yinbo Gan, Chang Liu, Hao Yu and Pierre Broun

The effective integration of hormone signals is essential to normal plant growth and development. Gibberellins (GA) and cytokinins act antagonistically in leaf formation and meristem maintenance and GA counteract some of the effects of cytokinins on epidermal differentiation. However, both can stimulate the initiation of defensive epidermal structures called trichomes. To understand how their relative influence on epidermal cell fate is modulated, we investigated the molecular mechanisms through which they regulate trichome initiation in Arabidopsis. The control by cytokinins of trichome production requires two genes expressed in late inflorescence organs, ZFP8 and GIS2, which encode C2H2 transcription factors related to GLABROUS INFLORESCENCE STEMS (GIS). Cytokinin-inducible GIS2 plays a prominent role in the cytokinin response, in which it acts downstream of SPINDLY and upstream of GLABROUS1. In addition, GIS2 and ZFP8 mediate, like GIS, the regulation of trichome initiation by gibberellins. By contrast, GIS does not play a significant role in the cytokinin response. Collectively, GIS, ZFP8 and GIS2, which encode proteins that are largely equivalent in function, play partially redundant and essential roles in inflorescence trichome initiation and in its regulation by GA and cytokinins. These roles are consistent with their pattern of expression and with the regional influence of GA and cytokinins on epidermal differentiation. Our findings show that functional specialization within a transcription factor gene family can facilitate the integration of different developmental cues in the regulation of plant cell differentiation.

https://dev.biologists.org/content/134/11/2073.full

Dissection of the phytohormonal regulation of trichome formation and biosynthesis of the antimalarial compound artemisinin in Artemisia annua plants.
Lies Maes, Filip C W Van Nieuwerburgh, Yansheng Zhang, Darwin W Reed, Jacob Pollier, Sofie R F Vande Casteele, Dirk Inzé, Patrick S Covello, Dieter L D Deforce, Alain Goossens

Biosynthesis of the sesquiterpene lactone and potent antimalarial drug artemisinin occurs in glandular trichomes of Artemisia annua plants and is subjected to a strict network of developmental and other regulatory cues. The effects of three hormones, jasmonate, gibberellin and cytokinin, were studied at the structural and molecular levels in two different A. annua chemotypes by microscopic analysis of gland development, and by targeted metabolite and transcript profiling. Furthermore, a genome-wide cDNA-amplified fragment length polymorphism (AFLP)-based transcriptome profiling was carried out of jasmonate-elicited leaves at different developmental stages. Although cytokinin and gibberellin positively affected at least one aspect of gland formation, these two hormones did not stimulate artemisinin biosynthesis. Only jasmonate simultaneously promoted gland formation and coordinated transcriptional activation of biosynthetic gene expression, which ultimately led to increased sesquiterpenoid accumulation with chemotype-dependent effects on the distinct pathway branches. Transcriptome profiling revealed a trichome-specific fatty acyl- coenzyme A reductase, trichome-specific fatty acyl-CoA reductase 1 (TFAR1), the expression of which correlates with trichome development and sesquiterpenoid biosynthesis. TFAR1 is potentially involved in cuticular wax formation during glandular trichome expansion in leaves and flowers of A. annua plants. Analysis of phytohormone-modulated transcriptional regulons provides clues to dissect the concerted regulation of metabolism and development of plant trichomes.

https://www.mendeley.com/research/dis...-annua-plants/

Hormone-mediated promotion of trichome initiation in plants is conserved but utilizes species- and trichome-specific regulatory mechanisms
Lies Maes and Alain Goossens

Plant trichome initiation is steered by diverse developmental and environmental cues, through molecular mechanisms that remain elusive in most plant species. Using a robust experimental method to investigate the molecular mechanisms by which phytohormones modulate leaf trichome formation, we verified the effect of jasmonates, cytokinins and gibberellins in Arabidopsis (Arabidopsis thaliana). All three phytohormones promoted Arabidopsis trichome initiation, but caused divergent effects on trichome maturation and other leaf parameters. Molecular analysis indicated that the phytohormones mediated trichome initiation by the transcriptional regulation of the components of the TRANSPARENT TESTA GLABRA1 (TTG1) activator/inhibitor complex. In this addendum, we additionally studied the effects of jasmonates, cytokinins and gibberellins on leaf trichome formation in a representative set of plant species, spanning the angiosperm lineage and covering different trichome types. We found that the general ability of the three phytohormones to impinge on trichome initiation is conserved across angiosperms, but that within a particular plant species distinct regulatory networks might be activated to steer the formation of the various trichome types.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884137/

6-Benzylaminopurine treatment induces increased pubescence on wheat leaves
Hidekazu Kobayashi, Mikiko Yanaka and Tatsuya M. Ikeda

The epidermis of wheat (Triticum aestivum L.) leaves contains trichomes that contribute to resistance to insect pests and drought tolerance. In the present study, we examined the effects of 6-benzylaminopurine (BA) and methyl jasmonate (MeJA) treatment on trichome development on the leaves of wheat cv. Norin 61 seedlings. Without phytohormone treatment, trichomes on the adaxial leaf surface were short (90 μm) and their density was low (3.6 trichomes/mm2). Both BA and MeJA treatments significantly increased the density of trichomes, and there were no significant differences between the phytohormone treatments. BA treatment increased trichome length to five times as long as that in the control, whereas MeJA treatment did not significantly affect trichome length. Since BA treatment concurrently increased the DNA content of the nuclei in trichome cells, endoreduplication of the nuclei is probably involved in trichome enlargement. These results indicate that even wheat cultivars with short trichomes retain the mechanisms for trichome enlargement and stimuli such as BA application can induce increased pubescence on wheat leaves.

https://www.springerlink.com/content/vk311113m3k25g11/

[dizzlekush]

Ive removed the formulation for the BAP stock solution due to the dangers of formulating the solution. The below formulation quoted by 'shirami' that uses ethanol will work just fine, however methanol is a much much better option for C3 plants. if anyone would like to have the formulation, you can PM me. make sure you know ALL of the potential risks of Potassium Hydroxide and Methanol before considering formulation. I dont want anyone going blind from my ideas.

I suggest that most people buy a preformulated commercial solution like the ones mofeta has pointed out, or following the below formulation quoted by 'shirami.' One's more expensive, ones less optimal, but both are much safer and easier than formulating the optimal solution yourself.

[IMO]

inspired. keep up the good work.

[shirami]

Originally Posted by dizzlekush

Soon i will make my own BAP stock solution. im going to make a half batch the first time in case anything goes wrong.

ALWAYS WEAR PROPER SKIN AND EYE PROTECTION WHEN HANDLING POTASSIUM HYDROXIDE.
(you should see how fast this stuff can melt an eyeball)

measure out 30ml of Ethanol
https://www.amazon.com/Reagent-Grade-...4281393&sr=1-3

Add 5.55g of Potassium Hydroxide (90% purity) [very caustic, will increase temperature of solution]
https://www.amazon.com/Grade-Devil-Po...3907506&sr=1-1

Add 5g of 6-Benzylaminopurine (100% purity)
https://www.phytotechlab.com/detail.aspx?ID=141

Mix until BAP is completely dissolved and homogeneous solution is achieved.

Add 136.6ml of ethanol

Add distilled water to 500ml of working solution. mix until homogeneous solution is formed [still caustic. use proper skin, eye, and respiratory protection when spraying.]

Resulting concentration of active ingredients (by weight):
~1.00% BAP
~0.68% K

(assuming that SG is not changed significantly by formulation. once the actual formula is completed, i will be able to get a more accurate %)

Optionally non ionic surfactants and/or humic/fulvic acids can be added to the stock solution to increase the effectiveness of BAP. I will personally be adding such additives separately in the working solution, as there is the possibility of wanting free floating cations in certain working solutions for optimum effects, where the humic/fulvic and some NIS will chelate the cations and render the solution less effective.

Why use ethanol instead of water?
That amount will easily dissolve in water containing KOH.

[dizzlekush]

Originally Posted by shirami

Why use ethanol instead of water?
That amount will easily dissolve in water containing KOH.

Yes it will dissolve just fine to make a stock solution, but after poring over patents on BAP it became clear that BAP stock solutions made from H2O & KOH/NaOH have issues with BAP precipitating once the solution is diluted down to workable levels. the addition of EtOH allows the BAP to remain dissolved at all dilutions, while EtOH is harmless/possibly beneficial to C3 plants at such concentrations. It also gives the stock solution an indefinite shelf life. Im fairly certain significantly less EtOH could be used to achieve the same results, but id rather be on the safe side.

Patents of interest:

U.S. Patent #5455220
https://www.patents.com/us-5455220.html

EP Patent #EP1579768A1
https://www.patsnap.com/patents/view/EP1579768A1.html

U.S. Patent #5744424
https://www.everypatent.com/comp/pat5744424.html

U.S. Patent #4326877
https://www.patentgenius.com/patent/4326877.html

[shirami]

Originally Posted by dizzlekush

Yes it will dissolve just fine to make a stock solution, but after poring over patents on BAP it became clear that BAP stock solutions made from H2O & KOH/NaOH have issues with BAP precipitating once the solution is diluted down to workable levels. the addition of EtOH allows the BAP to remain dissolved at all dilutions, while EtOH is harmless/possibly beneficial to C3 plants at such concentrations. It also gives the stock solution an indefinite shelf life. Im fairly certain significantly less EtOH could be used to achieve the same results, but id rather be on the safe side.

Patents of interest:

U.S. Patent # 5455220
https://www.patents.com/us-5455220.html

EP Patent # EP1579768A1
https://www.patsnap.com/patents/view/EP1579768A1.html

U.S. Patent # 5744424
https://www.everypatent.com/comp/pat5744424.html

U.S. Patent # 4326877
https://www.patentgenius.com/patent/4326877.html

I see. Thanks for the info.